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246 files changed, 31647 insertions, 3155 deletions
diff --git a/CHICKEN.html.markdown b/CHICKEN.html.markdown index bb2f91f0..3f7cc2db 100644 --- a/CHICKEN.html.markdown +++ b/CHICKEN.html.markdown @@ -81,7 +81,7 @@ supports R5RS and R7RS (work in progress) standards and many extensions. (string-append "pine" "apple") ;; => "pineapple" (string-ref "tapioca" 3) ;; => #\i;; character 'i' is at index 3 (string->list "CHICKEN") ;; => (#\C #\H #\I #\C #\K #\E #\N) -(string->intersperse '("1" "2") ":") ;; => "1:2" +(string-intersperse '("1" "2") ":") ;; => "1:2" (string-split "1:2:3" ":") ;; => ("1" "2" "3") diff --git a/CONTRIBUTING.markdown b/CONTRIBUTING.markdown index 5fa1d03d..455c3256 100644 --- a/CONTRIBUTING.markdown +++ b/CONTRIBUTING.markdown @@ -71,3 +71,10 @@ contributors: lang: ep-ep --- ``` + +### Should I add myself as a Contributor? + +If you want to add yourself to contributors, keep in mind that contributors get +equal billing, and the first contributor usually wrote the whole article. Please +use your judgement when deciding if your contribution constitutes a substantial +addition or not. diff --git a/ISSUE_TEMPLATE.md b/ISSUE_TEMPLATE.md index 022dedab..96278da9 100644 --- a/ISSUE_TEMPLATE.md +++ b/ISSUE_TEMPLATE.md @@ -1,3 +1,12 @@ +## Is this a major issue that you cannot fix? + +**Being a community driven documents of languages and tools,"YOUR" contributions +are also important. +If the issue you're reporting is trivial to report to maintainers why not contribute +to fix it. In that way, you will have contributed to an awesome open-source project. +The changes can be typo fix, fixing of data in examples or grammar fix. If you found it, +why not do it and take full credit for it?** + Make sure the issue title is prepended with '[language/lang-code]' if the language is already on the site. If it's a request for a new language, use: '[Request] [language/lang-code]' diff --git a/ansible.html.markdown b/ansible.html.markdown new file mode 100644 index 00000000..a319a89d --- /dev/null +++ b/ansible.html.markdown @@ -0,0 +1,663 @@ +--- +category: tool +tool: ansible +contributors: + - ["Jakub Muszynski" , "http://github.com/sirkubax"] +filename: LearnAnsible.txt +--- + +```yml +--- +"{{ Ansible }}" is an orchestration tool written in Python. + +``` + +## Example +An example playbook to install apache and configure log level +```yml +--- +- hosts: apache + + vars: + apache2_log_level: "warn" + + handlers: + - name: restart apache + service: + name: apache2 + state: restarted + enabled: True + notify: + - Wait for instances to listen on port 80 + become: True + + - name: reload apache + service: + name: apache2 + state: reloaded + notify: + - Wait for instances to listen on port 80 + become: True + + - name: Wait for instances to listen on port 80 + wait_for: + state: started + host: localhost + port: 80 + timeout: 15 + delay: 5 + + tasks: + - name: Update cache + apt: + update_cache: yes + cache_valid_time: 7200 + become: True + + - name: Install packages + apt: + name={{ item }} + with_items: + - apache2 + - logrotate + notify: + - restart apache + become: True + + - name: Configure apache2 log level + lineinfile: + dest: /etc/apache2/apache2.conf + line: "LogLevel {{ apache2_log_level }}" + regexp: "^LogLevel" + notify: + - reload apache + become: True + +``` + +## Installation +```bash +# Universal way +$ pip install ansible + +# Debian, Ubuntu +$ apt-get install ansible + +``` +* [Appendix A - How do I install ansible](#infrastructure-as-a-code) +* [Additional Reading.](http://docs.ansible.com/ansible/latest/intro_installation.html) + +### Your first ansible command (shell execution) +```bash +# This command ping the localhost (defined in default inventory: /etc/ansible/hosts) +$ ansible -m ping localhost +# you should see this output +localhost | SUCCESS => { + "changed": false, + "ping": "pong" +} + +``` +### Shell Commands +There are few commands you should know about + +* `ansible` (to run modules in CLI) +* `ansible-playbook` (to run playbooks) +* `ansible-vault` (to manage secrets) +* `ansible-galaxy` (to install roles from github/galaxy) +* and other! + +### Module +_program (usally python) that execute, do some work and return proper JSON output_ + +This *program* perform specialized task/action (like manage instances in the cloud, execute shell command). + +The simplest module is called `ping` - it just returns a JSON with `pong` message. + +Example of modules: +* Module: `ping` - the simplest module that is usefull to verify host connectivity +* Module: `shell` - a module that executes shell command on a specified host(s). + +Example of execution - `ping`, `shell` + +```bash +$ ansible -m ping all +$ ansible -m shell -a 'date; whoami' localhost #hostname_or_a_group_name +``` + +* Module: `command` - executes a single command that will not be processed through the shell, so variables like $HOME or operands like `|` `;` will not work. The command module is more secure, because it will not be affected by the user’s environment. For more complex command - use shell module. + + +```bash +$ ansible -m command -a 'date; whoami' # FAILURE + +$ ansible -m command -a 'date' all +$ ansible -m command -a 'whoami' all +``` + +* Module: `file` - performs file operations (stat, link, dir, ...) +* Module: `raw` - executes a low-down and dirty SSH command, not going through the module subsystem (usefull to install python2.7) + +### Task + Execution of a single Ansible **module** is called a **task** + + The simplest module is called `ping` as you could see above + + Another example of the module that allow you to execute command remotly on multiple resources is called `shell`. See above how you were using them already. + + +### Playbook +**Execution plan** written in a form of script file(s) is called **playbook**. +Playbook consist of multiple elements +* a list (or group) of hosts that 'the play' is executed against +* `task(s)` or `role(s)` that are going to be executed +* multiple optional settings (like default variables, and way more) + +Playbook script language is YAML. + +You can think that playbook is very advanced CLI script that you are executing. + + +#### Example of the playbook: +This example-playbook would execute (on all hosts defined in the inventory) two tasks: +* `ping` that would return message *pong* +* `shell` that execute three commands and return the output to our terminal + +```yml +- hosts: all + + tasks: + - name: "ping all" + ping: + + - name: "execute a shell command" + shell: "date; whoami; df -h;" +``` + +Run the playbook with the command: +```bash +$ ansible-playbook path/name_of_the_playbook.yml +``` +_Note: Example playbook is explained in the next chapter: 'Roles' +### More on ansible concept + +### Inventory +Inventory is a set of an objects or hosts, against which we are executing our playbooks or single tasks via shell commands +For this few minutes, lets asume that we are using default ansible inventory (which in Debian based system is placed in /etc/ansible/hosts) + +`/etc/ansible/hosts` +``` +localhost + +[some_group] +hostA.mydomain.com +hostB.localdomain +1.2.3.4 + +[a_group_of_a_groups:children] +some_group +some_other_group + +``` +* [Additional Reading.](http://docs.ansible.com/ansible/latest/intro_inventory.html) +### ansible-roles (a 'template-playbooks' with right structure) + + You already know that the tasks (modules) can be run via CLI. You also know the playbooks - the execution plans of multiple tasks (with variables and logic). + +A concept called `role` was introduced for parts of the code (playbooks) that should be reusable. + +**Role** is a structured way to manage your set of tasks, variables, handlers, default settings, and way more (meta, files, templates). +Role allows to reuse the same parts of code in multiple plybooks (you can parametrize the role 'further' during it's execution). +It is a great way to introduce `object oriented` management for your applications. + +Role can be included in your playbook (executed via your playbook). + + +```yml +- hosts: all + + tasks: + - name: "ping all" + ping: + - name: "execute a shell command" + shell: "date; whoami; df -h;" + + roles: + - some_role + - { role: another_role, some_variable: 'learnxiny', tags: ['my_tag'] } + + pre_tasks: + - name: some pre-task + shell: echo 'this task is the last, but would be executed before roles, and before tasks' +``` + +#### For remaining examples we would use additional repository +This example install ansible in `virtualenv` so it is independend from a system. You need to initialize it into your shell-context with `source environment.sh` command. + +We are going to use repository with examples: https://github.com/sirkubax/ansible-for-learnXinYminutes + +```bash +$ # The folowing example contains a shell-prompt to indicate the venv and relative path +$ git clone git@github.com:sirkubax/ansible-for-learnXinYminutes.git +user@host:~/$ cd ansible-for-learnXinYminutes +user@host:~/ansible-for-learnXinYminutes$ source environment.sh +$ +$ # First lets execute the simple_playbook.yml +(venv) user@host:~/ansible-for-learnXinYminutes$ ansible-playbook playbooks/simple_playbook.yml + +``` + +Run the playbook with roles example +```bash +$ source environment.sh +$ # Now we would run the above playbook with roles +(venv) user@host:~/ansible-for-learnXinYminutes$ ansible-playbook playbooks/simple_role.yml +``` + +#### Role directory structure: +``` +roles/ + some_role/ + defaults/ # contains default variables + files/ # for static files + templates/ # for jinja templates + tasks/ # tasks + handlers/ # handlers + vars/ # more variables (higher priority) + meta/ # meta - package (role) info +``` + +#### Role Handlers +Handlers are a tasks that can be triggered (notified) during execution of a playbook, but they itself execute at the very end of a playbook. +It is a best way to restart a service, check if application port is active (successfull deployment criteria), etc. + +Please get familiar how you can use role in simple_apache_role example +``` +playbooks/roles/simple_apache_role/ +├── tasks +│ └── main.yml +└── templates + └── main.yml +``` + +### ansible - variables + +Ansible is flexible - it has 21 levels of variable precedence + +[read more](http://docs.ansible.com/ansible/latest/playbooks_variables.html#variable-precedence-where-should-i-put-a-variable) + +For now you should know that CLI variables have the top priority. + +You should also know, that a nice way to pool some data is a **lookup** + +### Lookups +Awesome tool to query data from various sources!!! Awesome! +query from: + +* pipe (load shell command output into variable!) +* file +* stream +* etcd +* password management tools +* url + +```bash +# read playbooks/lookup.yml +# then run +(venv) user@host:~/ansible-for-learnXinYminutes$ ansible-playbook playbooks/lookup.yml +``` + +You can use them in CLI too +```yaml +ansible -m shell -a 'echo "{{ my_variable }}"' -e 'my_variable="{{ lookup("pipe", "date") }}"' localhost +ansible -m shell -a 'echo "{{ my_variable }}"' -e 'my_variable="{{ lookup("pipe", "hostname") }}"' all + +# Or use in playbook + +(venv) user@host:~/ansible-for-learnXinYminutes$ ansible-playbook playbooks/lookup.yml + +``` + +### Register and Conditional + +#### Register +Another way to dynamicaly generate the variable content is a `register` command. +`Register` is also useful to store an output of a task, and use it's value as a logic +for execution further tasks. +``` +(venv) user@host:~/ansible-for-learnXinYminutes$ ansible-playbook playbooks/register_and_when.yml +``` + +```yaml +--- +- hosts: localhost + tasks: + - name: check the system capacity + shell: df -h / + register: root_size + + - name: debug root_size + debug: + msg: "{{ root_size }}" + + - name: debug root_size return code + debug: + msg: "{{ root_size.rc }}" + +# when: example + + - name: Print this message when return code of 'check the system capacity' was ok + debug: + msg: "{{ root_size.rc }}" + when: root_size.rc == 0 + +``` +#### Conditionals - when: + +You can define complex logic with Ansible and Jinja functions. Most common is usage of `when:`, with some variable (often dynamicly generated in previous playbook steps with `register` or `lookup`) + +```yaml +--- +- hosts: localhost + tasks: + - name: check the system capacity + shell: df -h / + when: some_variable in 'a string' + roles: + - { role: mid_nagios_probe, when: allow_nagios_probes } +``` + + +### ansible - tags, limit + +You should know about a way to increase efficiency by this simple functionality + +#### TAGS +You can tag a task, role (and its tasks), include, etc, and then run only the tagged resources + + ansible-playbook playbooks/simple_playbook.yml --tags=tagA,tag_other + ansible-playbook playbooks/simple_playbook.yml -t tagA,tag_other + + There are special tags: + always + + --skip-tags can be used to exclude a block of code + --list-tags to list available tags + +[Read more](http://docs.ansible.com/ansible/latest/playbooks_tags.html) + +#### LIMIT +You can limit an execution of your tasks to defined hosts + + ansible-playbook playbooks/simple_playbook.yml --limmit localhost + + --limit my_hostname + --limit groupname + --limit some_prefix* + --limit hostname:group #JM + +### Templates + +Template is a powerfull way to deliver some (partially) dynamic content. Ansible uses **Jinja2** langueage to describe the template. + +```jinja2 +Some static content + +{{ a_variable }} + +{% for item in loop_items %} + this line item is {{ item }} +{% endfor %} +``` +Jinja may have some limitations, but it is a powerfull tool that you might like. + +Please examine this simple example that install apache2 and generate index.html from the template +"playbooks/roles/simple_apache_role/templates/index.html" + +```bash +$ source environment.sh +$ # Now we would run the above playbook with roles +(venv) user@host:~/ansible-for-learnXinYminutes$ ansible-playbook playbooks/simple_role.yml --tags apache2 +``` + + +#### Jinja2 CLI +You can use the jinja in the CLI too +```bash +ansible -m shell -a 'echo {{ my_variable }}` -e 'my_variable=something, playbook_parameter=twentytwo" localhost +``` +In fact - jinja is used to template parts of the playbooks too +```yml +#check part of this playbook: playbooks/roles/sys_debug/tasks/debug_time.yml +- local_action: shell date +'%F %T' + register: ts + become: False + changed_when: False + +- name: Timestamp + debug: msg="{{ ts.stdout }}" + when: ts is defined and ts.stdout is defined + become: False + +``` + +#### Jinja2 filters +Junja is powerfull. It has built-in many usefull functions. +```jinja +# get first item of the list +{{ some_list | first() }} +# if variable is undefined - use default value +{{ some_variable | default('default_value') }} +``` +[Read More](http://docs.ansible.com/ansible/latest/playbooks_filters.html) + +### ansible-vault +To maintain **ifrastructure as a code** you need to store secrets. + Ansible provides a way to encrypt the confidential files so you can store it in the repository, yet the files are decrypted in-fly during ansible execution. + +The best way to use the **ansible-vault** is to store the secret in some secure location, and configure ansible to use during runtime. + +```bash +# Try (this would fail) +$ ansible-playbook playbooks/vault_example.yml + +$ echo some_very_very_long_secret > ~/.ssh/secure_located_file + +# in ansible.cfg set the path to your secret file +$ vi ansible.cfg + ansible_vault_password_file = ~/.ssh/secure_located_file + +#or use env +$ export ANSIBLE_VAULT_PASSWORD_FILE=~/.ssh/secure_located_file + +$ ansible-playbook playbooks/vault_example.yml + + # encrypt the file +$ ansible-vault encrypt path/somefile + + # view the file +$ ansible-vault view path/somefile + + # check the file content: +$ cat path/somefile + + # decrypt the file +$ ansible-vault decrypt path/somefile +``` + +### dynamic inventory +You might like to know, that you can build your inventory dynamically. + +(For Ansible) inventory is just a JSON with proper structure - if you can deliver that to ansible - anything is possible. + +You do not need to invent the wheel - there are plenty ready to use inventory script for most popular Cloud provicers and a lot of in-house popular usecaseses. + +[AWS example](http://docs.ansible.com/ansible/latest/intro_dynamic_inventory.html#example-aws-ec2-external-inventory-script) + +```bash +$ etc/inv/ec2.py --refresh + +$ ansible -m ping all -i etc/inv/ec2.py +``` + +[Read more](http://docs.ansible.com/ansible/latest/intro_dynamic_inventory.html) + +### ansible profiling - callback +Playbook execution takes some time. It is OK. First make it run, then you may like to speed things up + +Since ansible 2.x there is built-in callback for task execution profiling + +``` +vi ansible.cfg +#set this to: +callback_whitelist = profile_tasks +``` + +### facts-cache and ansible-cmdb +You can pool some infrmations of you environment from another hosts. +If the informations does not change - you may consider using a facts_cache to speed things up. + +``` +vi ansible.cfg + +# if set to a persistent type (not 'memory', for example 'redis') fact values +# from previous runs in Ansible will be stored. This may be useful when +# wanting to use, for example, IP information from one group of servers +# without having to talk to them in the same playbook run to get their +# current IP information. +fact_caching = jsonfile +fact_caching_connection = ~/facts_cache +fact_caching_timeout = 86400 +``` + +I like to use `jsonfile` as my backend. It allows to use another project +`ansible-cmdb` [(project on github)](https://github.com/fboender/ansible-cmdb) that generates a HTML page of your inventory resources. A nice 'free' addition! + +### debugging ansible [chapter in progres] +When your job fails - it is good to be effective with debugging. + +1. Increase verbosiy by using multiple -v **[ -vvvvv]** +2. If variable is undefined + - grep -R path_of_your_inventory -e missing_variable +3. If variable (dictionary or a list) is undefined + - grep -R path_of_your_inventory -e missing_variable +4. Jinja template debug +5. Strange behaviour - try to run the code 'at the destination' + +### Infrastructure as a code +You already know, that ansible-vault allow you to store your confidential data along with your code (in repository). You can go further - and define your ansible installation and configuration as-a-code. +See `environment.sh` to learn how to install the ansible itself inside a `virtualenv` that is not attached to your operating system (can be changed by non-privilages user), and as additional benefit - upgrading version of ansible is as easy as installing new version in new virtualenv. What is more, you can have multiple versions of Ansible present in the same time. This is very helpfull! + +```bash + # recreate ansible 2.x venv +$ rm -rf venv2 +$ source environment2.sh + # execute playbook +(venv2)$ ansible-playbook playbooks/ansible1.9_playbook.yml # would fail - deprecated syntax + + # now lets install ansible 1.9.x next to ansible 2.x +(venv2)$ deactivate +$ source environment.1.9.sh + # execute playbook +(venv1.9)$ ansible-playbook playbooks/ansible1.9_playbook.yml # works! + + # please note that you have both venv1.9 and venv2 present - you need to (de)activate one - that is all +``` + +#### become-user, become +In Ansible - to become `sudo` - use the `become` parameter. Use `become_user` to specify the username. +``` +- name: Ensure the httpd service is running + service: + name: httpd + state: started + become: true +``` +Note: You may like to execute Ansible with `--ask-sudo-pass` or add the user to sudoers file in order to allow non-supervised execution if you require 'admin' privilages. + +[Read more](http://docs.ansible.com/ansible/latest/become.html) + +## Tips and tricks + +#### --check -C +Always make sure that your playbook can executes in 'dry run' mode (--check), and it's execution is not declaring 'Changed' objects. + +#### --diff -D +Diff is usefull to see nice detail of the files changed + +It compare 'in memory' the files like `diff -BbruN fileA fileB` + + +#### Execute hosts with 'regex' +```bash +ansible -m ping web* +``` + +#### +Host groups can be joined, negated, etc + +```bash +ansible -m ping web*:!backend:monitoring:&allow_change +``` + +#### Tagging +You should tag some (not all) objects - a task in a playbook, all tasks included form a role, etc. +It allows you to execute the choosen parts of the playbook. + +#### no_logs: True +You may see, that some roles print a lot of output in verbose mode. There is also a debug module. +This is the place where credentials may leak. Use `no_log` to hide the output. + +#### Debug module +allows to print a value to the screen - use it! + +#### Register the output of a task +You can register the output (stdout), rc (return code), stderr of a task with the `register` command. + +#### Conditionals: when: + +#### Loop: with, with_items, with_dict, with_together + +[Read more](http://docs.ansible.com/ansible/latest/playbooks_conditionals.html) + + +## Introduction +Ansible is (one of the many) orchestration tools. It allows you to controll your environment (infrastructure and a code) and automate the manual tasks. +'You can think as simple as writing in bash with python API +Of course the rabit hole is way deeper.' + +Ansible have great integration with multiple operating systems (even Windows) and some hardware (switches, Firewalls, etc). It has multiple tools that integrate with the could providers. Almost every worth-notice cloud provider is present in the ecosystem (AWS, Azure, Google, DigitalOcean, OVH, etc...) + + +But ansible is way more! It provides an execution plans, an API, library, callbacks, not forget to mention - COMMUNITY! and great support by developers! + + +### Main cons and pros + +#### Cons + +It is an agent-less tool - every agent consumes up to 16MB ram - in some environments, it may be noticable amount. +It is agent-less - you have to verify your environment consistency 'on-demand' - there is no built-in mechanism that would warn you about some change automatically (this can be achieved with reasonable effort) +Official GUI Tool (web inferface) - Ansible Tower - is great, but it is expensive. There is no 'small enterprice' payment plan. Easy workaround with Rundeck or Jenkins is possible with reasonable workload. + +#### Pros + +It is an agent-less tools In most scenarios, it use ssh as a transport layer. +In some way you can use it as 'bash on steroids'. +It is very-very-very easy to start. If you are familiar with ssh concept - you already know Ansible (ALMOST). My personal record is: 'I did show "how to install and use ansible" (for simple raspberry pi cluster management) - it took me 30 seconds to deliver a complete working example !!!)' +I do provide a training services - I'm able to teach a production-ready person - in 8 hours (1 training day)! It covers all needed to work aspects! No other tool can match this ease of use! +It executes 'as is' - other tools (salt, puppet, chef - might execute in different scenario than you would expect) +Documentation is at the world-class standard! +The comunity (github, stackOverflow) would help you very fast. +Writing own modules and extension is fairly easy. + +#### Neutral +Migration Ansible<->Salt is failrly easy - so if you would need an event-driven agent environment - it would be a good choice to start quick with Ansible, and convert to salt when needed. + +#### Some concepts + +Ansible uses ssh or paramiko as a transport layer. In a way you can imagine that you are using a ssh with API to perform your action. +The simplest way is to execute remote command in more controlled way (still using ssh). +On the other hand - in advanced scope - you can wrap Ansible (use python Ansible code as a library) with your own Python scrips! This is awesome! It would act a bit like Fabric then. + + diff --git a/asymptotic-notation.html.markdown b/asymptotic-notation.html.markdown index 6a6df968..a1dfe9e1 100644 --- a/asymptotic-notation.html.markdown +++ b/asymptotic-notation.html.markdown @@ -155,7 +155,7 @@ Small-o, commonly written as **o**, is an Asymptotic Notation to denote the upper bound (that is not asymptotically tight) on the growth rate of runtime of an algorithm. -`f(n)` is o(g(n)), if for some real constants c (c > 0) and n<sub>0</sub> (n<sub>0</sub> > 0), `f(n)` is < `c g(n)` +`f(n)` is o(g(n)), if for all real constants c (c > 0) and n<sub>0</sub> (n<sub>0</sub> > 0), `f(n)` is < `c g(n)` for every input size n (n > n<sub>0</sub>). The definitions of O-notation and o-notation are similar. The main difference @@ -168,7 +168,7 @@ Small-omega, commonly written as **ω**, is an Asymptotic Notation to denote the lower bound (that is not asymptotically tight) on the growth rate of runtime of an algorithm. -`f(n)` is ω(g(n)), if for some real constants c (c > 0) and n<sub>0</sub> (n<sub>0</sub> > 0), `f(n)` is > `c g(n)` +`f(n)` is ω(g(n)), if for all real constants c (c > 0) and n<sub>0</sub> (n<sub>0</sub> > 0), `f(n)` is > `c g(n)` for every input size n (n > n<sub>0</sub>). The definitions of Ω-notation and ω-notation are similar. The main difference diff --git a/awk.html.markdown b/awk.html.markdown index e3ea6318..3d2c4ccb 100644 --- a/awk.html.markdown +++ b/awk.html.markdown @@ -6,14 +6,15 @@ contributors: --- -AWK is a standard tool on every POSIX-compliant UNIX system. It's like a -stripped-down Perl, perfect for text-processing tasks and other scripting -needs. It has a C-like syntax, but without semicolons, manual memory -management, or static typing. It excels at text processing. You can call to it -from a shell script, or you can use it as a stand-alone scripting language. - -Why use AWK instead of Perl? Mostly because AWK is part of UNIX. You can always -count on it, whereas Perl's future is in question. AWK is also easier to read +AWK is a standard tool on every POSIX-compliant UNIX system. It's like +flex/lex, from the command-line, perfect for text-processing tasks and +other scripting needs. It has a C-like syntax, but without mandatory +semicolons (although, you should use them anyway, because they are required +when you're writing one-liners, something AWK excells at), manual memory +management, or static typing. It excels at text processing. You can call to +it from a shell script, or you can use it as a stand-alone scripting language. + +Why use AWK instead of Perl? Readability. AWK is easier to read than Perl. For simple text-processing scripts, particularly ones that read files line by line and split on delimiters, AWK is probably the right tool for the job. @@ -23,8 +24,23 @@ the job. # Comments are like this -# AWK programs consist of a collection of patterns and actions. The most -# important pattern is called BEGIN. Actions go into brace blocks. + +# AWK programs consist of a collection of patterns and actions. +pattern1 { action; } # just like lex +pattern2 { action; } + +# There is an implied loop and AWK automatically reads and parses each +# record of each file supplied. Each record is split by the FS delimiter, +# which defaults to white-space (multiple spaces,tabs count as one) +# You cann assign FS either on the command line (-F C) or in your BEGIN +# pattern + +# One of the special patterns is BEGIN. The BEGIN pattern is true +# BEFORE any of the files are read. The END pattern is true after +# an End-of-file from the last file (or standard-in if no files specified) +# There is also an output field separator (OFS) that you can assign, which +# defaults to a single space + BEGIN { # BEGIN will run at the beginning of the program. It's where you put all @@ -32,114 +48,116 @@ BEGIN { # have no text files, then think of BEGIN as the main entry point. # Variables are global. Just set them or use them, no need to declare.. - count = 0 + count = 0; # Operators just like in C and friends - a = count + 1 - b = count - 1 - c = count * 1 - d = count / 1 # integer division - e = count % 1 # modulus - f = count ^ 1 # exponentiation - - a += 1 - b -= 1 - c *= 1 - d /= 1 - e %= 1 - f ^= 1 + a = count + 1; + b = count - 1; + c = count * 1; + d = count / 1; # integer division + e = count % 1; # modulus + f = count ^ 1; # exponentiation + + a += 1; + b -= 1; + c *= 1; + d /= 1; + e %= 1; + f ^= 1; # Incrementing and decrementing by one - a++ - b-- + a++; + b--; # As a prefix operator, it returns the incremented value - ++a - --b + ++a; + --b; # Notice, also, no punctuation such as semicolons to terminate statements # Control statements if (count == 0) - print "Starting with count of 0" + print "Starting with count of 0"; else - print "Huh?" + print "Huh?"; # Or you could use the ternary operator - print (count == 0) ? "Starting with count of 0" : "Huh?" + print (count == 0) ? "Starting with count of 0" : "Huh?"; # Blocks consisting of multiple lines use braces while (a < 10) { print "String concatenation is done" " with a series" " of" - " space-separated strings" - print a + " space-separated strings"; + print a; - a++ + a++; } for (i = 0; i < 10; i++) - print "Good ol' for loop" + print "Good ol' for loop"; # As for comparisons, they're the standards: - a < b # Less than - a <= b # Less than or equal - a != b # Not equal - a == b # Equal - a > b # Greater than - a >= b # Greater than or equal + # a < b # Less than + # a <= b # Less than or equal + # a != b # Not equal + # a == b # Equal + # a > b # Greater than + # a >= b # Greater than or equal # Logical operators as well - a && b # AND - a || b # OR + # a && b # AND + # a || b # OR # In addition, there's the super useful regular expression match if ("foo" ~ "^fo+$") - print "Fooey!" + print "Fooey!"; if ("boo" !~ "^fo+$") - print "Boo!" + print "Boo!"; # Arrays - arr[0] = "foo" - arr[1] = "bar" - # Unfortunately, there is no other way to initialize an array. Ya just - # gotta chug through every value line by line like that. - - # You also have associative arrays - assoc["foo"] = "bar" - assoc["bar"] = "baz" + arr[0] = "foo"; + arr[1] = "bar"; + + # You can also initialize an array with the built-in function split() + + n = split("foo:bar:baz", arr, ":"); + + # You also have associative arrays (actually, they're all associative arrays) + assoc["foo"] = "bar"; + assoc["bar"] = "baz"; # And multi-dimensional arrays, with some limitations I won't mention here - multidim[0,0] = "foo" - multidim[0,1] = "bar" - multidim[1,0] = "baz" - multidim[1,1] = "boo" + multidim[0,0] = "foo"; + multidim[0,1] = "bar"; + multidim[1,0] = "baz"; + multidim[1,1] = "boo"; # You can test for array membership if ("foo" in assoc) - print "Fooey!" + print "Fooey!"; # You can also use the 'in' operator to traverse the keys of an array for (key in assoc) - print assoc[key] + print assoc[key]; # The command line is in a special array called ARGV for (argnum in ARGV) - print ARGV[argnum] + print ARGV[argnum]; # You can remove elements of an array # This is particularly useful to prevent AWK from assuming the arguments # are files for it to process - delete ARGV[1] + delete ARGV[1]; # The number of command line arguments is in a variable called ARGC - print ARGC + print ARGC; # AWK has several built-in functions. They fall into three categories. I'll # demonstrate each of them in their own functions, defined later. - return_value = arithmetic_functions(a, b, c) - string_functions() - io_functions() + return_value = arithmetic_functions(a, b, c); + string_functions(); + io_functions(); } # Here's how you define a function @@ -159,26 +177,26 @@ function arithmetic_functions(a, b, c, d) { # Now, to demonstrate the arithmetic functions # Most AWK implementations have some standard trig functions - localvar = sin(a) - localvar = cos(a) - localvar = atan2(a, b) # arc tangent of b / a + localvar = sin(a); + localvar = cos(a); + localvar = atan2(b, a); # arc tangent of b / a # And logarithmic stuff - localvar = exp(a) - localvar = log(a) + localvar = exp(a); + localvar = log(a); # Square root - localvar = sqrt(a) + localvar = sqrt(a); # Truncate floating point to integer - localvar = int(5.34) # localvar => 5 + localvar = int(5.34); # localvar => 5 # Random numbers - srand() # Supply a seed as an argument. By default, it uses the time of day - localvar = rand() # Random number between 0 and 1. + srand(); # Supply a seed as an argument. By default, it uses the time of day + localvar = rand(); # Random number between 0 and 1. # Here's how to return a value - return localvar + return localvar; } function string_functions( localvar, arr) { @@ -188,61 +206,66 @@ function string_functions( localvar, arr) { # Search and replace, first instance (sub) or all instances (gsub) # Both return number of matches replaced - localvar = "fooooobar" - sub("fo+", "Meet me at the ", localvar) # localvar => "Meet me at the bar" - gsub("e+", ".", localvar) # localvar => "m..t m. at th. bar" + localvar = "fooooobar"; + sub("fo+", "Meet me at the ", localvar); # localvar => "Meet me at the bar" + gsub("e+", ".", localvar); # localvar => "m..t m. at th. bar" # Search for a string that matches a regular expression # index() does the same thing, but doesn't allow a regular expression - match(localvar, "t") # => 4, since the 't' is the fourth character + match(localvar, "t"); # => 4, since the 't' is the fourth character # Split on a delimiter - split("foo-bar-baz", arr, "-") # a => ["foo", "bar", "baz"] + n = split("foo-bar-baz", arr, "-"); # a[1] = "foo"; a[2] = "bar"; a[3] = "baz"; n = 3 # Other useful stuff - sprintf("%s %d %d %d", "Testing", 1, 2, 3) # => "Testing 1 2 3" - substr("foobar", 2, 3) # => "oob" - substr("foobar", 4) # => "bar" - length("foo") # => 3 - tolower("FOO") # => "foo" - toupper("foo") # => "FOO" + sprintf("%s %d %d %d", "Testing", 1, 2, 3); # => "Testing 1 2 3" + substr("foobar", 2, 3); # => "oob" + substr("foobar", 4); # => "bar" + length("foo"); # => 3 + tolower("FOO"); # => "foo" + toupper("foo"); # => "FOO" } function io_functions( localvar) { # You've already seen print - print "Hello world" + print "Hello world"; # There's also printf - printf("%s %d %d %d\n", "Testing", 1, 2, 3) + printf("%s %d %d %d\n", "Testing", 1, 2, 3); # AWK doesn't have file handles, per se. It will automatically open a file # handle for you when you use something that needs one. The string you used # for this can be treated as a file handle, for purposes of I/O. This makes - # it feel sort of like shell scripting: + # it feel sort of like shell scripting, but to get the same output, the string + # must match exactly, so use a vaiable: + + outfile = "/tmp/foobar.txt"; - print "foobar" >"/tmp/foobar.txt" + print "foobar" > outfile; - # Now the string "/tmp/foobar.txt" is a file handle. You can close it: - close("/tmp/foobar.txt") + # Now the string outfile is a file handle. You can close it: + close(outfile); # Here's how you run something in the shell - system("echo foobar") # => prints foobar + system("echo foobar"); # => prints foobar # Reads a line from standard input and stores in localvar - getline localvar + getline localvar; - # Reads a line from a pipe - "echo foobar" | getline localvar # localvar => "foobar" - close("echo foobar") + # Reads a line from a pipe (again, use a string so you close it properly) + cmd = "echo foobar"; + cmd | getline localvar; # localvar => "foobar" + close(cmd); # Reads a line from a file and stores in localvar - getline localvar <"/tmp/foobar.txt" - close("/tmp/foobar.txt") + infile = "/tmp/foobar.txt"; + getline localvar < infile; + close(infile); } # As I said at the beginning, AWK programs consist of a collection of patterns -# and actions. You've already seen the all-important BEGIN pattern. Other +# and actions. You've already seen the BEGIN pattern. Other # patterns are used only if you're processing lines from files or standard # input. # @@ -257,7 +280,7 @@ function io_functions( localvar) { # expression, /^fo+bar$/, and will be skipped for any line that fails to # match it. Let's just print the line: - print + print; # Whoa, no argument! That's because print has a default argument: $0. # $0 is the name of the current line being processed. It is created @@ -268,16 +291,16 @@ function io_functions( localvar) { # does. And, like the shell, each field can be access with a dollar sign # This will print the second and fourth fields in the line - print $2, $4 + print $2, $4; # AWK automatically defines many other variables to help you inspect and # process each line. The most important one is NF # Prints the number of fields on this line - print NF + print NF; # Print the last field on this line - print $NF + print $NF; } # Every pattern is actually a true/false test. The regular expression in the @@ -286,7 +309,7 @@ function io_functions( localvar) { # currently processing. Thus, the complete version of it is this: $0 ~ /^fo+bar$/ { - print "Equivalent to the last pattern" + print "Equivalent to the last pattern"; } a > 0 { @@ -315,10 +338,10 @@ a > 0 { BEGIN { # First, ask the user for the name - print "What name would you like the average age for?" + print "What name would you like the average age for?"; # Get a line from standard input, not from files on the command line - getline name <"/dev/stdin" + getline name < "/dev/stdin"; } # Now, match every line whose first field is the given name @@ -335,8 +358,8 @@ $1 == name { # ...etc. There are plenty more, documented in the man page. # Keep track of a running total and how many lines matched - sum += $3 - nlines++ + sum += $3; + nlines++; } # Another special pattern is called END. It will run after processing all the @@ -348,7 +371,7 @@ $1 == name { END { if (nlines) - print "The average age for " name " is " sum / nlines + print "The average age for " name " is " sum / nlines; } ``` @@ -357,3 +380,4 @@ Further Reading: * [Awk tutorial](http://www.grymoire.com/Unix/Awk.html) * [Awk man page](https://linux.die.net/man/1/awk) * [The GNU Awk User's Guide](https://www.gnu.org/software/gawk/manual/gawk.html) GNU Awk is found on most Linux systems. +* [AWK one-liner collection](http://tuxgraphics.org/~guido/scripts/awk-one-liner.html) diff --git a/bash.html.markdown b/bash.html.markdown index 0c097c27..8c40931e 100644 --- a/bash.html.markdown +++ b/bash.html.markdown @@ -16,6 +16,7 @@ contributors: - ["Betsy Lorton", "https://github.com/schbetsy"] - ["John Detter", "https://github.com/jdetter"] - ["Harry Mumford-Turner", "https://github.com/harrymt"] + - ["Martin Nicholson", "https://github.com/mn113"] filename: LearnBash.sh --- @@ -25,7 +26,7 @@ Nearly all examples below can be a part of a shell script or executed directly i [Read more here.](http://www.gnu.org/software/bash/manual/bashref.html) ```bash -#!/bin/bash +#!/usr/bin/env bash # First line of the script is shebang which tells the system how to execute # the script: http://en.wikipedia.org/wiki/Shebang_(Unix) # As you already figured, comments start with #. Shebang is also a comment. @@ -76,6 +77,11 @@ echo ${Variable/Some/A} # => A string Length=7 echo ${Variable:0:Length} # => Some st # This will return only the first 7 characters of the value +echo ${Variable: -5} # => tring +# This will return the last 5 characters (note the space before -5) + +# String length +echo ${#Variable} # => 11 # Default value for variable echo ${Foo:-"DefaultValueIfFooIsMissingOrEmpty"} @@ -83,6 +89,25 @@ echo ${Foo:-"DefaultValueIfFooIsMissingOrEmpty"} # This works for null (Foo=) and empty string (Foo=""); zero (Foo=0) returns 0. # Note that it only returns default value and doesn't change variable value. +# Declare an array with 6 elements +array0=(one two three four five six) +# Print first element +echo $array0 # => "one" +# Print first element +echo ${array0[0]} # => "one" +# Print all elements +echo ${array0[@]} # => "one two three four five six" +# Print number of elements +echo ${#array0[@]} # => "6" +# Print number of characters in third element +echo ${#array0[2]} # => "5" +# Print 2 elements starting from forth +echo ${array0[@]:3:2} # => "four five" +# Print all elements. Each of them on new line. +for i in "${array0[@]}"; do + echo "$i" +done + # Brace Expansion { } # Used to generate arbitrary strings echo {1..10} # => 1 2 3 4 5 6 7 8 9 10 @@ -155,6 +180,23 @@ then echo "This will run if $Name is Daniya OR Zach." fi +# There is also the =~ operator, which tests a string against a Regex pattern: +Email=me@example.com +if [[ "$Email" =~ [a-z]+@[a-z]{2,}\.(com|net|org) ]] +then + echo "Valid email!" +fi +# Note that =~ only works within double [[ ]] square brackets, +# which are subtly different from single [ ]. +# See http://www.gnu.org/software/bash/manual/bashref.html#Conditional-Constructs for more on this. + +# Redefine command 'ping' as alias to send only 5 packets +alias ping='ping -c 5' +# Escape alias and use command with this name instead +\ping 192.168.1.1 +# Print all aliases +alias -p + # Expressions are denoted with the following format: echo $(( 10 + 5 )) # => 15 @@ -202,10 +244,13 @@ mv s0urc3.txt dst.txt # sorry, l33t hackers... # Since bash works in the context of a current directory, you might want to # run your command in some other directory. We have cd for changing location: cd ~ # change to home directory +cd # also goes to home directory cd .. # go up one directory # (^^say, from /home/username/Downloads to /home/username) cd /home/username/Documents # change to specified directory cd ~/Documents/.. # still in home directory..isn't it?? +cd - # change to last directory +# => /home/username/Documents # Use subshells to work across directories (echo "First, I'm here: $PWD") && (cd someDir; echo "Then, I'm here: $PWD") @@ -230,6 +275,7 @@ print("#stderr", file=sys.stderr) for line in sys.stdin: print(line, file=sys.stdout) EOF +# Variables will be expanded if the first "EOF" is not quoted # Run the hello.py Python script with various stdin, stdout, and # stderr redirections: diff --git a/bf.html.markdown b/bf.html.markdown index 69058a20..1e415a4d 100644 --- a/bf.html.markdown +++ b/bf.html.markdown @@ -1,6 +1,6 @@ --- -language: "Brainfuck" -filename: brainfuck.bf +language: bf +filename: bf.bf contributors: - ["Prajit Ramachandran", "http://prajitr.github.io/"] - ["Mathias Bynens", "http://mathiasbynens.be/"] diff --git a/bg-bg/logtalk-bg.html.markdown b/bg-bg/logtalk-bg.html.markdown new file mode 100644 index 00000000..e788b17d --- /dev/null +++ b/bg-bg/logtalk-bg.html.markdown @@ -0,0 +1,593 @@ +--- +language: Logtalk +filename: llearnlogtalk-bg.lgt +contributors: + - ["Paulo Moura", "http://github.com/pmoura"] +translators: + - ["vsraptor", "https://github.com/vsraptor"] +lang: bg-bg + +--- + +Logtalk е обектно-ориентиран (ОО) модерен логически език за програмиране, които разширява Prolog с възможности за капсулиране (еncapsulation) и многократно използване на кода без да компрометира декларативните възможности на езика. Logtalk е имплементиран така че да може да бъде адапртиран към всеки стандартен Prolog като back-end компилатор, тоест е напълно прозрачен за нормална Prolog програма. +Допълнително, Logtalk също може да интерпретира Prolog модули, като Logtalk обекти. + +Основната структурна единица за изграждане на програмни със Logtalk е чрез използване на обекти. +Logtalk поддържа както стандартния начин за изграждане на иерархий от класове познати ни от езици като Java, същто така и prototype-OOP познат ни от езици като JavaScript. +Запомнете че всичко стартира с дефинирането и създаването на обект. + + +## Syntax (Синтакс) + + +Logtalk използва стандартен Prolog синтакс, с минимум допълнителни оператори и директиви. +Важно последствие от това е че кода лесно се капсулира с много малко промени спрямо оригинален код. + +Операторите които Logtalk добавя към Prolog са : + + ::/2 - изпраща саобщение до обект (аналогично на метод в стандартните ООП езици) + ::/1 - изпраща саобщение до себе си (self) (тоест до обекта който е получил съобщението което обработваме в момента) + ^^/1 - super call (изпраща саобщение до наследен или импортиран предикат(predicate)) + + +## Entities and roles (Субекти и роли) + + +Logtalk предоставя обекти, портоколи и категории като първокласни-субекти (first-class entities). Връзката между тях описва ролята която субектите изпалняват. +Обектите могат да играят различни роли в зависимост от как ги дефинираме тоест какви директиви използваме при дефиницията. + +Например когато използваме обект А за да създадем нов обект Б, обект Б играе ролята на "инстанция", а обект А играе ролята на клас. +Ако използваме "extends"-дефиниция единия от обектите играе ролята на протоип(prototype) за другия. + + +## Defining an object (Дефиниране на обект) + + +Чрез дефинирането на обект ние капсулираме дефиницията на "предикатите". +Обекти могат да се създадат динамично или дефинират статично във код-файла. +Ето как дефинираме примерен обект : + +```logtalk +:- object(list). + + :- public(member/2). + member(Head, [Head| _]). + member(Head, [_| Tail]) :- + member(Head, Tail). + +:- end_object. +``` + +## Compiling source files (Компилиран) + + +Ако предположим че кода е записан във файл с име list.lgt, можем да го компилираме чрез logtalk_load/1 предиката или съкратения вариант {}/1. + + +```logtalk +?- {list}. +yes +``` + +## Sending a message to an object (Изпращане на събщение до обект) + + +Както казахме ::/2 infix оператор се използва за изпращане на съобщение до обекта. Както в Prolog, ние можем да backtrack-нем за алтернативни решения, понеже метода е просто стандартен предикат : + +```logtalk +?- list::member(X, [1,2,3]). +X = 1 ; +X = 2 ; +X = 3 +yes + +?- write_canonical(list::member(X, [1,2,3])). +::(list,member(_,[1,2,3])) +``` + +Кагато декларирме обект автоматично предикатите са капсулирани (еncapsulation), тоест извън обекта те са невидими за останалата част от програмата. Естествено има опции да променим това поведение чрез public, protected, или private предикати. + +```logtalk +:- object(scopes). + + :- private(bar/0). + bar. + + local. + +:- end_object. +``` + +Ако кода е записан в scopes.lgt фаил и се опитаме да изпратим саобщтение до частен(private) или локален предикат ще получим грешка: + +```logtalk +?- {scopes}. +yes + +?- catch(scopes::bar, Error, true). +Error = error( + permission_error(access, private_predicate, bar/0), + logtalk(scopes::bar, user) +) +yes + +?- catch(scopes::local, Error, true). +Error = error( + existence_error(predicate_declaration, local/0), + logtalk(scopes::local, user) +) +yes +``` + +Когато предиката е непознат за обекта това също генерира грешка. Например : + +```logtalk +?- catch(scopes::unknown, Error, true). +Error = error( + existence_error(predicate_declaration, unknown/0), + logtalk(scopes::unknown, user) +) +yes +``` + +## Протоколи (Defining and implementing a protocol) + + +За тези от вас свикнали със стандартно ООП, Protocols наподобяват Interfaces в Java. +Протоколите съдържат предикати които могат да бъдат в последствие имплементирани в обекти и категории : + +```logtalk +:- protocol(listp). + + :- public(member/2). + +:- end_protocol. + +:- object(list, + implements(listp)). + + member(Head, [Head| _]). + member(Head, [_| Tail]) :- + member(Head, Tail). + +:- end_object. +``` + +Обхвата(scope) на предикатите в протокола могат да бъде ограничени чрез protected или private клаузи. +Например: + +```logtalk +:- object(stack, + implements(private::listp)). + +:- end_object. +``` + +Всички субекти(entity) релации могат да бъдат пре-дефинирани с public, protected или private, подбно на начина показан по горе. + + +## Прототипи (Prototypes) + + +Всеки обект без instantiation или specialization спецификация с друг обект, играе ролята на прототип. +Прототип-обект може да предефинира и разщири протоипа-родител. + +```logtalk +% clyde, our prototypical elephant +:- object(clyde). + + :- public(color/1). + color(grey). + + :- public(number_of_legs/1). + number_of_legs(4). + +:- end_object. + +% fred, another elephant, is like clyde, except that he's white +:- object(fred, + extends(clyde)). + + color(white). + +:- end_object. +``` + +Когато системата отговаря на съобщение изпратено до обект който играе ролята на прототип, тя търси отговор първо в прототипа и ако не намери предикат делегира отговора на прототипа-родител-обект : + +```logtalk +?- fred::number_of_legs(N). +N = 4 +yes + +?- fred::color(C). +C = white +yes +``` + +Съобщението е валидно но няма да генерира грещка, ако предиката е дефиниран но не е деклариран/имплементиран. Това е така наречения closed-world assumption. +Например : + +```logtalk +:- object(foo). + + :- public(bar/0). + +:- end_object. +``` + +Ако заредим файла и се опитаме да извикаме bar/0, няма да получим отговор, както може да очакваме. Ако обаче предиката не е дори дефиниран, ще получим гращка : + +```logtalk +?- {foo}. +yes + +?- foo::bar. +no + +?- catch(foo::baz, Error, true). +Error = error( + existence_error(predicate_declaration, baz/0), + logtalk(foo::baz, user) +) +yes +``` + +## Класове и инстанции (Classes and instances) + + +За да саздадем обекти които играят ролята на класове и/или инстанции, трябва да използваме поне instantiation или specialization дефиниция с друг обект. Обектите които играят роля на мета-класове могат да се използват ако е нужно още за саздаване на инстанции на класа. +Следващия пример ще илюстрира как можем динамично да саздадаваме обекти : + +```logtalk +% a simple, generic, metaclass defining a new/2 predicate for its instances +:- object(metaclass, + instantiates(metaclass)). + + :- public(new/2). + new(Instance, Clauses) :- + self(Class), + create_object(Instance, [instantiates(Class)], [], Clauses). + +:- end_object. + +% a simple class defining age/1 and name/1 predicate for its instances +:- object(person, + instantiates(metaclass)). + + :- public([ + age/1, name/1 + ]). + + % a default value for age/1 + age(42). + +:- end_object. + +% a static instance of the class person +:- object(john, + instantiates(person)). + + name(john). + age(12). + +:- end_object. +``` + +Когато отговаряме на съобщение изпратено до обект който играе ролята на инстанция, системата валидира съобщението първо в текущия клас, след това класа-родител ако е необходимо. Ако съобщението е валидно тогава проверяваме инстанцията : + +```logtalk +?- person::new(Instance, [name(paulo)]). +Instance = o1 +yes + +?- o1::name(Name). +Name = paulo +yes + +?- o1::age(Age). +Age = 42 +yes + +?- john::age(Age). +Age = 12 +yes +``` + +## Категории (Categories) + + +Категорията е капсулран код който може да се рециклира (reuse) в различни обекти. Докато Протокола е само дефиниции Категорията е сащо и декларация/имплементация на предикатите които сме дефинирали. +В следващия пример ще дефинираме категории представящи автомобилни двигатели след което ще ги импортираме в автомобил-обекти : + + +```logtalk +% a protocol describing engine characteristics +:- protocol(carenginep). + + :- public([ + reference/1, + capacity/1, + cylinders/1, + horsepower_rpm/2, + bore_stroke/2, + fuel/1 + ]). + +:- end_protocol. + +% a typical engine defined as a category +:- category(classic, + implements(carenginep)). + + reference('M180.940'). + capacity(2195). + cylinders(6). + horsepower_rpm(94, 4800). + bore_stroke(80, 72.8). + fuel(gasoline). + +:- end_category. + +% a souped up version of the previous engine +:- category(sport, + extends(classic)). + + reference('M180.941'). + horsepower_rpm(HP, RPM) :- + ^^horsepower_rpm(ClassicHP, ClassicRPM), % "super" call + HP is truncate(ClassicHP*1.23), + RPM is truncate(ClassicRPM*0.762). + +:- end_category. + +% with engines (and other components), we may start "assembling" some cars +:- object(sedan, + imports(classic)). + +:- end_object. + +:- object(coupe, + imports(sport)). + +:- end_object. +``` + +Категориите се компилират отделно и разрешават импортираните обекти да бъдат обновени като просто обновим категориите без да е необходимо да прекомпилираме обекта: + +```logtalk +?- sedan::current_predicate(Predicate). +Predicate = reference/1 ; +Predicate = capacity/1 ; +Predicate = cylinders/1 ; +Predicate = horsepower_rpm/2 ; +Predicate = bore_stroke/2 ; +Predicate = fuel/1 +yes +``` + +## Hot patching + + +Категориите още могат да се използват за промяна на обекти "в движение", след като вече са били инстанциирани. +Например : + +```logtalk +:- object(buggy). + + :- public(p/0). + p :- write(foo). + +:- end_object. +``` + +Да предположим че обекта изпечатва грешното съобщение p/0 : + +```logtalk +?- {buggy}. +yes + +?- buggy::p. +foo +yes +``` + +Ако кода който описва този обект не е наличен и трябва да коригираме приложението, ние можем просто да създадем категория която да коригира необходимия предикат : + +```logtalk +:- category(patch, + complements(buggy)). + + % fixed p/0 def + p :- write(bar). + +:- end_category. +``` + +След компилиране и зареждане на категорията ще получим : + +```logtalk +?- {patch}. +yes + +?- buggy::p. +bar +yes +``` + + +## Parametric objects and categories + + +Обектите и категориите могат да се параметризират ако използваме за индентификатор комплексен-термин вместо атом. +Параметрите са логически променливи достъпни за всички капсулирани предикати. +Пример с геометрични кръгове : + +```logtalk +:- object(circle(_Radius, _Color)). + + :- public([ + area/1, perimeter/1 + ]). + + area(Area) :- + parameter(1, Radius), + Area is pi*Radius*Radius. + + perimeter(Perimeter) :- + parameter(1, Radius), + Perimeter is 2*pi*Radius. + +:- end_object. +``` + +Параметричните-обекти се използват като всеки друг обект, обикновенно осигуряваики стойности за параметрите когато изпращаме съобщение. + +```logtalk +?- circle(1.23, blue)::area(Area). +Area = 4.75291 +yes +``` + +Параметричните-обекти още осигуряват лесен начин за ассоцииране на различни предикати със нормални Prolog предикати. +Prolog факти могат да бъдат интерпретирани като посредници (proxies). +Например следните клаузи на circle/2 предикат : + + +```logtalk +circle(1.23, blue). +circle(3.71, yellow). +circle(0.39, green). +circle(5.74, black). +circle(8.32, cyan). +``` + +можем лесно да изчислим площа на всички кръгове : + +```logtalk +?- findall(Area, {circle(_, _)}::area(Area), Areas). +Areas = [4.75291, 43.2412, 0.477836, 103.508, 217.468] +yes +``` + +{Goal}::Message формата доказва(proves) Goal и изпраща съобщение до генерирания термин. + + +## Събития и мониторинг (Events and monitors) + + +Logtalk поддържа event-driven програмиране чрез дефинирането на събития и монитори за тези събития. +Събитие е просто изпращане на съобщение към обект. При обработването на съобщение системата разпознава before-събитие и after-събитие. +Мониторите дефинират предикати които ще прихаванат тези събития (before/3 и after/3). +Нампример следния монитор ще прихаване съобщенията изпратени чрез ::/2 : + +```logtalk +:- object(tracer, + implements(monitoring)). % built-in protocol for event handlers + + :- initialization(define_events(_, _, _, _, tracer)). + + before(Object, Message, Sender) :- + write('call: '), writeq(Object), write(' <-- '), writeq(Message), + write(' from '), writeq(Sender), nl. + + after(Object, Message, Sender) :- + write('exit: '), writeq(Object), write(' <-- '), writeq(Message), + write(' from '), writeq(Sender), nl. + +:- end_object. +``` + +Ето как можем да проследим реакцията на изпращане на съобщение : + +```logtalk +?- list::member(X, [1,2,3]). + +call: list <-- member(X, [1,2,3]) from user +exit: list <-- member(1, [1,2,3]) from user +X = 1 ; +exit: list <-- member(2, [1,2,3]) from user +X = 2 ; +exit: list <-- member(3, [1,2,3]) from user +X = 3 +yes +``` + +Събития могат да се изтрият динамично чрез define_events/5 и abolish_events/5 предикати. + + +## Lambda expressions + + +Logtalk поддържа lambda expressions. Lambda параметрите се предават чрез списък към (>>)/2 infix оператор свързвайки ги с lambda. +Ето няколко примера : + +```logtalk +?- {library(metapredicates_loader)}. +yes + +?- meta::map([X,Y]>>(Y is 2*X), [1,2,3], Ys). +Ys = [2,4,6] +yes +``` + +Currying се поддържа : + +```logtalk +?- meta::map([X]>>([Y]>>(Y is 2*X)), [1,2,3], Ys). +Ys = [2,4,6] +yes +``` + +Lambda free variables can be expressed using the extended syntax {Free1, ...}/[Parameter1, ...]>>Lambda. + + +## Макроси (Macros) + + +Термини и Цели могат да бъдат пре-интерпретирани (expanded) по време на компилация ако специфицираме hook-обект който дефинира прецедурите на пре-интерпретиране. +Нека следният обект е записан във фаил source.lgt : + +```logtalk +:- object(source). + + :- public(bar/1). + bar(X) :- foo(X). + + foo(a). foo(b). foo(c). + +:- end_object. +``` + +и следния hooк-обект е записан в my_macros.lgt, който пре-интерпретира foo/1 предиката : + +```logtalk +:- object(my_macros, + implements(expanding)). % built-in protocol for expanding predicates + + term_expansion(foo(Char), baz(Code)) :- + char_code(Char, Code). % standard built-in predicate + + goal_expansion(foo(X), baz(X)). + +:- end_object. +``` + +След зареждането на файла с макроси ние можем да пре-интерпретираме ползайки hook-флаг за компилатора : + +```logtalk +?- logtalk_load(my_macros), logtalk_load(source, [hook(my_macros)]). +yes + +?- source::bar(X). +X = 97 ; +X = 98 ; +X = 99 +true +``` + +## Допълнителна информация (Further information) + + +Посетете сайта на [Logtalk website](http://logtalk.org) за повече информация. + diff --git a/c++.html.markdown b/c++.html.markdown index 8d1c7a26..4113d5f4 100644 --- a/c++.html.markdown +++ b/c++.html.markdown @@ -71,10 +71,16 @@ void func(); // function which may accept any number of arguments // Use nullptr instead of NULL in C++ int* ip = nullptr; -// C standard headers are available in C++, -// but are prefixed with "c" and have no .h suffix. +// C standard headers are available in C++. +// C headers end in .h, while +// C++ headers are prefixed with "c" and have no ".h" suffix. + +// The C++ standard version: #include <cstdio> +//The C standard version: +#include <stdio.h> + int main() { printf("Hello, world!\n"); @@ -1051,6 +1057,8 @@ cout << ST.size(); // will print the size of set ST // Output: 0 // NOTE: for duplicate elements we can use multiset +// NOTE: For hash sets, use unordered_set. They are more efficient but +// do not preserve order. unordered_set is available since C++11 // Map // Maps store elements formed by a combination of a key value @@ -1078,6 +1086,8 @@ cout << it->second; // Output: 26 +// NOTE: For hash maps, use unordered_map. They are more efficient but do +// not preserve order. unordered_map is available since C++11. /////////////////////////////////// // Logical and Bitwise operators @@ -1127,7 +1137,6 @@ compl 4 // Performs a bitwise not ``` Further Reading: -An up-to-date language reference can be found at -<http://cppreference.com/w/cpp> - -Additional resources may be found at <http://cplusplus.com> +* An up-to-date language reference can be found at [CPP Reference](http://cppreference.com/w/cpp). +* Additional resources may be found at [CPlusPlus](http://cplusplus.com). +* A tutorial covering basics of language and setting up coding environment is available at [TheChernoProject - C++](https://www.youtube.com/playlist?list=PLlrATfBNZ98dudnM48yfGUldqGD0S4FFb). diff --git a/c.html.markdown b/c.html.markdown index 87a047be..7975a1c2 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -8,6 +8,8 @@ contributors: - ["Marco Scannadinari", "https://marcoms.github.io"] - ["Zachary Ferguson", "https://github.io/zfergus2"] - ["himanshu", "https://github.com/himanshu81494"] + - ["Joshua Li", "https://github.com/JoshuaRLi"] + - ["Dragos B. Chirila", "https://github.com/dchirila"] --- Ah, C. Still **the** language of modern high-performance computing. @@ -17,13 +19,14 @@ it more than makes up for it with raw speed. Just be aware of its manual memory management and C will take you as far as you need to go. > **About compiler flags** -> +> > By default, gcc and clang are pretty quiet about compilation warnings and -> errors, which can be very useful information. Using some -> stricter compiler flags is recommended. Here is an example you can -> tweak to your liking: +> errors, which can be very useful information. Explicitly using stricter +> compiler flags is recommended. Here are some recommended defaults: +> +> `-Wall -Wextra -Werror -O2 -std=c99 -pedantic` > -> `-Wall -Wextra -Werror -O0 -ansi -pedantic -std=c11` +> For information on what these flags do as well as other flags, consult the man page for your C compiler (e.g. `man 1 gcc`) or just search online. ```c // Single-line comments start with // - only available in C99 and later. @@ -87,6 +90,8 @@ int main (int argc, char** argv) // All variables MUST be declared at the top of the current block scope // we declare them dynamically along the code for the sake of the tutorial + // (however, C99-compliant compilers allow declarations near the point where + // the value is used) // ints are usually 4 bytes int x_int = 0; @@ -99,7 +104,7 @@ int main (int argc, char** argv) char y_char = 'y'; // Char literals are quoted with '' // longs are often 4 to 8 bytes; long longs are guaranteed to be at least - // 64 bits + // 8 bytes long x_long = 0; long long x_long_long = 0; @@ -139,6 +144,17 @@ int main (int argc, char** argv) // You can initialize an array to 0 thusly: char my_array[20] = {0}; + // where the "{0}" part is called an "array initializer". + // NOTE that you get away without explicitly declaring the size of the array, + // IF you initialize the array on the same line. So, the following declaration + // is equivalent: + char my_array[] = {0}; + // BUT, then you have to evaluate the size of the array at run-time, like this: + size_t my_array_size = sizeof(my_array) / sizeof(my_array[0]); + // WARNING If you adopt this approach, you should evaluate the size *before* + // you begin passing the array to function (see later discussion), because + // arrays get "downgraded" to raw pointers when they are passed to functions + // (so the statement above will produce the wrong result inside the function). // Indexing an array is like other languages -- or, // rather, other languages are like C @@ -372,8 +388,8 @@ int main (int argc, char** argv) // respectively, use the CHAR_MAX, SCHAR_MAX and UCHAR_MAX macros from <limits.h> // Integral types can be cast to floating-point types, and vice-versa. - printf("%f\n", (float)100); // %f formats a float - printf("%lf\n", (double)100); // %lf formats a double + printf("%f\n", (double) 100); // %f always formats a double... + printf("%f\n", (float) 100); // ...even with a float. printf("%d\n", (char)100.0); /////////////////////////////////////// @@ -431,7 +447,7 @@ int main (int argc, char** argv) // or when it's the argument of the `sizeof` or `alignof` operator: int arraythethird[10]; int *ptr = arraythethird; // equivalent with int *ptr = &arr[0]; - printf("%zu, %zu\n", sizeof arraythethird, sizeof ptr); + printf("%zu, %zu\n", sizeof(arraythethird), sizeof(ptr)); // probably prints "40, 4" or "40, 8" // Pointers are incremented and decremented based on their type @@ -447,7 +463,7 @@ int main (int argc, char** argv) for (xx = 0; xx < 20; xx++) { *(my_ptr + xx) = 20 - xx; // my_ptr[xx] = 20-xx } // Initialize memory to 20, 19, 18, 17... 2, 1 (as ints) - + // Be careful passing user-provided values to malloc! If you want // to be safe, you can use calloc instead (which, unlike malloc, also zeros out the memory) int* my_other_ptr = calloc(20, sizeof(int)); @@ -520,9 +536,11 @@ Example: in-place string reversal void str_reverse(char *str_in) { char tmp; - int ii = 0; + size_t ii = 0; size_t len = strlen(str_in); // `strlen()` is part of the c standard library - for (ii = 0; ii < len / 2; ii++) { + // NOTE: length returned by `strlen` DOESN'T include the + // terminating NULL byte ('\0') + for (ii = 0; ii < len / 2; ii++) { // in C99 you can directly declare type of `ii` here tmp = str_in[ii]; str_in[ii] = str_in[len - ii - 1]; // ii-th char from end str_in[len - ii - 1] = tmp; @@ -587,6 +605,14 @@ static int j = 0; //other files using testFunc2() cannot access variable j void testFunc2() { extern int j; } +// The static keyword makes a variable inaccessible to code outside the +// compilation unit. (On almost all systems, a "compilation unit" is a .c +// file.) static can apply both to global (to the compilation unit) variables, +// functions, and function-local variables. When using static with +// function-local variables, the variable is effectively global and retains its +// value across function calls, but is only accessible within the function it +// is declared in. Additionally, static variables are initialized to 0 if not +// declared with some other starting value. //**You may also declare functions as static to make them private** /////////////////////////////////////// @@ -701,7 +727,8 @@ typedef void (*my_fnp_type)(char *); "%3.2f"; // minimum 3 digits left and 2 digits right decimal float "%7.4s"; // (can do with strings too) "%c"; // char -"%p"; // pointer +"%p"; // pointer. NOTE: need to (void *)-cast the pointer, before passing + // it as an argument to `printf`. "%x"; // hexadecimal "%o"; // octal "%%"; // prints % diff --git a/chapel.html.markdown b/chapel.html.markdown index e9c4019a..354cd832 100644 --- a/chapel.html.markdown +++ b/chapel.html.markdown @@ -2,11 +2,11 @@ language: chapel filename: learnchapel.chpl contributors: - - ["Ian J. Bertolacci", "http://www.cs.colostate.edu/~ibertola/"] - - ["Ben Harshbarger", "http://github.com/benharsh/"] + - ["Ian J. Bertolacci", "https://www.cs.arizona.edu/~ianbertolacci/"] + - ["Ben Harshbarger", "https://github.com/benharsh/"] --- -You can read all about Chapel at [Cray's official Chapel website](http://chapel.cray.com). +You can read all about Chapel at [Cray's official Chapel website](https://chapel-lang.org). In short, Chapel is an open-source, high-productivity, parallel-programming language in development at Cray Inc., and is designed to run on multi-core PCs as well as multi-kilocore supercomputers. @@ -100,7 +100,7 @@ writeln(varCmdLineArg, ", ", constCmdLineArg, ", ", paramCmdLineArg); // be made to alias a variable other than the variable it is initialized with. // Here, refToActual refers to actual. var actual = 10; -ref refToActual = actual; +ref refToActual = actual; writeln(actual, " == ", refToActual); // prints the same value actual = -123; // modify actual (which refToActual refers to) writeln(actual, " == ", refToActual); // prints the same value @@ -444,7 +444,7 @@ arrayFromLoop = [value in arrayFromLoop] value + 1; // Procedures -// Chapel procedures have similar syntax functions in other languages. +// Chapel procedures have similar syntax functions in other languages. proc fibonacci(n : int) : int { if n <= 1 then return n; return fibonacci(n-1) + fibonacci(n-2); @@ -893,7 +893,6 @@ foo(); // We can declare a main procedure, but all the code above main still gets // executed. proc main() { - writeln("PARALLELISM START"); // A begin statement will spin the body of that statement off // into one new task. @@ -1124,16 +1123,16 @@ This tutorial is for people who want to learn the ropes of chapel without having to hear about what fiber mixture the ropes are, or how they were braided, or how the braid configurations differ between one another. It won't teach you how to develop amazingly performant code, and it's not exhaustive. -Refer to the [language specification](http://chapel.cray.com/language.html) and -the [module documentation](http://chapel.cray.com/docs/latest/) for more +Refer to the [language specification](https://chapel-lang.org/docs/latest/language/spec.html) and +the [module documentation](https://chapel-lang.org/docs/latest/) for more details. -Occasionally check back here and on the [Chapel site](http://chapel.cray.com) +Occasionally check back here and on the [Chapel site](https://chapel-lang.org) to see if more topics have been added or more tutorials created. ### What this tutorial is lacking: - * Exposition of the [standard modules](http://chapel.cray.com/docs/latest/modules/modules.html) + * Exposition of the [standard modules](https://chapel-lang.org/docs/latest/modules/standard.html) * Multiple Locales (distributed memory system) * Records * Parallel iterators @@ -1141,11 +1140,13 @@ to see if more topics have been added or more tutorials created. Your input, questions, and discoveries are important to the developers! ----------------------------------------------------------------------- -The Chapel language is still in-development (version 1.16.0), so there are +The Chapel language is still in active development, so there are occasional hiccups with performance and language features. The more information you give the Chapel development team about issues you encounter or features you -would like to see, the better the language becomes. Feel free to email the team -and other developers through the [sourceforge email lists](https://sourceforge.net/p/chapel/mailman). +would like to see, the better the language becomes. +There are several ways to interact with the developers: ++ [Gitter chat](https://gitter.im/chapel-lang/chapel) ++ [sourceforge email lists](https://sourceforge.net/p/chapel/mailman) If you're really interested in the development of the compiler or contributing to the project, [check out the master GitHub repository](https://github.com/chapel-lang/chapel). @@ -1154,12 +1155,14 @@ It is under the [Apache 2.0 License](http://www.apache.org/licenses/LICENSE-2.0) Installing the Compiler ----------------------- +[The Official Chapel documentation details how to download and compile the Chapel compiler.](https://chapel-lang.org/docs/usingchapel/QUICKSTART.html) + Chapel can be built and installed on your average 'nix machine (and cygwin). [Download the latest release version](https://github.com/chapel-lang/chapel/releases/) and it's as easy as - 1. `tar -xvf chapel-1.16.0.tar.gz` - 2. `cd chapel-1.16.0` + 1. `tar -xvf chapel-<VERSION>.tar.gz` + 2. `cd chapel-<VERSION>` 3. `source util/setchplenv.bash # or .sh or .csh or .fish` 4. `make` 5. `make check # optional` diff --git a/citron.html.markdown b/citron.html.markdown new file mode 100644 index 00000000..bd3c398c --- /dev/null +++ b/citron.html.markdown @@ -0,0 +1,212 @@ +--- +language: citron +filename: learncitron.ctr +contributors: + - ["AnotherTest", ""] +lang: en-us +--- +```ruby +# Comments start with a '#' +# All comments encompass a single line + +########################################### +## 1. Primitive Data types and Operators +########################################### + +# You have numbers +3. # 3 + +# Numbers are all doubles in interpreted mode + +# Mathematical operator precedence is not respected. +# binary 'operators' are evaluated in ltr order +1 + 1. # 2 +8 - 4. # 4 +10 + 2 * 3. # 36 + +# Division is always floating division +35 / 2 # 17.5. + +# Integer division is non-trivial, you may use floor +(35 / 2) floor # 17. + +# Booleans are primitives +True. +False. + +# Boolean messages +True not. # False +False not. # True +1 = 1. # True +1 !=: 1. # False +1 < 10. # True + +# Here, `not` is a unary message to the object `Boolean` +# Messages are comparable to instance method calls +# And they have three different forms: +# 1. Unary messages: Length > 1, and they take no arguments: + False not. +# 2. Binary Messages: Length = 1, and they take a single argument: + False & True. +# 3. Keyword messages: must have at least one ':', they take as many arguments +# as they have `:` s + False either: 1 or: 2. # 2 + +# Strings +'This is a string'. +'There are no character types exposed to the user'. +# "You cannot use double quotes for strings" <- Error + +# Strins can be summed +'Hello, ' + 'World!'. # 'Hello, World!' + +# Strings allow access to their characters +'This is a beautiful string' at: 0. # 'T' + +########################################### +## intermission: Basic Assignment +########################################### + +# You may assign values to the current scope: +var name is value. # assignes `value` into `name` + +# You may also assign values into the current object's namespace +my name is value. # assigns `value` into the current object's `name` property + +# Please note that these names are checked at compile (read parse if in interpreted mode) time +# but you may treat them as dynamic assignments anyway + +########################################### +## 2. Lists(Arrays?) and Tuples +########################################### + +# Arrays are allowed to have multiple types +Array new < 1 ; 2 ; 'string' ; Nil. # Array new < 1 ; 2 ; 'string' ; Nil + +# Tuples act like arrays, but are immutable. +# Any shenanigans degrade them to arrays, however +[1, 2, 'string']. # [1, 2, 'string'] + +# They can interoperate with arrays +[1, 'string'] + (Array new < 'wat'). # Array new < 1 ; 'string' ; 'wat' + +# Indexing into them +[1, 2, 3] at: 1. # 2 + +# Some array operations +var arr is Array new < 1 ; 2 ; 3. + +arr head. # 1 +arr tail. # Array new < 2 ; 3. +arr init. # Array new < 1 ; 2. +arr last. # 3 +arr push: 4. # Array new < 1 ; 2 ; 3 ; 4. +arr pop. # 4 +arr pop: 1. # 2, `arr` is rebound to Array new < 1 ; 3. + +# List comprehensions +[x * 2 + y,, arr, arr + [4, 5],, x > 1]. # Array ← 7 ; 9 ; 10 ; 11 +# fresh variable names are bound as they are encountered, +# so `x` is bound to the values in `arr` +# and `y` is bound to the values in `arr + [4, 5]` +# +# The general format is: [expr,, bindings*,, predicates*] + + +#################################### +## 3. Functions +#################################### + +# A simple function that takes two variables +var add is {:a:b ^a + b.}. + +# this function will resolve all its names except the formal arguments +# in the context it is called in. + +# Using the function +add applyTo: 3 and: 5. # 8 +add applyAll: [3, 5]. # 8 + +# Also a (customizable -- more on this later) pseudo-operator allows for a shorthand +# of function calls +# By default it is REF[args] + +add[3, 5]. # 8 + +# To customize this behaviour, you may simply use a compiler pragma: +#:callShorthand () + +# And then you may use the specified operator. +# Note that the allowed 'operator' can only be made of any of these: []{}() +# And you may mix-and-match (why would anyone do that?) + +add(3, 5). # 8 + +# You may also use functions as operators in the following way: + +3 `add` 5. # 8 +# This call binds as such: add[(3), 5] +# because the default fixity is left, and the default precedance is 1 + +# You may change the precedence/fixity of this operator with a pragma +#:declare infixr 1 add + +3 `add` 5. # 8 +# now this binds as such: add[3, (5)]. + +# There is another form of functions too +# So far, the functions were resolved in a dynamic fashion +# But a lexically scoped block is also possible +var sillyAdd is {\:x:y add[x,y].}. + +# In these blocks, you are not allowed to declare new variables +# Except with the use of Object::'letEqual:in:` +# And the last expression is implicitly returned. + +# You may also use a shorthand for lambda expressions +var mul is \:x:y x * y. + +# These capture the named bindings that are not present in their +# formal parameters, and retain them. (by ref) + +########################################### +## 5. Control Flow +########################################### + +# inline conditional-expressions +var citron is 1 = 1 either: 'awesome' or: 'awful'. # citron is 'awesome' + +# multiple lines is fine too +var citron is 1 = 1 + either: 'awesome' + or: 'awful'. + +# looping +10 times: {:x + Pen writeln: x. +}. # 10. -- side effect: 10 lines in stdout, with numbers 0 through 9 in them + +# Citron properly supports tail-call recursion in lexically scoped blocks +# So use those to your heart's desire + +# mapping most data structures is as simple as `fmap:` +[1, 2, 3, 4] fmap: \:x x + 1. # [2, 3, 4, 5] + +# You can use `foldl:accumulator:` to fold a list/tuple +[1, 2, 3, 4] foldl: (\:acc:x acc * 2 + x) accumulator: 4. # 90 + +# That expression is the same as +(2 * (2 * (2 * (2 * 4 + 1) + 2) + 3) + 4) + +################################### +## 6. IO +################################### + +# IO is quite simple +# With `Pen` being used for console output +# and Program::'input' and Program::'waitForInput' being used for console input + +Pen writeln: 'Hello, ocean!' # prints 'Hello, ocean!\n' to the terminal + +Pen writeln: Program waitForInput. # reads a line and prints it back +``` diff --git a/clojure.html.markdown b/clojure.html.markdown index 7830f228..c94625d6 100644 --- a/clojure.html.markdown +++ b/clojure.html.markdown @@ -150,7 +150,7 @@ x ; => 1 ; You can also use this shorthand to create functions: (def hello2 #(str "Hello " %1)) -(hello2 "Fanny") ; => "Hello Fanny" +(hello2 "Julie") ; => "Hello Julie" ; You can have multi-variadic functions, too (defn hello3 diff --git a/common-lisp.html.markdown b/common-lisp.html.markdown index 9a23bc26..b12e50ca 100644 --- a/common-lisp.html.markdown +++ b/common-lisp.html.markdown @@ -4,82 +4,91 @@ language: "Common Lisp" filename: commonlisp.lisp contributors: - ["Paul Nathan", "https://github.com/pnathan"] + - ["Rommel Martinez", "https://ebzzry.io"] --- -ANSI Common Lisp is a general purpose, multi-paradigm programming -language suited for a wide variety of industry applications. It is -frequently referred to as a programmable programming language. +Common Lisp is a general-purpose, multi-paradigm programming language suited for a wide variety of +industry applications. It is frequently referred to as a programmable programming language. -The classic starting point is [Practical Common Lisp and freely available.](http://www.gigamonkeys.com/book/) +The classic starting point is [Practical Common Lisp](http://www.gigamonkeys.com/book/). Another +popular and recent book is [Land of Lisp](http://landoflisp.com/). A new book about best practices, +[Common Lisp Recipes](http://weitz.de/cl-recipes/), was recently published. -Another popular and recent book is -[Land of Lisp](http://landoflisp.com/). +```lisp -```common_lisp - -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;----------------------------------------------------------------------------- ;;; 0. Syntax -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;----------------------------------------------------------------------------- -;;; General form. +;;; General form -;; Lisp has two fundamental pieces of syntax: the ATOM and the -;; S-expression. Typically, grouped S-expressions are called `forms`. +;;; CL has two fundamental pieces of syntax: ATOM and S-EXPRESSION. +;;; Typically, grouped S-expressions are called `forms`. -10 ; an atom; it evaluates to itself +10 ; an atom; it evaluates to itself +:thing ; another atom; evaluating to the symbol :thing +t ; another atom, denoting true +(+ 1 2 3 4) ; an s-expression +'(4 :foo t) ; another s-expression -:THING ;Another atom; evaluating to the symbol :thing. -t ; another atom, denoting true. +;;; Comments -(+ 1 2 3 4) ; an s-expression +;;; Single-line comments start with a semicolon; use four for file-level +;;; comments, three for section descriptions, two inside definitions, and one +;;; for single lines. For example, -'(4 :foo t) ;another one +;;;; life.lisp +;;; Foo bar baz, because quu quux. Optimized for maximum krakaboom and umph. +;;; Needed by the function LINULUKO. -;;; Comments +(defun meaning (life) + "Return the computed meaning of LIFE" + (let ((meh "abc")) + ;; Invoke krakaboom + (loop :for x :across meh + :collect x))) ; store values into x, then return it -;; Single line comments start with a semicolon; use two for normal -;; comments, three for section comments, and four for file-level -;; comments. +;;; Block comments, on the other hand, allow for free-form comments. They are +;;; delimited with #| and |# -#| Block comments - can span multiple lines and... +#| This is a block comment which + can span multiple lines and #| they can be nested! |# |# -;;; Environment. -;; A variety of implementations exist; most are -;; standard-conformant. CLISP is a good starting one. +;;; Environment -;; Libraries are managed through Quicklisp.org's Quicklisp system. +;;; A variety of implementations exist; most are standards-conformant. SBCL +;;; is a good starting point. Third party libraries can be easily installed with +;;; Quicklisp -;; Common Lisp is usually developed with a text editor and a REPL -;; (Read Evaluate Print Loop) running at the same time. The REPL -;; allows for interactive exploration of the program as it is "live" -;; in the system. +;;; CL is usually developed with a text editor and a Real Eval Print +;;; Loop (REPL) running at the same time. The REPL allows for interactive +;;; exploration of the program while it is running "live". -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;;; 1. Primitive Datatypes and Operators -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;----------------------------------------------------------------------------- +;;; 1. Primitive datatypes and operators +;;;----------------------------------------------------------------------------- ;;; Symbols 'foo ; => FOO Notice that the symbol is upper-cased automatically. -;; Intern manually creates a symbol from a string. +;;; INTERN manually creates a symbol from a string. -(intern "AAAA") ; => AAAA - -(intern "aaa") ; => |aaa| +(intern "AAAA") ; => AAAA +(intern "aaa") ; => |aaa| ;;; Numbers + 9999999999999999999999 ; integers #b111 ; binary => 7 #o111 ; octal => 73 @@ -89,313 +98,363 @@ t ; another atom, denoting true. 1/2 ; ratios #C(1 2) ; complex numbers +;;; Function application are written as (f x y z ...) where f is a function and +;;; x, y, z, ... are the arguments. + +(+ 1 2) ; => 3 + +;;; If you want to create literal data, use QUOTE to prevent it from being +;;; evaluated + +(quote (+ 1 2)) ; => (+ 1 2) +(quote a) ; => A + +;;; The shorthand for QUOTE is ' + +'(+ 1 2) ; => (+ 1 2) +'a ; => A + +;;; Basic arithmetic operations + +(+ 1 1) ; => 2 +(- 8 1) ; => 7 +(* 10 2) ; => 20 +(expt 2 3) ; => 8 +(mod 5 2) ; => 1 +(/ 35 5) ; => 7 +(/ 1 3) ; => 1/3 +(+ #C(1 2) #C(6 -4)) ; => #C(7 -2) + +;;; Booleans + +t ; true; any non-NIL value is true +nil ; false; also, the empty list: () +(not nil) ; => T +(and 0 t) ; => T +(or 0 nil) ; => 0 + +;;; Characters + +#\A ; => #\A +#\λ ; => #\GREEK_SMALL_LETTER_LAMDA +#\u03BB ; => #\GREEK_SMALL_LETTER_LAMDA + +;;; Strings are fixed-length arrays of characters -;; Function application is written (f x y z ...) -;; where f is a function and x, y, z, ... are operands -;; If you want to create a literal list of data, use ' to stop it from -;; being evaluated - literally, "quote" the data. -'(+ 1 2) ; => (+ 1 2) -;; You can also call a function manually: -(funcall #'+ 1 2 3) ; => 6 -;; Some arithmetic operations -(+ 1 1) ; => 2 -(- 8 1) ; => 7 -(* 10 2) ; => 20 -(expt 2 3) ; => 8 -(mod 5 2) ; => 1 -(/ 35 5) ; => 7 -(/ 1 3) ; => 1/3 -(+ #C(1 2) #C(6 -4)) ; => #C(7 -2) - - ;;; Booleans -t ; for true (any not-nil value is true) -nil ; for false - and the empty list -(not nil) ; => t -(and 0 t) ; => t -(or 0 nil) ; => 0 - - ;;; Characters -#\A ; => #\A -#\λ ; => #\GREEK_SMALL_LETTER_LAMDA -#\u03BB ; => #\GREEK_SMALL_LETTER_LAMDA - -;;; Strings are fixed-length arrays of characters. "Hello, world!" "Benjamin \"Bugsy\" Siegel" ; backslash is an escaping character -;; Strings can be concatenated too! -(concatenate 'string "Hello " "world!") ; => "Hello world!" +;;; Strings can be concatenated + +(concatenate 'string "Hello, " "world!") ; => "Hello, world!" + +;;; A string can be treated like a sequence of characters -;; A string can be treated like a sequence of characters (elt "Apple" 0) ; => #\A -;; format can be used to format strings: -(format nil "~a can be ~a" "strings" "formatted") +;;; FORMAT is used to create formatted output, which ranges from simple string +;;; interpolation to loops and conditionals. The first argument to FORMAT +;;; determines where will the formatted string go. If it is NIL, FORMAT +;;; simply returns the formatted string as a value; if it is T, FORMAT outputs +;;; to the standard output, usually the screen, then it returns NIL. + +(format nil "~A, ~A!" "Hello" "world") ; => "Hello, world!" +(format t "~A, ~A!" "Hello" "world") ; => NIL -;; Printing is pretty easy; ~% is the format specifier for newline. -(format t "Common Lisp is groovy. Dude.~%") +;;;----------------------------------------------------------------------------- +;;; 2. Variables +;;;----------------------------------------------------------------------------- -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; 2. Variables -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; You can create a global (dynamically scoped) using defparameter -;; a variable name can use any character except: ()",'`;#|\ +;;; You can create a global (dynamically scoped) variable using DEFVAR and +;;; DEFPARAMETER. The variable name can use any character except: ()",'`;#|\ -;; Dynamically scoped variables should have earmuffs in their name! +;;; The difference between DEFVAR and DEFPARAMETER is that re-evaluating a +;;; DEFVAR expression doesn't change the value of the variable. DEFPARAMETER, +;;; on the other hand, does. + +;;; By convention, dynamically scoped variables have earmuffs in their name. (defparameter *some-var* 5) *some-var* ; => 5 -;; You can also use unicode characters. +;;; You can also use unicode characters. (defparameter *AΛB* nil) +;;; Accessing a previously unbound variable results in an UNBOUND-VARIABLE +;;; error, however it is defined behavior. Don't do it. + +;;; You can create local bindings with LET. In the following snippet, `me` is +;;; bound to "dance with you" only within the (let ...). LET always returns +;;; the value of the last `form` in the LET form. -;; Accessing a previously unbound variable is an -;; undefined behavior (but possible). Don't do it. +(let ((me "dance with you")) me) ; => "dance with you" -;; Local binding: `me` is bound to "dance with you" only within the -;; (let ...). Let always returns the value of the last `form` in the -;; let form. +;;;-----------------------------------------------------------------------------; +;;; 3. Structs and collections +;;;-----------------------------------------------------------------------------; -(let ((me "dance with you")) - me) -;; => "dance with you" -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; 3. Structs and Collections -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;; Structs -;; Structs (defstruct dog name breed age) (defparameter *rover* (make-dog :name "rover" :breed "collie" :age 5)) -*rover* ; => #S(DOG :NAME "rover" :BREED "collie" :AGE 5) - -(dog-p *rover*) ; => true #| -p signifies "predicate". It's used to - check if *rover* is an instance of dog. |# +*rover* ; => #S(DOG :NAME "rover" :BREED "collie" :AGE 5) +(dog-p *rover*) ; => T (dog-name *rover*) ; => "rover" -;; Dog-p, make-dog, and dog-name are all created by defstruct! +;;; DOG-P, MAKE-DOG, and DOG-NAME are all automatically created by DEFSTRUCT + ;;; Pairs -;; `cons' constructs pairs, `car' and `cdr' extract the first -;; and second elements -(cons 'SUBJECT 'VERB) ; => '(SUBJECT . VERB) -(car (cons 'SUBJECT 'VERB)) ; => SUBJECT -(cdr (cons 'SUBJECT 'VERB)) ; => VERB + +;;; CONS constructs pairs. CAR and CDR return the head and tail of a CONS-pair. + +(cons 'SUBJECT 'VERB) ; => '(SUBJECT . VERB) +(car (cons 'SUBJECT 'VERB)) ; => SUBJECT +(cdr (cons 'SUBJECT 'VERB)) ; => VERB + ;;; Lists -;; Lists are linked-list data structures, made of `cons' pairs and end -;; with a `nil' (or '()) to mark the end of the list -(cons 1 (cons 2 (cons 3 nil))) ; => '(1 2 3) -;; `list' is a convenience variadic constructor for lists -(list 1 2 3) ; => '(1 2 3) -;; and a quote can also be used for a literal list value -'(1 2 3) ; => '(1 2 3) +;;; Lists are linked-list data structures, made of CONS pairs and end with a +;;; NIL (or '()) to mark the end of the list + +(cons 1 (cons 2 (cons 3 nil))) ; => '(1 2 3) + +;;; LIST is a convenience variadic constructor for lists + +(list 1 2 3) ; => '(1 2 3) -;; Can still use `cons' to add an item to the beginning of a list -(cons 4 '(1 2 3)) ; => '(4 1 2 3) +;;; When the first argument to CONS is an atom and the second argument is a +;;; list, CONS returns a new CONS-pair with the first argument as the first +;;; item and the second argument as the rest of the CONS-pair -;; Use `append' to - surprisingly - append lists together -(append '(1 2) '(3 4)) ; => '(1 2 3 4) +(cons 4 '(1 2 3)) ; => '(4 1 2 3) -;; Or use concatenate - +;;; Use APPEND to join lists -(concatenate 'list '(1 2) '(3 4)) +(append '(1 2) '(3 4)) ; => '(1 2 3 4) + +;;; Or CONCATENATE + +(concatenate 'list '(1 2) '(3 4)) ; => '(1 2 3 4) + +;;; Lists are a very central type, so there is a wide variety of functionality for +;;; them, a few examples: -;; Lists are a very central type, so there is a wide variety of functionality for -;; them, a few examples: (mapcar #'1+ '(1 2 3)) ; => '(2 3 4) (mapcar #'+ '(1 2 3) '(10 20 30)) ; => '(11 22 33) (remove-if-not #'evenp '(1 2 3 4)) ; => '(2 4) -(every #'evenp '(1 2 3 4)) ; => nil +(every #'evenp '(1 2 3 4)) ; => NIL (some #'oddp '(1 2 3 4)) ; => T (butlast '(subject verb object)) ; => (SUBJECT VERB) ;;; Vectors -;; Vector's literals are fixed-length arrays +;;; Vector's literals are fixed-length arrays + #(1 2 3) ; => #(1 2 3) -;; Use concatenate to add vectors together +;;; Use CONCATENATE to add vectors together + (concatenate 'vector #(1 2 3) #(4 5 6)) ; => #(1 2 3 4 5 6) + ;;; Arrays -;; Both vectors and strings are special-cases of arrays. +;;; Both vectors and strings are special-cases of arrays. -;; 2D arrays +;;; 2D arrays -(make-array (list 2 2)) +(make-array (list 2 2)) ; => #2A((0 0) (0 0)) +(make-array '(2 2)) ; => #2A((0 0) (0 0)) +(make-array (list 2 2 2)) ; => #3A(((0 0) (0 0)) ((0 0) (0 0))) -;; (make-array '(2 2)) works as well. +;;; Caution: the default initial values of MAKE-ARRAY are implementation-defined. +;;; To explicitly specify them: -; => #2A((0 0) (0 0)) +(make-array '(2) :initial-element 'unset) ; => #(UNSET UNSET) -(make-array (list 2 2 2)) +;;; To access the element at 1, 1, 1: -; => #3A(((0 0) (0 0)) ((0 0) (0 0))) +(aref (make-array (list 2 2 2)) 1 1 1) ; => 0 +;;; This value is implementation-defined: +;;; NIL on ECL, 0 on SBCL and CCL. -;; Caution- the default initial values are -;; implementation-defined. Here's how to define them: +;;; Adjustable vectors -(make-array '(2) :initial-element 'unset) +;;; Adjustable vectors have the same printed representation as +;;; fixed-length vector's literals. -; => #(UNSET UNSET) +(defparameter *adjvec* (make-array '(3) :initial-contents '(1 2 3) + :adjustable t :fill-pointer t)) +*adjvec* ; => #(1 2 3) -;; And, to access the element at 1,1,1 - -(aref (make-array (list 2 2 2)) 1 1 1) +;;; Adding new elements -; => 0 +(vector-push-extend 4 *adjvec*) ; => 3 +*adjvec* ; => #(1 2 3 4) -;;; Adjustable vectors -;; Adjustable vectors have the same printed representation -;; as fixed-length vector's literals. +;;; Sets, naively, are just lists: -(defparameter *adjvec* (make-array '(3) :initial-contents '(1 2 3) - :adjustable t :fill-pointer t)) +(set-difference '(1 2 3 4) '(4 5 6 7)) ; => (3 2 1) +(intersection '(1 2 3 4) '(4 5 6 7)) ; => 4 +(union '(1 2 3 4) '(4 5 6 7)) ; => (3 2 1 4 5 6 7) +(adjoin 4 '(1 2 3 4)) ; => (1 2 3 4) -*adjvec* ; => #(1 2 3) +;;; However, you'll need a better data structure than linked lists when working +;;; with larger data sets + +;;; Dictionaries are implemented as hash tables. + +;;; Create a hash table -;; Adding new element: -(vector-push-extend 4 *adjvec*) ; => 3 +(defparameter *m* (make-hash-table)) -*adjvec* ; => #(1 2 3 4) +;;; Set value +(setf (gethash 'a *m*) 1) +;;; Retrieve value -;;; Naively, sets are just lists: +(gethash 'a *m*) ; => 1, T -(set-difference '(1 2 3 4) '(4 5 6 7)) ; => (3 2 1) -(intersection '(1 2 3 4) '(4 5 6 7)) ; => 4 -(union '(1 2 3 4) '(4 5 6 7)) ; => (3 2 1 4 5 6 7) -(adjoin 4 '(1 2 3 4)) ; => (1 2 3 4) +;;; CL expressions have the ability to return multiple values. -;; But you'll want to use a better data structure than a linked list -;; for performant work! +(values 1 2) ; => 1, 2 -;;; Dictionaries are implemented as hash tables. +;;; which can be bound with MULTIPLE-VALUE-BIND -;; Create a hash table -(defparameter *m* (make-hash-table)) +(multiple-value-bind (x y) + (values 1 2) + (list y x)) -;; set a value -(setf (gethash 'a *m*) 1) +; => '(2 1) -;; Retrieve a value -(gethash 'a *m*) ; => 1, t +;;; GETHASH is an example of a function that returns multiple values. The first +;;; value it return is the value of the key in the hash table; if the key is +;;; not found it returns NIL. -;; Detail - Common Lisp has multiple return values possible. gethash -;; returns t in the second value if anything was found, and nil if -;; not. +;;; The second value determines if that key is indeed present in the hash +;;; table. If a key is not found in the table it returns NIL. This behavior +;;; allows us to check if the value of a key is actually NIL. -;; Retrieving a non-present value returns nil - (gethash 'd *m*) ;=> nil, nil +;;; Retrieving a non-present value returns nil + +(gethash 'd *m*) ;=> NIL, NIL + +;;; You can provide a default value for missing keys -;; You can provide a default value for missing keys (gethash 'd *m* :not-found) ; => :NOT-FOUND -;; Let's handle the multiple return values here in code. +;;; Let's handle the multiple return values here in code. -(multiple-value-bind - (a b) +(multiple-value-bind (a b) (gethash 'd *m*) (list a b)) ; => (NIL NIL) -(multiple-value-bind - (a b) +(multiple-value-bind (a b) (gethash 'a *m*) (list a b)) ; => (1 T) -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; 3. Functions -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; Use `lambda' to create anonymous functions. -;; A function always returns the value of its last expression. -;; The exact printable representation of a function will vary... +;;;----------------------------------------------------------------------------- +;;; 3. Functions +;;;----------------------------------------------------------------------------- + +;;; Use LAMBDA to create anonymous functions. Functions always returns the +;;; value of the last expression. The exact printable representation of a +;;; function varies between implementations. (lambda () "Hello World") ; => #<FUNCTION (LAMBDA ()) {1004E7818B}> -;; Use funcall to call lambda functions -(funcall (lambda () "Hello World")) ; => "Hello World" +;;; Use FUNCALL to call anonymous functions + +(funcall (lambda () "Hello World")) ; => "Hello World" +(funcall #'+ 1 2 3) ; => 6 + +;;; A call to FUNCALL is also implied when the lambda expression is the CAR of +;;; an unquoted list -;; Or Apply +((lambda () "Hello World")) ; => "Hello World" +((lambda (val) val) "Hello World") ; => "Hello World" + +;;; FUNCALL is used when the arguments are known beforehand. Otherwise, use APPLY + +(apply #'+ '(1 2 3)) ; => 6 (apply (lambda () "Hello World") nil) ; => "Hello World" -;; De-anonymize the function -(defun hello-world () - "Hello World") +;;; To name a function, use DEFUN + +(defun hello-world () "Hello World") (hello-world) ; => "Hello World" -;; The () in the above is the list of arguments for the function -(defun hello (name) - (format nil "Hello, ~a" name)) +;;; The () in the definition above is the list of arguments +(defun hello (name) (format nil "Hello, ~A" name)) (hello "Steve") ; => "Hello, Steve" -;; Functions can have optional arguments; they default to nil +;;; Functions can have optional arguments; they default to NIL (defun hello (name &optional from) - (if from - (format t "Hello, ~a, from ~a" name from) - (format t "Hello, ~a" name))) + (if from + (format t "Hello, ~A, from ~A" name from) + (format t "Hello, ~A" name))) - (hello "Jim" "Alpacas") ;; => Hello, Jim, from Alpacas - -;; And the defaults can be set... -(defun hello (name &optional (from "The world")) - (format t "Hello, ~a, from ~a" name from)) +(hello "Jim" "Alpacas") ; => Hello, Jim, from Alpacas -(hello "Steve") -; => Hello, Steve, from The world +;;; The default values can also be specified -(hello "Steve" "the alpacas") -; => Hello, Steve, from the alpacas +(defun hello (name &optional (from "The world")) + (format nil "Hello, ~A, from ~A" name from)) +(hello "Steve") ; => Hello, Steve, from The world +(hello "Steve" "the alpacas") ; => Hello, Steve, from the alpacas -;; And of course, keywords are allowed as well... usually more -;; flexible than &optional. +;;; Functions also have keyword arguments to allow non-positional arguments (defun generalized-greeter (name &key (from "the world") (honorific "Mx")) - (format t "Hello, ~a ~a, from ~a" honorific name from)) + (format t "Hello, ~A ~A, from ~A" honorific name from)) -(generalized-greeter "Jim") ; => Hello, Mx Jim, from the world +(generalized-greeter "Jim") +; => Hello, Mx Jim, from the world (generalized-greeter "Jim" :from "the alpacas you met last summer" :honorific "Mr") ; => Hello, Mr Jim, from the alpacas you met last summer -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; 4. Equality -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; Common Lisp has a sophisticated equality system. A couple are covered here. +;;;----------------------------------------------------------------------------- +;;; 4. Equality +;;;----------------------------------------------------------------------------- + +;;; CL has a sophisticated equality system. Some are covered here. + +;;; For numbers, use `=' +(= 3 3.0) ; => T +(= 2 1) ; => NIL -;; for numbers use `=' -(= 3 3.0) ; => t -(= 2 1) ; => nil +;;; For object identity (approximately) use EQL +(eql 3 3) ; => T +(eql 3 3.0) ; => NIL +(eql (list 3) (list 3)) ; => NIL -;; for object identity (approximately) use `eql` -(eql 3 3) ; => t -(eql 3 3.0) ; => nil -(eql (list 3) (list 3)) ; => nil +;;; for lists, strings, and bit-vectors use EQUAL +(equal (list 'a 'b) (list 'a 'b)) ; => T +(equal (list 'a 'b) (list 'b 'a)) ; => NIL -;; for lists, strings, and bit-vectors use `equal' -(equal (list 'a 'b) (list 'a 'b)) ; => t -(equal (list 'a 'b) (list 'b 'a)) ; => nil -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; 5. Control Flow -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;----------------------------------------------------------------------------- +;;; 5. Control Flow +;;;----------------------------------------------------------------------------- ;;; Conditionals @@ -404,71 +463,75 @@ nil ; for false - and the empty list "this is false") ; else expression ; => "this is true" -;; In conditionals, all non-nil values are treated as true +;;; In conditionals, all non-NIL values are treated as true + (member 'Groucho '(Harpo Groucho Zeppo)) ; => '(GROUCHO ZEPPO) (if (member 'Groucho '(Harpo Groucho Zeppo)) 'yep 'nope) ; => 'YEP -;; `cond' chains a series of tests to select a result +;;; COND chains a series of tests to select a result (cond ((> 2 2) (error "wrong!")) ((< 2 2) (error "wrong again!")) (t 'ok)) ; => 'OK -;; Typecase switches on the type of the value +;;; TYPECASE switches on the type of the value (typecase 1 (string :string) (integer :int)) - ; => :int -;;; Iteration -;; Of course recursion is supported: +;;; Looping -(defun walker (n) - (if (zerop n) - :walked - (walker (- n 1)))) +;;; Recursion -(walker 5) ; => :walked +(defun fact (n) + (if (< n 2) + 1 + (* n (fact(- n 1))))) -;; Most of the time, we use DOLIST or LOOP +(fact 5) ; => 120 +;;; Iteration -(dolist (i '(1 2 3 4)) - (format t "~a" i)) +(defun fact (n) + (loop :for result = 1 :then (* result i) + :for i :from 2 :to n + :finally (return result))) -; => 1234 +(fact 5) ; => 120 -(loop for i from 0 below 10 - collect i) +(loop :for x :across "abcd" :collect x) +; => (#\a #\b #\c #\d) -; => (0 1 2 3 4 5 6 7 8 9) +(dolist (i '(1 2 3 4)) + (format t "~A" i)) +; => 1234 -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; 6. Mutation -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;----------------------------------------------------------------------------- +;;; 6. Mutation +;;;----------------------------------------------------------------------------- -;; Use `setf' to assign a new value to an existing variable. This was -;; demonstrated earlier in the hash table example. +;;; Use SETF to assign a new value to an existing variable. This was +;;; demonstrated earlier in the hash table example. (let ((variable 10)) (setf variable 2)) - ; => 2 +; => 2 +;;; Good Lisp style is to minimize the use of destructive functions and to avoid +;;; mutation when reasonable. -;; Good Lisp style is to minimize destructive functions and to avoid -;; mutation when reasonable. -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; 7. Classes and Objects -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;----------------------------------------------------------------------------- +;;; 7. Classes and objects +;;;----------------------------------------------------------------------------- -;; No more Animal classes, let's have Human-Powered Mechanical -;; Conveyances. +;;; No more animal classes. Let's have Human-Powered Mechanical +;;; Conveyances. (defclass human-powered-conveyance () ((velocity @@ -479,14 +542,16 @@ nil ; for false - and the empty list :initarg :average-efficiency)) (:documentation "A human powered conveyance")) -;; defclass, followed by name, followed by the superclass list, -;; followed by slot list, followed by optional qualities such as -;; :documentation. +;;; The arguments to DEFCLASS, in order are: +;;; 1. class name +;;; 2. superclass list +;;; 3. slot list +;;; 4. optional specifiers -;; When no superclass list is set, the empty list defaults to the -;; standard-object class. This *can* be changed, but not until you -;; know what you're doing. Look up the Art of the Metaobject Protocol -;; for more information. +;;; When no superclass list is set, the empty list defaults to the +;;; standard-object class. This *can* be changed, but not until you +;;; know what you're doing. Look up the Art of the Metaobject Protocol +;;; for more information. (defclass bicycle (human-powered-conveyance) ((wheel-size @@ -500,7 +565,7 @@ nil ; for false - and the empty list (defclass recumbent (bicycle) ((chain-type :accessor chain-type - :initarg :chain-type))) + :initarg :chain-type))) (defclass unicycle (human-powered-conveyance) nil) @@ -509,8 +574,7 @@ nil ; for false - and the empty list :accessor number-of-rowers :initarg :number-of-rowers))) - -;; Calling DESCRIBE on the human-powered-conveyance class in the REPL gives: +;;; Calling DESCRIBE on the HUMAN-POWERED-CONVEYANCE class in the REPL gives: (describe 'human-powered-conveyance) @@ -532,47 +596,42 @@ nil ; for false - and the empty list ; Readers: AVERAGE-EFFICIENCY ; Writers: (SETF AVERAGE-EFFICIENCY) -;; Note the reflective behavior available to you! Common Lisp is -;; designed to be an interactive system +;;; Note the reflective behavior available. CL was designed to be an +;;; interactive system -;; To define a method, let's find out what our circumference of the -;; bike wheel turns out to be using the equation: C = d * pi +;;; To define a method, let's find out what our circumference of the +;;; bike wheel turns out to be using the equation: C = d * pi (defmethod circumference ((object bicycle)) (* pi (wheel-size object))) -;; pi is defined in Lisp already for us! +;;; PI is defined as a built-in in CL -;; Let's suppose we find out that the efficiency value of the number -;; of rowers in a canoe is roughly logarithmic. This should probably be set -;; in the constructor/initializer. +;;; Let's suppose we find out that the efficiency value of the number +;;; of rowers in a canoe is roughly logarithmic. This should probably be set +;;; in the constructor/initializer. -;; Here's how to initialize your instance after Common Lisp gets done -;; constructing it: +;;; To initialize your instance after CL gets done constructing it: (defmethod initialize-instance :after ((object canoe) &rest args) (setf (average-efficiency object) (log (1+ (number-of-rowers object))))) -;; Then to construct an instance and check the average efficiency... +;;; Then to construct an instance and check the average efficiency... (average-efficiency (make-instance 'canoe :number-of-rowers 15)) ; => 2.7725887 +;;;----------------------------------------------------------------------------- +;;; 8. Macros +;;;----------------------------------------------------------------------------- - -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; 8. Macros -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; - -;; Macros let you extend the syntax of the language - -;; Common Lisp doesn't come with a WHILE loop- let's add one. -;; If we obey our assembler instincts, we wind up with: +;;; Macros let you extend the syntax of the language. CL doesn't come +;;; with a WHILE loop, however, it's trivial to write one. If we obey our +;;; assembler instincts, we wind up with: (defmacro while (condition &body body) "While `condition` is true, `body` is executed. - `condition` is tested prior to each execution of `body`" (let ((block-name (gensym)) (done (gensym))) `(tagbody @@ -584,47 +643,47 @@ nil ; for false - and the empty list (go ,block-name) ,done))) -;; Let's look at the high-level version of this: - +;;; Let's look at the high-level version of this: (defmacro while (condition &body body) "While `condition` is true, `body` is executed. - `condition` is tested prior to each execution of `body`" `(loop while ,condition do (progn ,@body))) -;; However, with a modern compiler, this is not required; the LOOP -;; form compiles equally well and is easier to read. +;;; However, with a modern compiler, this is not required; the LOOP form +;;; compiles equally well and is easier to read. -;; Note that ``` is used, as well as `,` and `@`. ``` is a quote-type operator -;; known as quasiquote; it allows the use of `,` . `,` allows "unquoting" -;; variables. @ interpolates lists. +;;; Note that ``` is used, as well as `,` and `@`. ``` is a quote-type operator +;;; known as quasiquote; it allows the use of `,` . `,` allows "unquoting" +;;; variables. @ interpolates lists. -;; Gensym creates a unique symbol guaranteed to not exist elsewhere in -;; the system. This is because macros are expanded at compile time and -;; variables declared in the macro can collide with variables used in -;; regular code. +;;; GENSYM creates a unique symbol guaranteed to not exist elsewhere in +;;; the system. This is because macros are expanded at compile time and +;;; variables declared in the macro can collide with variables used in +;;; regular code. -;; See Practical Common Lisp for more information on macros. +;;; See Practical Common Lisp and On Lisp for more information on macros. ``` -## Further Reading +## Further reading + +- [Practical Common Lisp](http://www.gigamonkeys.com/book/) +- [Common Lisp: A Gentle Introduction to Symbolic Computation](https://www.cs.cmu.edu/~dst/LispBook/book.pdf) -* [Keep moving on to the Practical Common Lisp book.](http://www.gigamonkeys.com/book/) -* [A Gentle Introduction to...](https://www.cs.cmu.edu/~dst/LispBook/book.pdf) +## Extra information -## Extra Info +- [CLiki](http://www.cliki.net/) +- [common-lisp.net](https://common-lisp.net/) +- [Awesome Common Lisp](https://github.com/CodyReichert/awesome-cl) +- [Lisp Lang](http://lisp-lang.org/) -* [CLiki](http://www.cliki.net/) -* [common-lisp.net](https://common-lisp.net/) -* [Awesome Common Lisp](https://github.com/CodyReichert/awesome-cl) -## Credits. +## Credits Lots of thanks to the Scheme people for rolling up a great starting point which could be easily moved to Common Lisp. diff --git a/crystal.html.markdown b/crystal.html.markdown index 15cbc0b1..8210b443 100644 --- a/crystal.html.markdown +++ b/crystal.html.markdown @@ -301,7 +301,6 @@ end (1..3).each do |index| puts "Index: #{index}" end -# Index: 0 # Index: 1 # Index: 2 # Index: 3 @@ -422,7 +421,7 @@ class Human @name end - # The above functionality can be encapsulated using the attr_accessor method as follows + # The above functionality can be encapsulated using the propery method as follows property :name # Getter/setter methods can also be created individually like this diff --git a/cs-cz/elm.html.markdown b/cs-cz/elm.html.markdown index f19f9e8b..42ec89e5 100644 --- a/cs-cz/elm.html.markdown +++ b/cs-cz/elm.html.markdown @@ -75,8 +75,8 @@ List.head [] -- Nothing -- K získání hodnot z dvojice použijte funkce first a second. -- (Toto je pouze zkratka. Brzy si ukážeme, jak na to "správně".) -fst ("elm", 42) -- "elm" -snd ("elm", 42) -- 42 +Tuple.first ("elm", 42) -- "elm" +Tuple.second ("elm", 42) -- 42 -- Prázná n-tice, neboli "unit", se občas používá jako zástupný symbol. -- Je to jediná hodnota svého typu, který se také nazývá "Unit". diff --git a/cs-cz/javascript.html.markdown b/cs-cz/javascript.html.markdown index cbf7687e..c05a9138 100644 --- a/cs-cz/javascript.html.markdown +++ b/cs-cz/javascript.html.markdown @@ -9,33 +9,28 @@ lang: cs-cz filename: javascript-cz.js --- -JavaScript byl vytvořen Brendan Eichem v roce 1995 pro Netscape. Byl původně -zamýšlen jako jednoduchý skriptovací jazyk pro webové stránky, jako doplněk Javy, -která byla zamýšlena pro více komplexní webové aplikace, ale jeho úzké propojení -s webovými stránkami a vestavěná podpora v prohlížečích způsobila, že se stala -více běžná ve webovém frontendu než Java. +JavaScript byl vytvořen Brendanem Eichem v roce 1995 pro Netscape. Původně byl +zamýšlen jako jednoduchý skriptovací jazyk pro webové stránky, jako doplněk +Javy, která byla zamýšlena pro komplexnější webové aplikace. Úzké propojení +JavaScriptu s webovými stránkami a vestavěná podpora v prohlížečích způsobila, +že se stal ve webovém frontendu běžnějším než Java. - -JavaScript není omezen pouze na webové prohlížeče, např. projekt Node.js, -který zprostředkovává samostatně běžící prostředí V8 JavaScriptového enginu z -Google Chrome se stává více a více oblíbený pro serverovou část webových aplikací. - -Zpětná vazba je velmi ceněná. Autora článku můžete kontaktovat (anglicky) na -[@adambrenecki](https://twitter.com/adambrenecki), nebo -[adam@brenecki.id.au](mailto:adam@brenecki.id.au), nebo mě, jakožto překladatele, -na [martinek@ludis.me](mailto:martinek@ludis.me). +JavaScript není omezen pouze na webové prohlížeče. Např. projekt Node.js, +který zprostředkovává samostatně běžící prostředí V8 JavaScriptového jádra z +Google Chrome se stává stále oblíbenější i pro serverovou část webových +aplikací. ```js -// Komentáře jsou jako v zayku C. Jednořádkové komentáře začínájí dvojitým lomítkem, +// Jednořádkové komentáře začínají dvojitým lomítkem, /* a víceřádkové komentáře začínají lomítkem s hvězdičkou a končí hvězdičkou s lomítkem */ -// Vyrazu můžou být spuštěny pomocí ; +// Příkazy mohou být ukončeny středníkem ; delejNeco(); -// ... ale nemusí, středníky jsou automaticky vloženy kdekoliv, -// kde končí řádka, kromě pár speciálních případů -delejNeco() +// ... ale nemusí, protože středníky jsou automaticky vloženy kdekoliv, +// kde končí řádka, kromě pár speciálních případů. +delejNeco(); // Protože tyto případy můžou způsobit neočekávané výsledky, budeme // středníky v našem návodu používat. @@ -44,12 +39,12 @@ delejNeco() // 1. Čísla, řetězce a operátory // JavaScript má jeden číselný typ (čímž je 64-bitový IEEE 754 double). -// Double má 52-bit přesnost, což je dostatečně přesné pro ukládání celých čísel -// do 9✕10¹⁵. +// Double má 52-bitovou přesnost, což je dostatečně přesné pro ukládání celých +// čísel až do 9✕10¹⁵. 3; // = 3 1.5; // = 1.5 -// Základní matematické operace fungují, jak byste očekávali +// Základní matematické operace fungují tak, jak byste očekávali 1 + 1; // = 2 0.1 + 0.2; // = 0.30000000000000004 8 - 1; // = 7 @@ -65,30 +60,30 @@ delejNeco() 18.5 % 7; // = 4.5 // Bitové operace také fungují; když provádíte bitové operace, desetinné číslo -// (float) se převede na celé číslo (int) se znaménkem *do* 32 bitů +// (float) se převede na celé číslo (int) se znaménkem *až do* 32 bitů 1 << 2; // = 4 // Přednost se vynucuje závorkami. (1 + 3) * 2; // = 8 -// Existují 3 hodnoty mimo obor reálných čísel +// Existují 3 hodnoty mimo obor reálných čísel: Infinity; // + nekonečno; výsledek např. 1/0 -Infinity; // - nekonečno; výsledek např. -1/0 NaN; // výsledek např. 0/0, znamená, že výsledek není číslo ('Not a Number') -// Také existují hodnoty typu bool +// Také existují hodnoty typu boolean. true; // pravda false; // nepravda -// Řetězce znaků jsou obaleny ' nebo ". +// Řetězce znaků jsou obaleny ' nebo ". 'abc'; -"Ahoj světe!"; +"Hello, world"; -// Negace se tvoří pomocí ! +// Negace se tvoří pomocí znaku ! !true; // = false !false; // = true -// Rovnost se porovnává === +// Rovnost se porovnává pomocí === 1 === 1; // = true 2 === 1; // = false @@ -103,16 +98,16 @@ false; // nepravda 2 >= 2; // = true // Řetězce znaků se spojují pomocí + -"Ahoj " + "světe!"; // = "Ahoj světe!" +"Hello " + "world!"; // = "Hello world!" -// ... což funguje nejenom s řetězci +// ... což funguje nejen s řetězci "1, 2, " + 3; // = "1, 2, 3" -"Ahoj " + ["světe", "!"] // = "Ahoj světe,!" +"Hello " + ["world", "!"]; // = "Hello world,!" // a porovnávají se pomocí < nebo > "a" < "b"; // = true -// Rovnost s převodem typů se dělá pomocí == ... +// Rovnost s převodem typů se dělá za pomoci dvojitého rovnítka... "5" == 5; // = true null == undefined; // = true @@ -124,24 +119,24 @@ null === undefined; // = false 13 + !0; // 14 "13" + !0; // '13true' -// Můžeme přistupovat k jednotlivým znakům v řetězci pomocí charAt` +// Můžeme přistupovat k jednotlivým znakům v řetězci pomocí `charAt` "Toto je řetězec".charAt(0); // = 'T' -// ...nebo použít `substring` k získání podřetězce -"Ahoj světe".substring(0, 4); // = "Ahoj" +// ...nebo použít `substring` k získání podřetězce. +"Hello world".substring(0, 5); // = "Hello" -// `length` znamená délka a je to vlastnost, takže nepoužívejte () -"Ahoj".length; // = 4 +// `length` znamená délka a je to vlastnost, takže nepoužívejte (). +"Hello".length; // = 5 // Existují také typy `null` a `undefined`. -null; // značí, že žádnou hodnotu -undefined; // značí, že hodnota nebyla definovaná (ikdyž +null; // obvykle označuje něco záměrně bez hodnoty +undefined; // obvykle označuje, že hodnota není momentálně definovaná (ačkoli // `undefined` je hodnota sama o sobě) -// false, null, undefined, NaN, 0 and "" vrací nepravdu (false). Všechno ostatní -// vrací pravdu (true).. -// Všimněte si, že 0 vrací nepravdu, ale "0" vrací pravdu, ikdyž 0 == "0" -// vrací pravdu +// false, null, undefined, NaN, 0 a "" vrací nepravdu (false). Všechno ostatní +// vrací pravdu (true). +// Všimněte si, že 0 vrací nepravdu, ale "0" vrací pravdu, i když 0 == "0" +// vrací pravdu. /////////////////////////////////// // 2. Proměnné, pole a objekty @@ -151,11 +146,11 @@ undefined; // značí, že hodnota nebyla definovaná (ikdyž // znak `=`. var promenna = 5; -// když vynecháte slůvko 'var' nedostanete chybovou hlášku... +// Když vynecháte slůvko 'var', nedostanete chybovou hlášku... jinaPromenna = 10; -// ...ale vaše proměnná bude vytvořena globálně, bude vytvořena v globálním -// oblasti působnosti, ne jenom v lokálním tam, kde jste ji vytvořili +// ...ale vaše proměnná bude vytvořena globálně. Bude vytvořena v globální +// oblasti působnosti, tedy nejenom v lokální tam, kde jste ji vytvořili. // Proměnné vytvořené bez přiřazení obsahují hodnotu undefined. var dalsiPromenna; // = undefined @@ -163,114 +158,136 @@ var dalsiPromenna; // = undefined // Pokud chcete vytvořit několik proměnných najednou, můžete je oddělit čárkou var someFourthVar = 2, someFifthVar = 4; -// Existuje kratší forma pro matematické operace na proměnné +// Existuje kratší forma pro matematické operace nad proměnnými promenna += 5; // se provede stejně jako promenna = promenna + 5; -// promenna je ted 10 +// promenna je teď 10 promenna *= 10; // teď je promenna rovna 100 // a tohle je způsob, jak přičítat a odečítat 1 promenna++; // teď je promenna 101 promenna--; // zpět na 100 -// Pole jsou uspořádané seznamy hodnot jakéhokoliv typu -var mojePole = ["Ahoj", 45, true]; +// Pole jsou uspořádané seznamy hodnot jakéhokoliv typu. +var myArray = ["Ahoj", 45, true]; // Jednotlivé hodnoty jsou přístupné přes hranaté závorky. // Členové pole se začínají počítat na nule. myArray[1]; // = 45 -// Pole je proměnlivé délky a členové se můžou měnit -myArray.push("Světe"); +// Pole je proměnlivé délky a členové se můžou měnit. +myArray.push("World"); myArray.length; // = 4 // Přidání/změna na specifickém indexu myArray[3] = "Hello"; -// JavaScriptové objekty jsou stejné jako asociativní pole v jinných programovacích +// Přidání nebo odebrání člena ze začátku nebo konce pole +myArray.unshift(3); // Přidej jako první člen +someVar = myArray.shift(); // Odstraň prvního člena a vrať jeho hodnotu +myArray.push(3); // Přidej jako poslední člen +someVar = myArray.pop(); // Odstraň posledního člena a vrať jeho hodnotu + +// Spoj všechny členy pole středníkem +var myArray0 = [32,false,"js",12,56,90]; +myArray0.join(";") // = "32;false;js;12;56;90" + +// Vrať část pole s elementy od pozice 1 (včetně) do pozice 4 (nepočítaje) +myArray0.slice(1,4); // = [false,"js",12] + +// Odstraň čtyři členy od pozice 2, vlož následující +// "hi","wr" and "ld"; vrať odstraněné členy +myArray0.splice(2,4,"hi","wr","ld"); // = ["js",12,56,90] +// myArray0 === [32,false,"hi","wr","ld"] + +// JavaScriptové objekty jsou stejné jako asociativní pole v jiných programovacích // jazycích: je to neuspořádaná množina páru hodnot - klíč:hodnota. -var mujObjekt = {klic1: "Ahoj", klic2: "světe"}; +var mujObjekt = {klic1: "Hello", klic2: "World"}; -// Klíče jsou řetězce, ale nejsou povinné uvozovky, pokud jsou validní -// JavaScriptové identifikátory. Hodnoty můžou být jakéhokoliv typu- +// Klíče jsou řetězce, ale nemusí mít povinné uvozovky, pokud jsou validními +// JavaScriptovými identifikátory. Hodnoty můžou být jakéhokoliv typu. var mujObjekt = {klic: "mojeHodnota", "muj jiny klic": 4}; // K hodnotám můžeme přistupovat opět pomocí hranatých závorek -myObj["muj jiny klic"]; // = 4 +mujObjekt["muj jiny klic"]; // = 4 // ... nebo pokud je klíč platným identifikátorem, můžeme přistupovat k // hodnotám i přes tečku mujObjekt.klic; // = "mojeHodnota" // Objekty jsou měnitelné, můžeme upravit hodnoty, nebo přidat nové klíče. -myObj.mujDalsiKlic = true; +mujObjekt.mujDalsiKlic = true; -// Pokud se snažíte přistoupit ke klíči, který není nastaven, dostanete undefined -myObj.dalsiKlic; // = undefined +// Pokud se snažíte přistoupit ke klíči, který neexistuje, dostanete undefined. +mujObjekt.dalsiKlic; // = undefined /////////////////////////////////// // 3. Řízení toku programu -// Syntaxe pro tuto sekci je prakticky stejná jako pro Javu - -// `if` (když) funguje, jak byste čekali. +// Funkce `if` funguje, jak byste čekali. var pocet = 1; if (pocet == 3){ // provede, když se pocet rovná 3 } else if (pocet == 4){ // provede, když se pocet rovná 4 } else { - // provede, když je pocet cokoliv jinného + // provede, když je pocet cokoliv jiného } -// Stejně tak cyklus while +// Stejně tak cyklus `while`. while (true){ - // nekonečný cyklus + // nekonečný cyklus! } -// Do-while cyklus je stejný jako while, akorát se vždy provede aspoň jednou +// Do-while cyklus je stejný jako while, akorát se vždy provede aspoň jednou. var vstup; do { vstup = nactiVstup(); } while (!jeValidni(vstup)) -// Cyklus for je stejný jako v Javě nebo jazyku C +// Cyklus `for` je stejný jako v Javě nebo jazyku C: // inicializace; podmínka pro pokračování; iterace. -for (var i = 0; i < 3; i++){ - // provede třikrát +for (var i = 0; i < 5; i++){ + // provede se pětkrát } -// Cyklus For-in iteruje přes každo vlastnost prototypu -var popis = ""; -var osoba = {prijmeni:"Paul", jmeno:"Ken", vek:18}; -for (var x in osoba){ - popis += osoba[x] + " "; +// Opuštění cyklu s návěštím je podobné jako v Javě +outer: +for (var i = 0; i < 10; i++) { + for (var j = 0; j < 10; j++) { + if (i == 5 && j ==5) { + break outer; + // opustí vnější (outer) cyklus místo pouze vnitřního (inner) cyklu + } + } } -//Když chcete iterovat přes vlastnosti, které jsou přímo na objektu a nejsou -//zděněné z prototypů, kontrolujte vlastnosti přes hasOwnProperty() +// Cyklus For-in iteruje přes každou vlastnost prototypu var popis = ""; -var osoba = {prijmeni:"Jan", jmeno:"Novák", vek:18}; +var osoba = {prijmeni:"Paul", jmeno:"Ken", vek:18}; for (var x in osoba){ - if (osoba.hasOwnProperty(x)){ - popis += osoba[x] + " "; - } -} + popis += osoba[x] + " "; +} // popis = 'Paul Ken 18 ' -// for-in by neměl být použit pro pole, pokud záleží na pořadí indexů. -// Neexistuje jistota, že for-in je vrátí ve správném pořadí. +// Příkaz for/of umožňuje iterovat iterovatelné objekty (včetně vestavěných typů +// String, Array, například polím podobným argumentům nebo NodeList objektům, +// TypeArray, Map a Set, či uživatelsky definované iterovatelné objekty). +var myPets = ""; +var pets = ["cat", "dog", "hamster", "hedgehog"]; +for (var pet of pets){ + myPets += pet + " "; +} // myPets = 'cat dog hamster hedgehog ' // && je logické a, || je logické nebo if (dum.velikost == "velký" && dum.barva == "modrá"){ dum.obsahuje = "medvěd"; } if (barva == "červená" || barva == "modrá"){ - // barva je červená nebo modtrá + // barva je červená nebo modrá } // && a || jsou praktické i pro nastavení základních hodnot var jmeno = nejakeJmeno || "default"; - // `switch` zkoumá přesnou rovnost (===) // Používejte 'break;' po každé možnosti, jinak se provede i možnost za ní. znamka = 'B'; @@ -289,8 +306,9 @@ switch (znamka) { break; } + //////////////////////////////////////////////////////// -// 4. Funckce, Oblast platnosti (scope) a Vnitřní funkce +// 4. Funkce, Oblast platnosti (scope) a Vnitřní funkce // JavaScriptové funkce jsou definovány slůvkem `function`. function funkce(text){ @@ -302,12 +320,9 @@ funkce("něco"); // = "NĚCO" // jako slůvko return, jinak se vrátí 'undefined', kvůli automatickému vkládání // středníků. Platí to zejména pro Allmanův styl zápisu. -function funkce() -{ +function funkce(){ return // <- zde je automaticky vložen středník - { - tohleJe: "vlastnost objektu" - } + { tohleJe: "vlastnost objektu"}; } funkce(); // = undefined @@ -327,9 +342,9 @@ function myFunction(){ setInterval(myFunction, 5000); // Objekty funkcí nemusíme ani deklarovat pomocí jména, můžeme je napsat jako -// ananymní funkci přímo vloženou jako argument +// anonymní funkci přímo vloženou jako argument setTimeout(function(){ - // tento kód bude zavolán za 5 vteřin + // tento kód bude zavolán za 5 vteřin }, 5000); // JavaScript má oblast platnosti funkce, funkce ho mají, ale jiné bloky ne @@ -339,21 +354,21 @@ if (true){ i; // = 5 - ne undefined, jak byste očekávali v jazyku, kde mají bloky svůj // rámec působnosti -// Toto je běžný model,který chrání před únikem dočasných proměnných do +// Toto je běžný model, který chrání před únikem dočasných proměnných do //globální oblasti (function(){ var docasna = 5; - // Můžeme přistupovat k globálního oblasti přes přiřazování globalním + // Můžeme přistupovat ke globálního oblasti přes přiřazování globálním // objektům. Ve webovém prohlížeči je to vždy 'window`. Globální objekt - // může mít v jiných prostředích jako Node.js jinné jméno. + // může mít v jiných prostředích jako Node.js jiné jméno. window.trvala = 10; })(); docasna; // způsobí ReferenceError trvala; // = 10 -// Jedna z nejvice mocných vlastnosti JavaScriptu je vnitřní funkce. Je to funkce -// definovaná v jinné funkci, vnitřní funkce má přístup ke všem proměnným ve -// vnější funkci, dokonce i poté, co funkce skončí +// Jedna z nejmocnějších vlastností JavaScriptu je vnitřní funkce. Je to funkce +// definovaná v jiné funkci. Vnitřní funkce má přístup ke všem proměnným ve +// vnější funkci, dokonce i poté, co vnější funkce skončí. function ahojPoPetiVterinach(jmeno){ var prompt = "Ahoj, " + jmeno + "!"; // Vnitřní funkce je dána do lokální oblasti platnosti, jako kdyby byla @@ -362,33 +377,33 @@ function ahojPoPetiVterinach(jmeno){ alert(prompt); } setTimeout(vnitrni, 5000); - // setTimeout je asynchronní, takže funkce ahojPoPetiVterinach se ukončí - // okamžitě, ale setTimeout zavolá funkci vnitrni až poté. Avšak protože - // vnitrni je definována přes ahojPoPetiVterinach, má pořád přístup k + // setTimeout je asynchronní, takže se funkce ahojPoPetiVterinach ukončí + // okamžitě, ale setTimeout zavolá funkci vnitrni až poté. Avšak + // vnitrni je definována přes ahojPoPetiVterinach a má pořád přístup k // proměnné prompt, když je konečně zavolána. } ahojPoPetiVterinach("Adam"); // otevře popup s "Ahoj, Adam!" za 5s /////////////////////////////////////////////////// -// 5. Více o objektech, konstuktorech a prototypech +// 5. Více o objektech, konstruktorech a prototypech -// Objekty můžou obsahovat funkce +// Objekty můžou obsahovat funkce. var mujObjekt = { mojeFunkce: function(){ - return "Ahoj světe!"; + return "Hello world!"; } }; -mujObjekt.mojeFunkce(); // = "Ahoj světe!" +mujObjekt.mojeFunkce(); // = "Hello world!" // Když jsou funkce z objektu zavolány, můžou přistupovat k objektu přes slůvko // 'this'' var mujObjekt = { - text: "Ahoj světe!", + text: "Hello world!", mojeFunkce: function(){ return this.text; } }; -mujObjekt.mojeFunkce(); // = "Ahoj světe!" +mujObjekt.mojeFunkce(); // = "Hello world!" // Slůvko this je nastaveno k tomu, kde je voláno, ne k tomu, kde je definováno // Takže naše funkce nebude fungovat, když nebude v kontextu objektu. @@ -396,23 +411,23 @@ var mojeFunkce = mujObjekt.mojeFunkce; mojeFunkce(); // = undefined // Opačně, funkce může být přiřazena objektu a může přistupovat k objektu přes -// this, i když nebyla přímo v definici- +// this, i když nebyla přímo v definici. var mojeDalsiFunkce = function(){ return this.text.toUpperCase(); } mujObjekt.mojeDalsiFunkce = mojeDalsiFunkce; -mujObjekt.mojeDalsiFunkce(); // = "AHOJ SVĚTE!" +mujObjekt.mojeDalsiFunkce(); // = "HELLO WORLD!" // Můžeme také specifikovat, v jakém kontextu má být funkce volána pomocí // `call` nebo `apply`. var dalsiFunkce = function(s){ return this.text + s; -} -dalsiFunkce.call(mujObjekt, " A ahoj měsíci!"); // = "Ahoj světe! A ahoj měsíci!" +}; +dalsiFunkce.call(mujObjekt, " A ahoj měsíci!"); // = "Hello world! A ahoj měsíci!" -// Funkce `apply`je velmi podobná, akorát bere jako druhý argument pole argumentů -dalsiFunkce.apply(mujObjekt, [" A ahoj slunce!"]); // = "Ahoj světe! A ahoj slunce!" +// Funkce `apply`je velmi podobná, pouze bere jako druhý argument pole argumentů +dalsiFunkce.apply(mujObjekt, [" A ahoj slunce!"]); // = "Hello world! A ahoj slunce!" // To je praktické, když pracujete s funkcí, která bere sekvenci argumentů a // chcete předat pole. @@ -425,38 +440,42 @@ Math.min.apply(Math, [42, 6, 27]); // = 6 // použijte `bind`. var pripojenaFunkce = dalsiFunkce.bind(mujObjekt); -pripojenaFunkce(" A ahoj Saturne!"); // = "Ahoj světe! A ahoj Saturne!" +pripojenaFunkce(" A ahoj Saturne!"); // = "Hello world! A ahoj Saturne!" -// `bind` může být použito čatečně částečně i k používání +// `bind` může být použito částečně k provázání funkcí -var nasobeni = function(a, b){ return a * b; } +var nasobeni = function(a, b){ return a * b; }; var zdvojeni = nasobeni.bind(this, 2); zdvojeni(8); // = 16 // Když zavoláte funkci se slůvkem 'new', vytvoří se nový objekt a // a udělá se dostupný funkcím skrz slůvko 'this'. Funkcím volaným takto se říká -// konstruktory +// konstruktory. var MujKonstruktor = function(){ this.mojeCislo = 5; -} +}; mujObjekt = new MujKonstruktor(); // = {mojeCislo: 5} mujObjekt.mojeCislo; // = 5 -// Každý JsavaScriptový objekt má prototyp. Když budete přistupovat k vlasnosti -// objektu, který neexistuje na objektu, tak se JS koukne do prototypu. +// Na rozdíl od nejznámějších objektově orientovaných jazyků, JavaScript nezná +// koncept instancí vytvořených z tříd. Místo toho Javascript kombinuje +// vytváření instancí a dědění do konceptu zvaného 'prototyp'. + +// Každý JavaScriptový objekt má prototyp. Když budete přistupovat k vlastnosti +// objektu, který neexistuje na objektu, tak se JS podívá do prototypu. // Některé JS implementace vám umožní přistupovat k prototypu přes magickou // vlastnost '__proto__'. I když je toto užitečné k vysvětlování prototypů, není -// to součást standardu, ke standartní způsobu k používání prototypu se dostaneme -// později. +// to součást standardu. Ke standardnímu způsobu používání prototypu se +// dostaneme později. var mujObjekt = { - mujText: "Ahoj svete!" + mujText: "Hello world!" }; var mujPrototyp = { smyslZivota: 42, mojeFunkce: function(){ - return this.mujText.toLowerCase() + return this.mujText.toLowerCase(); } }; @@ -464,7 +483,7 @@ mujObjekt.__proto__ = mujPrototyp; mujObjekt.smyslZivota; // = 42 // Toto funguje i pro funkce -mujObjekt.mojeFunkce(); // = "Ahoj světe!" +mujObjekt.mojeFunkce(); // = "Hello world!" // Samozřejmě, pokud není vlastnost na vašem prototypu, tak se hledá na // prototypu od prototypu atd. @@ -474,21 +493,41 @@ mujPrototyp.__proto__ = { mujObjekt.mujBoolean; // = true -// Zde neni žádné kopírování; každý objekt ukládá referenci na svůj prototyp -// Toto znamená, že můžeme měnit prototyp a změny se projeví všude +// Zde není žádné kopírování; každý objekt ukládá referenci na svůj prototyp +// Toto znamená, že můžeme měnit prototyp a změny se projeví všude. mujPrototyp.smyslZivota = 43; -mujObjekt.smyslZivota // = 43 +mujObjekt.smyslZivota; // = 43 + +// Příkaz for/in umožňuje iterovat vlastnosti objektu až do úrovně null +// prototypu. +for (var x in myObj){ + console.log(myObj[x]); +} +///Vypíše: +// Hello world! +// 43 +// [Function: myFunc] + +// Pro výpis pouze vlastností patřících danému objektu a nikoli jeho prototypu, +// použijte kontrolu pomocí `hasOwnProperty()`. +for (var x in myObj){ + if (myObj.hasOwnProperty(x)){ + console.log(myObj[x]); + } +} +///Vypíše: +// Hello world! // Zmínili jsme již předtím, že '__proto__' není ve standardu a není cesta, jak // měnit prototyp existujícího objektu. Avšak existují možnosti, jak vytvořit -// nový objekt s daným prototypem +// nový objekt s daným prototypem. // První je Object.create, což je nedávný přídavek do JS a není dostupný zatím // ve všech implementacích. var mujObjekt = Object.create(mujPrototyp); -mujObjekt.smyslZivota // = 43 +mujObjekt.smyslZivota; // = 43 -// Druhý způsob, který funguje všude je pomocí konstuktoru. Konstruktor má +// Druhý způsob, který funguje všude, je pomocí konstruktoru. Konstruktor má // vlastnost jménem prototype. Toto *není* prototyp samotného konstruktoru, ale // prototyp nového objektu. MujKonstruktor.prototype = { @@ -499,10 +538,10 @@ MujKonstruktor.prototype = { }; var mujObjekt2 = new MujKonstruktor(); mujObjekt2.ziskejMojeCislo(); // = 5 -mujObjekt2.mojeCislo = 6 +mujObjekt2.mojeCislo = 6; mujObjekt2.ziskejMojeCislo(); // = 6 -// Vestavěnné typy jako čísla nebo řetězce mají také konstruktory, které vytváří +// Vestavěné typy jako čísla nebo řetězce mají také konstruktory, které vytváří // ekvivalentní obalovací objekty (wrappery). var mojeCislo = 12; var mojeCisloObj = new Number(12); @@ -521,7 +560,7 @@ if (new Number(0)){ // a objekty jsou vždy pravdivé } -// Avšak, obalovací objekty a normální vestavěnné typy sdílejí prototyp, takže +// Avšak, obalovací objekty a normální vestavěné typy sdílejí prototyp, takže // můžete přidat funkcionalitu k řetězci String.prototype.prvniZnak = function(){ return this.charAt(0); @@ -530,45 +569,60 @@ String.prototype.prvniZnak = function(){ // Tento fakt je často používán v polyfillech, což je implementace novějších // vlastností JavaScriptu do starších variant, takže je můžete používat třeba -// ve starých prohlížečích +// ve starých prohlížečích. -// Pro příkklad, zmínili jsme, že Object.create není dostupný ve všech -// implementacích, můžeme si avšak přidat pomocí polyfillu +// Na příklad jsme zmínili, že Object.create není dostupný ve všech +// implementacích, ale můžeme si ho přidat pomocí polyfillu: if (Object.create === undefined){ // nebudeme ho přepisovat, když existuje Object.create = function(proto){ // vytvoříme dočasný konstruktor var Constructor = function(){}; Constructor.prototype = proto; - // ten použijeme k vytvoření nového s prototypem + // ten použijeme k vytvoření nového objektu s prototypem return new Constructor(); - } + }; } ``` ## Kam dál -[Mozilla Developer -Network](https://developer.mozilla.org/en-US/docs/Web/JavaScript) obsahuje -perfektní dokumentaci pro JavaScript, který je používaný v prohlížečích. Navíc -je to i wiki, takže jakmile se naučíte více, můžete pomoci ostatním, tím, že -přispějete svými znalostmi. +[Mozilla Developer Network][1] obsahuje perfektní dokumentaci pro JavaScript, +který je používaný v prohlížečích. Navíc je to i wiki, takže jakmile se naučíte +více, můžete pomoci ostatním tím, že přispějete svými znalostmi. -MDN's [A re-introduction to -JavaScript](https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript) +MDN's [A re-introduction to JavaScript][2] pojednává o konceptech vysvětlených zde v mnohem větší hloubce. Tento návod -pokrývá hlavně JavaScript sám o sobě. Pokud se chcete naučit více, jak se používá -na webových stránkách, začněte tím, že se kouknete na [DOM](https://developer.mozilla.org/en-US/docs/Using_the_W3C_DOM_Level_1_Core) +pokrývá hlavně JavaScript sám o sobě. Pokud se chcete naučit, jak se používá +na webových stránkách, začněte tím, že se podíváte na [DOM][3] + +[Learn Javascript by Example and with Challenges][4] +je varianta tohoto návodu i s úkoly. + +[JavaScript Garden][5] je sbírka příkladů těch nejnepředvídatelnějších částí +tohoto jazyka. + +[JavaScript: The Definitive Guide][6] je klasická výuková kniha. + +[Eloquent Javascript][8] od Marijn Haverbeke je výbornou JS knihou/e-knihou. -[Learn Javascript by Example and with Challenges](http://www.learneroo.com/modules/64/nodes/350) je varianta tohoto -návodu i s úkoly- +[Javascript: The Right Way][10] je průvodcem JavaScriptem pro začínající +vývojáře i pomocníkem pro zkušené vývojáře, kteří si chtějí prohloubit své +znalosti. -[JavaScript Garden](http://bonsaiden.github.io/JavaScript-Garden/) je sbírka -příkladů těch nejvíce nepředvídatelných částí tohoto jazyka. +[Javascript:Info][11] je moderním JavaScriptovým průvodcem, který pokrývá +základní i pokročilé témata velice výstižným výkladem. -[JavaScript: The Definitive Guide](http://www.amazon.com/gp/product/0596805527/) -je klasická výuková kniha. +Jako dodatek k přímým autorům tohoto článku byly na těchto stránkách části +obsahu převzaty z Pythonního tutoriálu Louiho Dinha, a tak0 z [JS Tutorial][7] +na stránkách Mozilla Developer Network. -Jako dodatek k přímým autorům tohoto článku, některý obsah byl přizpůsoben z -Pythoního tutoriálu od Louie Dinh na této stráce, a z [JS -Tutorial](https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript) -z Mozilla Developer Network. +[1]: https://developer.mozilla.org/en-US/docs/Web/JavaScript +[2]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript +[3]: https://developer.mozilla.org/en-US/docs/Using_the_W3C_DOM_Level_1_Core +[4]: http://www.learneroo.com/modules/64/nodes/350 +[5]: http://bonsaiden.github.io/JavaScript-Garden/ +[6]: http://www.amazon.com/gp/product/0596805527/ +[7]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript +[8]: http://eloquentjavascript.net/ +[10]: http://jstherightway.org/ +[11]: https://javascript.info/ diff --git a/cs-cz/markdown.html.markdown b/cs-cz/markdown.html.markdown index 568e4343..35becf94 100644 --- a/cs-cz/markdown.html.markdown +++ b/cs-cz/markdown.html.markdown @@ -13,7 +13,7 @@ Markdown byl vytvořen Johnem Gruberem v roce 2004. Je zamýšlen jako lehce či a psatelná syntaxe, která je jednoduše převeditelná do HTML (a dnes i do mnoha dalších formátů) -```markdown +```md <!-- Markdown je nadstavba nad HTML, takže jakýkoliv kód HTML je validní Markdown, to znamená, že můžeme používat HTML elementy, třeba jako komentář, a nebudou ovlivněny parserem Markdownu. Avšak, pokud vytvoříte HTML element v diff --git a/cs-cz/python3.html.markdown b/cs-cz/python3.html.markdown index 581ed3a3..dbaae88b 100644 --- a/cs-cz/python3.html.markdown +++ b/cs-cz/python3.html.markdown @@ -76,9 +76,13 @@ False or True # => True # Používání logických operátorů s čísly 0 and 2 # => 0 -5 or 0 # => -5 -0 == False # => True -2 == True # => False -1 == True # => True + +# Při porovnání s boolean hodnotou nepoužívejte operátor rovnosti "==". +# Stejně jako u hodnoty None. +# Viz PEP8: https://www.python.org/dev/peps/pep-0008/ +0 is False # => True +2 is True # => False +1 is True # => True # Rovnost je == 1 == 1 # => True @@ -99,11 +103,11 @@ False or True # => True 2 < 3 < 2 # => False -# Řetězce používají " nebo ' a mohou obsahovat UTF8 znaky +# Řetězce používají " nebo ' a mohou obsahovat unicode znaky "Toto je řetězec." 'Toto je také řetězec.' -# Řetězce se také dají sčítat, ale nepoužívejte to +# Řetězce se také dají slučovat "Hello " + "world!" # => "Hello world!" # Dají se spojovat i bez '+' "Hello " "world!" # => "Hello world!" @@ -152,10 +156,12 @@ print("Jsem 3. Python 3.") # Konvence je používat male_pismo_s_podtrzitky nazev_promenne = 5 nazev_promenne # => 5 -# Názvy proměnných mohou obsahovat i UTF8 znaky +# Názvy proměnných mohou obsahovat i unicode znaky, ale nedělejte to. +# Viz PEP 3131 -- Supporting Non-ASCII Identifiers: +# https://www.python.org/dev/peps/pep-3131/ název_proměnné = 5 -# Přístup k předtím nepoužité proměnné vyvolá výjimku +# Přístup k předtím nedefinované proměnné vyvolá výjimku # Odchytávání vyjímek - viz další kapitola neznama_promenna # Vyhodí NameError @@ -199,7 +205,7 @@ sez[::-1] # => [3, 4, 2, 1] # Odebírat prvky ze seznamu lze pomocí del del sez[2] # sez je nyní [1, 2, 3] -# Seznamy můžete sčítat +# Seznamy můžete slučovat # Hodnoty sez a jiny_seznam přitom nejsou změněny sez + jiny_seznam # => [1, 2, 3, 4, 5, 6] diff --git a/csharp.html.markdown b/csharp.html.markdown index 963f38f4..f27adf18 100644 --- a/csharp.html.markdown +++ b/csharp.html.markdown @@ -132,6 +132,12 @@ namespace Learning.CSharp DateTime fooDate = DateTime.Now; Console.WriteLine(fooDate.ToString("hh:mm, dd MMM yyyy")); + // Verbatim String + // You can use the @ symbol before a string literal to escape all characters in the string + string path = "C:\\Users\\User\\Desktop"; + string verbatimPath = @"C:\Users\User\Desktop"; + Console.WriteLine(path == verbatimPath); // => true + // You can split a string over two lines with the @ symbol. To escape " use "" string bazString = @"Here's some stuff on a new line! ""Wow!"", the masses cried"; @@ -634,6 +640,54 @@ on a new line! ""Wow!"", the masses cried"; } } + + // DELEGATES AND EVENTS + public class DelegateTest + { + public static int count = 0; + public static int Increment() + { + // increment count then return it + return ++count; + } + + // A delegate is a reference to a method + // To reference the Increment method, + // first declare a delegate with the same signature + // ie. takes no arguments and returns an int + public delegate int IncrementDelegate(); + + // An event can also be used to trigger delegates + // Create an event with the delegate type + public static event IncrementDelegate MyEvent; + + static void Main(string[] args) + { + // Refer to the Increment method by instantiating the delegate + // and passing the method itself in as an argument + IncrementDelegate inc = new IncrementDelegate(Increment); + Console.WriteLine(inc()); // => 1 + + // Delegates can be composed with the + operator + IncrementDelegate composedInc = inc; + composedInc += inc; + composedInc += inc; + + // composedInc will run Increment 3 times + Console.WriteLine(composedInc()); // => 4 + + + // Subscribe to the event with the delegate + MyEvent += new IncrementDelegate(Increment); + MyEvent += new IncrementDelegate(Increment); + + // Trigger the event + // ie. run all delegates subscribed to this event + Console.WriteLine(MyEvent()); // => 6 + } + } + + // Class Declaration Syntax: // <public/private/protected/internal> class <class name>{ // //data fields, constructors, functions all inside. @@ -949,6 +1003,7 @@ on a new line! ""Wow!"", the masses cried"; // String interpolation by prefixing the string with $ // and wrapping the expression you want to interpolate with { braces } + // You can also combine both interpolated and verbatim strings with $@ public class Rectangle { public int Length { get; set; } @@ -961,6 +1016,9 @@ on a new line! ""Wow!"", the masses cried"; { Rectangle rect = new Rectangle { Length = 5, Width = 3 }; Console.WriteLine($"The length is {rect.Length} and the width is {rect.Width}"); + + string username = "User"; + Console.WriteLine($@"C:\Users\{username}\Desktop"); } } @@ -1096,25 +1154,144 @@ namespace Learning.More.CSharp } } +//New C# 7 Feature +//Install Microsoft.Net.Compilers Latest from Nuget +//Install System.ValueTuple Latest from Nuget using System; namespace Csharp7 { - //New C# 7 Feature - //Install Microsoft.Net.Compilers Latest from Nuget - //Install System.ValueTuple Latest from Nuget - class Program - { - static void Main(string[] args) - { - //Type 1 Declaration - (string FirstName, string LastName) names1 = ("Peter", "Parker"); - Console.WriteLine(names1.FirstName); - - //Type 2 Declaration - var names2 = (First:"Peter", Last:"Parker"); - Console.WriteLine(names2.Last); - } - } + // TUPLES, DECONSTRUCTION AND DISCARDS + class TuplesTest + { + public (string, string) GetName() + { + // Fields in tuples are by default named Item1, Item2... + var names1 = ("Peter", "Parker"); + Console.WriteLine(names1.Item2); // => Parker + + // Fields can instead be explicitly named + // Type 1 Declaration + (string FirstName, string LastName) names2 = ("Peter", "Parker"); + + // Type 2 Declaration + var names3 = (First:"Peter", Last:"Parker"); + + Console.WriteLine(names2.FirstName); // => Peter + Console.WriteLine(names3.Last); // => Parker + + return names3; + } + + public string GetLastName() { + var fullName = GetName(); + + // Tuples can be deconstructed + (string firstName, string lastName) = fullName; + + // Fields in a deconstructed tuple can be discarded by using _ + var (_, last) = fullName; + return last; + } + + // Any type can be deconstructed in the same way by + // specifying a Deconstruct method + public int randomNumber = 4; + public int anotherRandomNumber = 10; + + public void Deconstruct(out int randomNumber, out int anotherRandomNumber) + { + randomNumber = this.randomNumber; + anotherRandomNumber = this.anotherRandomNumber; + } + + static void Main(string[] args) + { + var tt = new TuplesTest(); + (int num1, int num2) = tt; + Console.WriteLine($"num1: {num1}, num2: {num2}"); // => num1: 4, num2: 10 + + Console.WriteLine(tt.GetLastName()); + } + } + + // PATTERN MATCHING + class PatternMatchingTest + { + public static (string, int)? CreateLogMessage(object data) + { + switch(data) + { + // Additional filtering using when + case System.Net.Http.HttpRequestException h when h.Message.Contains("404"): + return (h.Message, 404); + case System.Net.Http.HttpRequestException h when h.Message.Contains("400"): + return (h.Message, 400); + case Exception e: + return (e.Message, 500); + case string s: + return (s, s.Contains("Error") ? 500 : 200); + case null: + return null; + default: + return (data.ToString(), 500); + } + } + } + + // REFERENCE LOCALS + // Allow you to return a reference to an object instead of just its value + class RefLocalsTest + { + // note ref in return + public static ref string FindItem(string[] arr, string el) + { + for(int i=0; i<arr.Length; i++) + { + if(arr[i] == el) { + // return the reference + return ref arr[i]; + } + } + throw new Exception("Item not found"); + } + + public static void SomeMethod() + { + string[] arr = {"this", "is", "an", "array"}; + + // note refs everywhere + ref string item = ref FindItem(arr, "array"); + item = "apple"; + Console.WriteLine(arr[3]); // => apple + } + } + + // LOCAL FUNCTIONS + class LocalFunctionTest + { + private static int _id = 0; + public int id; + public LocalFunctionTest() + { + id = generateId(); + + // This local function can only be accessed in this scope + int generateId() + { + return _id++; + } + } + + public static void AnotherMethod() + { + var lf1 = new LocalFunctionTest(); + var lf2 = new LocalFunctionTest(); + Console.WriteLine($"{lf1.id}, {lf2.id}"); // => 0, 1 + + int id = generateId(); + // error CS0103: The name 'generateId' does not exist in the current context + } + } } ``` diff --git a/css.html.markdown b/css.html.markdown index 3b378d44..64dc097c 100644 --- a/css.html.markdown +++ b/css.html.markdown @@ -135,6 +135,10 @@ selector::after {} .parent * { } /* all descendants */ .parent > * { } /* all children */ +/* Group any number of selectors to define styles that affect all selectors + in the group */ +selector1, selector2 { } + /* #################### ## PROPERTIES #################### */ diff --git a/cypher.html.markdown b/cypher.html.markdown index b7be544a..acd44733 100644 --- a/cypher.html.markdown +++ b/cypher.html.markdown @@ -16,19 +16,19 @@ Nodes **Represents a record in a graph.** -```()``` +`()` It's an empty *node*, to indicate that there is a *node*, but it's not relevant for the query. -```(n)``` +`(n)` It's a *node* referred by the variable **n**, reusable in the query. It begins with lowercase and uses camelCase. -```(p:Person)``` +`(p:Person)` You can add a *label* to your node, here **Person**. It's like a type / a class / a category. It begins with uppercase and uses camelCase. -```(p:Person:Manager)``` +`(p:Person:Manager)` A node can have many *labels*. -```(p:Person {name : 'Théo Gauchoux', age : 22})``` +`(p:Person {name : 'Théo Gauchoux', age : 22})` A node can have some *properties*, here **name** and **age**. It begins with lowercase and uses camelCase. The types allowed in properties : @@ -40,7 +40,7 @@ The types allowed in properties : *Warning : there isn't datetime property in Cypher ! You can use String with a specific pattern or a Numeric from a specific date.* -```p.name``` +`p.name` You can access to a property with the dot style. @@ -49,16 +49,16 @@ Relationships (or Edges) **Connects two nodes** -```[:KNOWS]``` +`[:KNOWS]` It's a *relationship* with the *label* **KNOWS**. It's a *label* as the node's label. It begins with uppercase and use UPPER_SNAKE_CASE. -```[k:KNOWS]``` +`[k:KNOWS]` The same *relationship*, referred by the variable **k**, reusable in the query, but it's not necessary. -```[k:KNOWS {since:2017}]``` +`[k:KNOWS {since:2017}]` The same *relationship*, with *properties* (like *node*), here **since**. -```[k:KNOWS*..4]``` +`[k:KNOWS*..4]` It's a structural information to use in a *path* (seen later). Here, **\*..4** says "Match the pattern, with the relationship **k** which be repeated between 1 and 4 times. @@ -67,16 +67,16 @@ Paths **The way to mix nodes and relationships.** -```(a:Person)-[:KNOWS]-(b:Person)``` +`(a:Person)-[:KNOWS]-(b:Person)` A path describing that **a** and **b** know each other. -```(a:Person)-[:MANAGES]->(b:Person)``` +`(a:Person)-[:MANAGES]->(b:Person)` A path can be directed. This path describes that **a** is the manager of **b**. -```(a:Person)-[:KNOWS]-(b:Person)-[:KNOWS]-(c:Person)``` +`(a:Person)-[:KNOWS]-(b:Person)-[:KNOWS]-(c:Person)` You can chain multiple relationships. This path describes the friend of a friend. -```(a:Person)-[:MANAGES]->(b:Person)-[:MANAGES]->(c:Person)``` +`(a:Person)-[:MANAGES]->(b:Person)-[:MANAGES]->(c:Person)` A chain can also be directed. This path describes that **a** is the boss of **b** and the big boss of **c**. Patterns often used (from Neo4j doc) : @@ -230,13 +230,13 @@ DELETE n, r Other useful clauses --- -```PROFILE``` +`PROFILE` Before a query, show the execution plan of it. -```COUNT(e)``` +`COUNT(e)` Count entities (nodes or relationships) matching **e**. -```LIMIT x``` +`LIMIT x` Limit the result to the x first results. diff --git a/dart.html.markdown b/dart.html.markdown index 5027dc3e..76857306 100644 --- a/dart.html.markdown +++ b/dart.html.markdown @@ -500,8 +500,8 @@ main() { Dart has a comprehensive web-site. It covers API reference, tutorials, articles and more, including a useful Try Dart online. -http://www.dartlang.org/ -http://try.dartlang.org/ +[https://www.dartlang.org](https://www.dartlang.org) +[https://try.dartlang.org](https://try.dartlang.org) diff --git a/de-de/LOLCODE-de.html.markdown b/de-de/LOLCODE-de.html.markdown new file mode 100644 index 00000000..57eb0ff8 --- /dev/null +++ b/de-de/LOLCODE-de.html.markdown @@ -0,0 +1,188 @@ +--- +language: LOLCODE +filename: learnLOLCODE-de.lol +contributors: + - ["abactel", "https://github.com/abactel"] +translators: + - ["Henrik Jürges", "http://github.com/santifa"] +lang: de-de +--- + +LOLCODE ist eine esoterische Programmiersprache die die Sprache der [lolcats](https://upload.wikimedia.org/wikipedia/commons/a/ab/Lolcat_in_folder.jpg?1493656347257) nachahmt. + +``` +BTW Das ist ein Kommentar +BTW Das Programm muss mit `HAI <language version>` beginnen und mit `KTHXBYE` enden. + +HAI 1.3 +CAN HAS STDIO? BTW Standard Header importieren + +OBTW + ========================================================================== + ============================== Grundlegendes ============================= + ========================================================================== +TLDR + +BTW Texte anzeigen: +VISIBLE "HELLO WORLD" + +BTW Variablen deklarieren: +I HAS A MESSAGE ITZ "CATZ ARE GOOD" +VISIBLE MESSAGE + +OBTW + Variablen sind dynamisch typisiert und der Typ muss nicht explizit + angegeben werden. Die möglichen Typen sind: +TLDR + +I HAS A STRING ITZ "DOGZ ARE GOOOD" BTW Typ ist YARN +I HAS A INTEGER ITZ 42 BTW Typ ist NUMBR +I HAS A FLOAT ITZ 3.1415 BTW Typ ist NUMBAR +I HAS A BOOLEAN ITZ WIN BTW Typ ist TROOF +I HAS A UNTYPED BTW Typ ist NOOB + +BTW Eingaben von Nutzern: +I HAS A AGE +GIMMEH AGE +BTW Die Variable wird als YARN gespeichert und kann in eine +BTW NUMBR konvertiert werden: +AGE IS NOW A NUMBR + +OBTW + ========================================================================== + ================================== MATHE ================================= + ========================================================================== +TLDR + +BTW LOLCODE benutzt polnische Notation für Mathe. + +BTW grundlegende mathematische Notationen: + +SUM OF 21 AN 33 BTW 21 + 33 +DIFF OF 90 AN 10 BTW 90 - 10 +PRODUKT OF 12 AN 13 BTW 12 * 13 +QUOSHUNT OF 32 AN 43 BTW 32 / 43 +MOD OF 43 AN 64 BTW 43 modulo 64 +BIGGR OF 23 AN 53 BTW max(23, 53) +SMALLR OF 53 AN 45 BTW min(53, 45) + +BTW binäre Notation: + +BOTH OF WIN AN WIN BTW und: WIN if x=WIN, y=WIN +EITHER OF FAIL AN WIN BTW oder: FAIL if x=FAIL, y=FAIL +WON OF WIN AN FAIL BTW exklusives oder: FAIL if x=y +NOT FAIL BTW unäre Negation: WIN if x=FAIL +ALL OF WIN AN WIN MKAY BTW beliebige Stelligkeit bei AND +ANY OF WIN AN FAIL MKAY BTW beliebige Stelligkeit bei OR + +BTW Vergleiche: + +BOTH SAEM "CAT" AN "DOG" BTW WIN wenn x == y +DIFFRINT 732 AN 184 BTW WIN wenn x != y +BOTH SAEM 12 AN BIGGR OF 12 AN 4 BTW x >= y +BOTH SAEM 43 AN SMALLR OF 43 AN 56 BTW x <= y +DIFFRINT 64 AN SMALLR OF 64 AN 2 BTW x > y +DIFFRINT 75 AN BIGGR OF 75 AN 643 BTW x < y + +OBTW + ========================================================================== + ============================= Flusskontrolle ============================= + ========================================================================== +TLDR + +BTW If/then Statement: +I HAS A ANIMAL +GIMMEH ANIMAL +BOTH SAEM ANIMAL AN "CAT", O RLY? + YA RLY + VISIBLE "YOU HAV A CAT" + MEBBE BOTH SAEM ANIMAL AN "MAUS" + VISIBLE "NOM NOM NOM. I EATED IT." + NO WAI + VISIBLE "AHHH IS A WOOF WOOF" +OIC + +BTW Case Statement: +I HAS A COLOR +GIMMEH COLOR +COLOR, WTF? + OMG "R" + VISIBLE "RED FISH" + GTFO + OMG "Y" + VISIBLE "YELLOW FISH" + BTW Weil hier kein `GTFO` ist wird auch das nächste Statement überprüft + OMG "G" + OMG "B" + VISIBLE "FISH HAS A FLAVOR" + GTFO + OMGWTF + VISIBLE "FISH IS TRANSPARENT OHNO WAT" +OIC + +BTW For Schleife: +I HAS A TEMPERATURE +GIMMEH TEMPERATURE +TEMPERATURE IS NOW A NUMBR +IM IN YR LOOP UPPIN YR ITERATOR TIL BOTH SAEM ITERATOR AN TEMPERATURE + VISIBLE ITERATOR +IM OUTTA YR LOOP + +BTW While Schleife: +IM IN YR LOOP NERFIN YR ITERATOR WILE DIFFRINT ITERATOR AN -10 + VISIBLE ITERATOR +IM OUTTA YR LOOP + +OBTW + ========================================================================= + ================================ Strings ================================ + ========================================================================= +TLDR + +BTW Zeilenumbrüche: +VISIBLE "FIRST LINE :) SECOND LINE" + +BTW Tabulatoren: +VISIBLE ":>SPACES ARE SUPERIOR" + +BTW Bell (macht beep): +VISIBLE "NXT CUSTOMER PLS :o" + +BTW Anführungszeichen in Strings: +VISIBLE "HE SAID :"I LIKE CAKE:"" + +BTW Doppelpunkte in Strings : +VISIBLE "WHERE I LIVE:: CYBERSPACE" + +OBTW + ========================================================================= + =============================== Funktionen ============================== + ========================================================================= +TLDR + +BTW Definieren einer neuen Funktion: +HOW IZ I SELECTMOVE YR MOVE BTW `MOVE` ist ein Argument + BOTH SAEM MOVE AN "ROCK", O RLY? + YA RLY + VISIBLE "YOU HAV A ROCK" + NO WAI + VISIBLE "OH NO IS A SNIP-SNIP" + OIC + GTFO BTW Gibt NOOB zurück +IF U SAY SO + +BTW Eine Funktion deklarieren und einen Wert zurückgeben: +HOW IZ I IZYELLOW + FOUND YR "YELLOW" +IF U SAY SO + +BTW Eine Funktion aufrufen: +I IZ IZYELLOW MKAY + +KTHXBYE +``` + +## Weiterführende Informationen: + +- [LCI compiler](https://github.com/justinmeza/lci) +- [Official spec](https://github.com/justinmeza/lolcode-spec/blob/master/v1.2/lolcode-spec-v1.2.md) diff --git a/de-de/bash-de.html.markdown b/de-de/bash-de.html.markdown index 7928b136..7a0db157 100644 --- a/de-de/bash-de.html.markdown +++ b/de-de/bash-de.html.markdown @@ -180,7 +180,7 @@ esac # 'for' Schleifen iterieren über die angegebene Zahl von Argumenten: # Der Inhalt von $Variable wird dreimal ausgedruckt. -for $Variable in {1..3} +for Variable in {1..3} do echo "$Variable" done diff --git a/de-de/dynamic-programming-de.html.markdown b/de-de/dynamic-programming-de.html.markdown new file mode 100644 index 00000000..afa9a17c --- /dev/null +++ b/de-de/dynamic-programming-de.html.markdown @@ -0,0 +1,77 @@ +--- +category: Algorithms & Data Structures +name: Dynamic Programming +contributors: + - ["Akashdeep Goel", "http://github.com/akashdeepgoel"] +translators: + - ["Henrik Jürges", "http://github.com/santifa"] +lang: de-de +--- + +# Dynamische Programmierung + +## Einführung +Dynamische Programmierung ist eine leistungsfähige Technik, die zur Lösung +einer bestimmten Klasse von Problemen verwendet wird. +Die Idee ist sehr einfach, wenn Sie ein Problem mit der gegebenen Eingabe +gelöst haben, dann speichern Sie das Ergebnis für die spätere Referenz, um zu +vermeiden, das gleiche Problem noch einmal zu lösen. + +Denken Sie immer daran! +"Diejenigen, die sich nicht an die Vergangenheit erinnern können, +sind dazu verdammt, sie zu wiederholen." + +## Wege zur Lösung solcher Probleme + +1. *Top-Down*: Lösen Sie das gegebene Problem, indem Sie es aufteilen. +Wenn Sie sehen, dass das Problem bereits gelöst ist, geben Sie einfach die +gespeicherte Antwort zurück. Wenn es nicht gelöst wurde, lösen Sie es und +speichern Sie die Antwort. Dieser Ansatz ist leicht zu verfolgen und sehr +intuitiv. Er wird als Memoization bezeichnet. + +2. *Bottom-Up*: Analysieren Sie das Problem und beobachten Sie, in welcher +Reihenfolge die Teilprobleme gelöst werden können. Beginnen Sie mit der +Lösung vom trivialen Teilproblem bis zum gegebenen Problem. Dabei wird +sichergestellt, dass die Teilprobleme vor der Problemlösung gelöst werden. +Dies wird als Dynamische Programmierung bezeichnet. + +## Ein Beispiel für Dynamische Programmierung + +Das Problem mit der längsten ansteigenden Subsequenz besteht darin, +die längste ansteigende Subsequenz einer gegebenen Sequenz zu finden. +Gegeben die Sequenz `S= {a1, a2, a3, a3, a4,..............., an-1, an }`, +müssen wir die größte Teilmenge finden, so daß für alle `j` und `i`, `j<i` +in der Teilmenge `aj<ai` gilt. +Zuerst müssen wir bei jedem Index i den Wert der längsten Subsequenzen (LSi) +finden, wobei das letzte Element der Sequenz ai ist. Dann wäre die größte LSi +die längste Subsequenz in der gegebenen Sequenz. Am Anfang wird der LSi mit +eins belegt, da ai ein Element der Sequenz (Letztes Element) ist. +Dann ist für alle `j` mit `j<i` und `aj<ai`, so dass wir den größten LSj finden +und zum LSi hinzufügen. Der Algorithmus hat eine Laufzeit von *O(n2)*. + +Pseudocode zur Bestimmung der Länge der am längsten ansteigenden Subsequenz: +Die Komplexität des Algorithmus könnte durch eine bessere Datenstruktur anstelle +von Arrays reduziert werden. Das Speichern von Vorgänger-Array's und Variablen +wie `largest_sequences_so_far` und dessen Index würde eine Menge Zeit sparen. + +Ein ähnliches Konzept könnte auch bei der Suche nach dem längsten Weg +in gerichteten azyklischen Graphen angewandt werden. +```python +for i=0 to n-1 + LS[i]=1 + for j=0 to i-1 + if (a[i] > a[j] and LS[i]<LS[j]) + LS[i] = LS[j]+1 +for i=0 to n-1 + if (largest < LS[i]) +``` + +### Einige bekannte DP Probleme + +- Floyd Warshall Algorithm - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs---floyd-warshall-algorithm-with-c-program-source-code]() +- Integer Knapsack Problem - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---the-integer-knapsack-problem]() +- Longest Common Subsequence - Tutorial and C Program source code : [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---longest-common-subsequence]() + +## Online Ressourcen + +* [codechef](https://www.codechef.com/wiki/tutorial-dynamic-programming) diff --git a/de-de/edn-de.html.markdown b/de-de/edn-de.html.markdown new file mode 100644 index 00000000..2434d1bd --- /dev/null +++ b/de-de/edn-de.html.markdown @@ -0,0 +1,112 @@ +--- +language: edn +filename: learnedn-de.edn +contributors: + - ["Jason Yeo", "https://github.com/jsyeo"] + - ["Jonathan D Johnston", "https://github.com/jdjohnston"] +translators: + - ["Dennis Keller", "https://github.com/denniskeller"] +lang: de-de +--- + +Extensible Data Notation (EDN) ist ein Format für serialisierte Daten. + +EDN ist ein Subset der von Clojure verwendeten Syntax. Das Lesen von Daten, die durch EDN definiert werden, ist +sicherer als das, was durch die vollständige Clojure-Syntax definiert wird, insbesondere von nicht +vertrauenswürdigen Quellen. EDN ist beschränkt auf Daten, kein Code. Es ist ähnlich in seinen Zielen zu JSON. +Obwohl es mehr in Clojure verwendet wird, gibt es verschiedene Implementationen von EDN in vielen +verschiedenen anderen Sprachen. + +Der Hauptvorteil von EDN im Gegensatz zu JSON und YAML ist, dass es erweiterbar ist. +Wir werden später sehen wie es erweitert werden kann. + +```clojure +; Kommentare starten mit einem Semikolon. +; Alles nach dem Semikolon wird ignoriert. + +;;;;;;;;;;;;;;;;;;; +;;; Basistypen ;;; +;;;;;;;;;;;;;;;;;;; + +nil ; auch bekannt in anderen Sprachen als null + +; Booleans +true +false + +; Strings werden in Gänsefüßchen eingeschlossen. +"hungarian breakfast" +"farmer's cheesy omelette" + +; Charaktere werden einem Backslash vorangestellt +\g \r \a \c \e + +; Schlüsselwörter beginnen mit einem Doppelpunkt. Sie verhalten sich wie Enums. +; Ähnlich, wie Symbole in Ruby. +:eggs +:cheese +:olives + +; Symbole werden verwendet um Identifier zu repräsentieren. Sie beginnen mit einem #. +; Du kannst einen Namespace für Symbole nutzen, wenn du / verwendest. Egal was / vorangestellt wird +; ist der Namespace dieses Namens. +#spoon +#kitchen/spoon ; nicht das selbe, wie #spoon +#kitchen/fork +#github/fork ; damit kannst du nicht essen + +; Integers und Floats +42 +3.14159 + +; Listen sind Sequenzen von Werten +(:bun :beef-patty 9 "yum!") + +; Vektoren erlauben zufälligen Zugriff +[:gelato 1 2 -2] + +; Maps sind assoziative Datenstrukturen, die einen Schlüssel mit einem Wert verbinden. +{:eggs 2 + :lemon-juice 3.5 + :butter 1} + +; Du bist nicht beschränkt ausschließlich Schlüsselwörter als Schlüssel zu verwenden. +{[1 2 3 4] "tell the people what she wore", + [5 6 7 8] "the more you see the more you hate"} + +; Du kannst Kommas für eine bessere Lesbarkeit verwenden. Sie werden wie Leerraum behandelt. +; Sets sind Sammlungen, die eindeutige Elemente enthalten. +#{:a :b 88 "huat"} + +;;;;;;;;;;;;;;;;;;;;;;;;; +;;; markierte Elemente ;;; +;;;;;;;;;;;;;;;;;;;;;;;;; + +; EDN kann erweitert werden, indem Elemente mit # Symbolen makiert werden. + +#MyYelpClone/MenuItem {:name "eggs-benedict" :rating 10} + +; Lass mich das mit einem Clojure Beispiel erklären. +; Angenommen ich möchte dieses Stück EDM in einen MenuItem record umwandeln. +(defrecord MenuItem [name rating]) + +; Um EDN in clojure Werte umzuwandeln, muss ich den eingebauten EDN Leser +; edn/read-string verwenden + +(edn/read-string "{:eggs 2 :butter 1 :flour 5}") +; -> {:eggs 2 :butter 1 :flour 5} + +; Definiere die Leserfunktion, um markierte Elemente zu transformieren +; und übergebe eine Map, die Tags den Lesefunktionen als edn / read-string zuweisen + +(edn/read-string {:readers {'MyYelpClone/MenuItem map->menu-item}} + "#MyYelpClone/MenuItem {:name \"eggs-benedict\" :rating 10}") +; -> #user.MenuItem{:name "eggs-benedict", :rating 10} + +``` + +# Referenzen + +- [EDN spec](https://github.com/edn-format/edn) +- [Implementationen](https://github.com/edn-format/edn/wiki/Implementations) +- [makierte Elemente](http://www.compoundtheory.com/clojure-edn-walkthrough/) diff --git a/de-de/git-de.html.markdown b/de-de/git-de.html.markdown index a0ed120f..d2222d2c 100644 --- a/de-de/git-de.html.markdown +++ b/de-de/git-de.html.markdown @@ -10,7 +10,7 @@ lang: de-de Git ist eine verteilte Versions- und Quellcodeverwaltung. -Es nimmt Schnappschüsse der Projekte, um mit diesen Schnappschüssen verschiedene Versionen unterscheiden und den Quellcode verwalten zu können. +Es nimmt Schnappschüsse der Projekte auf, um mit diesen Schnappschüssen verschiedene Versionen unterscheiden und den Quellcode verwalten zu können. Anmerkung des Übersetzers: Einige englische Begriffe wie *Repository*, *Commit* oder *Head* sind idiomatische Bestandteile im Umgang mit Git. Sie wurden nicht übersetzt. @@ -43,7 +43,7 @@ Eine Versionsverwaltung erfasst die Änderungen einer Datei oder eines Verzeichn ### Repository (Repo) -Ein Satz von Dateien, Verzeichnisen, Historieneinträgen, Commits und Heads. Stell es dir wie eine Quellcode-Datenstruktur vor, unter anderem mit der Eigenschaft, dass alle *Elemente* dir Zugriff auf die Revisionshistorie geben. +Ein Satz von Dateien, Verzeichnissen, Historieneinträgen, Commits und Heads. Stell es dir wie eine Quellcode-Datenstruktur vor, unter anderem mit der Eigenschaft, dass alle *Elemente* dir Zugriff auf die Revisionshistorie geben. Ein Repository besteht in Git aus dem .git-Verzeichnis und dem Arbeitsverzeichnis. @@ -66,7 +66,7 @@ Ein Commit ist ein Schnappschuss von Änderungen in deinem Arbeitsverzeichnis. W ### Branch -Ein Branch, ein Ast oder Zweig, ist im Kern ein Pointer auf den letzten Commit, den du gemacht hast. Während des Commits wird der Pointer automatisch auf Stand gebracht und zeigt dann auf den neuen letzten Commit. +Ein Branch, ein Ast oder Zweig, ist im Kern ein Pointer auf den letzten Commit, den du gemacht hast. Während des Commits wird der Pointer automatisch auf diesen Stand gebracht und zeigt dann auf den neuen letzten Commit. ### HEAD und head (Teil des .git-Verzeichnisses) @@ -215,7 +215,7 @@ $ git commit --amend -m "Correct message" ### diff -Zeigt die Unterschiede zwischen Dateien von Arbeitsverzeichnisse, dem Index und Commits an. +Zeigt die Unterschiede zwischen Dateien vom Arbeitsverzeichnis, dem Index und Commits an. ```bash # Unterschiede zwischen deinem Arbeitsverzeichnis und dem Index anzeigen @@ -330,7 +330,7 @@ $ git push origin master ### rebase (mit Vorsicht einsetzen) -Nimm alle Änderungen, die in einem Branch durch Commits vorgenommen wurden, und übertrage sie auf einen anderen Branch. Achtung: Führe keinen Rebase von Commits durch, die auf ein öffentliches Repo gepusht wurden. +Nimm alle Änderungen, die in einem Branch durch Commits vorgenommen wurden, und übertrage sie auf einen anderen Branch. Achtung: Führe keinen Rebase von Commits durch, die auf ein öffentliches Repo gepusht wurden! ```bash # Rebase "experimentBranch" in den "master"-Branch diff --git a/de-de/go-de.html.markdown b/de-de/go-de.html.markdown index 817cb4ae..9409e181 100644 --- a/de-de/go-de.html.markdown +++ b/de-de/go-de.html.markdown @@ -94,7 +94,7 @@ Zeilenumbrüche beinhalten.` // Selber Zeichenketten-Typ // Arrays haben bei Kompile-Zeit festgelegte Größen var a4 [4]int // Ein Array mit 4 ints, alle mit Initialwert 0 - a3 := [...]int{3, 1, 5} // Ein Array mit 4 ints, Initialwerte wie angezeigt + a3 := [...]int{3, 1, 5} // Ein Array mit 3 ints, Initialwerte wie angezeigt // "slices" haben eine dynamische Größe. Arrays und Slices haben beide ihre // Vorzüge, aber slices werden viel häufiger verwendet diff --git a/de-de/hq9+-de.html.markdown b/de-de/hq9+-de.html.markdown new file mode 100644 index 00000000..b343201a --- /dev/null +++ b/de-de/hq9+-de.html.markdown @@ -0,0 +1,43 @@ +--- +language: HQ9+ +filename: hq9+.html +contributors: + - ["Alexey Nazaroff", "https://github.com/rogaven"] +translators: + - ["Dennis Keller", "https://github.com/denniskeller"] +lang: de-de +--- + +HQ9+ ist eine Parodie auf esoterische Programmiersprachen und wurde von Cliff Biffle kreiert. +Die Sprache hat nur vier Befehle und ist nicht Turing-vollständig. + +``` +Es gibt nur vier Befehle, die durch die folgenden vier Zeichen dargestellt werden +H: druckt "Hello, world!" +Q: druckt den Quellcode des Programms (ein Quine) +9: druckt den Liedtext von "99 Bottles of Beer" ++: erhöhe den Akkumulator um Eins (Der Wert des Akkumulators kann nicht gelesen werden) +Jedes andere Zeichen wird ignoriert. + +Ok. Lass uns ein Programm schreiben: + HQ + +Ergebnis: + Hello world! + HQ + +HQ9+ ist zwar sehr simpel, es erlaubt aber dir Sachen zu machen, die in +anderen Sprachen sehr schwierig sind. Zum Beispiel druckt das folgende Programm +drei Mal Kopien von sich selbst auf den Bildschirm: + QQQ +Dies druckt: + QQQ + QQQ + QQQ +``` + +Und das ist alles. Es gibt sehr viele Interpreter für HQ9+. +Unten findest du einen von ihnen. + ++ [One of online interpreters](https://almnet.de/esolang/hq9plus.php) ++ [HQ9+ official website](http://cliffle.com/esoterica/hq9plus.html) diff --git a/de-de/make-de.html.markdown b/de-de/make-de.html.markdown index 22c14a69..bc5c7bcb 100644 --- a/de-de/make-de.html.markdown +++ b/de-de/make-de.html.markdown @@ -2,6 +2,7 @@ language: make
contributors:
- ["Robert Steed", "https://github.com/robochat"]
+ - ["Stephan Fuhrmann", "https://github.com/sfuhrm"]
translators:
- ["Martin Schimandl", "https://github.com/Git-Jiro"]
filename: Makefile-de
@@ -58,7 +59,7 @@ file2.txt file3.txt: file0.txt file1.txt touch file3.txt
# Make wird sich beschweren wenn es mehrere Rezepte für die gleiche Regel gibt.
-# Leere Rezepte zählen nicht und können dazu verwendet werden weitere
+# Leere Rezepte zählen nicht und können dazu verwendet werden weitere
# Voraussetzungen hinzuzufügen.
#-----------------------------------------------------------------------
@@ -182,9 +183,9 @@ echo: name2 = Sara # Wahr innerhalb der passenden Regel und auch innerhalb # Ein paar Variablen die von Make automatisch definiert werden.
echo_inbuilt:
echo $(CC)
- echo ${CXX)}
+ echo ${CXX}
echo $(FC)
- echo ${CFLAGS)}
+ echo ${CFLAGS}
echo $(CPPFLAGS)
echo ${CXXFLAGS}
echo $(LDFLAGS)
diff --git a/de-de/markdown-de.html.markdown b/de-de/markdown-de.html.markdown index 2c838660..cccf5e68 100644 --- a/de-de/markdown-de.html.markdown +++ b/de-de/markdown-de.html.markdown @@ -14,7 +14,7 @@ Syntax, in der sich Dokumente leicht schreiben *und* lesen lassen. Außerdem sollte Markdown sich leicht nach HTML (und in andere Formate) konvertieren lassen. -```markdown +```md <!-- Markdown ist eine Obermenge von HTML - jede valide HTML-Datei ist also automatisch valides Markdown - was heisst dass wir jedes HTML-Element (also auch Kommentare) in Markdown benutzen können, ohne dass der Parser sie verändert. @@ -253,4 +253,4 @@ Ganz schön hässlich | vielleicht doch lieber | wieder aufhören Mehr Informationen gibt es in [John Gruber's offiziellem Blog-Post](http://daringfireball.net/projects/markdown/syntax) und bei Adam Pritchards [grandiosem Cheatsheet](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet). -Infos zu GitHub Flavored Markdown [gibt es hier](https://help.github.com/articles/github-flavored-markdown).
\ No newline at end of file +Infos zu GitHub Flavored Markdown [gibt es hier](https://help.github.com/articles/github-flavored-markdown). diff --git a/de-de/nix-de.html.markdown b/de-de/nix-de.html.markdown new file mode 100644 index 00000000..79b60d20 --- /dev/null +++ b/de-de/nix-de.html.markdown @@ -0,0 +1,358 @@ +--- +language: nix +filename: learnnix-de.nix +contributors: + - ["Chris Martin", "http://chris-martin.org/"] +translators: + - ["Dennis Keller", "https://github.com/denniskeller"] +lang: de-de +--- + +Nix ist eine simple funktionale Programmiersprache, die für den +[Nix package manager](https://nixos.org/nix/) und +[NixOS](https://nixos.org/) entwickelt wurde. + +Du kannst Nix Ausdrücke evaluieren mithilfe von +[nix-instantiate](https://nixos.org/nix/manual/#sec-nix-instantiate) +oder [`nix-repl`](https://github.com/edolstra/nix-repl). + +``` +with builtins; [ + + # Kommentare + #========================================= + + # Inline Kommentare sehen so aus. + + /* Multizeilen Kommentare + sehen so aus. */ + + + # Booleans + #========================================= + + (true && false) # Und + #=> false + + (true || false) # Oder + #=> true + + (if 3 < 4 then "a" else "b") # Bedingungen + #=> "a" + + + # Integers + #========================================= + + # Integers sind die einzigen numerischen Typen. + + 1 0 42 (-3) # Einige integers + + (4 + 6 + 12 - 2) # Addition + #=> 20 + + (7 / 2) # Division + #=> 3 + + + # Strings + #========================================= + + "String Literale sind in Anführungszeichen." + + " + String Literale können mehrere + Zeilen umspannen. + " + + '' + Dies wird als Literal mit eingerückten String bezeichnet. + Es entfernt intelligent führende Leerzeichen. + '' + + '' + a + b + '' + #=> "a\n b" + + ("ab" + "cd") # String Konkatenation + #=> "abcd" + + # Mit Antiquotation kannst du Werte in Strings einbetten. + ("Dein Homeverzeichnis ist ${getEnv "HOME"}") + #=> "Dein Homeverzeichnis ist /home/alice" + + + # Paths + #========================================= + + # Nix besitzt einen primitiven Datentyp für Pfade + /tmp/tutorials/learn.nix + + # Ein relativer Pfad wird beim Parsing zu einem absoluten Pfad aufgelöst, + # relativ zu der Datei in der es auftritt. + tutorials/learn.nix + #=> /the-base-path/tutorials/learn.nix + + # Ein Pfad muss mindestens einen Schrägstrich enthalten. Ein Pfad für eine + # Datei im selben Verzeichnis benötigt ein ./ Präfix. + ./learn.nix + #=> /the-base-path/learn.nix + + # Der / Operator muss von Leerraum umgeben sein wenn du dividieren möchtest. + 7/2 # Das ist ein Pfadliteral + (7 / 2) # Das ist ein Integerliteral + + + # Importe + #========================================= + + # Eine nix Datei besitzt einen einzelnen top-level Ausdruck mit keinen freien Variablen. + # Ein Import-Ausdruck wird zum Wert der Datei, die importiert wird, ausgewertet. + (import /tmp/foo.nix) + + # Importe können ebenso mit Strings spezifiziert werden. + (import "/tmp/foo.nix") + + # Import Pfade müssen absolut sein. Pfadliterale + # sind automatisch aufgelöst, das ist ein Ordnung. + (import ./foo.nix) + + # Jedoch passiert dies nicht mit Strings. + (import "./foo.nix") + #=> error: string ‘foo.nix’ doesn't represent an absolute path + + + # Let + #========================================= + + # `let` Blöcke erlauben es uns Werte zu Variablen zu binden. + (let x = "a"; in + x + x + x) + #=> "aaa" + + # Bindungen können auf sich gegenseitig verweisen. Die Reihenfolge spielt + # keine Rolle. + (let y = x + "b"; + x = "a"; in + y + "c") + #=> "abc" + + # Innere Bindungen überschatten Äußere. + (let a = 1; in + let a = 2; in + a) + #=> 2 + + + # Funktionen + #========================================= + + (n: n + 1) # Funktion, die 1 addiert + + ((n: n + 1) 5) # Dieselbe Funktion angewendet auf 5. + #=> 6 + + # Es gibt keine spezielle Syntax für benannte Funktionen, aber sie + # können mit `let` Blöcken, wie jeder andere Wert auch, gebunden werden. + (let succ = (n: n + 1); in succ 5) + #=> 6 + + # Eine Funktion hat genau ein Argument. + # Mehrere Argumente können erreicht werden mithilfe von Currying. + ((x: y: x + "-" + y) "a" "b") + #=> "a-b" + + # Benannte Funktionsargumente gibt es auch. Diese werden wir einführen, nachdem wir uns Sets + # angeschaut haben. + + # Listen + #========================================= + + # Listen werden durch eckige Klammern gekennzeichnet. + + (length [1 2 3 "x"]) + #=> 4 + + ([1 2 3] ++ [4 5]) + #=> [1 2 3 4 5] + + (concatLists [[1 2] [3 4] [5]]) + #=> [1 2 3 4 5] + + (head [1 2 3]) + #=> 1 + (tail [1 2 3]) + #=> [2 3] + + (elemAt ["a" "b" "c" "d"] 2) + #=> "c" + + (elem 2 [1 2 3]) + #=> true + (elem 5 [1 2 3]) + #=> false + + (filter (n: n < 3) [1 2 3 4]) + #=> [ 1 2 ] + + + # Sets + #========================================= + + # Ein "Set" ist eine ungeordnete Zuordnung mit Stringschlüsseln. + { foo = [1 2]; bar = "x"; } + + # Der . Operator nimmt einen Wert aus dem Set. + { a = 1; b = 2; }.a + #=> 1 + + # Der ? Operator testet, ob der Schlüssel in dem Set vorhanden ist. + ({ a = 1; b = 2; } ? a) + #=> true + ({ a = 1; b = 2; } ? c) + #=> false + + # Der // Operator mergt zwei Sets. + ({ a = 1; } // { b = 2; }) + #=> { a = 1; b = 2; } + + # Werte auf der rechten Seite überschreiben die Werte auf der linken Seite. + ({ a = 1; b = 2; } // { a = 3; c = 4; }) + #=> { a = 3; b = 2; c = 4; } + + # Das Schlüsselwort rec bezeichenet ein "rekursives Set", in dem sich Attribute + # aufeinander beziehen können. + (let a = 1; in { a = 2; b = a; }.b) + #=> 1 + (let a = 1; in rec { a = 2; b = a; }.b) + #=> 2 + + # Verschachtelte Sets können stückweise definiert werden. + { + a.b = 1; + a.c.d = 2; + a.c.e = 3; + }.a.c + #=> { d = 2; e = 3; } + + # Die Nachkommen eines Attributs können in diesem Feld nicht zugeordnet werden, wenn + # das Attribut selbst nicht zugewiesen wurde. + { + a = { b = 1; }; + a.c = 2; + } + #=> error: attribute ‘a’ already defined + + + # With + #========================================= + + # Der Körper eines Sets Blocks wird mit der Zuordnung eines Satzes an die Variablen gebunden. + (with { a = 1; b = 2; }; + a + b) + # => 3 + + # Innere Bindungen überschatten äußere Bindungen. + (with { a = 1; b = 2; }; + (with { a = 5; }; + a + b)) + #=> 7 + + # Die erste Linie diese Tutorials startet mit "with builtins;", + # weil builtins ein Set mit allen eingebauten + # Funktionen (length, head, tail, filter, etc.) umfasst. + # Das erspart uns beispielsweise "builtins.length" zu schreiben, + # anstatt nur "length". + + + # Set patterns + #========================================= + + # Sets sind nützlich, wenn du mehrere Werte einer Funktion + # übergeben musst. + (args: args.x + "-" + args.y) { x = "a"; y = "b"; } + #=> "a-b" + + # Dies kann mit Hilfe von Set patterns deutlicher geschrieben werden. + ({x, y}: x + "-" + y) { x = "a"; y = "b"; } + #=> "a-b" + + # Standardmäßig schlägt das Muster bei Sets mit zusätzlichen Schlüsseln fehl. + ({x, y}: x + "-" + y) { x = "a"; y = "b"; z = "c"; } + #=> error: anonymous function called with unexpected argument ‘z’ + + # Durch Hinzufügen von ", ..." können zusätzliche Schlüssel ignoriert werden. + ({x, y, ...}: x + "-" + y) { x = "a"; y = "b"; z = "c"; } + #=> "a-b" + + + # Errors + #========================================= + + # `throw` bewirkt, dass die Auswertung mit einer Fehlermeldung abgebrochen wird. + (2 + (throw "foo")) + #=> error: foo + + # `tryEval` fängt geworfene Fehler. + (tryEval 42) + #=> { success = true; value = 42; } + (tryEval (2 + (throw "foo"))) + #=> { success = false; value = false; } + + # `abort` ist ähnlich wie throw, aber es ist fatal. Es kann nicht gefangen werden. + (tryEval (abort "foo")) + #=> error: evaluation aborted with the following error message: ‘foo’ + + # `assert` evaluiert zu dem gegebenen Wert, wenn die Bedingung wahr ist, sonst + # löst es eine abfangbare Exception aus. + (assert 1 < 2; 42) + #=> 42 + (assert 1 > 2; 42) + #=> error: assertion failed at (string):1:1 + (tryEval (assert 1 > 2; 42)) + #=> { success = false; value = false; } + + + # Impurity + #========================================= + + # Da die Wiederholbarkeit von Builds für den Nix Packetmanager entscheidend ist, + # werden in der Nix Sprache reine funktionale Elemente betont. Es gibt aber ein paar + # unreine Elemente. + # Du kannst auf Umgebungsvariablen verweisen. + (getEnv "HOME") + #=> "/home/alice" + + # Die trace Funktion wird zum Debugging verwendet. Sie gibt das erste Argument zu stderr aus + # und evaluiert das zweite Argument. + (trace 1 2) + #=> trace: 1 + #=> 2 + + # Du kannst Dateien in den Nix Store schreiben. Obwohl unrein, kannst du dir relativ sicher sein, + # dass es sicher ist, da der Dateiname aus dem Hash des Inhalts abgeleitet wird. + # Du kannst Dateien von überall lesen. In diesem Beispiel schreiben wir Dateien in den Store + # und lesen wieder davon. + (let filename = toFile "foo.txt" "hello!"; in + [filename (builtins.readFile filename)]) + #=> [ "/nix/store/ayh05aay2anx135prqp0cy34h891247x-foo.txt" "hello!" ] + + # Außerdem können wir Dateien in den Nix Store herunterladen. + (fetchurl "https://example.com/package-1.2.3.tgz") + #=> "/nix/store/2drvlh8r57f19s9il42zg89rdr33m2rm-package-1.2.3.tgz" + +] +``` + +### Weitere Ressourcen + +* [Nix Manual - Nix expression language] + (https://nixos.org/nix/manual/#ch-expression-language) + +* [James Fisher - Nix by example - Part 1: The Nix expression language] + (https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55) + +* [Susan Potter - Nix Cookbook - Nix By Example] + (http://funops.co/nix-cookbook/nix-by-example/) diff --git a/de-de/opencv-de.html.markdown b/de-de/opencv-de.html.markdown new file mode 100644 index 00000000..2d9a2c4e --- /dev/null +++ b/de-de/opencv-de.html.markdown @@ -0,0 +1,153 @@ +--- +category: tool +tool: OpenCV +filename: learnopencv.py +contributors: + - ["Yogesh Ojha", "http://github.com/yogeshojha"] +translators: + - ["Dennis Keller", "https://github.com/denniskeller"] +lang: de-de +--- +### Opencv + +OpenCV (Open Source Computer Vision) ist eine Bibliothek von Programmierfunktionen, +die hauptsächlich auf maschinelles Sehen in Echtzeit ausgerichtet ist. +Ursprünglich wurde OpenCV von Intel entwickelt. Später wurde es von von +Willow Garage und dann Itseez (das später von Intel übernommen wurde) unterstützt. +OpenCV unterstützt derzeit eine Vielzahl von Sprachen, wie C++, Python, Java uvm. + +#### Installation + +Bitte lese diese Artikel für die Installation von OpenCV auf deinen Computer. + +* Windows Installationsanleitung: [https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_setup/py_setup_in_windows/py_setup_in_windows.html#install-opencv-python-in-windows]() +* Mac Installationsanleitung (High Sierra): [https://medium.com/@nuwanprabhath/installing-opencv-in-macos-high-sierra-for-python-3-89c79f0a246a]() +* Linux Installationsanleitung (Ubuntu 18.04): [https://www.pyimagesearch.com/2018/05/28/ubuntu-18-04-how-to-install-opencv]() + +### Hier werden wir uns auf die Pythonimplementierung von OpenCV konzentrieren. + +```python +# Bild in OpenCV lesen +import cv2 +img = cv2.imread('Katze.jpg') + +# Bild darstellen +# Die imshow() Funktion wird verwendet um das Display darzustellen. +cv2.imshow('Image',img) +# Das erste Argument ist der Titel des Fensters und der zweite Parameter ist das Bild +# Wenn du den Fehler Object Type None bekommst ist eventuell dein Bildpfad falsch. +# Bitte überprüfe dann den Pfad des Bildes erneut. +cv2.waitKey(0) +# waitKey() ist eine Tastaturbindungsfunktion, sie nimmt Argumente in +# Millisekunden an. Für GUI Ereignisse MUSST du die waitKey() Funktion verwenden. + +# Ein Bild schreiben +cv2.imwrite('graueKatze.png',img) +# Das erste Arkument ist der Dateiname und das Zweite ist das Bild + +# Konveriere das Bild zu Graustufen +gray_image = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) + +# Videoaufnahme von der Webcam +cap = cv2.VideoCapture(0) +# 0 ist deine Kamera, wenn du mehrere Kameras hast musst du deren Id eingeben +while(True): + # Erfassen von Einzelbildern + _, frame = cap.read() + cv2.imshow('Frame',frame) + # Wenn der Benutzer q drückt -> beenden + if cv2.waitKey(1) & 0xFF == ord('q'): + break +# Die Kamera muss wieder freigegeben werden +cap.release() + +# Wiedergabe von Videos aus einer Datei +cap = cv2.VideoCapture('film.mp4') +while(cap.isOpened()): + _, frame = cap.read() + # Das Video in Graustufen abspielen + gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) + cv2.imshow('frame',gray) + if cv2.waitKey(1) & 0xFF == ord('q'): + break +cap.release() + +# Zeichne eine Linie in OpenCV +# cv2.line(img,(x,y),(x1,y1),(color->r,g,b->0 to 255),thickness) +cv2.line(img,(0,0),(511,511),(255,0,0),5) + +# Zeichne ein Rechteck +# cv2.rectangle(img,(x,y),(x1,y1),(color->r,g,b->0 to 255),thickness) +# thickness = -1 wird zum Füllen des Rechtecks verwendet +cv2.rectangle(img,(384,0),(510,128),(0,255,0),3) + +# Zeichne ein Kreis +cv2.circle(img,(xCenter,yCenter), radius, (color->r,g,b->0 to 255), thickness) +cv2.circle(img,(200,90), 100, (0,0,255), -1) + +# Zeichne eine Ellipse +cv2.ellipse(img,(256,256),(100,50),0,0,180,255,-1) + +# Text auf Bildern hinzufügen +cv2.putText(img,"Hello World!!!", (x,y), cv2.FONT_HERSHEY_SIMPLEX, 2, 255) + +# Bilder zusammenfüggen +img1 = cv2.imread('Katze.png') +img2 = cv2.imread('openCV.jpg') +dst = cv2.addWeighted(img1,0.5,img2,0.5,0) + +# Schwellwertbild +# Binäre Schwellenwerte +_,thresImg = cv2.threshold(img,127,255,cv2.THRESH_BINARY) +# Anpassbare Schwellenwerte +adapThres = cv2.adaptiveThreshold(img,255,cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY,11,2) + +# Weichzeichnung von einem Bild +# Gausßscher Weichzeichner +blur = cv2.GaussianBlur(img,(5,5),0) +# Rangordnungsfilter +medianBlur = cv2.medianBlur(img,5) + +# Canny-Algorithmus +img = cv2.imread('Katze.jpg',0) +edges = cv2.Canny(img,100,200) + +# Gesichtserkennung mit Haarkaskaden +# Lade die Haarkaskaden von https://github.com/opencv/opencv/blob/master/data/haarcascades/ herunter +import cv2 +import numpy as np +face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml') +eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml') + +img = cv2.imread('Mensch.jpg') +gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) + +aces = face_cascade.detectMultiScale(gray, 1.3, 5) +for (x,y,w,h) in faces: + cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) + roi_gray = gray[y:y+h, x:x+w] + roi_color = img[y:y+h, x:x+w] + eyes = eye_cascade.detectMultiScale(roi_gray) + for (ex,ey,ew,eh) in eyes: + cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2) + +cv2.imshow('img',img) +cv2.waitKey(0) + +cv2.destroyAllWindows() +# destroyAllWindows() zerstört alle Fenster +# Wenn du ein bestimmtes Fenter zerstören möchtest musst du den genauen Namen des +# von dir erstellten Fensters übergeben. +``` + +### Weiterführende Literatur: +* Lade Kaskade hier herunter [https://github.com/opencv/opencv/blob/master/data/haarcascades]() +* OpenCV Zeichenfunktionen [https://docs.opencv.org/2.4/modules/core/doc/drawing_functions.html]() +* Eine aktuelle Sprachenreferenz kann hier gefunden werden [https://opencv.org]() +* Zusätzliche Ressourcen können hier gefunden werden [https://en.wikipedia.org/wiki/OpenCV]() +* Gute OpenCV Tutorials + * [https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_tutorials.html]() + * [https://realpython.com/python-opencv-color-spaces]() + * [https://pyimagesearch.com]() + * [https://www.learnopencv.com]() + * [https://docs.opencv.org/master/]() diff --git a/de-de/paren-de.html.markdown b/de-de/paren-de.html.markdown new file mode 100644 index 00000000..0d914c05 --- /dev/null +++ b/de-de/paren-de.html.markdown @@ -0,0 +1,200 @@ +--- + +language: Paren +filename: learnparen.paren +contributors: + - ["KIM Taegyoon", "https://github.com/kimtg"] + - ["Claudson Martins", "https://github.com/claudsonm"] +translators: + - ["Dennis Keller", "https://github.com/denniskeller"] +lang: de-de +--- + +[Paren](https://bitbucket.org/ktg/paren) ist ein Dialekt von Lisp. +Es ist als eingebettete Sprache konzipiert. + +Manche Beispiele sind von <http://learnxinyminutes.com/docs/racket/>. + +```scheme +;;; Kommentare +# Kommentare + +;; Einzeilige Kommentare starten mit einem Semikolon oder einem Hashtag + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; 1. Primitive Datentypen und Operatoren +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +;;; Zahlen +123 ; int +3.14 ; double +6.02e+23 ; double +(int 3.14) ; => 3 : int +(double 123) ; => 123 : double + +;; Funktionsapplikationen werden so geschrieben: (f x y z ...) +;; Dabei ist f eine Funktion und x, y, z sind die Operatoren. +;; Wenn du eine Literalliste von Daten erstelllen möchtest, +;; verwende (quote) um zu verhindern, dass sie ausgewertet zu werden. +(quote (+ 1 2)) ; => (+ 1 2) +;; Nun einige arithmetische Operationen +(+ 1 1) ; => 2 +(- 8 1) ; => 7 +(* 10 2) ; => 20 +(^ 2 3) ; => 8 +(/ 5 2) ; => 2 +(% 5 2) ; => 1 +(/ 5.0 2) ; => 2.5 + +;;; Wahrheitswerte +true ; for Wahr +false ; for Falsch +(! true) ; => Falsch +(&& true false (prn "doesn't get here")) ; => Falsch +(|| false true (prn "doesn't get here")) ; => Wahr + +;;; Zeichen sind Ints. +(char-at "A" 0) ; => 65 +(chr 65) ; => "A" + +;;; Zeichenketten sind ein Array von Zahlen mit fester Länge. +"Hello, world!" +"Benjamin \"Bugsy\" Siegel" ; Backslash ist ein Escape-Zeichen +"Foo\tbar\r\n" ; beinhaltet C Escapes: \t \r \n + +;; Zeichenketten können auch verbunden werden! +(strcat "Hello " "world!") ; => "Hello world!" + +;; Eine Zeichenketten kann als Liste von Zeichen behandelt werden +(char-at "Apple" 0) ; => 65 + +;; Drucken ist ziemlich einfach +(pr "Ich bin" "Paren. ") (prn "Schön dich zu treffen!") + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; 2. Variablen +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; Du kannst Variablen setzen indem du (set) verwedest +;; eine Variable kann alle Zeichen besitzen außer: ();#" +(set some-var 5) ; => 5 +some-var ; => 5 + +;; Zugriff auf eine zuvor nicht zugewiesene Variable erzeugt eine Ausnahme +; x ; => Unknown variable: x : nil + +;; Lokale Bindung: Verwende das Lambda Calculus! 'a' und 'b' +;; sind nur zu '1' und '2' innerhalb von (fn ...) gebunden. +((fn (a b) (+ a b)) 1 2) ; => 3 + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; 3. Sammlungen +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +;;; Listen + +;; Listen sind Vektrorartige Datenstrukturen. (Zufälliger Zugriff ist O(1). +(cons 1 (cons 2 (cons 3 (list)))) ; => (1 2 3) +;; 'list' ist ein komfortabler variadischer Konstruktor für Listen +(list 1 2 3) ; => (1 2 3) +;; und ein quote kann als literaler Listwert verwendet werden +(quote (+ 1 2)) ; => (+ 1 2) + +;; Du kannst 'cons' verwenden um ein Element an den Anfang einer Liste hinzuzufügen. +(cons 0 (list 1 2 3)) ; => (0 1 2 3) + +;; Listen sind ein sehr einfacher Typ, daher gibt es eine Vielzahl an Funktionen +;; für Sie. Ein paar Beispiele: +(map inc (list 1 2 3)) ; => (2 3 4) +(filter (fn (x) (== 0 (% x 2))) (list 1 2 3 4)) ; => (2 4) +(length (list 1 2 3 4)) ; => 4 + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; 3. Funktionen +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +;; Verwende 'fn' um Funktionen zu erstellen. +;; eine Funktion gibt immer den Wert ihres letzten Ausdrucks zurück +(fn () "Hello World") ; => (fn () Hello World) : fn + +;; Verwende Klammern um alle Funktionen aufzurufen, inklusive Lambda Ausdrücke +((fn () "Hello World")) ; => "Hello World" + +;; Zuweisung einer Funktion zu einer Variablen +(set hello-world (fn () "Hello World")) +(hello-world) ; => "Hello World" + +;; Du kannst dies mit syntaktischen Zucker für die Funktionsdefinition verkürzen: +(defn hello-world2 () "Hello World") + +;; Die () von oben ist eine Liste von Argumente für die Funktion. +(set hello + (fn (name) + (strcat "Hello " name))) +(hello "Steve") ; => "Hello Steve" + +;; ... oder gleichwertig, unter Verwendung mit syntaktischen Zucker: +(defn hello2 (name) + (strcat "Hello " name)) + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; 4. Gleichheit +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +;; Für Zahlen verwende '==' +(== 3 3.0) ; => wahr +(== 2 1) ; => falsch + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; 5. Kontrollfluss +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +;;; Bedingungen + +(if true ; test Ausdruck + "this is true" ; then Ausdruck + "this is false") ; else Ausdruck +; => "this is true" + +;;; Schleifen + +;; for Schleifen ist für Zahlen +;; (for SYMBOL START ENDE SCHRITT AUSDRUCK ..) +(for i 0 10 2 (pr i "")) ; => schreibt 0 2 4 6 8 10 +(for i 0.0 10 2.5 (pr i "")) ; => schreibt 0 2.5 5 7.5 10 + +;; while Schleife +((fn (i) + (while (< i 10) + (pr i) + (++ i))) 0) ; => schreibt 0123456789 + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; 6. Mutation +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +;; Verwende 'set' um einer Variablen oder einer Stelle einen neuen Wert zuzuweisen. +(set n 5) ; => 5 +(set n (inc n)) ; => 6 +n ; => 6 +(set a (list 1 2)) ; => (1 2) +(set (nth 0 a) 3) ; => 3 +a ; => (3 2) + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; 7. Makros +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +;; Makros erlauben es dir die Syntax der Sprache zu erweitern. +;; Parens Makros sind einfach. +;; Tatsächlich ist (defn) ein Makro. +(defmacro setfn (name ...) (set name (fn ...))) +(defmacro defn (name ...) (def name (fn ...))) + +;; Lass uns eine Infix Notation hinzufügen +;; Let's add an infix notation +(defmacro infix (a op ...) (op a ...)) +(infix 1 + 2 (infix 3 * 4)) ; => 15 + +;; Makros sind nicht hygenisch, Du kannst bestehende Variablen überschreiben! +;; Sie sind Codetransformationenen. +``` diff --git a/de-de/pyqt-de.html.markdown b/de-de/pyqt-de.html.markdown new file mode 100644 index 00000000..93ee20d4 --- /dev/null +++ b/de-de/pyqt-de.html.markdown @@ -0,0 +1,89 @@ +--- +category: tool +tool: PyQT +filename: learnpyqt-de.py +contributors: + - ["Nathan Hughes", "https://github.com/sirsharpest"] +translators: + - ["Dennis Keller", "https://github.com/denniskeller"] +lang: de-de +--- + +**Qt** ist eine weit bekanntes Framework mit den man plattformunabhängige Programme schreiben kann, +die auf verschiedenen Sotfware und Hardware Plattformen laufen mit kleinen oder keinen Änderungen im Code. +Dabei besitzen sie trozdem die Power und Geschwindigkeit von nativen Anwendungen. +**Qt** wurde ursprünglich in *C++** geschrieben. + +Das ist eine Adaption von dem C++ Intro für QT von [Aleksey Kholovchuk](https://github.com/vortexxx192), +manche der Codebeispiele sollte in der selben Funktionalität resultieren. +Diese Version wurde in pyqt erstellt. + +```python +import sys +from PyQt4 import QtGui + +def window(): + # Erschafft ein Anwendungsobjekt. + app = QtGui.QApplication(sys.argv) + # Erschafft ein Widget, auf dem unser Label platziert wird. + w = QtGui.QWidget() + # Fügt ein Label zu dem Widget hinzu. + b = QtGui.QLabel(w) + # Setzt einen Text für das Label. + b.setText("Hello World!") + # Setzt die Größe und die Platzierungsinfomationen. + w.setGeometry(100, 100, 200, 50) + b.move(50, 20) + # Setzt unserem Fenster einen schönen Titel. + w.setWindowTitle("PyQt") + # Lässt alles anzeigen. + w.show() + # Führe alles aus, nachdem wir alles aufgebaut haben. + sys.exit(app.exec_()) + +if __name__ == '__main__': + window() + +``` + +Damit wir weitere fortgeschrittene Funktionen in **pyqt** verwenden können, +müssen wir anfangen zusätzliche Elemente zu bauen. +Hier zeigen wir wie man eine Dialog Popup Box einführt. +Diese ist nützlich, um den Benutzer eine Entscheidung zu bestätigen oder um Informationen anzuzeigen. + +```Python +import sys +from PyQt4.QtGui import * +from PyQt4.QtCore import * + + +def window(): + app = QApplication(sys.argv) + w = QWidget() + # Erschafft einen Knopf und fügt das Widget w hinzu + b = QPushButton(w) + b.setText("drücke mich") + b.move(50, 50) + # Wenn b gedrückt wird, wird diese Funktion aufgerufen. + # Bemerke das Fehlen von () bei dem Funktionsaufruf. + b.clicked.connect(showdialog) + w.setWindowTitle("PyQt Dialog") + w.show() + sys.exit(app.exec_()) + +# Diese Funktion soll ein Dialogfenster mit einem Knopf erschaffen. +# Der Knopf wartet bis er geklickt wird und beendet das Programm +def showdialog(): + d = QDialog() + b1 = QPushButton("ok", d) + b1.move(50, 50) + d.setWindowTitle("Dialog") + # Diese Modalität sagt dem Popup, dass es den Parent blocken soll, solange es aktiv ist. + d.setWindowModality(Qt.ApplicationModal) + # Beim klicken möchte ich, dass der gesamte Prozess beendet wird. + b1.clicked.connect(sys.exit) + d.exec_() + +if __name__ == '__main__': + window() +``` diff --git a/de-de/python3-de.html.markdown b/de-de/python3-de.html.markdown index 33897225..b313727c 100644 --- a/de-de/python3-de.html.markdown +++ b/de-de/python3-de.html.markdown @@ -152,7 +152,7 @@ print("Ich bin Python. Schön, dich kennenzulernen!") some_var = 5 # kleinschreibung_mit_unterstrichen entspricht der Norm some_var #=> 5 -# Das Ansprechen einer noch nicht deklarierte Variable löst eine Exception aus. +# Das Ansprechen einer noch nicht deklarierten Variable löst eine Exception aus. # Unter "Kontrollstruktur" kann noch mehr über # Ausnahmebehandlung erfahren werden. some_unknown_var # Löst einen NameError aus @@ -225,7 +225,7 @@ a, b, c = (1, 2, 3) # a ist jetzt 1, b ist jetzt 2 und c ist jetzt 3 # Tupel werden standardmäßig erstellt, wenn wir uns die Klammern sparen d, e, f = 4, 5, 6 # Es ist kinderleicht zwei Werte zu tauschen -e, d = d, e # d is now 5 and e is now 4 +e, d = d, e # d ist nun 5 und e ist nun 4 # Dictionarys (Wörterbucher) speichern Schlüssel-Werte-Paare @@ -379,8 +379,8 @@ with open("meineDatei.txt") as f: print(line) # Python bietet ein fundamentales Konzept der Iteration. -# Das Objekt, auf das die Interation, also die Wiederholung einer Methode angewandt wird heißt auf Englisch "iterable". -# Die range Method gibt ein solches Objekt aus. +# Das Objekt, auf das die Iteration, also die Wiederholung einer Methode angewandt wird heißt auf Englisch "iterable". +# Die range Methode gibt ein solches Objekt aus. filled_dict = {"one": 1, "two": 2, "three": 3} our_iterable = filled_dict.keys() @@ -396,8 +396,8 @@ our_iterable[1] # TypeError # Ein iterable ist ein Objekt, das weiß wie es einen Iteratoren erschafft. our_iterator = iter(our_iterable) -# Unser Iterator ist ein Objekt, das sich merkt, welchen Status es geraden hat während wir durch es gehen. -# Das jeweeils nächste Objekt bekommen wir mit "next()" +# Unser Iterator ist ein Objekt, das sich merkt, welchen Status es gerade hat während wir durch es gehen. +# Das jeweils nächste Objekt bekommen wir mit "next()" next(our_iterator) #=> "one" # Es hält den vorherigen Status @@ -442,7 +442,7 @@ def keyword_args(**kwargs): # Rufen wir es mal auf, um zu sehen, was passiert keyword_args(big="foot", loch="ness") #=> {"big": "foot", "loch": "ness"} -# Wir können beides gleichzeitig machem, wenn wir wollen +# Wir können beides gleichzeitig machen, wenn wir wollen def all_the_args(*args, **kwargs): print(args) print(kwargs) diff --git a/de-de/qt-de.html.markdown b/de-de/qt-de.html.markdown new file mode 100644 index 00000000..480030fe --- /dev/null +++ b/de-de/qt-de.html.markdown @@ -0,0 +1,175 @@ +--- +category: tool +tool: Qt Framework +language: c++ +filename: learnqt-de.cpp +contributors: + - ["Aleksey Kholovchuk", "https://github.com/vortexxx192"] +translators: + - ["Dennis Keller", "https://github.com/denniskeller"] +lang: de-de +--- + +**Qt** ist ein weithin bekanntes Framework zum Entwickeln von cross-platform Software, +die auf verschiedenen Hard- und Softwareplatformen mit wenig oder keinen Veränderungen im Code läuft. +Dabei besitzt man die Power und Geschiwindigkeit von nativen Anwendungen. +Obwohl **Qt** ursprünglich in *C++* geschrieben wurde, +gibt es verschiedene Ports für andere Sprachen: *[PyQt](https://learnxinyminutes.com/docs/pyqt/)*, *QtRuby*, *PHP-Qt*, etc. + +**Qt** eignet sich hervorragend zum Erstellen von Anwendungen mit grafischer Benutzeroberfläche (GUI). +Dieses Tutorial zeigt, wie man das in *C++* macht. + +```c++ +/* + * Lass uns klassisch starten + */ + +// Alle Header vom Qt Framework starten mit dem Großbuchstaben 'Q'. +#include <QApplication> +#include <QLineEdit> + +int main(int argc, char *argv[]) { + // Erstellt ein Objekt um applikationsweit die Resourcen zu managen. + QApplication app(argc, argv); + + // Erstellt ein Line edit Widget und zeigt es auf dem Bildschirm + QLineEdit lineEdit("Hello world!"); + lineEdit.show(); + + // Startet die Event Loop der Anwendung. + return app.exec(); +} +``` + +Die GUI bezogene Teile von **Qt** bestehen aus *Widgets* und den *Verbindungen* +dazwischen. + +[Lies mehr über Widgets](http://doc.qt.io/qt-5/qtwidgets-index.html) + +```c++ +/* + * Lass uns Label und einen Button machen. + * Ein Label soll auftauchen, wenn der Button gedrückt wird. + * + * Der Qt Code spricht für sich selbst. + */ + +#include <QApplication> +#include <QDialog> +#include <QVBoxLayout> +#include <QPushButton> +#include <QLabel> + +int main(int argc, char *argv[]) { + QApplication app(argc, argv); + + QDialog dialogWindow; + dialogWindow.show(); + + // Füge ein vertikales Layout hinzu + QVBoxLayout layout; + dialogWindow.setLayout(&layout); + + QLabel textLabel("Danke für das Knopf drücken"); + layout.addWidget(&textLabel); + textLabel.hide(); + + QPushButton button("Drück mich"); + layout.addWidget(&button); + + // Zeigt verstecktes Label, wenn der Button gedrückt wird. + QObject::connect(&button, &QPushButton::pressed, + &textLabel, &QLabel::show); + + return app.exec(); +} +``` + +Beachte den *QObject::connect* Teil. Diese Methode wird verwendet, +um *Signale* eines Objekts mit den *Slots* eines Objektes zu verbinden. + +**Signale** werden ausgegeben, wenn bestimmte Dinge mit Objekten passieren. +Beispielsweise wird das *pressed* Signal ausgegeben, +wenn der Benutzer auf das QPushButton Objekt drückt. + +**Slots** sind Aktionen, die als Reaktion auf empfangene Signale ausgeführt werden können. + +[Lies mehr über Slots und Signale](http://doc.qt.io/qt-5/signalsandslots.html) + + +Als Nächstes lernen wir, dass wir nicht nur Standard Widgets verwenden können, +sondern auch ihr Verhalten mithilfe von Vererbung verändern können. +Lass uns einen Button erschaffen, der zählt, wie häufig er gedrückt wird. +Dafür definieren wir unsere eigene Klasse *CounterLabel*. +Diese muss wegen der speziellen Qt Architektur in einer seperaten Datei deklariert werden. + +```c++ +// counterlabel.hpp + +#ifndef COUNTERLABEL +#define COUNTERLABEL + +#include <QLabel> + +class CounterLabel : public QLabel { + Q_OBJECT // Qt definiertes Makro, welches in jedem modifizierten Widget vorhanden sein muss. + +public: + CounterLabel() : counter(0) { + setText("Zähler wurde noch nicht erhöht."); // Methode von QLabel + } + +public slots: + // Aktion, die ausgeführt wird, wenn der Button gedrückt wird. + void increaseCounter() { + setText(QString("Zähler Wert: %1").arg(QString::number(++counter))); + } + +private: + int counter; +}; + +#endif // Zähllabel +``` + +```c++ +// main.cpp +// Fast das Gleiche, wie das vorherige Beispiel + +#include <QApplication> +#include <QDialog> +#include <QVBoxLayout> +#include <QPushButton> +#include <QString> +#include "counterlabel.hpp" + +int main(int argc, char *argv[]) { + QApplication app(argc, argv); + + QDialog dialogWindow; + dialogWindow.show(); + + QVBoxLayout layout; + dialogWindow.setLayout(&layout); + + CounterLabel counterLabel; + layout.addWidget(&counterLabel); + + QPushButton button("Drück mich nochmal."); + layout.addWidget(&button); + QObject::connect(&button, &QPushButton::pressed, + &counterLabel, &CounterLabel::increaseCounter); + + return app.exec(); +} +``` + +Das wars! Natürlich ist das Qt Framework erheblich größer, als der der Teil der in diesem Tutorial behandelt wurde. +Das heißt, es gibt viel zu lesen und zu üben. + +## Further reading + +- [Qt 4.8 tutorials](http://doc.qt.io/qt-4.8/tutorials.html) +- [Qt 5 tutorials](http://doc.qt.io/qt-5/qtexamplesandtutorials.html) + +Viel Erfolg und viel Spaß! diff --git a/de-de/rst-de.html.markdown b/de-de/rst-de.html.markdown new file mode 100644 index 00000000..bcfe21bd --- /dev/null +++ b/de-de/rst-de.html.markdown @@ -0,0 +1,119 @@ +--- +language: restructured text (RST) +filename: restructuredtext.rst +contributors: + - ["DamienVGN", "https://github.com/martin-damien"] + - ["Andre Polykanine", "https://github.com/Oire"] +translators: + - ["Dennis Keller", "https://github.com/denniskeller"] +lang: de-de +--- + +RST ist ein Dateiformat, das von der Python Community entwickelt wurde, + +um Dokumentation zu schreiben (und ist somit Teil von Docutils). + +RST-Dateien sind simple Textdateien mit einer leichtgewichtigen Syntax (im Vergleich zu HTML). + + +## Installation + +Um Restructured Text zu vewenden musst du [Python](http://www.python.org) + +installieren und das `docutils` Packet installieren. `docutils` kann mit dem folgenden + +Befehl auf der Kommandozeile installiert werden: + +```bash +$ easy_install docutils +``` + +Wenn auf deinem System `pip` installiert kannst du es statdessen auch verwenden: + +```bash +$ pip install docutils +``` + + +## Dateisyntax + +Ein einfaches Beispiel für die Dateisyntax: + +``` +.. Zeilen, die mit zwei Punkten starten sind spezielle Befehle. + +.. Wenn kein Befehl gefunden wird, wird die Zeile als Kommentar gewertet. + +============================================================================ +Haupttitel werden mit Gleichheitszeichen darüber und darunter gekennzeichnet +============================================================================ + +Beachte das es genau so viele Gleichheitszeichen, wie Hauptitelzeichen +geben muss. + +Titel werden auch mit Gleichheitszeichen unterstrichen +====================================================== + +Untertitel werden mit Strichen gekennzeichnet +--------------------------------------------- + +Text in *kursiv* oder in **fett**. Du kannst Text als Code "makieren", wenn +du doppelte Backquotes verwendest ``: ``print()``. + +Listen sind so einfach wie in Markdown: + +- Erstes Element +- Zweites Element + - Unterelement + +oder + +* Erstes Element +* Zweites Element + * Unterelement + +Tabellen sind einfach zu schreiben: + +=========== ========== +Land Hauptstadt +=========== ========== +Frankreich Paris +Japan Tokyo +=========== ======== + +Komplexere Tabellen (zusammengeführte Spalten und Zeilen) können einfach +erstellt werden, aber ich empfehle dir dafür die komplette Dokumentation zu lesen :) + +Es gibt mehrere Möglichkeiten um Links zu machen: + +- Wenn man einen Unterstrich hinter einem Wort hinzufügt: Github_ Zusätzlich +muss man die Zielurl nach dem Text hinzufügen. +(Dies hat den Vorteil, dass man keine unnötigen Urls in lesbaren Text einfügt. +- Wenn man die vollständige Url eingibt : https://github.com/ +(Dies wird automatisch in ein Link konvertiert.) +- Wenn man es mehr Markdown ähnlich eingibt: `Github <https://github.com/>`_ . + +.. _Github https://github.com/ + +``` + + +## Wie man es verwendet + +RST kommt mit docutils, dort hast du den Befehl `rst2html`, zum Beispiel: + +```bash +$ rst2html myfile.rst output.html +``` + +*Anmerkung : Auf manchen Systemen könnte es rst2html.py sein* + +Es gibt komplexere Anwendungen, die das RST Format verwenden: + +- [Pelican](http://blog.getpelican.com/), ein statischer Websitengenerator +- [Sphinx](http://sphinx-doc.org/), Ein Dokumentationsgenerator +- und viele Andere + +## Zum Lesen + +- [Offizielle Schnellreferenz](http://docutils.sourceforge.net/docs/user/rst/quickref.html) diff --git a/de-de/shutit-de.html.markdown b/de-de/shutit-de.html.markdown new file mode 100644 index 00000000..f66ed906 --- /dev/null +++ b/de-de/shutit-de.html.markdown @@ -0,0 +1,330 @@ +--- +category: tool +filename: learnshutit.html +tool: ShutIt +contributors: + - ["Ian Miell", "http://ian.meirionconsulting.tk"] +translators: + - ["Dennis Keller", "https://github.com/denniskeller"] +lang: de-de +--- + +## ShutIt + +ShuIt ist eine Shellautomationsframework, welches für eine einfache +Handhabung entwickelt wurde. + +Er ist ein Wrapper, der auf einem Python expect Klon (pexpect) basiert. + +Es ist damit ein 'expect ohne Schmerzen'. + +Es ist verfügbar als pip install. + +## Hello World + +Starten wir mit dem einfachsten Beispiel. Erstelle eine Datei names example.py + +```python + +import shutit +session = shutit.create_session('bash') +session.send('echo Hello World', echo=True) +``` + +Führe es hiermit aus: + +```bash +python example.py +``` + +gibt aus: + +```bash +$ python example.py +echo "Hello World" +echo "Hello World" +Hello World +Ians-MacBook-Air.local:ORIGIN_ENV:RhuebR2T# +``` + +Das erste Argument zu 'send' ist der Befehl, den du ausführen möchtest. +Das 'echo' Argument gibt die Terminalinteraktion aus. ShuIt ist standardmäßig leise. + +'Send' kümmert sich um die nervige Arbeiten mit den Prompts und macht +alles was du von 'expect' erwarten würdest. + + +## Logge dich auf einen Server ein + +Sagen wir du möchtest dich auf einen Server einloggen und einen Befehl ausführen. +Ändere dafür example.py folgendermaßen: + +```python +import shutit +session = shutit.create_session('bash') +session.login('ssh you@example.com', user='du', password='meinpassword') +session.send('hostname', echo=True) +session.logout() +``` + +Dies erlaubt dir dich auf deinen Server einzuloggen +(ersetze die Details mit deinen Eigenen) und das Programm gibt dir deinen Hostnamen aus. + +``` +$ python example.py +hostname +hostname +example.com +example.com:cgoIsdVv:heDa77HB# +``` + + +Es ist klar das das nicht sicher ist. Stattdessen kann man Folgendes machen: + +```python +import shutit +session = shutit.create_session('bash') +password = session.get_input('', ispass=True) +session.login('ssh you@example.com', user='du', password=password) +session.send('hostname', echo=True) +session.logout() +``` + +Dies zwingt dich dein Passwort einzugeben: + +``` +$ python example.py +Input Secret: +hostname +hostname +example.com +example.com:cgoIsdVv:heDa77HB# +``` + + +Die 'login' Methode übernimmt wieder das veränderte Prompt für den Login. +Du übergibst ShutIt den User und das Passwort, falls es benötigt wird, +mit den du dich einloggen möchtest. ShutIt übernimmt den Rest. + +'logout' behandelt das Ende von 'login' und übernimmt alle Veränderungen des +Prompts für dich. + +## Einloggen auf mehrere Server + +Sagen wir, dass du eine Serverfarm mit zwei Servern hast und du dich in +beide Server einloggen möchtest. Dafür musst du nur zwei Session und +Logins erstellen und kannst dann Befehle schicken: + +```python +import shutit +session1 = shutit.create_session('bash') +session2 = shutit.create_session('bash') +password1 = session1.get_input('Password für server1', ispass=True) +password2 = session2.get_input('Password für server2', ispass=True) +session1.login('ssh you@one.example.com', user='du', password=password1) +session2.login('ssh you@two.example.com', user='du', password=password2) +session1.send('hostname', echo=True) +session2.send('hostname', echo=True) +session1.logout() +session2.logout() +``` + +Gibt aus: + +```bash +$ python example.py +Password for server1 +Input Secret: + +Password for server2 +Input Secret: +hostname +hostname +one.example.com +one.example.com:Fnh2pyFj:qkrsmUNs# hostname +hostname +two.example.com +two.example.com:Gl2lldEo:D3FavQjA# +``` + +## Beispiel: Überwachen mehrerer Server + +Wir können das obige Programm in ein einfaches Überwachungstool bringen indem +wir Logik hinzufügen um die Ausgabe von einem Befehl zu betrachten. + +```python +import shutit +capacity_command="""df / | awk '{print $5}' | tail -1 | sed s/[^0-9]//""" +session1 = shutit.create_session('bash') +session2 = shutit.create_session('bash') +password1 = session.get_input('Passwort für Server1', ispass=True) +password2 = session.get_input('Passwort für Server2', ispass=True) +session1.login('ssh you@one.example.com', user='du', password=password1) +session2.login('ssh you@two.example.com', user='du', password=password2) +capacity = session1.send_and_get_output(capacity_command) +if int(capacity) < 10: + print(kein Platz mehr auf Server1!') +capacity = session2.send_and_get_output(capacity_command) +if int(capacity) < 10: + print(kein Platz mehr auf Server2!') +session1.logout() +session2.logout() +``` + +Hier kannst du die 'send\_and\_get\_output' Methode verwenden um die Ausgabe von dem +Kapazitätsbefehl (df) zu erhalten. + +Es gibt elegantere Wege als oben (z.B. kannst du ein Dictionary verwenden um über +die Server zu iterieren), aber es hängt and dir wie clever das Python sein muss. + + +## kompliziertere IO - Expecting + +Sagen wir du hast eine Interaktion mit einer interaktiven Kommandozeilenprogramm, +die du automatisieren möchtest. Hier werden wir Telnet als triviales Beispiel verwenden: + +```python +import shutit +session = shutit.create_session('bash') +session.send('telnet', expect='elnet>', echo=True) +session.send('open google.com 80', expect='scape character', echo=True) +session.send('GET /', echo=True, check_exit=False) +session.logout() +``` + +Beachte das 'expect' Argument. Du brauchst nur ein Subset von Telnets +Eingabeaufforderung um es abzugleichen und fortzufahren. + +Beachte auch das neue Argument 'check\_exit'. Wir werden nachher nochmal +darauf zurückkommen. Die Ausgabe von oben ist: + +```bash +$ python example.py +telnet +telnet> open google.com 80 +Trying 216.58.214.14... +Connected to google.com. +Escape character is '^]'. +GET / +HTTP/1.0 302 Found +Cache-Control: private +Content-Type: text/html; charset=UTF-8 +Referrer-Policy: no-referrer +Location: http://www.google.co.uk/?gfe_rd=cr&ei=huczWcj3GfTW8gfq0paQDA +Content-Length: 261 +Date: Sun, 04 Jun 2017 10:57:10 GMT + +<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8"> +<TITLE>302 Moved</TITLE></HEAD><BODY> +<H1>302 Moved</H1> +The document has moved +<A HREF="http://www.google.co.uk/?gfe_rd=cr&ei=huczWcj3GfTW8gfq0paQDA"> +here +</A>. +</BODY></HTML> +Connection closed by foreign host. +``` + +Nun zurück zu 'check\_exit=False'. Da das Telnet Programm einen Fehler mit +Fehlercode (1) zurückgibt und wir nicht möchten das das Skript fehlschlägt +kannst du 'check\_exit=False' setzen und damit ShuIt wissen lassen, dass +der Ausgabecode dich nicht interessiert. + +Wenn du das Argument nicht mitgegeben hättest, dann hätte dir ShutIt +ein interaktives Terminal zurückgegeben, falls es ein Terminal zum +kommunizieren gibt. Dies nennt sich ein 'Pause point'. + + +## Pause Points + +Du kannst jederzeit 'pause point' auslösen, wenn du Folgendes in deinem Skript aufrufst: + +```python +[...] +session.pause_point('Das ist ein pause point') +[...] +``` + +Danach kannst du das Skript fortführen, wenn du CTRL und ']' zur selben Zeit drückst. +Dies ist gut für Debugging: Füge ein Pause Point hinzu und schaue dich um. +Danach kannst du das Programm weiter ausführen. Probiere folgendes aus: + +```python +import shutit +session = shutit.create_session('bash') +session.pause_point('Schaue dich um!') +session.send('echo "Hat dir der Pause point gefallen?"', echo=True) +``` + +Dies würde folgendes ausgeben: + +```bash +$ python example.py +Schaue dich um! + +Ians-Air.home:ORIGIN_ENV:I00LA1Mq# bash +imiell@Ians-Air:/space/git/shutit ⑂ master + +CTRL-] caught, continuing with run... +2017-06-05 15:12:33,577 INFO: Sending: exit +2017-06-05 15:12:33,633 INFO: Output (squashed): exitexitIans-Air.home:ORIGIN_ENV:I00LA1Mq# [...] +echo "Hat dir der Pause point gefallen?" +echo "Hat dir der Pause point gefallen?" +Hat dir der Pause point gefallen? +Ians-Air.home:ORIGIN_ENV:I00LA1Mq# +``` + + +## noch kompliziertere IO - Hintergrund + +Kehren wir zu unseren Beispiel mit dem Überwachen von mehreren Servern zurück. +Stellen wir uns vor, dass wir eine langlaufende Aufgabe auf jedem Server durchführen möchten. +Standardmäßig arbeitet ShutIt seriell, was sehr lange dauern würde. +Wir können jedoch die Aufgaben im Hintergrund laufen lassen um sie zu beschleunigen. + +Hier ist ein Beispiel, welches du ausprobieren kannst. +Es verwendet den trivialen Befehl: 'sleep'. + + +```python +import shutit +import time +long_command="""sleep 60""" +session1 = shutit.create_session('bash') +session2 = shutit.create_session('bash') +password1 = session1.get_input('Password for server1', ispass=True) +password2 = session2.get_input('Password for server2', ispass=True) +session1.login('ssh you@one.example.com', user='du', password=password1) +session2.login('ssh you@two.example.com', user='du', password=password2) +start = time.time() +session1.send(long_command, background=True) +session2.send(long_command, background=True) +print('Es hat: ' + str(time.time() - start) + ' Sekunden zum Starten gebraucht') +session1.wait() +session2.wait() +print('Es hat:' + str(time.time() - start) + ' Sekunden zum Vollenden gebraucht') +``` + +Mein Computer meint, dass er 0.5 Sekunden gebraucht hat um die Befehle zu starten +und dann nur etwas über eine Minute gebraucht um sie zu beenden +(mit Verwendung der 'wait' Methode). + + +Das alles ist trivial, aber stelle dir vor das du hunderte an Servern so managen +kannst und man kann nun das Potential sehen, die in ein paar Zeilen Code und ein Python +import liegen können. + + +## Lerne mehr + +Es gibt noch viel mehr, was mit ShutIt erreicht werden kann. + +Um mehr zu erfahren, siehe: + +[ShutIt](https://ianmiell.github.io/shutit/) +[GitHub](https://github.com/ianmiell/shutit/blob/master/README.md) + +Es handelt sich um ein breiteres Automatiesierungsframework, und das oben +genannte ist der sogennante 'standalone Modus'. + +Feedback, feature requests, 'Wie mache ich es' sind herzlich willkommen! Erreiche mit unter +[@ianmiell](https://twitter.com/ianmiell) diff --git a/dynamic-programming.html.markdown b/dynamic-programming.html.markdown index 4db8e92e..aed169fc 100644 --- a/dynamic-programming.html.markdown +++ b/dynamic-programming.html.markdown @@ -42,9 +42,9 @@ for i=0 to n-1 ### Some Famous DP Problems -- Floyd Warshall Algorithm - Tutorial and C Program source code:http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs---floyd-warshall-algorithm-with-c-program-source-code -- Integer Knapsack Problem - Tutorial and C Program source code: http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---the-integer-knapsack-problem -- Longest Common Subsequence - Tutorial and C Program source code : http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---longest-common-subsequence +- Floyd Warshall Algorithm - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs---floyd-warshall-algorithm-with-c-program-source-code]() +- Integer Knapsack Problem - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---the-integer-knapsack-problem]() +- Longest Common Subsequence - Tutorial and C Program source code : [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---longest-common-subsequence]() ## Online Resources diff --git a/edn.html.markdown b/edn.html.markdown index 9ecfb24f..f47853f0 100644 --- a/edn.html.markdown +++ b/edn.html.markdown @@ -84,22 +84,26 @@ github/fork ; you can't eat with this #MyYelpClone/MenuItem {:name "eggs-benedict" :rating 10} -; Let me explain this with a clojure example. Suppose I want to transform that +; Let me explain this with a Clojure example. Suppose I want to transform that ; piece of EDN into a MenuItem record. (defrecord MenuItem [name rating]) -; To transform EDN to clojure values, I will need to use the built in EDN -; reader, edn/read-string +; defrecord defined, among other things, map->MenuItem which will take a map +; of field names (as keywords) to values and generate a user.MenuItem record -(edn/read-string "{:eggs 2 :butter 1 :flour 5}") +; To transform EDN to Clojure values, I will need to use the built-in EDN +; reader, clojure.edn/read-string + +(clojure.edn/read-string "{:eggs 2 :butter 1 :flour 5}") ; -> {:eggs 2 :butter 1 :flour 5} -; To transform tagged elements, define the reader function and pass a map -; that maps tags to reader functions to edn/read-string like so +; To transform tagged elements, pass to clojure.edn/read-string an option map +; with a :readers map that maps tag symbols to data-reader functions, like so -(edn/read-string {:readers {'MyYelpClone/MenuItem map->menu-item}} - "#MyYelpClone/MenuItem {:name \"eggs-benedict\" :rating 10}") +(clojure.edn/read-string + {:readers {'MyYelpClone/MenuItem map->MenuItem}} + "#MyYelpClone/MenuItem {:name \"eggs-benedict\" :rating 10}") ; -> #user.MenuItem{:name "eggs-benedict", :rating 10} ``` diff --git a/elixir.html.markdown b/elixir.html.markdown index a74baa38..e82509e7 100644 --- a/elixir.html.markdown +++ b/elixir.html.markdown @@ -287,7 +287,11 @@ end PrivateMath.sum(1, 2) #=> 3 # PrivateMath.do_sum(1, 2) #=> ** (UndefinedFunctionError) -# Function declarations also support guards and multiple clauses: +# Function declarations also support guards and multiple clauses. +# When a function with multiple clauses is called, the first function +# that satisfies the clause will be invoked. +# Example: invoking area({:circle, 3}) will call the second area +# function defined below, not the first: defmodule Geometry do def area({:rectangle, w, h}) do w * h diff --git a/elm.html.markdown b/elm.html.markdown index 23ae9eeb..ad80adc9 100644 --- a/elm.html.markdown +++ b/elm.html.markdown @@ -72,8 +72,8 @@ List.head [] -- Nothing -- Access the elements of a pair with the first and second functions. -- (This is a shortcut; we'll come to the "real way" in a bit.) -fst ("elm", 42) -- "elm" -snd ("elm", 42) -- 42 +Tuple.first ("elm", 42) -- "elm" +Tuple.second ("elm", 42) -- 42 -- The empty tuple, or "unit", is sometimes used as a placeholder. -- It is the only value of its type, also called "Unit". diff --git a/es-es/awk-es.html.markdown b/es-es/awk-es.html.markdown index 307ba817..0516ea92 100644 --- a/es-es/awk-es.html.markdown +++ b/es-es/awk-es.html.markdown @@ -166,7 +166,7 @@ function arithmetic_functions(a, b, c, localvar) { # trigonométricas estándar localvar = sin(a) localvar = cos(a) - localvar = atan2(a, b) # arcotangente de b / a + localvar = atan2(b, a) # arcotangente de b / a # Y cosas logarítmicas localvar = exp(a) diff --git a/es-es/bf-es.html.markdown b/es-es/bf-es.html.markdown index 90c6202f..df1ae2e7 100644 --- a/es-es/bf-es.html.markdown +++ b/es-es/bf-es.html.markdown @@ -1,6 +1,6 @@ --- -language: Brainfuck -filename: brainfuck-es.bf +language: bf +filename: bf-es.bf contributors: - ["Prajit Ramachandran", "http://prajitr.github.io/"] - ["Mathias Bynens", "http://mathiasbynens.be/"] diff --git a/es-es/c++-es.html.markdown b/es-es/c++-es.html.markdown index bd1ad07c..2c3762d5 100644 --- a/es-es/c++-es.html.markdown +++ b/es-es/c++-es.html.markdown @@ -823,7 +823,6 @@ v.swap(vector<Foo>()); ``` Otras lecturas: -Una referencia del lenguaje hasta a la fecha se puede encontrar en -<http://cppreference.com/w/cpp> - -Recursos adicionales se pueden encontrar en <http://cplusplus.com> +* Una referencia del lenguaje hasta a la fecha se puede encontrar en [CPP Reference](http://cppreference.com/w/cpp). +* Recursos adicionales se pueden encontrar en [[CPlusPlus]](http://cplusplus.com). +* Un tutorial que cubre los conceptos básicos del lenguaje y la configuración del entorno de codificación está disponible en [TheChernoProject - C ++](https://www.youtube.com/playlist?list=PLlrATfBNZ98dudnM48yfGUldqGD0S4FF). diff --git a/es-es/csharp-es.html.markdown b/es-es/csharp-es.html.markdown index 5d730497..72a0f90c 100644 --- a/es-es/csharp-es.html.markdown +++ b/es-es/csharp-es.html.markdown @@ -5,7 +5,7 @@ contributors: - ["Irfan Charania", "https://github.com/irfancharania"] - ["Max Yankov", "https://github.com/golergka"] translators: - - ["Olfran Jiménez", "https://twitter.com/neslux"] + - ["Olfran Jiménez", "https://twitter.com/neslux"] lang: es-es --- diff --git a/es-es/erlang-es.html.markdown b/es-es/erlang-es.html.markdown new file mode 100644 index 00000000..bc6317a5 --- /dev/null +++ b/es-es/erlang-es.html.markdown @@ -0,0 +1,293 @@ +--- +language: erlang +lang: es-es +contributors: + - ["Giovanni Cappellotto", "http://www.focustheweb.com/"] +translators: + - ["Ernesto Pelayo", "http://github.com/ErnestoPelayo"] +filename: learnerlang-es.erl +--- + +# Erlang +% Signo de porcentaje inicia un comentario de una línea. + +%% Se usarán dos por ciento de caracteres para comentar funciones. + +%%% Se usarán tres por ciento de caracteres para comentar los módulos. + +### Utilizamos tres tipos de puntuación en Erlang. + ++ **Comas (`,`)** argumentos separados en llamadas a funciones, constructores de +datos y patrones. + ++ **Periodos (`.`)** (seguido de espacios en blanco) separa funciones completas y +expresiones en el shell. + ++ **Semicolons (`;`)** cláusulas separadas. Encontramos cláusulas en varios contextos: de definiciones de funciones y en **`case`**,**` if`**, **`try..catch`**, y **` receive`** de expresiones. + + ## 1.-Variables y coincidencia de patrones. + + +- En Erlang, las nuevas variables están vinculadas con una instrucción **`=`**. +>**Num = 42.** + +- Todos los nombres de variables deben comenzar con una letra mayúscula. + +- Erlang tiene variables de asignación única; si intentas asignar un diferente de valor a la variable **`Num`**, obtendrá un error. +Num = 43. **error de excepción**: no coincide con el valor del lado derecho 43 + +- En la mayoría de los idiomas, **`=`** denota una declaración de asignación. En Erlang, sin embargo,**`=`** denota una operación de coincidencia de patrones. + +- Cuando se usa una variable vacía en el del lado izquierdo del operador `=` to está vinculado (asignado), pero cuando está atado variable se usa en el lado izquierdo, se observa el siguiente comportamiento. +>**`Lhs = Rhs`** realmente significa esto: evaluar el lado derecho (**` Rhs`**), y luego coincide con el resultado contra el patrón en el lado izquierdo (**`Lhs`**). +>**Num = 7 * 6.** + +- Número de punto flotante. +Pi = 3.14159. + +- Los átomos se usan para representar diferentes valores constantes no numéricos. + +- Átomos comienza con letras minúsculas, seguido de una secuencia de caracteres + +- alfanuméricos de caracteres o el signo de subrayado (**`_`**) o en (**` @ `**). +>**Hola = hola.** + **OtherNode = ejemplo @ nodo.** + +- Los átomos con valores no alfanuméricos se pueden escribir al encerrar los átomos con apóstrofes. +>**AtomWithSpace = 'algún átomo con espacio'.** + ++ Tuples son similares a las estructuras en C. +>**Point = {point, 10, 45}.** + +- Si queremos extraer algunos valores de una tupla, usamos el patrón de coincidencia + operador **`=`**. +> **{punto, X, Y} = Punto. % X = 10, Y = 45** + +- Podemos usar **`_`** como marcador de posición para variables que no nos interesan. + +- El símbolo **`_`** se llama una variable anónima. A diferencia de las variables regulares,varias apariciones de `_` en el mismo patrón no tienen que vincularse a mismo valor. +>**Person = {person, {name, {first, joe}, {last, armstrong}}, {footsize, 42}}.** +**{_, {_, {_, who }, _}, _} = Persona. % Who = joe** + ++ Creamos una lista al encerrar los elementos de la lista entre corchetes y separándolos con comas. + ++ Los elementos individuales de una lista pueden ser de cualquier tipo. + +- El primer elemento de una lista es el encabezado de la lista. Si te imaginas eliminar del encabezado de la lista, lo que queda se llama cola de la lista. +>**ThingsToBuy = [{manzanas, 10}, {peras, 6}, {leche, 3}].** + +- Si `T` es una lista, entonces **` [H | T] `** también es una lista, con la cabeza **` H`** y la cola **`T`**. + ++ La barra vertical (**`|`**) separa el encabezado de una lista de su cola. + **`[]`** es la lista vacía. + ++ Podemos extraer elementos de una lista con una operación de coincidencia de + patrones. Si nosotros tiene una lista no vacía **`L`**, luego la expresión **` [X | Y] = L`**, donde **`X`** y **` Y`** son variables independientes, extraerán el encabezado de la lista en **`X`** y la cola de la lista en **`Y`**. +>**[FirstThing | OtherThingsToBuy] = ThingsToBuy.** +**FirstThing = {manzanas, 10}** +**OtherThingsToBuy = [{peras, 6}, {leche, 3}]** + ++ No hay cadenas en Erlang. Las cadenas son realmente solo listas de enteros. + ++ Las cadenas están entre comillas dobles (**`" `**). +>**Nombre = "Hola". +[72, 101, 108, 108, 111] = "Hola".** + +## 2. Programación secuencial. + + +- Los módulos son la unidad básica de código en Erlang. Todas las funciones que escribimos son almacenado en módulos. + +- Los módulos se almacenan en archivos con extensiones **`.erl`**. +- Los módulos deben compilarse antes de poder ejecutar el código. Un módulo compilado tiene el extensión **`.beam`**. +>**-módulo (geometría). +-export ([area / 1]). de la lista de funciones exportadas desde el módulo.** + ++ La función **`área`** consta de dos cláusulas. Las cláusulas están separadas por un punto y coma, y la cláusula final termina con punto-espacio en blanco. Cada cláusula tiene una cabeza y un cuerpo; la cabeza consiste en un nombre de función seguido de un patrón (entre paréntesis), y el cuerpo consiste en una secuencia de expresiones, que se evalúan si el patrón en la cabeza es exitoso coincide con los argumentos de llamada. Los patrones se combinan en el orden aparecen en la definición de la función. +>**área ({rectángulo, ancho, Ht}) -> ancho * Ht; +área ({círculo, R}) -> 3.14159 * R * R** . + + ### Compila el código en el archivo geometry.erl. +c (geometría). {ok, geometría} + ++ Necesitamos incluir el nombre del módulo junto con el nombre de la función para identifica exactamente qué función queremos llamar. +>**geometría: área ({rectángulo, 10, 5}). % 50** +**geometría: área ({círculo, 1.4}). % 6.15752** + ++ En Erlang, dos funciones con el mismo nombre y arity diferente (número de argumentos) en el mismo módulo representan funciones completamente diferentes. +>-**module (lib_misc)**. +-**export ([sum / 1])**. + +- función de exportación **`suma`** de arity 1 acepta un argumento: +>**lista de enteros. +suma (L) -> suma (L, 0). +suma ([], N) -> N; +suma ([H | T], N) -> suma (T, H + N).** ++ Funs son funciones **"anónimas"**. Se llaman así porque tienen sin nombre. Sin embargo, pueden asignarse a variables. +Doble = diversión (X) -> 2 * X final. **`Doble`** apunta a una función anónima con el controlador: **#Fun <erl_eval.6.17052888> +Doble (2). % 4** + +- Functions acepta funs como sus argumentos y puede devolver funs. +>**Mult = diversión (Times) -> (fun (X) -> X * Times end) end. +Triple = Mult (3). +Triple (5). % 15** + +- Las listas de comprensión son expresiones que crean listas sin tener que usar + funs, mapas o filtros. + - La notación **`[F (X) || X <- L] `** significa" la lista de **`F (X)`** donde se toma **`X`**% de la lista **`L`."** +>**L = [1,2,3,4,5]. +[2 * X || X <- L]. % [2,4,6,8,10]** + +- Una lista de comprensión puede tener generadores y filtros, que seleccionan un subconjunto de los valores generados +>**EvenNumbers = [N || N <- [1, 2, 3, 4], N rem 2 == 0]. % [2, 4]** + +- Los protectores son construcciones que podemos usar para aumentar el poder del patrón coincidencia. Usando guardias, podemos realizar pruebas simples y comparaciones en el de variables en un patrón. +Puede usar guardias en la cabeza de las definiciones de funciones donde están introducido por la palabra clave **`when`**, o puede usarlos en cualquier lugar del lenguaje donde se permite una expresión. +>**max (X, Y) cuando X> Y -> X; +max (X, Y) -> Y.** + +- Un guardia es una serie de expresiones de guardia, separadas por comas (**`,`**). +- La guardia **`GuardExpr1, GuardExpr2, ..., GuardExprN`** es verdadera si todos los guardias expresiones **`GuardExpr1`,` GuardExpr2`, ..., `GuardExprN`** evalúan **`true`**. +>**is_cat (A) cuando is_atom (A), A =: = cat -> true; +is_cat (A) -> false. +is_dog (A) cuando is_atom (A), A =: = dog -> true; +is_dog (A) -> false.** + +No nos detendremos en el operador **`=: =`** aquí; Solo tenga en cuenta que está acostumbrado a comprueba si dos expresiones de Erlang tienen el mismo valor * y * del mismo tipo. Contrasta este comportamiento con el del operador **`==`**: + +>**1 + 2 =: = 3.% true +1 + 2 =: = 3.0. % false +1 + 2 == 3.0. % true** + + Una secuencia de guardia es una guardia individual o una serie de guardias, separadas por punto y coma (**`;`**). La secuencia de guardia **`G1; G2; ...; Gn`** es verdadero si en menos uno de los guardias **`G1`,` G2`, ..., `Gn`** se evalúa como **` true`**. +>**is_pet (A) cuando is_atom (A), (A =: = dog); (A =: = cat) -> true; +is_pet (A) -> false.** + +- **Advertencia**: no todas las expresiones de Erlang válidas se pueden usar como expresiones de guarda; en particular, nuestras funciones **`is_cat`** y **`is_dog`** no se pueden usar dentro del secuencia de protección en la definición de **`is_pet`**. Para una descripción de expresiones permitidas en secuencias de guarda, consulte la sección específica en el manual de referencia de Erlang: +### http://erlang.org/doc/reference_manual/expressions.html#guards + +- Los registros proporcionan un método para asociar un nombre con un elemento particular en un de tupla De las definiciones de registros se pueden incluir en los archivos de código fuente de Erlang o poner en archivos con la extensión **`.hrl`**, que luego están incluidos en el código fuente de Erlang de archivos. + +>**-record (todo, { + status = recordatorio,% valor predeterminado + quien = joe, + texto +}).** + +- Tenemos que leer las definiciones de registro en el shell antes de que podamos definir un + de registro. Usamos la función shell **`rr`** (abreviatura de los registros de lectura) para hacer esto. + +>**rr ("records.hrl").** % [que hacer] + +- **Creando y actualizando registros:** +>**X = #todo {}. +% #todo {status = recordatorio, who = joe, text = undefined} +X1 = #todo {estado = urgente, texto = "Corregir errata en el libro"}. +% #todo {status = urgent, who = joe, text = "Corregir errata en el libro"} +X2 = X1 # todo {estado = hecho}. +% #todo {status = done, who = joe, text = "Corregir errata en el libro"} +expresiones `case`**. + +**`filter`** devuelve una lista de todos los elementos **` X`** en una lista **`L`** para la cual **` P (X) `** es true. +>**filter(P, [H|T]) -> + case P(H) of + true -> [H|filter(P, T)]; + false -> filter(P, T) + end; +filter(P, []) -> []. +filter(fun(X) -> X rem 2 == 0 end, [1, 2, 3, 4]). % [2, 4]** + +expresiones **`if`**. +>**max(X, Y) -> + if + X > Y -> X; + X < Y -> Y; + true -> nil + end.** + +**Advertencia:** al menos uno de los guardias en la expresión **`if`** debe evaluar a **`true`**; de lo contrario, se generará una excepción. + +## 3. Excepciones. + + +- El sistema genera excepciones cuando se encuentran errores internos o explícitamente en el código llamando **`throw (Exception)`**, **`exit (Exception)`**, o **`erlang: error (Exception)`**. +>**generate_exception (1) -> a; +generate_exception (2) -> throw (a); +generate_exception (3) -> exit (a); +generate_exception (4) -> {'EXIT', a}; +generate_exception (5) -> erlang: error (a).** + +- Erlang tiene dos métodos para atrapar una excepción. Una es encerrar la llamada a de la función que genera la excepción dentro de una expresión **`try ... catch`**. +>**receptor (N) -> + prueba generar_excepción (N) de + Val -> {N, normal, Val} + captura + throw: X -> {N, atrapado, arrojado, X}; + exit: X -> {N, atrapado, salido, X}; + error: X -> {N, atrapado, error, X} + end.** + +- El otro es encerrar la llamada en una expresión **`catch`**. Cuando atrapas un de excepción, se convierte en una tupla que describe el error. +>**catcher (N) -> catch generate_exception (N).** + +## 4. Concurrencia + +- Erlang se basa en el modelo de actor para concurrencia. Todo lo que necesitamos para escribir de programas simultáneos en Erlang son tres primitivos: procesos de desove, de envío de mensajes y recepción de mensajes. + +- Para comenzar un nuevo proceso, usamos la función **`spawn`**, que toma una función como argumento. + +>**F = diversión () -> 2 + 2 final. % #Fun <erl_eval.20.67289768> +spawn (F). % <0.44.0>** + +- **`spawn`** devuelve un pid (identificador de proceso); puedes usar este pid para enviar de mensajes al proceso. Para pasar mensajes, usamos el operador **`!`**. + +- Para que todo esto sea útil, debemos poder recibir mensajes. Esto es logrado con el mecanismo **`receive`**: + +>**-module (calcular Geometría). +-compile (export_all). +calculateArea () -> + recibir + {rectángulo, W, H} -> + W * H; + {circle, R} -> + 3.14 * R * R; + _ -> + io: format ("Solo podemos calcular el área de rectángulos o círculos") + end.** + +- Compile el módulo y cree un proceso que evalúe **`calculateArea`** en cáscara. +>**c (calcular Geometría). +CalculateArea = spawn (calcular Geometría, calcular Área, []). +CalculateArea! {círculo, 2}. % 12.56000000000000049738** + +- El shell también es un proceso; puedes usar **`self`** para obtener el pid actual. +**self(). % <0.41.0>** + +## 5. Prueba con EUnit + +- Las pruebas unitarias se pueden escribir utilizando los generadores de prueba de EUnits y afirmar macros +>**-módulo (fib). +-export ([fib / 1]). +-include_lib ("eunit / include / eunit.hrl").** + +>**fib (0) -> 1; +fib (1) -> 1; +fib (N) when N> 1 -> fib (N-1) + fib (N-2).** + +>**fib_test_ () -> + [? _assert (fib (0) =: = 1), + ? _assert (fib (1) =: = 1), + ? _assert (fib (2) =: = 2), + ? _assert (fib (3) =: = 3), + ? _assert (fib (4) =: = 5), + ? _assert (fib (5) =: = 8), + ? _assertException (error, function_clause, fib (-1)), + ? _assert (fib (31) =: = 2178309) + ]** + +- EUnit exportará automáticamente a una función de prueba () para permitir la ejecución de las pruebas en el shell Erlang +fib: test () + +- La popular barra de herramientas de construcción de Erlang también es compatible con EUnit +**`` ` de la unidad de barras de refuerzo + ``** diff --git a/es-es/fsharp-es.html.markdown b/es-es/fsharp-es.html.markdown new file mode 100644 index 00000000..b7f80c44 --- /dev/null +++ b/es-es/fsharp-es.html.markdown @@ -0,0 +1,629 @@ +--- +language: F# +lang: es-es +contributors: + - ['Scott Wlaschin', 'http://fsharpforfunandprofit.com/'] +translators: + - ['Angel Arciniega', 'https://github.com/AngelsProjects'] +filename: learnfsharp-es.fs +--- + +F# es un lenguaje de programación funcional y orientado a objetos. Es gratis y su código fuente está abierto. Se ejecuta en Linux, Mac, Windows y más. + +Tiene un poderoso sistema de tipado que atrapa muchos errores de tiempo de compilación, pero usa inferencias de tipados que le permiten ser leídos como un lenguaje dinámico. + +La sintaxis de F# es diferente de los lenguajes que heredan de C. + +- Las llaves no se usan para delimitar bloques de código. En cambio, se usa sangría (como en Python). +- Los espacios se usan para separar parámetros en lugar de comas. + +Si quiere probar el siguiente código, puede ir a [tryfsharp.org](http://www.tryfsharp.org/Create) y pegarlo en [REPL](https://es.wikipedia.org/wiki/REPL). + +```fsharp +// Los comentarios de una línea se escibren con una doble diagonal +(* Los comentarios multilínea usan parentesis (* . . . *) + +-final del comentario multilínea- *) + +// ================================================ +// Syntaxis básica +// ================================================ + +// ------ "Variables" (pero no realmente) ------ +// La palabra reservada "let" define un valor (inmutable) +let miEntero = 5 +let miFlotante = 3.14 +let miCadena = "hola" // Tenga en cuenta que no es necesario ningún tipado + +// ------ Listas ------ +let dosACinco = [2;3;4;5] // Los corchetes crean una lista con + // punto y coma para delimitadores. +let unoACinco = 1 :: dosACinco // :: Crea una lista con un nuevo elemento +// El resultado es [1;2;3;4;5] +let ceroACinco = [0;1] @ dosACinco // @ Concatena dos listas + +// IMPORTANTE: las comas no se usan para delimitar, +// solo punto y coma ! + +// ------ Funciones ------ +// La palabra reservada "let" también define el nombre de una función. +let cuadrado x = x * x // Tenga en cuenta que no se usa paréntesis. +cuadrado 3 // Ahora, ejecutemos la función. + // De nuevo, sin paréntesis. + +let agregar x y = x + y // ¡No use add (x, y)! Eso significa + // algo completamente diferente. +agregar 2 3 // Ahora, ejecutemos la función. + +// Para definir una función en varias líneas, usemos la sangría. +// Los puntos y coma no son necesarios. +let pares lista = + let esPar x = x%2 = 0 // Establece "esPar" como una función anidada + List.filter esPar lista // List.filter es una función de la biblioteca + // dos parámetros: una función que devuelve un + // booleano y una lista en la que trabajar + +pares unoACinco // Ahora, ejecutemos la función. + +// Puedes usar paréntesis para aclarar. +// En este ejemplo, "map" se ejecuta primero, con dos argumentos, +// entonces "sum" se ejecuta en el resultado. +// Sin los paréntesis, "List.map" se pasará como argumento a List.sum. +let sumaDeCuadradosHasta100 = + List.sum ( List.map cuadrado [1..100] ) + +// Puedes redirigir la salida de una función a otra con "|>" +// Redirigir datos es muy común en F#, como con los pipes de UNIX. + +// Aquí está la misma función sumOfSquares escrita usando pipes +let sumaDeCuadradosHasta100piped = + [1..100] |> List.map cuadrado |> List.sum // "cuadrado" se declara antes + +// Puede definir lambdas (funciones anónimas) gracias a la palabra clave "fun" +let sumaDeCuadradosHasta100ConFuncion = + [1..100] |> List.map (fun x -> x*x) |> List.sum + +// En F#, no hay palabra clave "return". Una función siempre regresa +// el valor de la última expresión utilizada. + +// ------ Coincidencia de patrones ------ +// Match..with .. es una sobrecarga de la condición de case/ switch. +let coincidenciaDePatronSimple = + let x = "a" + match x with + | "a" -> printfn "x es a" + | "b" -> printfn "x es b" + | _ -> printfn "x es algo mas" // guion bajo corresponde con todos los demás + +// F# no permite valores nulos por defecto - debe usar el tipado de Option +// y luego coincide con el patrón. +// Some(..) y None son aproximadamente análogos a los envoltorios Nullable +let valorValido = Some(99) +let valorInvalido = None + +// En este ejemplo, match..with encuentra una coincidencia con "Some" y "None", +// y muestra el valor de "Some" al mismo tiempo. +let coincidenciaDePatronDeOpciones entrada = + match entrada with + | Some i -> printfn "la entrada es un int=%d" i + | None -> printfn "entrada faltante" + +coincidenciaDePatronDeOpciones validValue +coincidenciaDePatronDeOpciones invalidValue + +// ------ Viendo ------ +// Las funciones printf/printfn son similares a las funciones +// Console.Write/WriteLine de C#. +printfn "Imprimiendo un int %i, a float %f, a bool %b" 1 2.0 true +printfn "Un string %s, y algo generico %A" "hola" [1;2;3;4] + +// También hay funciones printf/sprintfn para formatear datos +// en cadena. Es similar al String.Format de C#. + +// ================================================ +// Mas sobre funciones +// ================================================ + +// F# es un verdadero lenguaje funcional - las funciones son +// entidades de primer nivel y se pueden combinar fácilmente +// para crear construcciones poderosas + +// Los módulos se utilizan para agrupar funciones juntas. +// Se requiere sangría para cada módulo anidado. +module EjemploDeFuncion = + + // define una función de suma simple + let agregar x y = x + y + + // uso básico de una función + let a = agregar 1 2 + printfn "1+2 = %i" a + + // aplicación parcial para "hornear en" los parámetros (?) + let agregar42 = agregar 42 + let b = agregar42 1 + printfn "42+1 = %i" b + + // composición para combinar funciones + let agregar1 = agregar 1 + let agregar2 = agregar 2 + let agregar3 = agregar1 >> agregar2 + let c = agregar3 7 + printfn "3+7 = %i" c + + // funciones de primer nivel + [1..10] |> List.map agregar3 |> printfn "la nueva lista es %A" + + // listas de funciones y más + let agregar6 = [agregar1; agregar2; agregar3] |> List.reduce (>>) + let d = agregar6 7 + printfn "1+2+3+7 = %i" d + +// ================================================ +// Lista de colecciones +// ================================================ + +// Il y a trois types de collection ordonnée : +// * Les listes sont les collections immutables les plus basiques +// * Les tableaux sont mutables et plus efficients +// * Les séquences sont lazy et infinies (e.g. un enumerator) +// +// Des autres collections incluent des maps immutables et des sets +// plus toutes les collections de .NET + +module EjemplosDeLista = + + // las listas utilizan corchetes + let lista1 = ["a";"b"] + let lista2 = "c" :: lista1 // :: para una adición al principio + let lista3 = lista1 @ lista2 // @ para la concatenación + + // Lista de comprensión (alias generadores) + let cuadrados = [for i in 1..10 do yield i*i] + + // Generador de números primos + let rec tamiz = function + | (p::xs) -> p :: tamiz [ for x in xs do if x % p > 0 then yield x ] + | [] -> [] + let primos = tamiz [2..50] + printfn "%A" primos + + // coincidencia de patrones para listas + let listaDeCoincidencias unaLista = + match unaLista with + | [] -> printfn "la lista esta vacia" + | [primero] -> printfn "la lista tiene un elemento %A " primero + | [primero; segundo] -> printfn "la lista es %A y %A" primero segundo + | _ -> printfn "la lista tiene mas de dos elementos" + + listaDeCoincidencias [1;2;3;4] + listaDeCoincidencias [1;2] + listaDeCoincidencias [1] + listaDeCoincidencias [] + + // Récursion en utilisant les listes + let rec suma unaLista = + match unaLista with + | [] -> 0 + | x::xs -> x + suma xs + suma [1..10] + + // ----------------------------------------- + // Funciones de la biblioteca estándar + // ----------------------------------------- + + // mapeo + let agregar3 x = x + 3 + [1..10] |> List.map agregar3 + + // filtrado + let par x = x % 2 = 0 + [1..10] |> List.filter par + + // mucho más - consulte la documentación + +module EjemploDeArreglo = + + // los arreglos usan corchetes con barras. + let arreglo1 = [| "a";"b" |] + let primero = arreglo1.[0] // se accede al índice usando un punto + + // la coincidencia de patrones de los arreglos es la misma que la de las listas + let coincidenciaDeArreglos una Lista = + match unaLista with + | [| |] -> printfn "la matriz esta vacia" + | [| primero |] -> printfn "el arreglo tiene un elemento %A " primero + | [| primero; second |] -> printfn "el arreglo es %A y %A" primero segundo + | _ -> printfn "el arreglo tiene mas de dos elementos" + + coincidenciaDeArreglos [| 1;2;3;4 |] + + // La biblioteca estándar funciona como listas + [| 1..10 |] + |> Array.map (fun i -> i+3) + |> Array.filter (fun i -> i%2 = 0) + |> Array.iter (printfn "el valor es %i. ") + +module EjemploDeSecuencia = + + // Las secuencias usan llaves + let secuencia1 = seq { yield "a"; yield "b" } + + // Las secuencias pueden usar yield y + // puede contener subsecuencias + let extranio = seq { + // "yield" agrega un elemento + yield 1; yield 2; + + // "yield!" agrega una subsecuencia completa + yield! [5..10] + yield! seq { + for i in 1..10 do + if i%2 = 0 then yield i }} + // prueba + extranio |> Seq.toList + + // Las secuencias se pueden crear usando "unfold" + // Esta es la secuencia de fibonacci + let fib = Seq.unfold (fun (fst,snd) -> + Some(fst + snd, (snd, fst + snd))) (0,1) + + // prueba + let fib10 = fib |> Seq.take 10 |> Seq.toList + printf "Los primeros 10 fib son %A" fib10 + +// ================================================ +// Tipos de datos +// ================================================ + +module EejemploDeTipoDeDatos = + + // Todos los datos son inmutables por defecto + + // las tuplas son tipos anónimos simples y rápidos + // - Usamos una coma para crear una tupla + let dosTuplas = 1,2 + let tresTuplas = "a",2,true + + // Combinación de patrones para desempaquetar + let x,y = dosTuplas // asignado x=1 y=2 + + // ------------------------------------ + // Los tipos de registro tienen campos con nombre + // ------------------------------------ + + // Usamos "type" con llaves para definir un tipo de registro + type Persona = {Nombre:string; Apellido:string} + + // Usamos "let" con llaves para crear un registro + let persona1 = {Nombre="John"; Apellido="Doe"} + + // Combinación de patrones para desempaquetar + let {Nombre=nombre} = persona1 // asignado nombre="john" + + // ------------------------------------ + // Los tipos de unión (o variantes) tienen un conjunto de elección + // Solo un caso puede ser válido a la vez. + // ------------------------------------ + + // Usamos "type" con barra/pipe para definir una unión estándar + type Temp = + | GradosC of float + | GradosF of float + + // Una de estas opciones se usa para crear una + let temp1 = GradosF 98.6 + let temp2 = GradosC 37.0 + + // Coincidencia de patrón en todos los casos para desempaquetar (?) + let imprimirTemp = function + | GradosC t -> printfn "%f gradC" t + | GradosF t -> printfn "%f gradF" t + + imprimirTemp temp1 + imprimirTemp temp2 + + // ------------------------------------ + // Tipos recursivos + // ------------------------------------ + + // Los tipos se pueden combinar recursivamente de formas complejas + // sin tener que crear subclases + type Empleado = + | Trabajador of Persona + | Gerente of Empleado lista + + let jdoe = {Nombre="John";Apellido="Doe"} + let trabajador = Trabajador jdoe + + // ------------------------------------ + // Modelado con tipados (?) + // ------------------------------------ + + // Los tipos de unión son excelentes para modelar el estado sin usar banderas (?) + type DireccionDeCorreo = + | DireccionDeCorreoValido of string + | DireccionDeCorreoInvalido of string + + let intentarEnviarCorreo correoElectronico = + match correoElectronico with // uso de patrones de coincidencia + | DireccionDeCorreoValido direccion -> () // enviar + | DireccionDeCorreoInvalido direccion -> () // no enviar + + // Combinar juntos, los tipos de unión y tipos de registro + // ofrece una base excelente para el diseño impulsado por el dominio. + // Puedes crear cientos de pequeños tipos que reflejarán fielmente + // el dominio. + + type ArticuloDelCarrito = { CodigoDelProducto: string; Cantidad: int } + type Pago = Pago of float + type DatosActivosDelCarrito = { ArticulosSinPagar: ArticuloDelCarrito lista } + type DatosPagadosDelCarrito = { ArticulosPagados: ArticuloDelCarrito lista; Pago: Pago} + + type CarritoDeCompras = + | CarritoVacio // sin datos + | CarritoActivo of DatosActivosDelCarrito + | CarritoPagado of DatosPagadosDelCarrito + + // ------------------------------------ + // Comportamiento nativo de los tipos + // ------------------------------------ + + // Los tipos nativos tienen el comportamiento más útil "listo para usar", sin ningún código para agregar. + // * Inmutabilidad + // * Bonita depuración de impresión + // * Igualdad y comparación + // * Serialización + + // La impresión bonita se usa con %A + printfn "dosTuplas=%A,\nPersona=%A,\nTemp=%A,\nEmpleado=%A" + dosTuplas persona1 temp1 trabajador + + // La igualdad y la comparación son innatas + // Aquí hay un ejemplo con tarjetas. + type JuegoDeCartas = Trebol | Diamante | Espada | Corazon + type Rango = Dos | Tres | Cuatro | Cinco | Seis | Siete | Ocho + | Nueve | Diez | Jack | Reina | Rey | As + + let mano = [ Trebol,As; Corazon,Tres; Corazon,As; + Espada,Jack; Diamante,Dos; Diamante,As ] + + // orden + List.sort mano |> printfn "la mano ordenada es (de menos a mayor) %A" + List.max mano |> printfn "la carta más alta es%A" + List.min mano |> printfn "la carta más baja es %A" + +// ================================================ +// Patrones activos +// ================================================ + +module EjemplosDePatronesActivos = + + // F# tiene un tipo particular de coincidencia de patrón llamado "patrones activos" + // donde el patrón puede ser analizado o detectado dinámicamente. + + // "clips de banana" es la sintaxis de los patrones activos + + // por ejemplo, definimos un patrón "activo" para que coincida con los tipos de "caracteres" ... + let (|Digito|Latra|EspacioEnBlanco|Otros|) ch = + if System.Char.IsDigit(ch) then Digito + else if System.Char.IsLetter(ch) then Letra + else if System.Char.IsWhiteSpace(ch) then EspacioEnBlanco + else Otros + + // ... y luego lo usamos para hacer que la lógica de análisis sea más clara + let ImprimirCaracter ch = + match ch with + | Digito -> printfn "%c es un Digito" ch + | Letra -> printfn "%c es una Letra" ch + | Whitespace -> printfn "%c es un Espacio en blanco" ch + | _ -> printfn "%c es algo mas" ch + + // ver una lista + ['a';'b';'1';' ';'-';'c'] |> List.iter ImprimirCaracter + + // ----------------------------------------- + // FizzBuzz usando patrones activos + // ----------------------------------------- + + // Puede crear un patrón de coincidencia parcial también + // Solo usamos un guión bajo en la definición y devolvemos Some si coincide. + let (|MultDe3|_|) i = if i % 3 = 0 then Some MultDe3 else None + let (|MultDe5|_|) i = if i % 5 = 0 then Some MultDe5 else None + + // la función principal + let fizzBuzz i = + match i with + | MultDe3 & MultDe5 -> printf "FizzBuzz, " + | MultDe3 -> printf "Fizz, " + | MultDe5 -> printf "Buzz, " + | _ -> printf "%i, " i + + // prueba + [1..20] |> List.iter fizzBuzz + +// ================================================ +// concisión +// ================================================ + +module EjemploDeAlgoritmo = + + // F# tiene una alta relación señal / ruido, lo que permite leer el código + // casi como un algoritmo real + + // ------ Ejemplo: definir una función sumaDeCuadrados ------ + let sumaDeCuadrados n = + [1..n] // 1) Tome todos los números del 1 al n + |> List.map cuadrado // 2) Elevar cada uno de ellos al cuadrado + |> List.sum // 3) Realiza su suma + + // prueba + sumaDeCuadrados 100 |> printfn "Suma de cuadrados = %A" + + // ------ Ejemplo: definir una función de ordenación ------ + let rec ordenar lista = + match lista with + // Si la lista está vacía + | [] -> + [] // devolvemos una lista vacía + // si la lista no está vacía + | primerElemento::otrosElementos -> // tomamos el primer elemento + let elementosMasPequenios = // extraemos los elementos más pequeños + otrosElementos // tomamos el resto + |> List.filter (fun e -> e < primerElemento) + |> ordenar // y los ordenamos + let elementosMasGrandes = // extraemos el mas grande + otrosElementos // de los que permanecen + |> List.filter (fun e -> e >= primerElemento) + |> ordenar // y los ordenamos + // Combinamos las 3 piezas en una nueva lista que devolvemos + List.concat [elementosMasPequenios; [primerElemento]; elementosMasGrandes] + + // prueba + ordenar [1;5;23;18;9;1;3] |> printfn "Ordenado = %A" + +// ================================================ +// Código asíncrono +// ================================================ + +module AsyncExample = + + // F# incluye características para ayudar con el código asíncrono + // sin conocer la "pirámide del destino" + // + // El siguiente ejemplo descarga una secuencia de página web en paralelo. + + open System.Net + open System + open System.IO + open Microsoft.FSharp.Control.CommonExtensions + + // Recuperar el contenido de una URL de forma asincrónica + let extraerUrlAsync url = + async { // La palabra clave "async" y llaves + // crear un objeto "asincrónico" + let solicitud = WebRequest.Create(Uri(url)) + use! respuesta = solicitud.AsyncGetResponse() + // use! es una tarea asincrónica + use flujoDeDatos = resp.GetResponseStream() + // "use" dispara automáticamente la funcion close() + // en los recursos al final de las llaves + use lector = new IO.StreamReader(flujoDeDatos) + let html = lector.ReadToEnd() + printfn "terminó la descarga %s" url + } + + // una lista de sitios para informar + let sitios = ["http://www.bing.com"; + "http://www.google.com"; + "http://www.microsoft.com"; + "http://www.amazon.com"; + "http://www.yahoo.com"] + + // ¡Aqui vamos! + sitios + |> List.map extraerUrlAsync // crear una lista de tareas asíncrona + |> Async.Parallel // decirle a las tareas que se desarrollan en paralelo + |> Async.RunSynchronously // ¡Empieza! + +// ================================================ +// Compatibilidad .NET +// ================================================ + +module EjemploCompatibilidadNet = + + // F# puede hacer casi cualquier cosa que C# pueda hacer, y se ajusta + // perfectamente con bibliotecas .NET o Mono. + + // ------- Trabaja con las funciones de las bibliotecas existentes ------- + + let (i1success,i1) = System.Int32.TryParse("123"); + if i1success then printfn "convertido como %i" i1 else printfn "conversion fallida" + + // ------- Implementar interfaces sobre la marcha! ------- + + // Crea un nuevo objeto que implemente IDisposable + let crearRecurso name = + { new System.IDisposable + with member this.Dispose() = printfn "%s creado" name } + + let utilizarYDisponerDeRecursos = + use r1 = crearRecurso "primer recurso" + printfn "usando primer recurso" + for i in [1..3] do + let nombreDelRecurso = sprintf "\tinner resource %d" i + use temp = crearRecurso nombreDelRecurso + printfn "\thacer algo con %s" nombreDelRecurso + use r2 = crearRecurso "segundo recurso" + printfn "usando segundo recurso" + printfn "hecho." + + // ------- Código orientado a objetos ------- + + // F# es también un verdadero lenguaje OO. + // Admite clases, herencia, métodos virtuales, etc. + + // interfaz de tipo genérico + type IEnumerator<'a> = + abstract member Actual : 'a + abstract MoverSiguiente : unit -> bool + + // Clase base abstracta con métodos virtuales + [<AbstractClass>] + type Figura() = + // propiedades de solo lectura + abstract member Ancho : int with get + abstract member Alto : int with get + // método no virtual + member this.AreaDelimitadora = this.Alto * this.Ancho + // método virtual con implementación de la clase base + abstract member Imprimir : unit -> unit + default this.Imprimir () = printfn "Soy una Figura" + + // clase concreta que hereda de su clase base y sobrecarga + type Rectangulo(x:int, y:int) = + inherit Figura() + override this.Ancho = x + override this.Alto = y + override this.Imprimir () = printfn "Soy un Rectangulo" + + // prueba + let r = Rectangulo(2,3) + printfn "La anchura es %i" r.Ancho + printfn "El area es %i" r.AreaDelimitadora + r.Imprimir() + + // ------- extensión de método ------- + + // Al igual que en C#, F# puede extender las clases existentes con extensiones de método. + type System.String with + member this.EmpiezaConA = this.EmpiezaCon "A" + + // prueba + let s = "Alice" + printfn "'%s' empieza con una 'A' = %A" s s.EmpiezaConA + + // ------- eventos ------- + + type MiBoton() = + let eventoClick = new Event<_>() + + [<CLIEvent>] + member this.AlHacerClick = eventoClick.Publish + + member this.PruebaEvento(arg) = + eventoClick.Trigger(this, arg) + + // prueba + let miBoton = new MiBoton() + miBoton.AlHacerClick.Add(fun (sender, arg) -> + printfn "Haga clic en el evento con arg=%O" arg) + + miBoton.PruebaEvento("Hola Mundo!") +``` + +## Más información + +Para más demostraciones de F#, visite el sitio [Try F#](http://www.tryfsharp.org/Learn), o sigue la serie [why use F#](http://fsharpforfunandprofit.com/why-use-fsharp/). + +Aprenda más sobre F# en [fsharp.org](http://fsharp.org/). diff --git a/es-es/learnsmallbasic-es.html.markdown b/es-es/learnsmallbasic-es.html.markdown index 21208792..ff320afb 100644 --- a/es-es/learnsmallbasic-es.html.markdown +++ b/es-es/learnsmallbasic-es.html.markdown @@ -18,7 +18,7 @@ SmallBASIC fue desarrollado originalmente por Nicholas Christopoulos a finales d Versiones de SmallBASIC se han hecho para una serie dispositivos de mano antiguos, incluyendo Franklin eBookman y el Nokia 770. También se han publicado varias versiones de escritorio basadas en una variedad de kits de herramientas GUI, algunas de las cuales han desaparecido. Las plataformas actualmente soportadas son Linux y Windows basadas en SDL2 y Android basadas en NDK. También está disponible una versión de línea de comandos de escritorio, aunque no suele publicarse en formato binario. Alrededor de 2008 una gran corporación lanzó un entorno de programación BASIC con un nombre de similar. SmallBASIC no está relacionado con este otro proyecto. -```SmallBASIC +``` REM Esto es un comentario ' y esto tambien es un comentario diff --git a/es-es/markdown-es.html.markdown b/es-es/markdown-es.html.markdown index 0505b4cb..e23a94ea 100644 --- a/es-es/markdown-es.html.markdown +++ b/es-es/markdown-es.html.markdown @@ -14,7 +14,7 @@ fácilmente a HTML (y, actualmente, otros formatos también). ¡Denme toda la retroalimentación que quieran! / ¡Sientanse en la libertad de hacer forks o pull requests! -```markdown +```md <!-- Markdown está basado en HTML, así que cualquier archivo HTML es Markdown válido, eso significa que podemos usar elementos HTML en Markdown como, por ejemplo, el comentario y no serán afectados por un parseador Markdown. Aún diff --git a/es-es/matlab-es.html.markdown b/es-es/matlab-es.html.markdown new file mode 100644 index 00000000..9f1656bb --- /dev/null +++ b/es-es/matlab-es.html.markdown @@ -0,0 +1,568 @@ +--- +language: Matlab +filename: learnmatlab-es.mat +contributors: + - ["mendozao", "http://github.com/mendozao"] + - ["jamesscottbrown", "http://jamesscottbrown.com"] + - ["Colton Kohnke", "http://github.com/voltnor"] + - ["Claudson Martins", "http://github.com/claudsonm"] +translators: + - ["Ivan Alburquerque", "https://github.com/AlburIvan"] +lang: es-es +--- + +MATLAB significa 'MATrix LABoratory'. Es un poderoso lenguaje de computación numérica comúnmente usado en ingeniería y matemáticas. + +Si tiene algún comentario, no dude en ponerse en contacto el autor en +[@the_ozzinator](https://twitter.com/the_ozzinator), o +[osvaldo.t.mendoza@gmail.com](mailto:osvaldo.t.mendoza@gmail.com). + +```matlab +%% Una sección de código comienza con dos símbolos de porcentaje. Los títulos de la sección van en la misma líneas. +% Los comentarios comienzan con un símbolo de porcentaje. + +%{ +Los Comentarios de multiples líneas se +ven +como +esto +%} + +% Dos símbolos de porcentaje denotan el comienzo de una nueva sección de código. +% Secciones de código individuales pueden ser ejecutadas moviendo el cursor hacia la sección, +% seguida por un clic en el botón de “Ejecutar Sección” +% o usando Ctrl+Shift+Enter (Windows) o Cmd+Shift+Return (OS X) + +%% Este es el comienzo de una sección de código +% Una forma de usar las secciones es separar un código de inicio costoso que no cambia, como cargar datos +load learnmatlab.mat y + +%% Esta es otra sección de código +% Esta sección puede ser editada y ejecutada de manera repetida por sí misma, +% y es útil para la programación exploratoria y demostraciones. +A = A * 2; +plot(A); + +%% Las secciones de código también son conocidas como celdas de código o modo celda (no ha de ser confundido con arreglo de celdas) + + +% Los comandos pueden abarcar varias líneas, usando '...' + a = 1 + 2 + ... + + 4 + +% Los comandos se pueden pasar al sistema operativo +!ping google.com + +who % Muestra todas las variables en la memoria +whos % Muestra todas las variables en la memoria con sus tipos +clear % Borra todas tus variables de la memoria +clear('A') % Borra una variable en particular +openvar('A') % Variable abierta en editor de variables + +clc % Borra la escritura en la ventana de Comando +diary % Alterna la escritura del texto de la ventana de comandos al archivo +ctrl-c % Aborta el cálculo actual + +edit('myfunction.m') % Abrir función/script en el editor +type('myfunction.m') % Imprime la fuente de la función/script en la ventana de comandos + +profile on % Enciende el generador de perfilador de código +profile off % Apaga el generador de perfilador de código +profile viewer % Abre el perfilador de código + +help command % Muestra la documentación del comando en la ventana de comandos +doc command % Muestra la documentación del comando en la ventana de Ayuda +lookfor command % Busca el comando en la primera línea comentada de todas las funciones +lookfor command -all % busca el comando en todas las funciones + + +% Formato de salida +format short % 4 decimales en un número flotante +format long % 15 decimales +format bank % solo dos dígitos después del punto decimal - para cálculos financieros +fprintf('texto') % imprime "texto" en la pantalla +disp('texto') % imprime "texto" en la pantalla + +% Variables y expresiones +myVariable = 4 % Espacio de trabajo de aviso muestra la variable recién creada +myVariable = 4; % Punto y coma suprime la salida a la Ventana de Comando +4 + 6 % ans = 10 +8 * myVariable % ans = 32 +2 ^ 3 % ans = 8 +a = 2; b = 3; +c = exp(a)*sin(pi/2) % c = 7.3891 + +% Llamar funciones se pueden realizar de dos maneras: +% Sintaxis de función estándar: +load('myFile.mat', 'y') % argumentos entre paréntesis, separados por comas +% Sintaxis del comando: +load myFile.mat y % sin paréntesis, y espacios en lugar de comas +% Tenga en cuenta la falta de comillas en el formulario de comandos: +% las entradas siempre se pasan como texto literal; no pueden pasar valores de variables. +% Además, no puede recibir salida: +[V,D] = eig(A); % esto no tiene equivalente en forma de comando +[~,D] = eig(A); % si solo se quiere D y no V + + + +% Operadores lógicos +1 > 5 % ans = 0 +10 >= 10 % ans = 1 +3 ~= 4 % No es igual a -> ans = 1 +3 == 3 % Es igual a -> ans = 1 +3 > 1 && 4 > 1 % AND -> ans = 1 +3 > 1 || 4 > 1 % OR -> ans = 1 +~1 % NOT -> ans = 0 + +% Los operadores lógicos se pueden aplicar a matrices: +A > 5 +% para cada elemento, si la condición es verdadera, ese elemento es 1 en la matriz devuelta +A( A > 5 ) +% devuelve un vector que contiene los elementos en A para los que la condición es verdadera + +% Cadenas +a = 'MiCadena' +length(a) % ans = 8 +a(2) % ans = y +[a,a] % ans = MiCadenaMiCadena + + +% Celdas +a = {'uno', 'dos', 'tres'} +a(1) % ans = 'uno' - retorna una celda +char(a(1)) % ans = uno - retorna una cadena + +% Estructuras +A.b = {'uno','dos'}; +A.c = [1 2]; +A.d.e = false; + +% Vectores +x = [4 32 53 7 1] +x(2) % ans = 32, los índices en Matlab comienzan 1, no 0 +x(2:3) % ans = 32 53 +x(2:end) % ans = 32 53 7 1 + +x = [4; 32; 53; 7; 1] % Vector de columna + +x = [1:10] % x = 1 2 3 4 5 6 7 8 9 10 +x = [1:2:10] % Incrementa por 2, i.e. x = 1 3 5 7 9 + +% Matrices +A = [1 2 3; 4 5 6; 7 8 9] +% Las filas están separadas por un punto y coma; los elementos se separan con espacio o coma +% A = + +% 1 2 3 +% 4 5 6 +% 7 8 9 + +A(2,3) % ans = 6, A(fila, columna) +A(6) % ans = 8 +% (concatena implícitamente columnas en el vector, luego indexa en base a esto) + + +A(2,3) = 42 % Actualiza la fila 2 col 3 con 42 +% A = + +% 1 2 3 +% 4 5 42 +% 7 8 9 + +A(2:3,2:3) % Crea una nueva matriz a partir de la anterior +%ans = + +% 5 42 +% 8 9 + +A(:,1) % Todas las filas en la columna 1 +%ans = + +% 1 +% 4 +% 7 + +A(1,:) % Todas las columnas en la fila 1 +%ans = + +% 1 2 3 + +[A ; A] % Concatenación de matrices (verticalmente) +%ans = + +% 1 2 3 +% 4 5 42 +% 7 8 9 +% 1 2 3 +% 4 5 42 +% 7 8 9 + +% esto es lo mismo que +vertcat(A,A); + + +[A , A] % Concatenación de matrices (horizontalmente) + +%ans = + +% 1 2 3 1 2 3 +% 4 5 42 4 5 42 +% 7 8 9 7 8 9 + +% esto es lo mismo que +horzcat(A,A); + + +A(:, [3 1 2]) % Reorganiza las columnas de la matriz original +%ans = + +% 3 1 2 +% 42 4 5 +% 9 7 8 + +size(A) % ans = 3 3 + +A(1, :) =[] % Elimina la primera fila de la matriz +A(:, 1) =[] % Elimina la primera columna de la matriz + +transpose(A) % Transponer la matriz, que es lo mismo que: +A one +ctranspose(A) % Hermitian transpone la matriz +% (la transposición, seguida de la toma del conjugado complejo de cada elemento) +A' % Versión concisa de transposición compleja +A.' % Versión concisa de transposición (sin tomar complejo conjugado) + + + + +% Elemento por elemento Aritmética vs. Matriz Aritmética +% Por sí solos, los operadores aritméticos actúan sobre matrices completas. Cuando preceden +% por un punto, actúan en cada elemento en su lugar. Por ejemplo: +A * B % Multiplicación de matrices +A .* B % Multiplica cada elemento en A por su elemento correspondiente en B + +% Hay varios pares de funciones, donde una actúa sobre cada elemento y +% la otra (cuyo nombre termina en m) actúa sobre la matriz completa. +exp(A) % exponencializar cada elemento +expm(A) % calcular la matriz exponencial +sqrt(A) % tomar la raíz cuadrada de cada elemento +sqrtm(A) % encuentra la matriz cuyo cuadrado es A + + +% Trazando +x = 0:.10:2*pi; % Crea un vector que comienza en 0 y termina en 2 * pi con incrementos de .1 +y = sin(x); +plot(x,y) +xlabel('x axis') +ylabel('y axis') +title('Plot of y = sin(x)') +axis([0 2*pi -1 1]) % x rango de 0 a 2 * pi, y rango de -1 a 1 + +plot(x,y1,'-',x,y2,'--',x,y3,':') % Para múltiples funciones en una parcela. +legend('Line 1 label', 'Line 2 label') % Etiquetar curvas con una leyenda. + +% Método alternativo para trazar múltiples funciones en una parcela. +% mientras 'hold' está activado, los comandos se agregan al gráfico existente en lugar de reemplazarlo. +plot(x, y) +hold on +plot(x, z) +hold off + +loglog(x, y) % Un diagrama de log-log. +semilogx(x, y) % Un diagrama con el eje x logarítmico. +semilogy(x, y) % Un diagrama con el eje y logarítmico. + +fplot (@(x) x^2, [2,5]) % Un diagrama con el eje y logarítmico... + +grid on % Muestra la cuadrícula; apague con 'grid off'. +axis square % Hace que la región actual de los ejes sea cuadrada. +axis equal % Establece la relación de aspecto para que las unidades de datos sean las mismas en todas las direcciones. + +scatter(x, y); % Gráfico de dispersión +hist(x); % Histograma +stem(x); % Traza los valores como tallos, útiles para mostrar datos discretos. +bar(x); % Diagrama de barras + +z = sin(x); +plot3(x,y,z); % Trazado de línea 3D. + +pcolor(A) % Trazado de línea 3D... +contour(A) % Diagrama de contorno de la matriz. +mesh(A) % Traza una superficie de malla. + +h = figure % Crea nuevo objeto figura, con el mango h. +figure(h) % Hace que la figura correspondiente al mango h la figura actual. +close(h) % Cierra la figura con mango h. +close all % Cierra todas las ventanas con figura abierta. +close % Cierra ventana de figura actual. + +shg % Trae una ventana gráfica existente hacia adelante, o crea una nueva si es necesario. +clf clear % Borra la ventana de la figura actual y restablece la mayoría de las propiedades de la figura. + +% Las propiedades se pueden establecer y cambiar a través de un identificador de figura. +% Puede guardar un identificador de una figura cuando la crea. +% La función get devuelve un handle a la figura actual +h = plot(x, y); % Puedes guardar un control de una figura cuando la creas +set(h, 'Color', 'r') +% 'y' yellow; 'm' magenta, 'c' cyan, 'r' red, 'g' green, 'b' blue, 'w' white, 'k' black +set(h, 'LineStyle', '--') +% '--' es línea continua, '---' discontinua, ':' punteada, '-.' dash-dot, 'none' es sin línea +get (h, 'LineStyle') + + +% La función gca devuelve un mango a los ejes para la figura actual +set(gca, 'XDir', 'reverse'); % invierte la dirección del eje x + +% Para crear una figura que contenga varios ejes en posiciones de mosaico, use 'subplot' +subplot(2,3,1); % seleccione la primera posición en una grilla de subtramas de 2 por 3 +plot(x1); title('First Plot') % traza algo en esta posición +subplot(2,3,2); % selecciona la segunda posición en la grilla +plot(x2); title('Second Plot') % trazar algo allí + + +% Para usar funciones o scripts, deben estar en su ruta o directorio actual +path % muestra la ruta actual +addpath /path/to/dir % agrega a la ruta +rmpath /path/to/dir % elimina de la ruta +cd /path/to/move/into % cambia de directorio + + +% Las variables se pueden guardar en archivos .mat +save('myFileName.mat') % Guarda las variables en su espacio de trabajo +load('myFileName.mat') % Carga las variables guardadas en espacio de trabajo + +% M-file Scripts +% Un archivo de script es un archivo externo que contiene una secuencia de instrucciones. +% Permiten evitar escribir repetidamente el mismo código en la ventana de comandos +% Tienen extensiones .m + +% M-file Functions +% Al igual que los scripts, y tienen la misma extensión .m +% Pero pueden aceptar argumentos de entrada y devolver una salida +% Además, tienen su propio espacio de trabajo (es decir, diferente alcance variable). +% El nombre de la función debe coincidir con el nombre del archivo (por lo tanto, guarde este ejemplo como double_input.m). +% 'help double_input.m' devuelve los comentarios en la línea que comienza la función +function output = double_input(x) + % double_input(x) devuelve el doble del valor de x + output = 2*x; +end +double_input(6) % ans = 12 + + +% También puede tener subfunciones y funciones anidadas. +% Las subfunciones están en el mismo archivo que la función primaria, y solo pueden ser +% llamadas por funciones en el archivo. Las funciones anidadas se definen dentro de otra +% otras funciones y tienen acceso tanto a su área de trabajo como a su propio espacio de trabajo. + +% Si desea crear una función sin crear un nuevo archivo, puede usar una +% función anónima. Útil cuando se define rápidamente una función para pasar a +% otra función (por ejemplo, trazar con fplot, evaluar una integral indefinida +% con quad, encuentra roots con fzero, o encuentra mínimo con fminsearch). +% Ejemplo que devuelve el cuadrado de su entrada, asignado al identificador sqr: +sqr = @(x) x.^2; +sqr(10) % ans = 100 +doc function_handle % averiguar más + +% User input +a = input('Ingrese el valor:') + +% Detiene la ejecución del archivo y le da control al teclado: el usuario puede examinar +% o cambiar las variables. Escriba 'return' para continuar la ejecución, o 'dbquit' para salir del teclado + +% Lectura de datos (también xlsread / importdata / imread para archivos de excel / CSV / image) +fopen(filename) + +% Salida +disp(a) % Imprime el valor de la variable a +disp('Hola Mundo') % Imprime una cadena +fprintf % Imprime en la ventana de comandos con más control + +% Declaraciones condicionales (los paréntesis son opcionales, pero buen estilo) +if (a > 15) + disp('Mayor que 15') +elseif (a == 23) + disp('a es 23') +else + disp('Ninguna condicion se ha cumplido') +end + +% Bucles +% NB. haciendo un bucle sobre los elementos de un vector / matriz es lento! +% Siempre que sea posible, use funciones que actúen en todo el vector / matriz a la vez +for k = 1:5 + disp(k) +end + +k = 0; +while (k < 5) + k = k + 1; +end + +% Ejecución del código de tiempo: 'toc' imprime el tiempo desde que se llamó 'tic' +tic +A = rand(1000); +A*A*A*A*A*A*A; +toc + +% Conectarse a una base de datos MySQL +dbname = 'database_name'; +username = 'root'; +password = 'root'; +driver = 'com.mysql.jdbc.Driver'; +dburl = ['jdbc:mysql://localhost:8889/' dbname]; +javaclasspath('mysql-connector-java-5.1.xx-bin.jar'); %xx depende de la versión, descarga disponible en http://dev.mysql.com/downloads/connector/j/ +conn = database(dbname, username, password, driver, dburl); +sql = ['SELECT * from table_name where id = 22'] % Ejemplo de instrucción sql +a = fetch(conn, sql) %a contendrá sus datos + + +% Funciones matemáticas comunes +sin(x) +cos(x) +tan(x) +asin(x) +acos(x) +atan(x) +exp(x) +sqrt(x) +log(x) +log10(x) +abs(x) % Si x es complejo, devuelve la magnitud +min(x) +max(x) +ceil(x) +floor(x) +round(x) +rem(x) +rand % Números pseudoaleatorios distribuidos uniformemente +randi % Enteros pseudoaleatorios distribuidos uniformemente +randn % Números pseudoaleatorios distribuidos normalmente + +% Operaciones matemáticas complejas +abs(x) % Magnitud de la variable compleja x +phase(x) % Fase (o ángulo) de la variable compleja x +real(x) % Retorna la parte real de x (es decir, devuelve a si x = a + jb) +imag(x) % Retorna la parte imaginaria de x (es decir, devuelve b si x = a + jb) +conj(x) % Retorna el complejo conjugado + + +% Constantes comunes +pi +NaN +inf + +% Resolviendo ecuaciones matriciales (si no hay solución, devuelve una solución de mínimos cuadrados) +%Los operadores \ y / son equivalentes a las funciones mldivide y mrdivide +x=A\b % Resuelve Ax = b. Más rápido y más numéricamente preciso que usar inv (A) * b. +x=b/A % Resuelve xA = b + +inv(A) % calcular la matriz inversa +pinv(A) % calcular el pseudo-inverso + +% Funciones de matriz comunes +zeros(m,n) % m x n matriz de 0 +ones(m,n) % m x n matriz de 1 +diag(A) % Extrae los elementos diagonales de una matriz A +diag(x) % Construya una matriz con elementos diagonales enumerados en x, y ceros en otra parte +eye(m,n) % Matriz de identidad +linspace(x1, x2, n) % Devuelve n puntos equiespaciados, con min x1 y max x2 +inv(A) % Inverso de la matriz A +det(A) % Determinante de A +eig(A) % Valores propios y vectores propios de A +trace(A) % Traza de la matriz: equivalente a sum(diag(A)) +isempty(A) % Determina si la matriz está vacía +all(A) % Determina si todos los elementos son distintos de cero o verdaderos +any(A) % Determina si alguno de los elementos es distinto de cero o verdadero +isequal(A, B) % Determina la igualdad de dos matrices +numel(A) % Cantidad de elementos en matriz +triu(x) % Devuelve la parte triangular superior de x +tril(x) % Devuelve la parte triangular inferior de x +cross(A,B) % Devuelve el producto cruzado de los vectores A y B +dot(A,B) % Devuelve un producto escalar de dos vectores (debe tener la misma longitud) +transpose(A) % Devuelve la transposición de A +fliplr(A) % Voltea la matriz de izquierda a derecha +flipud(A) % Voltea la matriz de arriba hacia abajo + +% Factorizaciones de matrices +[L, U, P] = lu(A) % Descomposición LU: PA = LU, L es triangular inferior, U es triangular superior, P es matriz de permutación +[P, D] = eig(A) % eigen-decomposition: AP = PD, las columnas de P son autovectores y las diagonales de D'son valores propios +[U,S,V] = svd(X) % SVD: XV = US, U y V son matrices unitarias, S tiene elementos diagonales no negativos en orden decreciente + +% Funciones comunes de vectores +max % componente más grande +min % componente más pequeño +length % longitud de un vector +sort % ordenar en orden ascendente +sum % suma de elementos +prod % producto de elementos +mode % valor modal +median % valor mediano +mean % valor medio +std % desviación estándar +perms(x) % enumera todas las permutaciones de elementos de x +find(x) % Encuentra todos los elementos distintos de cero de x y devuelve sus índices, puede usar operadores de comparación, + % i.e. find( x == 3 ) devuelve índices de elementos que son iguales a 3 + % i.e. find( x >= 3 ) devuelve índices de elementos mayores o iguales a 3 + + +% Clases +% Matlab puede soportar programación orientada a objetos. +% Las clases deben colocarse en un archivo del nombre de la clase con la extensión .m. +% Para comenzar, creamos una clase simple para almacenar puntos de referencia de GPS. +% Comience WaypointClass.m +classdef WaypointClass % El nombre de la clase. + properties % Las propiedades de la clase se comportan como Estructuras + latitude + longitude + end + methods + % Este método que tiene el mismo nombre de la clase es el constructor. + function obj = WaypointClass(lat, lon) + obj.latitude = lat; + obj.longitude = lon; + end + + % Otras funciones que usan el objeto Waypoint + function r = multiplyLatBy(obj, n) + r = n*[obj.latitude]; + end + + % Si queremos agregar dos objetos Waypoint juntos sin llamar + % a una función especial, podemos sobrecargar la aritmética de Matlab así: + function r = plus(o1,o2) + r = WaypointClass([o1.latitude] +[o2.latitude], ... + [o1.longitude]+[o2.longitude]); + end + end +end +% Fin WaypointClass.m + +% Podemos crear un objeto de la clase usando el constructor +a = WaypointClass(45.0, 45.0) + +% Las propiedades de clase se comportan exactamente como estructuras de Matlab. +a.latitude = 70.0 +a.longitude = 25.0 + +% Los métodos se pueden llamar de la misma manera que las funciones +ans = multiplyLatBy(a,3) + +% El método también se puede llamar usando notación de puntos. En este caso, el objeto +% no necesita ser pasado al método. +ans = a.multiplyLatBy(a,1/3) + +% Las funciones de Matlab pueden sobrecargarse para manejar objetos. +% En el método anterior, hemos sobrecargado cómo maneja Matlab +% la adición de dos objetos Waypoint. +b = WaypointClass(15.0, 32.0) +c = a + b + +``` + +## Más sobre Matlab + +* [The official website (EN)](http://www.mathworks.com/products/matlab/) +* [The official MATLAB Answers forum (EN)](http://www.mathworks.com/matlabcentral/answers/) +* [Loren on the Art of MATLAB (EN)](http://blogs.mathworks.com/loren/) +* [Cleve's Corner (EN)](http://blogs.mathworks.com/cleve/) + diff --git a/es-es/objective-c-es.html.markdown b/es-es/objective-c-es.html.markdown index bdbce524..26cd14d9 100644 --- a/es-es/objective-c-es.html.markdown +++ b/es-es/objective-c-es.html.markdown @@ -13,7 +13,7 @@ Objective C es el lenguaje de programación principal utilizado por Apple para l Es un lenguaje de programación para propósito general que le agrega al lenguaje de programación C una mensajería estilo "Smalltalk". -```objective_c +```objectivec // Los comentarios de una sola línea inician con // /* diff --git a/es-es/perl6-es.html.markdown b/es-es/perl6-es.html.markdown new file mode 100644 index 00000000..bf3ae65e --- /dev/null +++ b/es-es/perl6-es.html.markdown @@ -0,0 +1,1935 @@ +--- +name: perl6 +category: language +language: perl6 +filename: perl6-es.p6 +contributors: + - ["vendethiel", "http://github.com/vendethiel"] + - ["Samantha McVey", "https://cry.nu"] +translators: + - ["Luis F. Uceta", "https://github.com/uzluisf"] +lang: es-es +--- + +Perl 6 es un lenguaje de programación altamente capaz y con características +abundantes para hacerlo el lenguage ideal por los próximos 100 años. + +El compilador primario de Perl 6 se llama [Rakudo](http://rakudo.org), el cual +se ejecuta en JVM y en [MoarVM](http://moarvm.com). + +Meta-nota: dos signos de números (##) son usados para indicar párrafos, +mientras que un solo signo de número (#) indica notas. + +`#=>` representa la salida de un comando. + +```perl6 +# Un comentario de una sola línea comienza con un signo de número + +#`( + Comentarios multilíneas usan #` y signos de encerradura tales + como (), [], {}, 「」, etc. +) +``` + +## Variables + +```perl6 +## En Perl 6, se declara una variable lexical usando `my` +my $variable; +## Perl 6 tiene 3 tipos básicos de variables: escalares, arrays, y hashes. +``` + +### Escalares + +```perl6 +# Un escalar representa un solo valor. Variables escalares comienzan +# con un `$` + +my $str = 'Cadena'; +# Las comillas inglesas ("") permiten la intepolación (lo cual veremos +# luego): +my $str2 = "Cadena"; + +## Los nombres de variables pueden contener pero no terminar con comillas +## simples y guiones. Sin embargo, pueden contener +## (y terminar con) guiones bajos (_): +my $nombre'de-variable_ = 5; # Esto funciona! + +my $booleano = True; # `True` y `False` son valores booleanos en Perl 6. +my $inverso = !$booleano; # Puedes invertir un booleano con el operador prefijo `!` +my $bool-forzado = so $str; # Y puedes usar el operador prefijo `so` que + # convierte su operador en un Bool +``` + +### Arrays y Listas + +```perl6 +## Un array representa varios valores. Variables arrays comienzan con `@`. +## Las listas son similares pero son un tipo inmutable. + +my @array = 'a', 'b', 'c'; +# equivalente a: +my @letras = <a b c>; # array de palabras, delimitado por espacios. + # Similar al qw de perl5, o el %w de Ruby. +my @array = 1, 2, 3; + +say @array[2]; # Los índices de un array empiezan por el 0 -- Este es + # el tercer elemento. + +say "Interpola todos los elementos de un array usando [] : @array[]"; +#=> Interpola todos los elementos de un array usando [] : 1 2 3 + +@array[0] = -1; # Asigna un nuevo valor a un índice del array +@array[0, 1] = 5, 6; # Asigna varios valores + +my @llaves = 0, 2; +@array[@llaves] = @letras; # Asignación usando un array que contiene valores + # índices +say @array; #=> a 6 b +``` + +### Hashes, o Pairs (pares) de llaves-valores. + +```perl6 +## Un hash contiene parejas de llaves y valores. +## Puedes construir un objeto Pair usando la sintaxis `LLave => Valor`. +## Tablas de hashes son bien rápidas para búsqueda, y son almacenadas +## sin ningún orden. +## Ten en cuenta que las llaves son "aplanadas" en contexto de hash, y +## cualquier llave duplicada es deduplicada. +my %hash = 1 => 2, + 3 => 4; +my %hash = foo => "bar", # las llaves reciben sus comillas + # automáticamente. + "some other" => "value", # las comas colgantes estań bien. + ; + +## Aunque los hashes son almacenados internamente de forma diferente a los +## arrays, Perl 6 te permite crear un hash usando un array +## con un número par de elementos fácilmente. +my %hash = <llave1 valor1 llave2 valor2>; + +my %hash = llave1 => 'valor1', llave2 => 'valor2'; # ¡el mismo resultado! + +## También puedes usar la sintaxis "pareja con dos puntos": +## (especialmente útil para parámetros nombrados que verás más adelante) +my %hash = :w(1), # equivalente a `w => 1` + # esto es útil para el atajo `True`: + :truey, # equivalente a `:truey(True)`, o `truey => True` + # y para el `False`: + :!falsey, # equivalente a `:falsey(False)`, o `falsey => False` + ; + +say %hash{'llave1'}; # Puedes usar {} para obtener el valor de una llave +say %hash<llave2>; # Si es una cadena de texto, puedes actualmente usar <> + # (`{llave1}` no funciona, debido a que Perl 6 no tiene + # palabras desnudas (barewords en inglés)) +``` + +## Subrutinas + +```perl6 +## Subrutinas, o funciones como otros lenguajes las llaman, son +## creadas con la palabra clave `sub`. +sub di-hola { say "¡Hola, mundo!" } + +## Puedes proveer argumentos (tipados). Si especificado, +## el tipo será chequeado al tiempo de compilación si es posible. +## De lo contrario, al tiempo de ejecución. +sub di-hola-a(Str $nombre) { + say "¡Hola, $nombre!"; +} + +## Una subrutina devuelve el último valor evaluado del bloque. +sub devolver-valor { + 5; +} +say devolver-valor; # imprime 5 +sub devolver-vacio { +} +say devolver-vacio; # imprime Nil + +## Algunas estructuras de control producen un valor. Por ejemplo if: +sub devuelva-si { + if True { + "Truthy"; + } +} +say devuelva-si; # imprime Truthy + +## Otras no, como un bucle for: +sub return-for { + for 1, 2, 3 { } +} +say return-for; # imprime Nil + +## Una subrutina puede tener argumentos opcionales: +sub con-opcional($arg?) { # el signo "?" marca el argumento opcional + say "Podría returnar `(Any)` (valor de Perl parecido al 'null') si no me pasan + un argumento, o returnaré mi argumento"; + $arg; +} +con-opcional; # devuelve Any +con-opcional(); # devuelve Any +con-opcional(1); # devuelve 1 + +## También puedes proveer un argumento por defecto para +## cuando los argumentos no son proveídos: +sub hola-a($nombre = "Mundo") { + say "¡Hola, $nombre!"; +} +hola-a; #=> ¡Hola, Mundo! +hola-a(); #=> ¡Hola, Mundo! +hola-a('Tú'); #=> ¡Hola, Tú! + +## De igual manera, al usar la sintaxis parecida a la de los hashes +## (¡Hurra, sintaxis unificada!), puedes pasar argumentos *nombrados* +## a una subrutina. Ellos son opcionales, y por defecto son del tipo "Any". +sub con-nombre($arg-normal, :$nombrado) { + say $arg-normal + $nombrado; +} +con-nombre(1, nombrado => 6); #=> 7 +## Sin embargo, debes tener algo en cuenta aquí: +## Si pones comillas alrededor de tu llave, Perl 6 no será capaz de verla +## al tiempo de compilación, y entonces tendrás un solo objeto Pair como +## un argumento posicional, lo que significa que el siguiente ejemplo +## falla: +con-nombre(1, 'nombrado' => 6); + +con-nombre(2, :nombrado(5)); #=> 7 + +## Para hacer un argumento nombrado mandatorio, puedes utilizar el +## inverso de `?`, `!`: +sub con-nombre-mandatorio(:$str!) { + say "$str!"; +} +con-nombre-mandatorio(str => "Mi texto"); #=> Mi texto! +con-nombre-mandatorio; # error al tiempo de ejecución: + # "Required named parameter not passed" + # ("Parámetro nombrado requerido no proveído") +con-nombre-mandatorio(3);# error al tiempo de ejecución: + # "Too many positional parameters passed" + # ("Demasiados argumentos posicionales proveídos") + +## Si una subrutina toma un argumento booleano nombrado ... +sub toma-un-bool($nombre, :$bool) { + say "$nombre toma $bool"; +} +## ... puedes usar la misma sintaxis de hash de un "booleano corto": +takes-a-bool('config', :bool); # config toma True +takes-a-bool('config', :!bool); # config toma False + +## También puedes proveer tus argumentos nombrados con valores por defecto: +sub nombrado-definido(:$def = 5) { + say $def; +} +nombrado-definido; #=> 5 +nombrado-definido(def => 15); #=> 15 + +## Dado que puedes omitir los paréntesis para invocar una función sin +## argumentos, necesitas usar "&" en el nombre para almacenar la función +## `di-hola` en una variable. +my &s = &di-hola; +my &otra-s = sub { say "¡Función anónima!" } + +## Una subrutina puede tener un parámetro "slurpy", o "no importa cuantos", +## indicando que la función puede recibir cualquier número de parámetros. +sub muchos($principal, *@resto) { #`*@` (slurpy) consumirá lo restante +## Nota: Puedes tener parámetros *antes que* un parámetro "slurpy" (como +## aquí) pero no *después* de uno. + say @resto.join(' / ') ~ "!"; +} +say muchos('Feliz', 'Cumpleaño', 'Cumpleaño'); #=> Feliz / Cumpleaño! + # Nota que el asterisco (*) no + # consumió el parámetro frontal. + +## Puedes invocar un función con un array usando el +## operador "aplanador de lista de argumento" `|` +## (actualmente no es el único rol de este operador pero es uno de ellos) +sub concat3($a, $b, $c) { + say "$a, $b, $c"; +} +concat3(|@array); #=> a, b, c + # `@array` fue "aplanado" como parte de la lista de argumento +``` + +## Contenedores + +```perl6 +## En Perl 6, valores son actualmente almacenados en "contenedores". +## El operador de asignación le pregunta al contenedor en su izquierda +## almacenar el valor a su derecha. Cuando se pasan alrededor, contenedores +## son marcados como inmutables. Esto significa que, en una función, tu +## tendrás un error si tratas de mutar uno de tus argumentos. +## Si realmente necesitas hacerlo, puedes preguntar por un contenedor +## mutable usando `is rw`: +sub mutar($n is rw) { + $n++; + say "¡\$n es ahora $n!"; +} + +my $m = 42; +mutar $m; # ¡$n es ahora 43! + +## Esto funciona porque estamos pasando el contenedor $m para mutarlo. Si +## intentamos pasar un número en vez de pasar una variable, no funcionará +## dado que no contenedor ha sido pasado y números enteros son inmutables +## por naturaleza: + +mutar 42; # Parámetro '$n' esperaba un contenedor mutable, + # pero recibió un valor Int + +## Si en cambio quieres una copia, debes usar `is copy`. + +## Por si misma, una subrutina devuelve un contenedor, lo que significa +## que puede ser marcada con rw: +my $x = 42; +sub x-almacena() is rw { $x } +x-almacena() = 52; # En este caso, los paréntesis son mandatorios + # (porque de otra forma, Perl 6 piensa que la función + # `x-almacena` es un identificador). +say $x; #=> 52 +``` + +## Estructuras de control +### Condicionales + +```perl6 +## - `if` +## Antes de hablar acerca de `if`, necesitamos saber cuales valores son +## "Truthy" (representa True (verdadero)), y cuales son "Falsey" +## (o "Falsy") -- representa False (falso). Solo estos valores son +## Falsey: 0, (), {}, "", Nil, un tipo (como `Str` o`Int`) y +## por supuesto False. Todos los valores son Truthy. +if True { + say "¡Es verdadero!"; +} + +unless False { + say "¡No es falso!"; +} + +## Como puedes observar, no necesitas paréntesis alrededor de condiciones. +## Sin embargo, necesitas las llaves `{}` alrededor del cuerpo de un bloque: +# if (true) say; # !Esto no funciona! + +## También puedes usar sus versiones sufijos seguidas por la palabra clave: +say "Un poco verdadero" if True; + +## - La condicional ternaria, "?? !!" (como `x ? y : z` en otros lenguajes) +## devuelve $valor-si-verdadera si la condición es verdadera y +## $valor-si-falsa si es falsa. +## my $resultado = $valor condición ?? $valor-si-verdadera !! $valor-si-falsa; + +my $edad = 30; +say $edad > 18 ?? "Eres un adulto" !! "Eres menor de 18"; +``` + +### given/when, ó switch + +```perl6 +## - `given`-`when` se parece al `switch` de otros lenguajes, pero es más +## poderoso gracias a la coincidencia inteligente ("smart matching" en inglés) +## y la "variable tópica" $_ de Perl. +## +## Esta variable ($_) contiene los argumentos por defecto de un bloque, +## la iteración actual de un loop (a menos que sea explícitamente +## nombrado), etc. +## +## `given` simplemente pone su argumento en `$_` (como un bloque lo haría), +## y `when` lo compara usando el operador de "coincidencia inteligente" (`~~`). +## +## Dado que otras construcciones de Perl 6 usan esta variable (por ejemplo, +## el bucle `for`, bloques, etc), esto se significa que el poderoso `when` no +## solo se aplica con un `given`, sino que se puede usar en cualquier +## lugar donde exista una variable `$_`. + +given "foo bar" { + say $_; #=> foo bar + when /foo/ { # No te preocupies acerca de la coincidencia inteligente – + # solo ten presente que `when` la usa. + # Esto es equivalente a `if $_ ~~ /foo/`. + say "¡Yay!"; + } + when $_.chars > 50 { # coincidencia inteligente con cualquier cosa True es True, + # i.e. (`$a ~~ True`) + # por lo tanto puedes también poner condiciones "normales". + # Este `when` es equivalente a este `if`: + # if $_ ~~ ($_.chars > 50) {...} + # que significa: + # if $_.chars > 50 {...} + say "¡Una cadena de texto bien larga!"; + } + default { # lo mismo que `when *` (usando la Whatever Star) + say "Algo más"; + } +} +``` + +### Construcciones de bucle + +```perl6 +## - `loop` es un bucle infinito si no le pasas sus argumentos, +## pero también puede ser un bucle for al estilo de C: +loop { + say "¡Este es un bucle infinito!"; + last; # last interrumpe el bucle, como la palabra clave `break` + # en otros lenguajes. +} + +loop (my $i = 0; $i < 5; $i++) { + next if $i == 3; # `next` salta a la siguiente iteración, al igual + # que `continue` en otros lenguajes. Ten en cuenta que + # también puedes usar la condicionales postfix (sufijas) + # bucles, etc. + say "¡Este es un bucle al estilo de C!"; +} + +## - `for` - Hace iteraciones en un array +for @array -> $variable { + say "¡He conseguido una $variable!"; +} + +## Como vimos con `given`, la variable de una "iteración actual" por defecto +## es `$_`. Esto significa que puedes usar `when` en un bucle `for` como +## normalmente lo harías con `given`. +for @array { + say "he conseguido a $_"; + + .say; # Esto es también permitido. + # Una invocación con punto (dot call) sin "tópico" (recibidor) es + # enviada a `$_` por defecto. + $_.say; # lo mismo de arriba, lo cual es equivalente. +} + +for @array { + # Puedes... + next if $_ == 3; # Saltar a la siguiente iteración (`continue` en + # lenguages parecido a C) + redo if $_ == 4; # Re-hacer la iteración, manteniendo la + # misma variable tópica (`$_`) + last if $_ == 5; # Salir fuera del bucle (como `break` + # en lenguages parecido a C) +} + +## La sintaxis de "bloque puntiagudo" no es específica al bucle for. +## Es solo una manera de expresar un bloque en Perl 6. +if computación-larga() -> $resultado { + say "El resultado es $resultado"; +} +``` + +## Operadores + +```perl6 +## Dados que los lenguajes de la familia Perl son lenguages basados +## mayormente en operadores, los operadores de Perl 6 son actualmente +## subrutinas un poco cómicas en las categorías sintácticas. Por ejemplo, +## infix:<+> (adición) o prefix:<!> (bool not). + +## Las categorías son: +## - "prefix" (prefijo): anterior a (como `!` en `!True`). +## - "postfix" (sufijo): posterior a (como `++` en `$a++`). +## - "infix" (infijo): en medio de (como `*` en `4 * 3`). +## - "circumfix" (circunfijo): alrededor de (como `[`-`]` en `[1, 2]`). +## - "post-circumfix" (pos-circunfijo): alrededor de un término, +## posterior a otro término. +## (como `{`-`}` en `%hash{'key'}`) + +## La lista de asociatividad y precedencia se explica más abajo. + +## ¡Bueno, ya estás listo(a)! + +## * Chequeando igualdad + +## - `==` se usa en comparaciones numéricas. +3 == 4; # Falso +3 != 4; # Verdadero + +## - `eq` se usa en comparaciones de cadenas de texto. +'a' eq 'b'; +'a' ne 'b'; # no igual +'a' !eq 'b'; # lo mismo que lo anterior + +## - `eqv` es equivalencia canónica (or "igualdad profunda") +(1, 2) eqv (1, 3); + +## - Operador de coincidencia inteligente (smart matching): `~~` +## Asocia (aliasing en inglés) el lado izquierda a la variable $_ +## y después evalúa el lado derecho. +## Aquí algunas comparaciones semánticas comunes: + +## Igualdad de cadena de texto o numérica + +'Foo' ~~ 'Foo'; # True si las cadenas de texto son iguales. +12.5 ~~ 12.50; # True si los números son iguales. + +## Regex - Para la comparación de una expresión regular en contra +## del lado izquierdo. Devuelve un objeto (Match), el cual evalúa +## como True si el regex coincide con el patrón. + +my $obj = 'abc' ~~ /a/; +say $obj; # ｢a｣ +say $obj.WHAT; # (Match) + +## Hashes +'llave' ~~ %hash; # True si la llave existe en el hash + +## Tipo - Chequea si el lado izquierdo "tiene un tipo" (puede chequear +## superclases y roles) + +1 ~~ Int; # True (1 es un número entero) + +## Coincidencia inteligente contra un booleano siempre devuelve ese +## booleano (y lanzará una advertencia). + +1 ~~ True; # True +False ~~ True; # True + +## La sintaxis general es $arg ~~ &función-returnando-bool; +## Para una lista completa de combinaciones, usa esta tabla: +## http://perlcabal.org/syn/S03.html#Smart_matching + +## También, por supuesto, tienes `<`, `<=`, `>`, `>=`. +## Sus equivalentes para cadenas de texto están disponibles: +## `lt`, `le`, `gt`, `ge`. +3 > 4; + +## * Constructores de rango +3 .. 7; # 3 a 7, ambos incluidos +## `^` en cualquier lado excluye a ese lado: +3 ^..^ 7; # 3 a 7, no incluidos (básicamente `4 .. 6`) +## Esto también funciona como un atajo para `0..^N`: +^10; # significa 0..^10 + +## Esto también nos permite demostrar que Perl 6 tiene arrays +## ociosos/infinitos, usando la Whatever Star: +my @array = 1..*; # 1 al Infinito! `1..Inf` es lo mismo. +say @array[^10]; # puedes pasar arrays como subíndices y devolverá + # un array de resultados. Esto imprimirá + # "1 2 3 4 5 6 7 8 9 10" (y no se quedaré sin memoria!) +## Nota: Al leer una lista infinita, Perl 6 "cosificará" los elementos que +## necesita y los mantendrá en la memoria. Ellos no serán calculados más de +## una vez. Tampoco calculará más elementos de los que necesita. + +## Un índice de array también puede ser una clausura ("closure" en inglés). +## Será llamada con la longitud como el argumento +say join(' ', @array[15..*]); #=> 15 16 17 18 19 +## lo que es equivalente a: +say join(' ', @array[-> $n { 15..$n }]); +## Nota: Si tratas de hacer cualquiera de esos con un array infinito, +## provocará un array infinito (tu programa nunca terminará) + +## Puedes usar eso en los lugares que esperaría, como durante la asignación +## a un array +my @números = ^20; + +## Aquí los números son incrementados por "6"; más acerca del +## operador `...` adelante. +my @seq = 3, 9 ... * > 95; # 3 9 15 21 27 [...] 81 87 93 99; +@números[5..*] = 3, 9 ... *; # aunque la secuencia es infinita, + # solo los 15 números necesarios será calculados. +say @números; #=> 0 1 2 3 4 3 9 15 21 [...] 81 87 + # (solamente 20 valores) + +## * And &&, Or || +3 && 4; # 4, el cual es Truthy. Invoca `.Bool` en `4` y obtiene `True`. +0 || False; # False. Invoca `.Bool` en `0` + +## * Versiones circuito corto de lo de arriba +## && Devuelve el primer argumento que evalúa a False, o el último. + +my ( $a, $b, $c ) = 1, 0, 2; +$a && $b && $c; # Devuelve 0, el primer valor que es False + +## || Devuelve el primer argumento que evalúa a True. +$b || $a; # 1 + +## Y porque tu lo querrás, también tienes operadores de asignación +## compuestos: +$a *= 2; # multiplica y asigna. Equivalente a $a = $a * 2; +$b %%= 5; # divisible por y asignación. Equivalente $b = $b %% 5; +@array .= sort; # invoca el método `sort` y asigna el resultado devuelto. +``` + +## ¡Más sobre subrutinas! + +```perl6 +## Como dijimos anteriormente, Perl 6 tiene subrutinas realmente poderosas. +## Veremos unos conceptos claves que la hacen mejores que en cualquier otro +## lenguaje :-). +``` + +### !Desempacado! + +```perl6 +## Es la abilidad de extraer arrays y llaves (También conocido como +## "destructuring"). También funcionará en `my` y en las listas de parámetros. +my ($f, $g) = 1, 2; +say $f; #=> 1 +my ($, $, $h) = 1, 2, 3; # mantiene los anónimos no interesante +say $h; #=> 3 + +my ($cabeza, *@cola) = 1, 2, 3; # Sí, es lo mismo que con subrutinas "slurpy" +my (*@small) = 1; + +sub desempacar_array(@array [$fst, $snd]) { + say "Mi primero es $fst, mi segundo es $snd! De todo en todo, soy un @array[]."; + # (^ recuerda que `[]` interpola el array) +} +desempacar_array(@cola); #=> My first is 2, my second is 3 ! All in all, I'm 2 3 + + +## Si no está usando el array, puedes también mantenerlo anónimo, como un +## escalar: +sub primero-de-array(@ [$fst]) { $fst } +primero-de-array(@small); #=> 1 +primero-de-array(@tail); # Lanza un error "Demasiados argumentos posicionales + # proveídos" + # (lo que significa que el array es muy grande). + +## También puedes usar un slurp ... +sub slurp-en-array(@ [$fst, *@rest]) { # Podrías mantener `*@rest` anónimos + say $fst + @rest.elems; # `.elems` returna la longitud de una lista. + # Aquí, `@rest` es `(3,)`, since `$fst` holds the `2`. +} +slurp-en-array(@tail); #=> 3 + +## Hasta podrías hacer un extracción usando una slurpy (pero no sería útil ;-).) +sub fst(*@ [$fst]) { # o simplemente: `sub fst($fst) { ... }` + say $fst; +} +fst(1); #=> 1 +fst(1, 2); # errores con "Too many positional parameters passed" + +## También puedes desestructurar hashes (y clases, las cuales +## veremos adelante). La sintaxis es básicamente +## `%nombre-del-hash (:llave($variable-para-almacenar))`. +## El hash puede permanecer anónimos si solo necesitas los valores extraídos. +sub llave-de(% (:azul($val1), :red($val2))) { + say "Valores: $val1, $val2."; +} +## Después invócala con un hash: (necesitas mantener las llaves +## de los parejas de llave y valor para ser un hash) +llave-de({azul => 'blue', rojo => "red"}); +#llave-de(%hash); # lo mismo (para un `%hash` equivalente) + +## La última expresión de una subrutina es devuelta inmediatamente +## (aunque puedes usar la palabra clave `return`): +sub siguiente-indice($n) { + $n + 1; +} +my $nuevo-n= siguiente-indice(3); # $nuevo-n es ahora 4 + +## Este es cierto para todo, excepto para las construcciones de bucles +## (debido a razones de rendimiento): Hay una razón de construir una lista +## si la vamos a desechar todos los resultados. +## Si todavías quieres construir una, puedes usar la sentencia prefijo `do`: +## (o el prefijo `gather`, el cual veremos luego) +sub lista-de($n) { + do for ^$n { # nota el uso del operador de rango `^` (`0..^N`) + $_ # iteración de bucle actual + } +} +my @list3 = lista-de(3); #=> (0, 1, 2) +``` + +### lambdas + +```perl6 +## Puedes crear una lambda con `-> {}` ("bloque puntiagudo") o `{}` ("bloque") +my &lambda = -> $argumento { "El argumento pasado a esta lambda es $argumento" } +## `-> {}` y `{}` son casi la misma cosa, excepto que la primerra puede +## tomar argumentos, y la segunda puede ser malinterpretada como un hash +## por el parseador. + +## Podemos, por ejemplo, agregar 3 a cada valor de un array usando map: +my @arraymas3 = map({ $_ + 3 }, @array); # $_ es el argumento implícito + +## Una subrutina (`sub {}`) tiene semánticas diferentes a un +## bloque (`{}` or `-> {}`): Un bloque no tiene "contexto funcional" +## (aunque puede tener argumentos), lo que significa que si quieres devolver +## algo desde un bloque, vas a returnar desde la función parental. Compara: +sub is-in(@array, $elem) { + # esto `devolverá` desde la subrutina `is-in` + # Una vez que la condición evalúa a True, el bucle terminará + map({ return True if $_ == $elem }, @array); +} +sub truthy-array(@array) { + # esto producirá un array de `True` Y `False`: + # (también puedes decir `anon sub` para "subrutina anónima") + map(sub ($i) { if $i { return True } else { return False } }, @array); + # ^ el `return` solo devuelve desde la `sub` +} + +## También puedes usar la "whatever star" para crear una función anónima +## (terminará con el último operador en la expresión actual) +my @arraymas3 = map(*+3, @array); # `*+3` es lo mismo que `{ $_ + 3 }` +my @arraymas3 = map(*+*+3, @array); # lo mismo que `-> $a, $b { $a + $b + 3 }` + # también `sub ($a, $b) { $a + $b + 3 }` +say (*/2)(4); #=> 2 + # Inmediatamente ejecuta la función que Whatever creó. +say ((*+3)/5)(5); #=> 1.6 + # ¡funciona hasta con los paréntesis! + +## Pero si necesitas más que un argumento (`$_`) en un bloque +## (sin depender en `-> {}`), también puedes usar la sintaxis implícita +## de argumento, `$` : +map({ $^a + $^b + 3 }, @array); # equivalente a lo siguiente: +map(sub ($a, $b) { $a + $b + 3 }, @array); # (aquí con `sub`) + +## Nota : Esos son ordernados lexicográficamente. +# `{ $^b / $^a }` es como `-> $a, $b { $b / $a }` +``` + +### Acerca de tipos... + +```perl6 +## Perl 6 es gradualmente tipado. Esto quiere decir que tu especifica el +## tipo de tus variables/argumentos/devoluciones (return), o puedes omitirlos +## y serán "Any" por defecto. +## Obviamente tienes acceso a algunas tipos básicos, como Int y Str. +## Las construcciones para declarar tipos son "class", "role", lo cual +## verás más adelante. + +## Por ahora, examinemos "subset" (subconjunto). +## Un "subset" es un "sub-tipo" con chequeos adicionales. +## Por ejemplo: "un número entero bien grande es un Int que es mayor que 500" +## Puedes especificar el tipo del que creas el subconjunto (por defecto, Any), +## y añadir chequeos adicionales con la palabra clave "where" (donde): +subset EnteroGrande of Int where * > 500; +``` + +### Despacho Múltiple (Multiple Dispatch) + +```perl6 +## Perl 6 puede decidir que variante de una subrutina invocar basado en el +## tipo de los argumento, o precondiciones arbitrarias, como con un tipo o +## un `where`: + +## con tipos +multi sub dilo(Int $n) { # nota la palabra clave `multi` aquí + say "Número: $n"; +} +multi dilo(Str $s) { # un multi es una subrutina por defecto + say "Cadena de texto: $s"; +} +dilo("azul"); # prints "Cadena de texto: azul" +dilo(True); # falla al *tiempo de compilación* con + # "calling 'dilo' will never work with arguments of types ..." + # (invocar 'dilo' nunca funcionará con argumentos de tipos ...") +## con precondición arbitraria (¿recuerdas los subconjuntos?): +multi es-grande(Int $n where * > 50) { "¡Sí!" } # usando una clausura +multi es-grande(Int $ where 10..50) { "Tal vez." } # Usando coincidencia inteligente + # (podrías usar un regexp, etc) +multi es-grande(Int $) { "No" } + +subset Par of Int where * %% 2; + +multi inpar-o-par(Par) { "Par" } # El caso principal usando el tipo. + # No nombramos los argumentos, +multi inpar-o-par($) { "Inpar" } # "else" + +## ¡Podrías despachar basado en la presencia de argumentos posicionales! +multi sin_ti-o-contigo(:$with!) { # Necesitas hacerlo mandatorio + # para despachar en contra del argumento. + say "¡Puedo vivir! Actualmente, no puedo."; +} +multi sin_ti-o-contigo { + say "Definitivamente no puedo vivir."; +} +## Esto es muy útil para muchos propósitos, como subrutinas `MAIN` (de las +## cuales hablaremos luego), y hasta el mismo lenguaje la está usando +## en muchos lugares. +## +## - `is`, por ejemplo, es actualmente un `multi sub` llamado +## `trait_mod:<is>`. +## - `is rw`, es simplemente un despacho a una función con esta signatura: +## sub trait_mod:<is>(Routine $r, :$rw!) {} +## +## (¡lo pusimos en un comentario dado que ejecutando esto sería una terrible +## idea!) +``` + +## Ámbito (Scoping) + +```perl6 +## En Perl 6, a diferencia de otros lenguajes de scripting, (tales como +## (Python, Ruby, PHP), debes declarar tus variables antes de usarlas. El +## declarador `my`, del cual aprendiste anteriormente, usa "ámbito léxical". +## Hay otros declaradores (`our`, `state`, ..., ) los cuales veremos luego. +## Esto se llama "ámbito léxico", donde en los bloques internos, +## puedes acceder variables de los bloques externos. +my $archivo-en-ámbito = 'Foo'; +sub externo { + my $ámbito-externo = 'Bar'; + sub interno { + say "$archivo-en-ámbito $ámbito-externo"; + } + &interno; # devuelve la función +} +outer()(); #=> 'Foo Bar' + +## Como puedes ver, `$archivo-en-ámbito` y `$ámbito-externo` +## fueron capturados. Pero si intentaramos usar `$bar` fuera de `foo`, +## la variable estaría indefinida (y obtendrías un error al tiempo de +## compilación). +``` + +## Twigils + +```perl6 +## Hay muchos `twigils` especiales (sigilos compuestos) en Perl 6. +## Los twigils definen el ámbito de las variables. +## Los twigils * y ? funcionan con variables regulares: +## * Variable dinámica +## ? Variable al tiempo de compilación +## Los twigils ! y . son usados con los objetos de Perl 6: +## ! Atributo (miembro de la clase) +## . Método (no una variable realmente) + +## El twigil `*`: Ámbito dinámico +## Estas variables usan el twigil `*` para marcar variables con ámbito +## dinámico. Variables con ámbito dinámico son buscadas a través del +## invocador, no a través del ámbito externo. + +my $*ambito_din_1 = 1; +my $*ambito_din_2 = 10; + +sub di_ambito { + say "$*ambito_din_1 $*ambito_din_2"; +} + +sub invoca_a_di_ambito { + my $*ambito_din_1 = 25; # Define a $*ambito_din_1 solo en esta subrutina. + $*ambito_din_2 = 100; # Cambiará el valor de la variable en ámbito. + di_ambito(); #=> 25 100 $*ambito_din_1 y 2 serán buscadas en la invocación. + # Se usa el valor de $*ambito_din_1 desde el ámbito léxico de esta + # subrutina aunque los bloques no están anidados (están anidados por + # invocación). +} +di_ambito(); #=> 1 10 +invoca_a_di_ambito(); #=> 25 100 + # Se usa a $*ambito_din_1 como fue definida en invoca_a_di_ambito + # aunque la estamos invocando desde afuera. +di_ambito(); #=> 1 100 Cambiamos el valor de $*ambito_din_2 en invoca_a_di_ambito + # por lo tanto su valor a cambiado. +``` + +## Modelo de Objeto + +```perl6 +## Para invocar a un método en un objeto, agrega un punto seguido por el +## nombre del objeto: +## => $object.method +## Las classes son declaradas usando la palabra clave `class`. Los atributos +## son declarados con la palabra clave `has`, y los métodos con `method`. +## Cada atributo que es privado usa el twigil `!`. Por ejemplo: `$!attr`. +## Atributos públicos inmutables usan el twigil `.` (los puedes hacer +## mutables con `is rw`). +## La manera más fácil de recordar el twigil `$.` is comparándolo +## con como los métodos son llamados. + +## El modelo de objeto de Perl 6 ("SixModel") es muy flexible, y te permite +## agregar métodos dinámicamente, cambiar la semántica, etc ... +## (no hablaremos de todo esto aquí. Por lo tanto, refiérete a: +## https://docs.perl6.org/language/objects.html). + +class Clase-Atrib { + has $.atrib; # `$.atrib` es inmutable. + # Desde dentro de la clase, usa `$!atrib` para modificarlo. + has $.otro-atrib is rw; # Puedes marcar un atributo como público con `rw`. + has Int $!atrib-privado = 10; + + method devolver-valor { + $.atrib + $!atrib-privado; + } + + method asignar-valor($param) { # Métodos pueden tomar parámetros. + $!attrib = $param; # Esto funciona porque `$!` es siempre mutable. + # $.attrib = $param; # Incorrecto: No puedes usar la versión inmutable `$.`. + + $.otro-atrib = 5; # Esto funciona porque `$.otro-atrib` es `rw`. + } + + method !metodo-privado { + say "Este método es privado para la clase !"; + } +}; + +## Crear una nueva instancia de Clase-Atrib con $.atrib asignado con 5: +## Nota: No puedes asignarle un valor a atrib-privado desde aquí (más de +## esto adelante). +my $class-obj = Clase-Atrib.new(atrib => 5); +say $class-obj.devolver-valor; #=> 5 +# $class-obj.atrib = 5; # Esto falla porque `has $.atrib` es inmutable +$class-obj.otro-atrib = 10; # En cambio, esto funciona porque el atributo + # público es mutable (`rw`). +``` + +### Herencia de Objeto + +```perl6 +## Perl 6 también tiene herencia (junto a herencia múltiple) +## Mientras los métodos declarados con `method` son heredados, aquellos +## declarados con `submethod` no lo son. +## Submétodos son útiles para la construcción y destrucción de tareas, +## tales como BUILD, o métodos que deben ser anulados por subtipos. +## Aprenderemos acerca de BUILD más adelante. + +class Padre { + has $.edad; + has $.nombre; + # Este submétodo no será heredado por la clase Niño. + submethod color-favorito { + say "Mi color favorito es Azul"; + } + # Este método será heredado + method hablar { say "Hola, mi nombre es $!nombre" } +} +# Herencia usa la palabra clave `is` +class Niño is Padre { + method hablar { say "Goo goo ga ga" } + # Este método opaca el método `hablar` de Padre. + # Este niño no ha aprendido a hablar todavía. +} +my Padre $Richard .= new(edad => 40, nombre => 'Richard'); +$Richard.color-favorito; #=> "Mi color favorito es Azul" +$Richard.hablar; #=> "Hola, mi nombre es Richard" +## $Richard es capaz de acceder el submétodo; él sabe como decir su nombre. + +my Niño $Madison .= new(edad => 1, nombre => 'Madison'); +$Madison.hablar; # imprime "Goo goo ga ga" dado que el método fue cambiado + # en la clase Niño. +# $Madison.color-favorito # no funciona porque no es heredado + +## Cuando se usa `my T $var` (donde `T` es el nombre de la clase), `$var` +## inicia con `T` en si misma, por lo tanto puedes invocar `new` en `$var`. +## (`.=` es sólo la invocación por punto y el operador de asignación: +## `$a .= b` es lo mismo que `$a = $a.b`) +## Por ejemplo, la instancia $Richard pudo también haber sido declarada así: +## my $Richard = Padre.new(edad => 40, nombre => 'Richard'); + +## También observa que `BUILD` (el método invocado dentro de `new`) +## asignará propiedades de la clase padre, por lo que puedes pasar +## `val => 5`. +``` + +### Roles, o Mixins + +```perl6 +## Roles son suportados también (comúnmente llamados Mixins en otros +## lenguajes) +role PrintableVal { + has $!counter = 0; + method print { + say $.val; + } +} + +## Se "importa" un mixin (un "role") con "does": +class Item does PrintableVal { + has $.val; + + ## Cuando se utiliza `does`, un `rol` se mezcla en al clase literalmente: + ## los métodos y atributos se ponen juntos, lo que significa que una clase + ## puede acceder los métodos y atributos privados de su rol (pero no lo inverso!): + method access { + say $!counter++; + } + + ## Sin embargo, esto: + ## method print {} + ## es SÓLO válido cuando `print` no es una `multi` con el mismo dispacho. + ## (esto significa que una clase padre puede opacar una `multi print() {}` + ## de su clase hijo/a, pero es un error sin un rol lo hace) + + ## NOTA: Puedes usar un rol como una clase (con `is ROLE`). En este caso, + ## métodos serán opacados, dado que el compilador considerará `ROLE` + ## como una clase. +} +``` + +## Excepciones + +```perl6 +## Excepciones están construidas al tope de las clases, en el paquete +## `X` (como `X::IO`). +## En Perl 6, excepciones son lanzadas automáticamente. +open 'foo'; #=> Failed to open file foo: no such file or directory +## También imprimirá la línea donde el error fue lanzado y otra información +## concerniente al error. + +## Puedes lanzar una excepción usando `die`: +die 'Error!'; #=> Error! + +## O más explícitamente: +die X::AdHoc.new(payload => 'Error!'); + +## En Perl 6, `orelse` es similar al operador `or`, excepto que solamente +## coincide con variables indefinidas, en cambio de cualquier cosa +## que evalúa a falso. +## Valores indefinidos incluyen: `Nil`, `Mu` y `Failure`, también como +## `Int`, `Str` y otros tipos que no han sido inicializados a ningún valor +## todavía. +## Puedes chequear si algo está definido o no usando el método defined: +my $no-inicializada; +say $no-inicializada.defined; #=> False +## Al usar `orelse`, se desarmará la excepción y creará un alias de dicho +## fallo en $_ +## Esto evitará que sea automáticamente manejado e imprima una marejada de +## mensajes de errores en la pantalla. +## Podemos usar el método de excepción en $_ para acceder la excepción: +open 'foo' orelse say "Algo pasó {.exception}"; + +## Esto también funciona: +open 'foo' orelse say "Algo pasó $_"; #=> Algo pasó + #=> Failed to open file foo: no such file or directory +## Ambos ejemplos anteriores funcionan pero en caso de que consigamos un +## objeto desde el lado izquierdo que no es un fallo, probablemente +## obtendremos una advertencia. Más abajo vemos como usar `try` y `CATCH` +## para ser más expecíficos con las excepciones que capturamos. +``` + +### Usando `try` y `CATCH` + +```perl6 +## Al usar `try` y `CATCH`, puedes contener y manejar excepciones sin +## interrumpir el resto del programa. `try` asignará la última excepción +## a la variable especial `$!`. +## Nota: Esto no tiene ninguna relación con las variables $!. + +try open 'foo'; +say "Bueno, lo intenté! $!" if defined $!; #=> Bueno, lo intenté! Failed to open file + #foo: no such file or directory +## Ahora, ¿qué debemos hacer si queremos más control sobre la excepción? +## A diferencia de otros lenguajes, en Perl 6 se pone el bloque `CATCH` +## *dentro* del bloque a intentar (`try`). Similarmente como $_ fue asignada +## cuando 'disarmamos' la excepción con `orelse`, también usamos $_ en el +## bloque CATCH. +## Nota: ($! es solo asignada *después* del bloque `try`) +## Por defecto, un bloque `try` tiene un bloque `CATCH` que captura +## cualquier excepción (`CATCH { default {} }`). + +try { my $a = (0 %% 0); CATCH { say "Algo pasó: $_" } } + #=> Algo pasó: Attempt to divide by zero using infix:<%%> + +## Puedes redefinir lo anterior usando `when` y (`default`) +## para manejar las excepciones que desees: +try { + open 'foo'; + CATCH { # En el bloque `CATCH`, la excepción es asignada a $_ + when X::AdHoc { say "Error: $_" } + #=>Error: Failed to open file /dir/foo: no such file or directory + + ## Cualquier otra excepción será levantada de nuevo, dado que no + ## tenemos un `default`. + ## Básicamente, si un `when` + ## Basically, if a `when` matches (or there's a `default`) marks the + ## exception as + ## "handled" so that it doesn't get re-thrown from the `CATCH`. + ## You still can re-throw the exception (see below) by hand. + } +} + +## En Perl 6, excepciones poseen ciertas sutilezas. Algunas +## subrutinas en Perl 6 devuelven un `Failure`, el cual es un tipo de +## "excepción no levantada". Ellas no son levantadas hasta que tu intentas +## mirar a sus contenidos, a menos que invoques `.Bool`/`.defined` sobre +## ellas - entonces, son manejadas. +## (el método `.handled` es `rw`, por lo que puedes marcarlo como `False` +## por ti mismo) +## Puedes levantar un `Failure` usando `fail`. Nota que si el pragma +## `use fatal` estás siendo utilizado, `fail` levantará una excepión (como +## `die`). +fail "foo"; # No estamos intentando acceder el valor, por lo tanto no problema. +try { + fail "foo"; + CATCH { + default { say "Levantó un error porque intentamos acceder el valor del fallo!" } + } +} + +## También hay otro tipo de excepción: Excepciones de control. +## Esas son excepciones "buenas", las cuales suceden cuando cambias el flujo +## de tu programa, usando operadores como `return`, `next` or `last`. +## Puedes capturarlas con `CONTROL` (no lista un 100% en Rakudo todavía). +``` + +## Paquetes + +```perl6 +## Paquetes son una manera de reusar código. Paquetes son como +## "espacio de nombres" (namespaces en inglés), y cualquier elemento del +## modelo seis (`module`, `role`, `class`, `grammar`, `subset` y `enum`) +## son paquetes por ellos mismos. (Los paquetes son como el mínimo común +## denominador) +## Los paquetes son importantes - especialmente dado que Perl es bien +## reconocido por CPAN, the Comprehensive Perl Archive Nertwork. + +## Puedes usar un módulo (traer sus declaraciones al ámbito) con `use` +use JSON::Tiny; # si intalaste Rakudo* o Panda, tendrás este módulo +say from-json('[1]').perl; #=> [1] + +## A diferencia de Perl 5, no deberías declarar paquetes usando +## la palabra clave `package`. En vez, usa `class Nombre::Paquete::Aquí;` +## para declarar una clase, o si solamente quieres exportar +## variables/subrutinas, puedes usar `module`. + +module Hello::World { # forma de llaves + # Si `Hello` no existe todavía, solamente será una cola ("stub"), + # que puede ser redeclarada más tarde. + # ... declaraciones aquí ... +} +unit module Parse::Text; # forma de ámbito de archivo + +grammar Parse::Text::Grammar { # Una gramática (grammar en inglés) es un paquete, + # en el cual puedes usar `use` +} # Aprenderás más acerca de gramáticas en la sección de regex + +## Como se dijo anteriormente, cualquier parte del modelo seis es también un +## paquete. Dado que `JSON::Tiny` usa su propia clase `JSON::Tiny::Actions`, +## tu puedes usarla de la manera siguiente: +my $acciones = JSON::Tiny::Actions.new; + +## Veremos como exportar variables y subrutinas en la siguiente parte: +``` + +## Declaradores + +```perl6 +## En Perl 6, tu obtienes diferentes comportamientos basado en como declaras +## una variable. +## Ya has visto `my` y `has`, ahora exploraremos el resto. + +## * las declaraciones `our` ocurren al tiempo `INIT` (ve "Phasers" más abajo) +## Es como `my`, pero también crea una variable paquete. +## (Todas las cosas relacionadas con paquetes (`class`, `role`, etc) son +## `our` por defecto) +module Var::Incrementar { + our $nuestra-var = 1; # Nota: No puedes colocar una restricción de tipo + my $mi-var = 22; # como Int (por ejemplo) en una variable `our`. + our sub Inc { + + our sub disponible { # Si tratas de hacer subrutinas internas `our`... + # Mejor que sepas lo que haces (No lo haga!). + say "No hagas eso. En serio. Estás jugando con fuego y te quemarás."; + } + + my sub no-disponible { # `my sub` es por defecto + say "No puedes acceder aquí desde fuera. Soy 'my'!"; + } + say ++$nuestra-var; # Incrementa la variable paquete y muestra su valor + } + +} +say $Var::Incrementar::nuestra-var; #=> 1 Esto funciona +say $Var::Incrementar::mi-var; #=> (Any) Esto no funcionará. + +Var::Incrementar::Inc; #=> 2 +Var::Incrementar::Inc; #=> 3 # Nota como el valor de $nuestra-var fue + # retenido +Var::Incrementar::no-disponible; #=> Could not find symbol '&no-disponible' + +## * `constant` (ocurre al tiempo `BEGIN`) +## Puedes usar la palabra clave `constant` para declarar una +## variable/símbolo al tiempo de compilación: +constant Pi = 3.14; +constant $var = 1; + +## Y por si te estás preguntando, sí, también puede contener listas infinitas. +constant porque-no = 5, 15 ... *; +say porque-no[^5]; #=> 5 15 25 35 45 + +## * `state` (ocurre al tiempo de ejecución, pero una sola vez) +## Variables "states" son solo inicializadas una vez. +## (ellas existen en otros lenguaje como `static` en C) +sub aleatorio-fijo { + state $valor = rand; + say $valor; +} +aleatorio-fijo for ^10; # imprimirá el mismo número 10 veces + +## Nota, sin embargo, que ellas existen separadamente en diferentes contextos. +## Si declaras una función con un `state` dentro de un bucle, recreará la +## variable por cada iteración del bucle. Observa: +for ^5 -> $a { + sub foo { + state $valor = rand; # Esto imprimirá un valor diferente + # por cada valor de `$a` + } + for ^5 -> $b { + say foo; # Esto imprimirá el mismo valor 5 veces, pero sólo 5. + # La siguiente iteración ejecutará `rand` nuevamente. + } +} +``` + +## Phasers + +```perl6 +## Un phaser en Perl 6 es un bloque que ocurre a determinados puntos de tiempo +## en tu programa. Se les llama phaser porque marca un cambio en la fase de +## de tu programa. Por ejemplo, cuando el programa es compilado, un bucle +## for se ejecuta, dejas un bloque, o una excepción se levanta. +## (¡`CATCH` es actualmente un phaser!) +## Algunos de ellos pueden ser utilizados por sus valores devueltos, otros +## no pueden (aquellos que tiene un "[*]" al inicio de su texto de +## explicación). +## ¡Tomemos una mirada! + +## * Phasers al tiempo de compilación +BEGIN { say "[*] Se ejecuta al tiempo de compilación, " ~ + "tan pronto como sea posible, una sola vez" } +CHECK { say "[*] Se ejecuta al tiempo de compilación, " ~ + "tan tarde como sea posible, una sola vez" } + +## * Phasers al tiempo de ejecución +INIT { say "[*] Se ejecuta al tiempo de ejecución, " ~ + "tan pronto como sea posible, una sola vez" } +END { say "Se ejecuta al tiempo de ejecución, " ~ + "tan tarde como sea posible, una sola vez" } + +## * Phasers de bloques +ENTER { say "[*] Se ejecuta cada vez que entra en un bloque, " ~ + "se repite en bloques de bucle" } +LEAVE { say "Se ejecuta cada vez que abandona un bloque, incluyendo " ~ + "cuando una excepción ocurre. Se repite en bloques de bucle"} + +PRE { + say "Impone una precondición a cada entrada de un bloque, " ~ + "antes que ENTER (especialmente útil para bucles)"; + say "Si este bloque no returna un valor truthy, " ~ + "una excepción del tipo X::Phaser::PrePost será levantada."; +} + +## Ejemplos: +for 0..2 { + PRE { $_ > 1 } # Esto fallará con un "Precondition failed" +} + +POST { + say "Impone una postcondAsserts a poscondición a la salida de un bloque, " ~ + "después de LEAVE (especialmente útil para bucles)"; + say "Si este bloque no returna un valor truthy, " ~ + "una excepción del tipo X::Phaser::PrePost será levantada, como con PRE."; +} +for 0..2 { + POST { $_ < 2 } # Esto fallará con un "Postcondition failed" +} + +## * Phasers de bloques/excepciones +sub { + KEEP { say "Se ejecuta cuando sales de un bloque exitosamente + (sin lanzar un excepción)" } + UNDO { say "Se ejecuta cuando sale de bloque sin éxito + (al lanzar una excepción)" } +} + +## * Phasers de bucle +for ^5 { + FIRST { say "[*] La primera vez que un bucle se ejecuta, antes que ENTER" } + NEXT { say "Al tiempo de la continuación del bucle, antes que LEAVE" } + LAST { say "Al tiempo de la terminación del bucle, después de LEAVE" } +} + +## * Phasers de rol/clase +COMPOSE { "Cuando un rol es compuesto en una clase. /!\ NO IMPLEMENTADO TODAVÍA" } + +## Ellos permite pequeños trucos o código brillante...: +say "Este código tomó " ~ (time - CHECK time) ~ "s para compilar"; + +## ... o brillante organización: +sub do-db-stuff { + $db.start-transaction; # comienza una transacción nueva + KEEP $db.commit; # commit (procede con) la transacción si todo estuvo bien + UNDO $db.rollback; # o retrocede si todo falló +} +``` + +## Prefijos de sentencias + +```perl6 +## Los prefijos de sentencias actúan como los phasers: Ellos afectan el +## comportamiento del siguiente código. +## Debido a que son ejecutados en línea con el código ejecutable, ellos +## se escriben en letras minúsculas. (`try` and `start` están teoréticamente +## en esa lista, pero serán explicados en otra parte) +## Nota: Ningunos de estos (excepto `start`) necesitan las llaves `{` y `}`. + +## - `do` (el cual ya viste) - ejecuta un bloque o una sentencia como un +## término. +## Normalmente no puedes usar una sentencia como un valor (o término): +## +## my $valor = if True { 1 } # `if` es una sentencia - error del parseador +## +## Esto funciona: +my $a = do if True { 5 } # con `do`, `if` ahora se comporta como un término. + +## - `once` - se asegura que una porción de código se ejecute una sola vez. +for ^5 { once say 1 }; #=> 1 + # solo imprime ... una sola vez. +## Al igual que `state`, ellos son clonados por ámbito +for ^5 { sub { once say 1 }() } #=> 1 1 1 1 1 + # Imprime una sola vez por ámbito léxico + +## - `gather` - Hilo de co-rutina +## `gather` te permite tomar (`take`) varios valores en un array, +## al igual que `do`. Encima de esto, te permite tomar cualquier expresión. +say gather for ^5 { + take $_ * 3 - 1; + take $_ * 3 + 1; +} #=> -1 1 2 4 5 7 8 10 11 13 +say join ',', gather if False { + take 1; + take 2; + take 3; +} # no imprime nada. + +## - `eager` - Evalúa una sentencia ávidamente (forza contexto ávido) +## No intentes esto en casa: +## +## eager 1..*; # esto probablemente se colgará por un momento +## # (y podría fallar...). +## +## Pero considera lo siguiente: +constant tres-veces = gather for ^3 { say take $_ }; # No imprime nada + +## frente a esto: +constant tres-veces = eager gather for ^3 { say take $_ }; #=> 0 1 2 +``` + +## Iterables + +```perl6 +## En Perl 6, los iterables son objetos que pueden ser iterados similar +## a la construcción `for`. +## `flat`, aplana iterables: +say (1, 10, (20, 10) ); #=> (1 10 (20 10)) Nota como la agrupación se mantiene +say (1, 10, (20, 10) ).flat; #=> (1 10 20 10) Ahora el iterable es plano + +## - `lazy` - Aplaza la evaluación actual hasta que el valor sea requirido +## (forza contexto perezoso) +my @lazy-array = (1..100).lazy; +say @lazy-array.is-lazy; #=> True # Chequea por "pereza" con el método `is-lazy`. +say @lazy-array; #=> [...] No se ha iterado sobre la lista +for @lazy-array { .print }; # Esto funciona y hará tanto trabajo como sea necesario. + +[//]: # ( TODO explica que gather/take y map son todos perezosos) +## - `sink` - Un `eager` que desecha los resultados (forza el contexto sink) +constant nilthingie = sink for ^3 { .say } #=> 0 1 2 +say nilthingie.perl; #=> Nil + +## - `quietly` - Un bloque `quietly` reprime las advertencias: +quietly { warn 'Esto es una advertencia!' }; #=> No salida + +## - `contend` - Intenta efectos secundarios debajo de STM +## ¡No implementado todavía! +``` + +## ¡Más operadores! + +```perl6 +## ¡Todo el mundo ama los operadores! Tengamos más de ellos. + +## La lista de precedencia puede ser encontrada aquí: +## https://docs.perl6.org/language/operators#Operator_Precedence +## Pero primero, necesitamos un poco de explicación acerca +## de la asociatividad: + +## * Operadores binarios: +$a ! $b ! $c; # con asociatividad izquierda `!`, esto es `($a ! $b) ! $c` +$a ! $b ! $c; # con asociatividad derecha `!`, esto es `$a ! ($b ! $c)` +$a ! $b ! $c; # sin asociatividad `!`, esto es ilegal +$a ! $b ! $c; # con una cadena de asociatividad `!`, esto es `($a ! $b) and ($b ! $c)` +$a ! $b ! $c; # con asociatividad de lista `!`, esto es `infix:<>` + +## * Operadores unarios: +!$a! # con asociatividad izquierda `!`, esto es `(!$a)!` +!$a! # con asociatividad derecha `!`, esto es `!($a!)` +!$a! # sin asociatividad `!`, esto es ilegal +``` + +### ¡Crea tus propios operadores! + +```perl6 +## Okay, has leído todo esto y me imagino que debería mostrarte +## algo interesante. +## Te mostraré un pequeño secreto (o algo no tan secreto): +## En Perl 6, todos los operadores son actualmente solo subrutinas. + +## Puedes declarar un operador como declaras una subrutina: +sub prefix:<ganar>($ganador) { # se refiere a las categorías de los operadores + # (exacto, es el "operador de palabras" `<>`) + say "¡$ganador ganó!"; +} +ganar "El Rey"; #=> ¡El Rey Ganó! + # (prefijo se pone delante) + +## todavías puedes invocar la subrutina con su "nombre completo": +say prefix:<!>(True); #=> False + +sub postfix:<!>(Int $n) { + [*] 2..$n; # usando el meta-operador reduce ... Ve más abajo! +} +say 5!; #=> 120 + # Operadores sufijos (postfix) van *directamente* después del témino. + # No espacios en blanco. Puedes usar paréntesis para disambiguar, + # i.e. `(5!)!` + + +sub infix:<veces>(Int $n, Block $r) { # infijo va en el medio + for ^$n { + $r(); # Necesitas los paréntesis explícitos para invocar la función + # almacenada en la variable `$r`. De lo contrario, te estaría + # refiriendo a la variable (no a la función), como con `&r`. + } +} +3 veces -> { say "hola" }; #=> hola + #=> hola + #=> hola + # Se te recomienda que ponga espacios + # alrededor de la invocación de operador infijo. + +## Para los circunfijos y pos-circunfijos +sub circumfix:<[ ]>(Int $n) { + $n ** $n +} +say [5]; #=> 3125 + # un circunfijo va alrededor. De nuevo, no espacios en blanco. + +sub postcircumfix:<{ }>(Str $s, Int $idx) { + ## un pos-circunfijo es + ## "después de un término y alrededor de algo" + $s.substr($idx, 1); +} +say "abc"{1}; #=> b + # depués del término `"abc"`, y alrededor del índice (1) + +## Esto es de gran valor -- porque todo en Perl 6 usa esto. +## Por ejemplo, para eliminar una llave de un hash, tu usas el adverbio +## `:delete` (un simple argumento con nombre debajo): +%h{$llave}:delete; +## es equivalente a: +postcircumfix:<{ }>(%h, $llave, :delete); # (puedes invocar + # operadores de esta forma) +## ¡*Todos* usan los mismos bloques básicos! +## Categorías sintácticas (prefix, infix, ...), argumentos nombrados +## (adverbios), ... - usados para construir el lenguaje - están al alcance +## de tus manos y disponibles para ti. +## (obviamente, no se te recomienda que hagas un operador de *cualquier +## cosa* -- Un gran poder conlleva una gran responsabilidad.) +``` + +### Meta-operadores! + +```perl6 +## ¡Prepárate! Prepárate porque nos estamos metiendo bien hondo +## en el agujero del conejo, y probablemente no querrás regresar a +## otros lenguajes después de leer esto. +## (Me imagino que ya no quieres a este punto). +## Meta-operadores, como su nombre lo sugiere, son operadores *compuestos*. +## Básicamente, ellos son operadores que se aplican a otros operadores. + +## * El meta-operador reduce (reducir) +## Es un meta-operador prefijo que toman una función binaria y +## una o varias listas. Sino se pasa ningún argumento, +## returna un "valor por defecto" para este operador +## (un valor sin significado) o `Any` si no hay ningún valor. +## +## De lo contrario, remueve un elemento de la(s) lista(s) uno a uno, y +## aplica la función binaria al último resultado (o al primer elemento de +## la lista y el elemento que ha sido removido). +## +## Para sumar una lista, podrías usar el meta-operador "reduce" con `+`, +## i.e.: +say [+] 1, 2, 3; #=> 6 +## es equivalente a `(1+2)+3` + +say [*] 1..5; #=> 120 +## es equivalente a `((((1*2)*3)*4)*5)`. + +## Puedes reducir con cualquier operador, no solo con operadores matemáticos. +## Por ejemplo, podrías reducir con `//` para conseguir +## el primer elemento definido de una lista: +say [//] Nil, Any, False, 1, 5; #=> False + # (Falsey, pero definido) + +## Ejemplos con valores por defecto: +say [*] (); #=> 1 +say [+] (); #=> 0 + # valores sin significado, dado que N*1=N y N+0=N. +say [//]; #=> (Any) + # No hay valor por defecto para `//`. +## También puedes invocarlo con una función de tu creación usando +## los dobles corchetes: +sub add($a, $b) { $a + $b } +say [[&add]] 1, 2, 3; #=> 6 + +## * El meta-operador zip +## Este es un meta-operador infijo que también puede ser usado como un +## operador "normal". Toma una función binaria opcional (por defecto, solo +## crear un par), y remueve un valor de cada array e invoca su función +## binaria hasta que no tenga más elementos disponibles. Al final, returna +## un array con todos estos nuevos elementos. +(1, 2) Z (3, 4); # ((1, 3), (2, 4)), dado que por defecto, la función + # crea un array. +1..3 Z+ 4..6; # (5, 7, 9), usando la función personalizada infix:<+> + +## Dado que `Z` tiene asociatividad de lista (ve la lista más arriba), +## puedes usarlo en más de una lista +(True, False) Z|| (False, False) Z|| (False, False); # (True, False) + +## Y pasa que también puedes usarlo con el meta-operador reduce: +[Z||] (True, False), (False, False), (False, False); # (True, False) + + +## Y para terminar la lista de operadores: + +## * El operador secuencia +## El operador secuencia es uno de la más poderosas características de +## Perl 6: Está compuesto, en la izquierda, de la lista que quieres que +## Perl 6 use para deducir (y podría incluir una clausura), y en la derecha, +## un valor o el predicado que dice cuando parar (o Whatever para una +## lista infinita perezosa). +my @list = 1, 2, 3 ... 10; # deducción básica +#my @list = 1, 3, 6 ... 10; # esto muere porque Perl 6 no puede deducir el final +my @list = 1, 2, 3 ...^ 10; # como con rangos, puedes excluir el último elemento + # (la iteración cuando el predicado iguala). +my @list = 1, 3, 9 ... * > 30; # puedes usar un predicado + # (con la Whatever Star, aquí). +my @list = 1, 3, 9 ... { $_ > 30 }; # (equivalente a lo de arriba) + +my @fib = 1, 1, *+* ... *; # lista infinita perezosa de la serie fibonacci, + # computada usando una clausura! +my @fib = 1, 1, -> $a, $b { $a + $b } ... *; # (equivalene a lo de arriba) +my @fib = 1, 1, { $^a + $^b } ... *; #(... también equivalene a lo de arriba) +## $a and $b siempre tomarán el valor anterior, queriendo decir que +## ellos comenzarán con $a = 1 y $b = 1 (valores que hemos asignado +## de antemano). Por lo tanto, $a = 1 y $b = 2 (resultado del anterior $a+$b), +## etc. + +say @fib[^10]; #=> 1 1 2 3 5 8 13 21 34 55 + # (usandi un rango como el índice) +## Nota: Los elementos de un rango, una vez cosificados, no son re-calculados. +## Esta es la razón por la cual `@primes[^100]` tomará más tiempo la primera +## vez que se imprime. Después de esto, será hará en un instante. +``` + +## Expresiones Regulares + +```perl6 +## Estoy seguro que has estado esperando por esta parte. Bien, ahora que +## sabes algo acerca de Perl 6, podemos comenzar. Primeramente, tendrás +## que olvidarte acerca de "PCRE regexps" (perl-compatible regexps) +## (expresiones regulares compatible de perl). +## +## IMPORTANTE: No salte esto porque ya sabes acerca de PCRE. Son totalmente +## distintos. Algunas cosas son las mismas (como `?`, `+`, y `*`) pero +## algunas veces la semántica cambia (`|`). Asegúrate de leer esto +## cuidadosamente porque podrías trospezarte sino lo haces. +## +## Perl 6 tiene muchas características relacionadas con RegExps. Después de +## todo, Rakudo se parsea a si mismo. Primero vamos a estudiar la sintaxis +## por si misma, después hablaremos acerca de gramáticas (parecido a PEG), +## las diferencias entre los declaradores `token`, `regex`, y `rule` y +## mucho más. +## Nota aparte: Todavía tienes acceso a los regexes PCRE usando el +## mofificador `:P5` (Sin embargo, no lo discutiremos en este tutorial). +## +## En esencia, Perl 6 implementa PEG ("Parsing Expression Grammars") +## ("Parseado de Expresiones de Gramáticas") nativamente. El orden jerárquico +## para los parseos ambiguos es determinado por un examen multi-nivel de +## desempate: +## - La coincidencia de token más larga. `foo\s+` le gana a `foo` +## (por 2 o más posiciones) +## - El prefijo literal más largo. `food\w*` le gana a `foo\w*` (por 1) +## - Declaración desde la gramática más derivada a la menos derivada +## (las gramáticas son actualmente clases) +## - La declaración más temprana gana +say so 'a' ~~ /a/; #=> True +say so 'a' ~~ / a /; #=> True # ¡Más legible con los espacios! + +## Nota al lector (del traductor): +## Como pudiste haber notado, he decidido traducir "match" y sus diferentes +## formas verbales como "coincidir" y sus diferentes formas. Cuando digo que +## un regex (o regexp) coincide con cierto texto, me refiero a que el regex +## describe cierto patrón dentro del texto. Por ejemplo, el regex "cencia" +## coincide con el texto "reminiscencia", lo que significa que dentro del +## texto aparece ese patrón de caracteres (una `c`, seguida de una `e`, +## (seguida de una `n`, etc.) + +## En todos nuestros ejemplos, vamos a usar el operador de +## "coincidencia inteligente" contra una expresión regular ("regexp" or +## "regex" de aquí en adelante). Estamos convirtiendo el resultado usando `so`, +## pero en efecto, está devolviendo un objeto Match. Ellos saben como responder +## a la indexación de lista, indexación de hash, y devolver la cadena de +## texto coincidente. +## Los resultados de la coincidencia están disponible como `$/` (en +## ámbito implícito lexical). También puedes usar las variables de captura +## las cuales comienzan con 0: +## `$0`, `$1', `$2`... +## +## Nota que `~~` no hace un chequeo de inicio/final (es decir, +## el regexp puede coincider con solo un carácter de la cadena de texto). +## Explicaremos luego como hacerlo. + +## En Perl 6, puedes tener un carácter alfanumérico como un literal, +## todo lo demás debe escaparse usando una barra invertida o comillas. +say so 'a|b' ~~ / a '|' b /; # `True`. No sería lo mismo si no se escapara `|` +say so 'a|b' ~~ / a \| b /; # `True`. Otra forma de escaparlo + +## El espacio en blanco actualmente no se significa nada en un regexp, +## a menos que uses el adverbio `:s` (`:sigspace`, espacio significante). +say so 'a b c' ~~ / a b c /; #=> `False`. Espacio no significa nada aquí. +say so 'a b c' ~~ /:s a b c /; #=> `True`. Agregamos el modificador `:s` aquí. +## Si usamos solo un espacio entre cadenas de texto en un regexp, Perl 6 +## nos advertirá: +say so 'a b c' ~~ / a b c /; #=> 'False' # Espacio no significa nada aquí. +## Por favor usa comillas o el modificador :s (:sigspace) para suprimir +## esta advertencia, omitir el espacio, o cambiar el espaciamiento. Para +## arreglar esto y hacer los espacios menos ambiguos, usa por lo menos +## dos espacios entre las cadenas de texto o usa el adverbio `:s`. + +## Como vimos anteriormente, podemos incorporar `:s` dentro de los +## delimitadores de barras. También podemos ponerlos fuera de ellos si +## especificamos `m` for `match` (coincidencia): +say so 'a b c' ~~ m:s/a b c/; #=> `True` +## Al usar `m` para especificar 'match', podemos también otros delimitadore: +say so 'abc' ~~ m{a b c}; #=> `True` +say so 'abc' ~~ m[a b c]; #=> `True` + +## Usa el adverbio :i para especificar que no debería haber distinción entre +## minúsculas y mayúsculas: +say so 'ABC' ~~ m:i{a b c}; #=> `True` + +## Sin embargo, es importante para como los modificadores son aplicados +## (lo cual verás más abajo)... + +## Cuantificando - `?`, `+`, `*` y `**`. +## - `?` - 0 o 1 +so 'ac' ~~ / a b c /; # `False` +so 'ac' ~~ / a b? c /; # `True`, la "b" coincidió (apareció) 0 veces. +so 'abc' ~~ / a b? c /; # `True`, la "b" coincidió 1 vez. + +## ... Como debes saber, espacio en blancos son importante porque +## determinan en que parte del regexp es el objetivo del modificador: +so 'def' ~~ / a b c? /; # `False`. Solamente la `c` es opcional +so 'def' ~~ / a b? c /; # `False`. Espacio en blanco no es significante +so 'def' ~~ / 'abc'? /; # `True`. El grupo "abc"completo es opcional. + +## Aquí (y más abajo) el cuantificador aplica solamente a la `b` + +## - `+` - 1 o más +so 'ac' ~~ / a b+ c /; # `False`; `+` quiere por lo menos una coincidencia +so 'abc' ~~ / a b+ c /; # `True`; una es suficiente +so 'abbbbc' ~~ / a b+ c /; # `True`, coincidió con 4 "b"s + +## - `*` - 0 o más +so 'ac' ~~ / a b* c /; # `True`, todos son opcionales. +so 'abc' ~~ / a b* c /; # `True` +so 'abbbbc' ~~ / a b* c /; # `True` +so 'aec' ~~ / a b* c /; # `False`. "b"(s) son opcionales, no reemplazables. + +## - `**` - Cuantificador (sin límites) +## Si entrecierras los ojos lo suficiente, pueder ser que entiendas +## por qué la exponenciación es usada para la cantidad. +so 'abc' ~~ / a b**1 c /; # `True` (exactamente una vez) +so 'abc' ~~ / a b**1..3 c /; # `True` (entre una y tres veces) +so 'abbbc' ~~ / a b**1..3 c /; # `True` +so 'abbbbbbc' ~~ / a b**1..3 c /; # `False` (demasiado) +so 'abbbbbbc' ~~ / a b**3..* c /; # `True` (rangos infinitos no son un problema) + +## - `<[]>` - Clases de carácteres +## Las clases de carácteres son equivalentes a las clases `[]` de PCRE, +## pero usan una sintaxis de Perl 6: +say 'fooa' ~~ / f <[ o a ]>+ /; #=> 'fooa' + +## Puedes usar rangos: +say 'aeiou' ~~ / a <[ e..w ]> /; #=> 'ae' + +## Al igual que regexes normales, si quieres usar un carácter especial, +## escápalo (el último está escapando un espacio) +say 'he-he !' ~~ / 'he-' <[ a..z \! \ ]> + /; #=> 'he-he !' + +## Obtendrás una advertencia si pones nombres duplicados +## (lo cual tiene el efecto de capturar la frase escrita) +'he he' ~~ / <[ h e ' ' ]> /; # Advierte "Repeated characters found in characters + # class" + +## También puedes negarlos... (equivalenta a `[^]` en PCRE) +so 'foo' ~~ / <-[ f o ]> + /; # False + +## ... y componerlos: +so 'foo' ~~ / <[ a..z ] - [ f o ]> + /; # False (cualquier letra excepto f y o) +so 'foo' ~~ / <-[ a..z ] + [ f o ]> + /; # True (no letra excepto f and o) +so 'foo!' ~~ / <-[ a..z ] + [ f o ]> + /; # True (el signo + no reemplaza la + # parte de la izquierda) +``` + +### Grupos y Capturas + +```perl6 +## Grupo: Puedes agrupar partes de tu regexp con `[]`. +## Estos grupos *no son* capturados (como con `(?:)` en PCRE). +so 'abc' ~~ / a [ b ] c /; # `True`. El agrupamiento no hace casi nada +so 'foo012012bar' ~~ / foo [ '01' <[0..9]> ] + bar /; +## La línea anterior returna `True`. +## Coincidimos (o encotramos el patrón) "012" una o más de una vez ( +## (el signo `+` fue aplicado al grupo). +## Pero esto no va demasiado lejos, porque no podemos actualmente obtener +## devuelta el patrón que coincidió. + +## Captura: Podemos actualmente *capturar* los resultados del regexp, +## usando paréntesis. +so 'fooABCABCbar' ~~ / foo ( 'A' <[A..Z]> 'C' ) + bar /; # `True`. (usando `so` + # aquí, `$/` más abajo) + +## Ok. Comenzando con las explicaciones de grupos. Como dijimos, +### nuestra objeto `Match` está disponible en la variable `$/`: +say $/; # Imprimirá algo extraño (explicaremos luego) o + # "Nil" si nada coincidió + +## Como dijimos anteriormente, un objeto Match tiene indexación de array: +say $/[0]; #=> ｢ABC｣ ｢ABC｣ + # Estos corchetes extranos son los objetos `Match`. + # Aquí, tenemos un array de ellos. +say $0; # Lo mismo que lo anterior. + +## Nuestra captura es `$0` porque es la primera y única captura en el +## regexp. Podrías estarte preguntando porque un array y la respuesta es +## simple: Algunas capturas (indezadas usando `$0`, `$/[0]` o una nombrada) +## será un array si y solo si puedes tener más de un elemento. +## (Así que, con `*`, `+` y `**` (cualquiera los operandos), pero no con `?`). +## Usemos algunos ejemplos para ver como funciona: + +## Nota: Pusimos A B C entre comillas para demostrar que el espacio en blanco +## entre ellos no es significante. Si queremos que el espacio en blanco +## *sea* significante, podemos utilizar el modificador `:sigspace`. +so 'fooABCbar' ~~ / foo ( "A" "B" "C" )? bar /; # `True` +say $/[0]; #=> ｢ABC｣ +say $0.WHAT; #=> (Match) + # Puede haber más de uno, por lo tanto es solo un solo objeto match. +so 'foobar' ~~ / foo ( "A" "B" "C" )? bar /; #=> True +say $0.WHAT; #=> (Any) + # Esta captura no coincidió, por lo tanto está vacía +so 'foobar' ~~ / foo ( "A" "B" "C" ) ** 0..1 bar /; # `True` +say $0.WHAT; #=> (Array) + # Un cuantificador específico siempre capturará un Array, + # puede ser un rango o un valor específico (hasta 1). + +## Las capturas son indezadas por anidación. Esto quiere decir que un grupo +## dentro de un grup estará anidado dentro de su grupo padre: `$/[0][0]`, +## para este código: +'hello-~-world' ~~ / ( 'hello' ( <[ \- \~ ]> + ) ) 'world' /; +say $/[0].Str; #=> hello~ +say $/[0][0].Str; #=> ~ + +## Esto se origina de un hecho bien simple: `$/` no contiene cadenas de +## texto, números enteros o arrays sino que solo contiene objetos Match. +## Estos objetos contienen los métodos `.list`, `.hash` y `.Str`. (Pero +## también puedes usar `match<llave>` para accesar un hash y `match[indice]` +## para accesar un array. +say $/[0].list.perl; #=> (Match.new(...),).list + # Podemos ver que es una lista de objetos Match. + # Estos contienen un montón de información: dónde la + # coincidencia comenzó o terminó, el "ast" + # (chequea las acciones más abajo), etc. + # Verás capturas nombradas más abajo con las gramáticas. + +## Alternativas - el `or` de regexes +## Advertencia: Es diferente a los regexes de PCRE. +so 'abc' ~~ / a [ b | y ] c /; # `True`. o "b" o "y". +so 'ayc' ~~ / a [ b | y ] c /; # `True`. Obviamente suficiente... + +## La diferencia entre este `|` y el otro al que estás acustombrado es LTM. +## LTM significa "Longest Token Matching", traducido libremente como +## "Coincidencia de Token Más Larga". Esto significa que el motor ("engine") +## siempre intentará coindidir tanto como sea posible en la cadena de texto. +## Básicamente, intentará el patrón más largo que concuerde con el regexp. +'foo' ~~ / fo | foo /; # `foo` porque es más largo. +## Para decidir cual parte es la "más larga", primero separa el regex en +## dos partes: +## El "prefijo declarativo" (la parte que puede ser analizada estáticamente) +## y las partes procedimentales. +## Los prefijos declarativos incluyen alternaciones (`|`), conjunciones (`&`), +## invocaciones de sub-reglas (no han sido introducidos todavía), clases de +## caracteres y cuantificadores. +## Las partes procidimentales incluyen todo lo demás: referencias a elementos +## anteriores, aserciones de código, y otras cosas que tradicionalmente no pueden +## ser representadas por regexes normales. +## +## Entonces, todas las alternativas se intentan al mismo tiempo, y la +## más larga gana. +## Ejemplos: +## DECLARATIVO | PROCEDIMENTAL +/ 'foo' \d+ [ <subrule1> || <subrule2> ] /; +## DECLARATIVO (grupos anidados no son un problema) +/ \s* [ \w & b ] [ c | d ] /; +## Sin embargo, las clausuras y la recursión (de regexes nombrados) +## son procedimentales. +## ... Hay más reglas complicadas, como la especifidad (los literales ganan +## son las clases de caracteres) ++ +## Nota: la primera coincidencia `or` todavía existen, pero ahora se +## deletrea `||` +'foo' ~~ / fo || foo /; # `fo` ahora. +``` + +## Extra: la subrutina MAIN + +```perl6 +## La subrutina `MAIN` se invoca cuando tu ejecuta un archivo de Perl 6 +## directamente. Es realmente poderosa porque Perl 6 actualmente parsea +## los argumentos y los pasas a la subrutina. También maneja argumentos +## nombrados (`--foo`) y hasta autogenerará un `--help`. +sub MAIN($nombre) { say "¡Hola, $nombre!" } +## Esto produce: +## $ perl6 cli.pl +## Uso: +## t.pl <nombre> + +## Y dado que una subrutina regular en Perl 6, puedes tener múltiples +## despachos: +## (usando un "Bool" por un argumento nombrado para que podamos hacer +## `--replace` a cambio de `--replace=1`) +subset File of Str where *.IO.d; # convierte a un objeto IO para chequear si + # un archivo existe + +multi MAIN('add', $key, $value, Bool :$replace) { ... } +multi MAIN('remove', $key) { ... } +multi MAIN('import', File, Str :$as) { ... } # omitiendo parámetros nombrados +## Esto produce: +## $ perl6 cli.pl +## Uso: +## t.pl [--replace] add <key> <value> +## t.pl remove <key> +## t.pl [--as=<Str>] import (File) +## Como puedes ver, esto es *realmente* poderoso. +## Fue tan lejos como para mostrar las constantes en líneas. +## (el tipo solo se muestra cuando el argumento `$`/ es nombrado) +``` + +## APÉNDICE A: +### Lista de cosas + +```perl6 +## Consideramos que por ahora ya sabes lo básico de Perl 6. +## Esta sección es solo para listar algunas operaciones comunes +## las cuales no están en la "parte principal" del tutorial. + +## Operadores + +## * Comparación para ordenar +## Ellos returnan un valor de los enum `Order`: `Less`, `Same` y `More` +## (los cuales representan los números -1, 0 o +1). +1 <=> 4; # comparación de orden para caracteres numéricos +'a' leg 'b'; # comparación de orden para cadenas de texto +$obj eqv $obj2; # comparación de orden usando la semántica eqv + +## * Ordenación genérica +3 before 4; # True +'b' after 'a'; # True + +## * Operador (por defecto) de circuito corto +## Al igual que `or` y `||`, pero devuelve el primer valor *defined* +## (definido): +say Any // Nil // 0 // 5; #=> 0 + +## * Circuito corto exclusivo or (XOR) +## Devuelve `True` si uno (y solo uno) de sus argumentos es verdadero: +say True ^^ False; #=> True + +## * Flip Flop +## Los operadores flip flop (`ff` y `fff`, equivalente a `..`/`...` en P5) +## son operadores que toman dos predicados para evalualarlos: +## Ellos son `False` hasta que su lado izquierdo devuelve `True`, entonces +## son `True` hasta que su lado derecho devuelve `True`. +## Como los rangos, tu puedes excluir la iteración cuando se convierte en +## `True`/`False` usando `^` en cualquier lado. +## Comencemos con un ejemplo: +for <well met young hero we shall meet later> { + # por defecto, `ff`/`fff` hace coincidencia inteligente (`~~`) contra `$_`: + if 'met' ^ff 'meet' { # no entrará el bucle if por "met" + # (se explica más abajo). + .say + } + + if rand == 0 ff rand == 1 { # compara variables más que `$_` + say "Esto ... probablemente nunca se ejecutará ..."; + } +} +## Esto imprimirá "young hero we shall meet" (exluyendo "met"): +## el flip-flop comenzará devolviendo `True` cuando primero encuentra "met" +## (pero no returnará `False` por "met" dabido al `^` al frente de `ff`), +## hasta que ve "meet", lo cual es cuando comenzará devolviendo `False`. + +## La diferencia entre `ff` (al estilo de awk) y `fff` (al estilo de sed) +## es que `ff` probará su lado derecho cuando su lado izquierdo cambia +## a `True`, y puede returnar a `False` inmediamente (*excepto* que será +## `True` por la iteración con la cual coincidió). Por lo contrario, +## `fff` esperará por la próxima iteración para intentar su lado +## derecho, una vez que su lado izquierdo ha cambiado: +.say if 'B' ff 'B' for <A B C B A>; #=> B B + # porque el lado derecho se puso a prueba + # directamente (y returnó `True`). + # Las "B"s se imprimen dadó que coincidió + # en ese momento (returnó a `False` + # inmediatamente). +.say if 'B' fff 'B' for <A B C B A>; #=> B C B + # El lado derecho no se puso a prueba + # hasta que `$_` se convirtió en "C" + # (y por lo tanto no coincidió + # inmediamente). + +## Un flip-flop puede cambiar estado cuantas veces se necesite: +for <test start print it stop not printing start print again stop not anymore> { + .say if $_ eq 'start' ^ff^ $_ eq 'stop'; # excluye a "start" y "stop", + #=> "print it print again" +} + +## También podrías usar una Whatever Star, lo cual es equivalente +## a `True` para el lado izquierdo o `False` para el lado derecho: +for (1, 3, 60, 3, 40, 60) { # Nota: los paréntesis son superfluos aquí + # (algunas veces se les llaman "paréntesis superticiosos") + .say if $_ > 50 ff *; # Una vez el flip-flop alcanza un número mayor que 50, + # no returnará jamás a `False` + #=> 60 3 40 60 +} + +## También puedes usar esta propiedad para crear un `If` +## que no pasará la primera vez: +for <a b c> { + .say if * ^ff *; # el flip-flop es `True` y nunca returna a `False`, + # pero el `^` lo hace *que no se ejecute* en la + # primera iteración + #=> b c +} + +## - `===` es la identidad de valor y usa `.WHICH` +## en los objetos para compararlos. +## - `=:=` es la identidad de contenedor y usa `VAR()` +## en los objetos para compararlos. + +``` +Si quieres ir más allá de lo que se muestra aquí, puedes: + + - Leer la [documentación de Perl 6](https://docs.perl6.org/). Esto es un recurso + grandioso acerca de Perl 6. Si estás buscando por algo en particular, usa la + barra de búsquedas. Esto te dará un menú de todas las páginas concernientes + a tu término de búsqueda (¡Es mucho mejor que usar Google para encontrar + documentos acerca de Perl 6!) + - Leer el [Perl 6 Advent Calendar](http://perl6advent.wordpress.com/). Este es + un gran recurso de fragmentos de código de Perl 6 y explicaciones. Si la documentación + no describe algo lo suficientemente bien, puedes encontrar información más detallada + aquí. Esta información puede ser un poquito más antigua pero hay muchos ejemplos y + explicaciones. Las publicaciones fueron suspendidas al final del 2015 cuando + el lenguaje fue declarado estable y Perl 6.c fue lanzado. + - Unirte a `#perl6` en `irc.freenode.net`. Las personas aquí son siempre serviciales. + - Chequear la [fuente de las funciones y clases de Perl 6 + ](https://github.com/rakudo/rakudo/tree/nom/src/core). Rakudo está principalmente + escrito en Perl 6 (con mucho de NQP, "Not Quite Perl" ("No Perl Todavía"), un + subconjunto de Perl 6 que es más fácil de implementar y optimizar). + - Leer [documentos acerca del diseño del lenguaje](http://design.perl6.org). + Estos explican P6 desde la perspectiva de un implementador, lo cual es bastante + interesante. diff --git a/es-es/python3-es.html.markdown b/es-es/python3-es.html.markdown index 05fd7065..3236e73a 100644 --- a/es-es/python3-es.html.markdown +++ b/es-es/python3-es.html.markdown @@ -14,8 +14,6 @@ Es básicamente pseudocódigo ejecutable. ¡Comentarios serán muy apreciados! Pueden contactarme en [@louiedinh](http://twitter.com/louiedinh) o louiedinh [at] [servicio de email de google] -Nota: Este artículo aplica a Python 2.7 específicamente, pero debería ser aplicable a Python 2.x. ¡Pronto un recorrido por Python 3! - ```python # Comentarios de una línea comienzan con una almohadilla (o signo gato) @@ -39,6 +37,8 @@ Nota: Este artículo aplica a Python 2.7 específicamente, pero debería ser apl # Excepto la división la cual por defecto retorna un número 'float' (número de coma flotante) 35 / 5 # => 7.0 +# Sin embargo también tienes disponible división entera +34 // 5 # => 6 # Cuando usas un float, los resultados son floats 3 * 2.0 # => 6.0 @@ -87,11 +87,14 @@ not False # => True # .format puede ser usaro para darle formato a los strings, así: "{} pueden ser {}".format("strings", "interpolados") -# Puedes repetir los argumentos de formateo para ahorrar tipeos. +# Puedes reutilizar los argumentos de formato si estos se repiten. "{0} sé ligero, {0} sé rápido, {0} brinca sobre la {1}".format("Jack", "vela") #=> "Jack sé ligero, Jack sé rápido, Jack brinca sobre la vela" # Puedes usar palabras claves si no quieres contar. -"{nombre} quiere comer {comida}".format(nombre="Bob", food="lasaña") #=> "Bob quiere comer lasaña" - +"{nombre} quiere comer {comida}".format(nombre="Bob", comida="lasaña") #=> "Bob quiere comer lasaña" +# También puedes interpolar cadenas usando variables en el contexto +nombre = 'Bob' +comida = 'Lasaña' +f'{nombre} quiere comer {comida}' #=> "Bob quiere comer lasaña" # None es un objeto None # => None @@ -101,12 +104,13 @@ None # => None "etc" is None #=> False None is None #=> True -# None, 0, y strings/listas/diccionarios vacíos(as) todos se evalúan como False. +# None, 0, y strings/listas/diccionarios/conjuntos vacíos(as) todos se evalúan como False. # Todos los otros valores son True bool(0) # => False bool("") # => False bool([]) #=> False bool({}) #=> False +bool(set()) #=> False #################################################### @@ -170,7 +174,7 @@ lista + otra_lista #=> [1, 2, 3, 4, 5, 6] - Nota: lista y otra_lista no se tocan # Concatenar listas con 'extend' lista.extend(otra_lista) # lista ahora es [1, 2, 3, 4, 5, 6] -# Chequea la existencia en una lista con 'in' +# Verifica la existencia en una lista con 'in' 1 in lista #=> True # Examina el largo de una lista con 'len' @@ -196,7 +200,7 @@ d, e, f = 4, 5, 6 e, d = d, e # d ahora es 5 y e ahora es 4 -# Diccionarios almacenan mapeos +# Diccionarios relacionan llaves y valores dicc_vacio = {} # Aquí está un diccionario prellenado dicc_lleno = {"uno": 1, "dos": 2, "tres": 3} @@ -213,7 +217,7 @@ list(dicc_lleno.keys()) #=> ["tres", "dos", "uno"] list(dicc_lleno.values()) #=> [3, 2, 1] # Nota - Lo mismo que con las llaves, no se garantiza el orden. -# Chequea la existencia de una llave en el diccionario con 'in' +# Verifica la existencia de una llave en el diccionario con 'in' "uno" in dicc_lleno #=> True 1 in dicc_lleno #=> False @@ -253,7 +257,7 @@ conjunto_lleno | otro_conjunto #=> {1, 2, 3, 4, 5, 6} # Haz diferencia de conjuntos con - {1,2,3,4} - {2,3,5} #=> {1, 4} -# Chequea la existencia en un conjunto con 'in' +# Verifica la existencia en un conjunto con 'in' 2 in conjunto_lleno #=> True 10 in conjunto_lleno #=> False @@ -262,7 +266,7 @@ conjunto_lleno | otro_conjunto #=> {1, 2, 3, 4, 5, 6} ## 3. Control de Flujo #################################################### -# Let's just make a variable +# Creemos una variable para experimentar some_var = 5 # Aquí está una declaración de un 'if'. ¡La indentación es significativa en Python! @@ -275,18 +279,17 @@ else: # Esto también es opcional. print("una_variable es de hecho 10.") """ -For itera sobre listas +For itera sobre iterables (listas, cadenas, diccionarios, tuplas, generadores...) imprime: perro es un mamifero gato es un mamifero raton es un mamifero """ for animal in ["perro", "gato", "raton"]: - # Puedes usar % para interpolar strings formateados print("{} es un mamifero".format(animal)) """ -`range(número)` retorna una lista de números +`range(número)` retorna un generador de números desde cero hasta el número dado imprime: 0 @@ -323,7 +326,7 @@ except IndexError as e: dicc_lleno = {"uno": 1, "dos": 2, "tres": 3} nuestro_iterable = dicc_lleno.keys() -print(nuestro_iterable) #=> range(1,10). Este es un objeto que implementa nuestra interfaz Iterable +print(nuestro_iterable) #=> dict_keys(['uno', 'dos', 'tres']). Este es un objeto que implementa nuestra interfaz Iterable Podemos recorrerla. for i in nuestro_iterable: @@ -420,6 +423,10 @@ filter(lambda x: x > 5, [3, 4, 5, 6, 7]) #=> [6, 7] # Podemos usar listas por comprensión para mapeos y filtros agradables [add_10(i) for i in [1, 2, 3]] #=> [11, 12, 13] [x for x in [3, 4, 5, 6, 7] if x > 5] #=> [6, 7] +# también hay diccionarios +{k:k**2 for k in range(3)} #=> {0: 0, 1: 1, 2: 4} +# y conjuntos por comprensión +{c for c in "la cadena"} #=> {'d', 'l', 'a', 'n', ' ', 'c', 'e'} #################################################### ## 5. Classes diff --git a/es-es/visualbasic-es.html.markdown b/es-es/visualbasic-es.html.markdown index c7f581c0..ca00626b 100644 --- a/es-es/visualbasic-es.html.markdown +++ b/es-es/visualbasic-es.html.markdown @@ -10,7 +10,7 @@ filename: learnvisualbasic-es.vb lang: es-es --- -```vb +``` Module Module1 Sub Main() diff --git a/factor.html.markdown b/factor.html.markdown index 79596d83..53c692df 100644 --- a/factor.html.markdown +++ b/factor.html.markdown @@ -9,7 +9,7 @@ Factor is a modern stack-based language, based on Forth, created by Slava Pestov Code in this file can be typed into Factor, but not directly imported because the vocabulary and import header would make the beginning thoroughly confusing. -``` +```factor ! This is a comment ! Like Forth, all programming is done by manipulating the stack. diff --git a/fi-fi/markdown-fi.html.markdown b/fi-fi/markdown-fi.html.markdown index c5ee52b0..defc7100 100644 --- a/fi-fi/markdown-fi.html.markdown +++ b/fi-fi/markdown-fi.html.markdown @@ -10,7 +10,7 @@ lang: fi-fi John Gruber loi Markdownin vuona 2004. Sen tarkoitus on olla helposti luettava ja kirjoitettava syntaksi joka muuntuu helposti HTML:ksi (ja nyt myös moneksi muuksi formaatiksi). -```markdown +```md <!-- Jokainen HTML-tiedosto on pätevää Markdownia. Tämä tarkoittaa että voimme käyttää HTML-elementtejä Markdownissa, kuten kommentteja, ilman että markdown -jäsennin vaikuttaa niihin. Tästä johtuen et voi kuitenkaan käyttää markdownia diff --git a/fr-fr/c++-fr.html.markdown b/fr-fr/c++-fr.html.markdown index acbaed58..863162f7 100644 --- a/fr-fr/c++-fr.html.markdown +++ b/fr-fr/c++-fr.html.markdown @@ -910,7 +910,6 @@ v.swap(vector<Foo>()); ``` Lecture complémentaire : -Une référence à jour du langage est disponible à -<http://cppreference.com/w/cpp> - -Des ressources supplémentaires sont disponibles à <http://cplusplus.com> +* Une référence à jour du langage est disponible à [CPP Reference](http://cppreference.com/w/cpp). +* Des ressources supplémentaires sont disponibles à [CPlusPlus](http://cplusplus.com). +* Un tutoriel couvrant les bases du langage et la configuration d'un environnement de codage est disponible à l'adresse [TheChernoProject - C ++](https://www.youtube.com/playlist?list=PLlrATfBNZ98dudnM48yfGUldqGD0S4FFb). diff --git a/fr-fr/crystal-fr.html.markdown b/fr-fr/crystal-fr.html.markdown index 2c4e3dad..2bb17fc5 100644 --- a/fr-fr/crystal-fr.html.markdown +++ b/fr-fr/crystal-fr.html.markdown @@ -305,7 +305,6 @@ end (1..3).each do |index| puts "Index: #{index}" end -# Index: 0 # Index: 1 # Index: 2 # Index: 3 diff --git a/fr-fr/d.html.markdown b/fr-fr/d-fr.html.markdown index 8d98f9dc..8d98f9dc 100644 --- a/fr-fr/d.html.markdown +++ b/fr-fr/d-fr.html.markdown diff --git a/fr-fr/dynamic-programming-fr.html.markdown b/fr-fr/dynamic-programming-fr.html.markdown index 24e8c95f..54cca001 100644 --- a/fr-fr/dynamic-programming-fr.html.markdown +++ b/fr-fr/dynamic-programming-fr.html.markdown @@ -8,7 +8,6 @@ translators: lang: fr-fr --- - # Programmation dynamique ## Introduction @@ -17,9 +16,9 @@ La programmation dynamique est une technique très efficace pour résoudre une c ## Moyens de résoudre ces problèmes -1.) *De haut en bas* : Commençons à résoudre le problème en le séparant en morceaux. Si nous voyons que le problème a déjà été résolu, alors nous retournons la réponse précédemment sauvegardée. Si le problème n'a pas été résolu, alors nous le résolvons et sauvegardons la réponse. C'est généralement facile et intuitif de réfléchir de cette façon. Cela s'appelle la Mémorisation. +1. *De haut en bas* : Commençons à résoudre le problème en le séparant en morceaux. Si nous voyons que le problème a déjà été résolu, alors nous retournons la réponse précédemment sauvegardée. Si le problème n'a pas été résolu, alors nous le résolvons et sauvegardons la réponse. C'est généralement facile et intuitif de réfléchir de cette façon. Cela s'appelle la Mémorisation. -2.) *De bas en haut* : Il faut analyser le problème et trouver les sous-problèmes, et l'ordre dans lequel il faut les résoudre. Ensuite, nous devons résoudre les sous-problèmes et monter jusqu'au problème que nous voulons résoudre. De cette façon, nous sommes assurés que les sous-problèmes sont résolus avant de résoudre le vrai problème. Cela s'appelle la Programmation Dynamique. +2. *De bas en haut* : Il faut analyser le problème et trouver les sous-problèmes, et l'ordre dans lequel il faut les résoudre. Ensuite, nous devons résoudre les sous-problèmes et monter jusqu'au problème que nous voulons résoudre. De cette façon, nous sommes assurés que les sous-problèmes sont résolus avant de résoudre le vrai problème. Cela s'appelle la Programmation Dynamique. ## Exemple de Programmation Dynamique @@ -27,7 +26,7 @@ Le problème de la plus grande sous-chaîne croissante est de trouver la plus gr Premièrement, nous avons à trouver la valeur de la plus grande sous-chaîne (LSi) à chaque index `i`, avec le dernier élément de la sous-chaîne étant ai. Alors, la plus grande sous-chaîne sera le plus gros LSi. Pour commencer, LSi est égal à 1, car ai est le seul élément de la chaîne (le dernier). Ensuite, pour chaque `j` tel que `j<i` et `aj<ai`, nous trouvons le plus grand LSj et ajoutons le à LSi. L'algorithme fonctionne en temps *O(n2)*. Pseudo-code pour trouver la longueur de la plus grande sous-chaîne croissante : -La complexité de cet algorithme peut être réduite en utilisant une meilleure structure de données qu'un tableau. Par exemple, si nous sauvegardions le tableau d'origine, ou une variable comme plus_grande_chaîne_jusqu'à_maintenant et son index, nous pourrions sauver beaucoup de temps. +La complexité de cet algorithme peut être réduite en utilisant une meilleure structure de données qu'un tableau. Par exemple, si nous sauvegardions le tableau d'origine, ou une variable comme `plus_grande_chaîne_jusqu'à_maintenant` et son index, nous pourrions sauver beaucoup de temps. Le même concept peut être appliqué pour trouver le chemin le plus long dans un graphe acyclique orienté. @@ -43,12 +42,9 @@ Le même concept peut être appliqué pour trouver le chemin le plus long dans u ### Problèmes classiques de programmation dynamique -L'algorithme de Floyd Warshall(EN)) - Tutorial and C Program source code:http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs---floyd-warshall-algorithm-with-c-program-source-code - -Problème du sac à dos(EN) - Tutorial and C Program source code: http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---the-integer-knapsack-problem - - -Plus longue sous-chaîne commune(EN) - Tutorial and C Program source code : http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---longest-common-subsequence +- L'algorithme de Floyd Warshall(EN) - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs---floyd-warshall-algorithm-with-c-program-source-code]() +- Problème du sac à dos(EN) - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---the-integer-knapsack-problem]() +- Plus longue sous-chaîne commune(EN) - Tutorial and C Program source code : [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---longest-common-subsequence]() ## Online Resources diff --git a/fr-fr/haskell.html.markdown b/fr-fr/haskell-fr.html.markdown index a34dc098..a34dc098 100644 --- a/fr-fr/haskell.html.markdown +++ b/fr-fr/haskell-fr.html.markdown diff --git a/fr-fr/java-fr.html.markdown b/fr-fr/java-fr.html.markdown index d0f91611..d6c68343 100644 --- a/fr-fr/java-fr.html.markdown +++ b/fr-fr/java-fr.html.markdown @@ -11,7 +11,7 @@ contributors: - ["Michael Dähnert", "https://github.com/JaXt0r"] - ["Rob Rose", "https://github.com/RobRoseKnows"] - ["Sean Nam", "https://github.com/seannam"] -filename: JavaFr.java +filename: java-fr.java translators: - ['Mathieu Gemard', 'https://github.com/mgemard'] lang: fr-fr diff --git a/fr-fr/jquery-fr.html.markdown b/fr-fr/jquery-fr.html.markdown index 1842e02b..1a5baf71 100644 --- a/fr-fr/jquery-fr.html.markdown +++ b/fr-fr/jquery-fr.html.markdown @@ -13,6 +13,7 @@ jQuery est une bibliothèque JavaScript dont le but est de permettre de "faire p C'est pourquoi aujourd'hui, jQuery est utilisée par de nombreuses grandes entreprises et par des développeurs du monde entier. Étant donné que jQuery est une bibliothèque JavaScript, vous devriez d'abord [apprendre le JavaScript](https://learnxinyminutes.com/docs/fr-fr/javascript-fr/) + ```js @@ -138,5 +139,5 @@ $('p').each(function() { }); -`` +``` diff --git a/fr-fr/lambda-calculus-fr.html.markdown b/fr-fr/lambda-calculus-fr.html.markdown new file mode 100644 index 00000000..c91f21d6 --- /dev/null +++ b/fr-fr/lambda-calculus-fr.html.markdown @@ -0,0 +1,106 @@ +--- +category: Algorithms & Data Structures +name: Lambda Calculus +contributors: + - ["Max Sun", "http://github.com/maxsun"] +translators: + - ["Yvan Sraka", "https://github.com/yvan-sraka"] +lang: fr-fr +--- + +# Lambda-calcul + +Le Lambda-calcul (λ-calcul), créé à l'origine par [Alonzo Church](https://en.wikipedia.org/wiki/Alonzo_Church), est le plus petit langage de programmation au monde. En dépit de ne pas avoir de nombres, de chaînes, de booléens, ou de tout type de données sans fonction, le lambda calcul peut être utilisé pour représenter n'importe quelle machine de Turing! + +Le Lambda-calcul est composé de 3 éléments : **variables**, **fonctions** et **applications**. + + +| Nom | Syntaxe | Exemple | Explication | +|-------------|------------------------------------|-----------|---------------------------------------------------| +| Variable | `<nom>` | `x` | une variable nommée "x" | +| Fonction | `λ<paramètres>.<corps>` | `λx.x` | une fonction avec le paramètre "x" et le corps "x"| +| Application | `<fonction><variable ou function>` | `(λx.x)a` | appel de la fonction "λx.x" avec l'argument "a" | + +La fonction la plus fondamentale est la fonction identité: `λx.x` qui est équivalente à `f(x) = x`. Le premier "x" est l'argument de la fonction, et le second est le corps de la fonction. + +## Variables libres et liées : + +- Dans la fonction `λx.x`, "x" s'appelle une variable liée car elle est à la fois dans le corps de la fonction et l'un des paramètres. +- Dans `λx.y`, "y" est appelé une variable libre car elle n'a pas été déclarée plus tôt. + +## Évaluation : + +L'évaluation est réalisée par [β-Réduction](https://en.wikipedia.org/wiki/Lambda_calculus#Beta_reduction), qui est essentiellement une substitution lexicale. + +Lors de l'évaluation de l'expression `(λx.x)a`, nous remplaçons toutes les occurrences de "x" dans le corps de la fonction par "a". + +- `(λx.x)a` vaut après évaluation: `a` +- `(λx.y)a` vaut après évaluation: `y` + +Vous pouvez même créer des fonctions d'ordre supérieur: + +- `(λx.(λy.x))a` vaut après évaluation: `λy.a` + +Bien que le lambda-calcul ne prenne traditionnellement en charge que les fonctions à un seul paramètre, nous pouvons créer des fonctions multi-paramètres en utilisant une technique appelée currying. + +- `(λx.λy.λz.xyz)` est équivalent à `f(x, y, z) = x(y(z))` + +Parfois, `λxy.<corps>` est utilisé de manière interchangeable avec: `λx.λy.<corps>` + +---- + +Il est important de reconnaître que le lambda-calcul traditionnel n'a pas de nombres, de caractères ou tout autre type de données sans fonction! + +## Logique booléenne : + +Il n'y a pas de "Vrai" ou de "Faux" dans le calcul lambda. Il n'y a même pas 1 ou 0. + +Au lieu: + +`T` est représenté par: `λx.λy.x` + +`F` est représenté par: `λx.λy.y` + +Premièrement, nous pouvons définir une fonction "if" `λbtf` qui renvoie `t` si `b` est vrai et `f` si `b` est faux + +`IF` est équivalent à: `λb.λt.λf.b t f` + +En utilisant `IF`, nous pouvons définir les opérateurs logiques de base booléens: + +`a AND b` est équivalent à: `λab.IF a b F` + +`a OR b` est équivalent à: `λab.IF a T b` + +`a NOT b` est équivalent à: `λa.IF a F T` + +*Note: `IF a b c` est equivalent à : `IF(a(b(c)))`* + +## Nombres : + +Bien qu'il n'y ait pas de nombres dans le lambda-calcul, nous pouvons encoder des nombres en utilisant les [nombres de Church](https://en.wikipedia.org/wiki/Church_encoding). + +Pour tout nombre n: <code>n = λf.f<sup>n</sup></code> donc: + +`0 = λf.λx.x` + +`1 = λf.λx.f x` + +`2 = λf.λx.f(f x)` + +`3 = λf.λx.f(f(f x))` + +Pour incrémenter un nombre de Church, nous utilisons la fonction successeur `S(n) = n + 1` qui est: + +`S = λn.λf.λx.f((n f) x)` + +En utilisant `S`, nous pouvons définir la fonction `ADD`: + +`ADD = λab.(a S)n` + +**Défi:** essayez de définir votre propre fonction de multiplication! + +## Pour aller plus loin : + +1. [A Tutorial Introduction to the Lambda Calculus](http://www.inf.fu-berlin.de/lehre/WS03/alpi/lambda.pdf) +2. [Cornell CS 312 Recitation 26: The Lambda Calculus](http://www.cs.cornell.edu/courses/cs3110/2008fa/recitations/rec26.html) +3. [Wikipedia - Lambda Calculus](https://en.wikipedia.org/wiki/Lambda_calculus) diff --git a/fr-fr/markdown-fr.html.markdown b/fr-fr/markdown-fr.html.markdown new file mode 100644 index 00000000..b3b7de85 --- /dev/null +++ b/fr-fr/markdown-fr.html.markdown @@ -0,0 +1,367 @@ +--- +language: markdown +contributors: +- ["Andrei Curelaru", "http://www.infinidad.fr"] +filename: markdown-fr.md +lang: fr-fr +--- + + +Markdown a été créé par John Gruber en 2004. Il se veut être d'une syntaxe +facile à lire et à écrire, aisément convertible en HTML (et dans beaucoup +d'autres formats aussi). + +Les implémentations du Markdown varient d'un analyseur syntaxique à un autre. +Ce guide va essayer de clarifier quand une fonctionnalité est universelle ou +quand elle est specifique à un certain analyseur syntaxique. + +- [Balises HTML](#balises-html) +- [En-têtes](#en-tetes) +- [Styles de texte basiques](#style-de-text-basiques) +- [Paragraphes](#paragraphes) +- [Listes](#listes) +- [Blocs de code](#blocs-de-code) +- [Séparateur horizontal](#separateur-horizontal) +- [Liens hypertextes](#liens-hypertextes) +- [Images](#images) +- [Divers](#divers) + +## Balises HTML + +Markdown est un sur-ensemble du HTML, donc tout fichier HTML est un ficher +Markdown valide. + +```md +<!-- Ce qui veut dire que vous pouvez utiliser des balises HTML dans un fichier +Markdown, comme la balise commentaire dans laquelle nous sommes à présent, car +celle-ci ne sera pas affectée par l'analyseur syntaxique du Markdown. +Toutefois, si vous voulez créer une balise HTML dans un fichier Markdown, +vous ne pourrez pas utiliser du Markdown à l'intérieur de cette derniere. --> +``` + +## En-têtes + +Vous pouvez facilement créer des balises HTML `<h1>` à `<h6>` en précédant le +texte de votre futur titre par un ou plusieurs dièses ( # ), de un à six, selon +le niveau de titre souhaité. + +```md +# Ceci est un <h1> +## Ceci est un <h2> +### Ceci est un <h3> +#### Ceci est un <h4> +##### Ceci est un <h5> +###### Ceci est un <h6> +``` + +Markdown fournit également une façon alternative de marquer les `<h1>` et `<h2>` + +```md +Ceci est un h1 +============= + +Ceci est un h2 +------------- +``` + +## Styles de texte basiques + +On peut facilement rendre un texte "gras" ou "italique" en Markdown. + +```md +*Ce texte est en italique.* +_Celui-ci aussi._ + +**Ce texte est en gras.** +__Celui-là aussi.__ + +***Ce texte a les deux styles.*** +**_Pareil ici_** +*__Et là!__* +``` + +Dans le "GitHub Flavored Markdown", utilisé pour interpréter le Markdown sur +GitHub, on a également le texte barré. + +```md +~~Ce texte est barré.~~ +``` + +## Paragraphes + +Les paragraphes sont représentés par une ou plusieurs lignes de texte séparées +par une ou plusieurs lignes vides. + +```md +Ceci est un paragraphe. Là, je suis dans un paragraphe, facile non? + +Maintenant je suis dans le paragraphe 2. +Je suis toujours dans le paragraphe 2! + + +Puis là, eh oui, le paragraphe 3! +``` + +Si jamais vous souhaitez insérer une balise HTML `<br />`, vous pouvez ajouter +un ou plusieurs espaces à la fin de votre paragraphe, et en commencer un +nouveau. + +```md +J'ai deux espaces vides à la fin (sélectionnez moi pour les voir). + +Bigre, il y a un <br /> au dessus de moi! +``` + +Les blocs de citations sont générés aisément, grâce au caractère `>`. + +```md +> Ceci est une superbe citation. Vous pouvez même +> revenir à la ligne quand ça vous chante, et placer un `>` +> devant chaque bout de ligne faisant partie +> de la citation. +> La taille ne compte pas^^ tant que chaque ligne commence par un `>`. + +> Vous pouvez aussi utiliser plus d'un niveau +>> d'imbrication! +> Classe et facile, pas vrai? +``` + +## Listes + +Les listes non ordonnées sont marquées par des asterisques, signes plus ou +signes moins. + +```md +* Item +* Item +* Un autre item +``` + +ou + +```md ++ Item ++ Item ++ Encore un item +``` + +ou + +```md +- Item +- Item +- Un dernier item +``` + +Les listes ordonnées sont générées via un nombre suivi d'un point. + +```md +1. Item un +2. Item deux +3. Item trois +``` + +Vous pouvez même vous passer de tout numéroter, et Markdown générera les bons +chiffres. Ceci dit, cette variante perd en clarté. + +```md +1. Item un +1. Item deux +1. Item trois +``` + +(Cette liste sera interprétée de la même façon que celle au dessus) + +Vous pouvez également utiliser des sous-listes. + +```md +1. Item un +2. Item deux +3. Item trois +* Sub-item +* Sub-item +4. Item quatre +``` + +Il y a même des listes de taches. Elles génèrent des champs HTML de type case à +cocher. + +```md +Les [ ] ci-dessous, n'ayant pas de [ x ], deviendront des cases à cocher HTML +non-cochées. +- [ ] Première tache à réaliser. +- [ ] Une autre chose à faire. +La case suivante sera une case à cocher HTML cochée. +- [x] Ça ... c'est fait! +``` + +## Blocs de code + +Pour marquer du texte comme étant du code (qui utilise la balise `<code>`), il +suffit d'indenter chaque ligne avec 4 espaces ou une tabulation. + +```md + echo "Ça, c'est du Code!"; + var Ça = "aussi !"; +``` + +L'indentation par tabulation (ou série de quatre espaces) fonctionne aussi à +l'intérieur du bloc de code. + +```md + my_array.each do |item| + puts item + end +``` + +Des bouts de code en mode en ligne s'ajoutent en utilisant le caractères +`` ` ``. + +```md +La fonction `run()` ne vous oblige pas à aller courir! +``` + +En Markdown GitHub, vous pouvez utiliser des syntaxes spécifiques. + + ```ruby + def foobar + puts "Hello world!" + end + ``` + +Pas besoin d'indentation pour le code juste au-dessus, de plus, GitHub +va utiliser une coloration syntaxique pour le langage indiqué après les ```. + +## Ligne Horizontale + +Pour insérer une ligne horizontale, utilisez trois ou plusieurs astérisques ou tirets, avec ou sans espaces entre. + +```md +*** +--- +- - - +**************** +``` + +## Liens hypertextes + +Une des fonctionnalités sympathiques du Markdown est la facilité d'ajouter des +liens hypertextes. Le texte du lien entre crochet `` [] ``, l'url entre +parenthèses `` () ``, et voilà le travail. + +```md +[Clic moi!](http://test.com/) +``` + +Pour ajouter un attribut `Title`, collez-le entre guillemets, avec le lien. + +```md +[Clic moi!](http://test.com/ "Lien vers Test.com") +``` + +Markdown supporte aussi les liens relatifs. + +```md +[En avant la musique](/music/). +``` + +Les liens de références sont eux aussi disponibles en Markdown. + +```md +[Cliquez ici][link1] pour plus d'information! +[Regardez aussi par ici][foobar] si vous voulez. + +[link1]: http://test.com/ "Cool!" +[foobar]: http://foobar.biz/ "Génial!" +``` + +Le titre peut aussi être entouré de guillemets simples, ou de parenthèses, ou +absent. Les références peuvent être placées où vous voulez dans le document et +les identifiants peuvent être n'importe quoi tant qu'ils sont uniques. + +Il y a également le nommage implicite qui transforme le texte du lien en +identifiant. + +```md +[Ceci][] est un lien. + +[ceci]: http://ceciestunlien.com/ +``` + +Mais ce n'est pas beaucoup utilisé. + +## Images + +Pour les images, la syntaxe est identique à celle des liens, sauf que précédée +d'un point d'exclamation! + +```md + +``` + +Là aussi, on peut utiliser le mode "références". + + +```md +![Ceci est l'attribut ALT de l'image][monimage] + +[monimage]: relative/urls/cool/image.jpg "si vous voulez un titre, c'est ici." +``` + +## Divers + +### Liens Automatiques + +```md +<http://testwebsite.com/> est équivalent à : +[http://testwebsite.com/](http://testwebsite.com/) +``` + +### Liens Automatiques pour emails + +```md +<foo@bar.com> +``` + +### Caracteres d'echappement + +Il suffit de précéder les caractères spécifiques à ignorer par des backslash `\`. + +```md +Pour taper *ce texte* entouré d'astérisques mais pas en italique : +Tapez \*ce texte\*. +``` + +### Touches de clavier + +Avec le "Github Flavored Markdown", vous pouvez utiliser la balise `<kdb>` +pour représenter une touche du clavier. + +```md +Ton ordinateur a planté? Essayer de taper : +<kbd>Ctrl</kbd>+<kbd>Alt</kbd>+<kbd>Del</kbd> +``` + +### Tableaux + +Les tableaux ne sont disponibles que dans le "GitHub Flavored Markdown" et +ne sont pas tres agréable d'utilisation. Mais si vous en avez besoin : + +```md +| Col1 | Col2 | Col3 | +| :----------- | :------: | ------------: | +| Alignement Gauche | Centé | Alignement Droite | +| bla | bla | bla | +``` + +ou bien, pour un résultat équivalent : + +```md +Col 1 | Col2 | Col3 +:-- | :-: | --: +Ough que c'est moche | svp | arrêtez +``` + +Pour plus d'information, consultez le post officiel de Jhon Gruber à propos de +la syntaxe [ici](http://daringfireball.net/projects/markdown/syntax) et la +superbe fiche pense-bête de Adam Pritchard [là](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet). diff --git a/fr-fr/markdown.html.markdown b/fr-fr/markdown.html.markdown deleted file mode 100644 index 2e4e8461..00000000 --- a/fr-fr/markdown.html.markdown +++ /dev/null @@ -1,289 +0,0 @@ ---- -language: markdown -contributors: -- ["Andrei Curelaru", "http://www.infinidad.fr"] -filename: markdown-fr.md -lang: fr-fr ---- - -Markdown a été créé par John Gruber en 2004. Il se veut être d'une syntaxe -facile à lire et à écrire, aisément convertible en HTML - (et beaucoup d'autres formats aussi à présent). - -Faites moi autant de retours que vous voulez! Sentez vous libre de "forker" -et envoyer des pull request! - - -```markdown -<!-- Markdown est une sorte de cousin du HTML, si bien que tout document HTML -est un document Markdown valide. Autrement dit, vous pouvez utiliser des -balises HTML dans un fichier Markdown, comme la balise commentaire dans -laquelle nous sommes à présent, car celle-ci ne sera pas affectée par -le parser( analyseur syntaxique ) Markdown. --> - -<!-- Toutefois, si vous voulez créer un élément HTML dans un fichier Markdown, - vous ne pourrez pas utiliser du Markdown à l'intérieur de ce dernier. --> - -<!-- Le Markdown est implémenté de différentes manières, selon le parser. -Ce guide va alors tenter de trier les fonctionnalités universelles de celles -spécifiques à un parser. --> - -<!-- Headers ( En-têtes ) --> -<!-- Vous pouvez facilement créer des éléments HTML <h1> à <h6> en précédant - le texte de votre futur titre par un ou plusieurs dièses ( # ), de un à six, - selon le niveau de titre souhaité. --> -# Ceci est un <h1> -## Ceci est un <h2> -### Ceci est un <h3> -#### Ceci est un <h4> -##### Ceci est un <h5> -###### Ceci est un <h6> - -<!-- -Markdown fournit également une façon alternative de marquer les h1 et h2 ---> - -Ceci est un h1 -============= - -Ceci est un h2 -------------- - -<!-- Styles basiques pour du texte --> -<!-- On peut facilement rendre un texte "gras" ou "italique" en Markdown --> - -*Ce texte est en italique.* -_Celui-ci aussi._ - -**Ce texte est en gras.** -__Celui-là aussi.__ - -***Ce texte a les deux styles.*** -**_Pareil ici_** -*__Et là!__* - -<!-- Dans le "GitHub Flavored Markdown", utilisé pour interpréter le Markdown -sur GitHub, on a également le strikethrough ( texte barré ) : --> - -~~Ce texte est barré avec strikethrough.~~ - -<!-- Les Paragraphes sont représentés par une ou plusieurs lignes de texte -séparées par une ou plusieurs lignes vides. --> - -Ceci est un paragraphe. Là, je suis dans un paragraphe, facile non? - -Maintenant je suis dans le paragraphe 2. -Je suis toujours dans le paragraphe 2! - - -Puis là, eh oui, le paragraphe 3! - -<!-- -Si jamais vous souhaitez insérer une balise HTML <br />, vous pouvez ajouter -un ou plusieurs espaces à la fin de votre paragraphe, et en commencer -un nouveau. ---> - -J'ai deux espaces vides à la fin (sélectionnez moi pour les voir). - -Bigre, il y a un <br /> au dessus de moi! - -<!-- Les 'Blocs de Citations' sont générés aisément, grâce au caractère > --> - -> Ceci est une superbe citation. Vous pouvez même -> revenir à la ligne quand ça vous chante, et placer un `>` -> devant chaque bout de ligne faisant partie -> de la citation. -> La taille ne compte pas^^ tant que chaque ligne commence par un `>`. - -> Vous pouvez aussi utiliser plus d'un niveau ->> d'imbrication! -> Classe et facile, pas vrai? - -<!-- les Listes --> -<!-- les Listes non ordonnées sont marquées par des asterisques, -signes plus ou signes moins. --> - -* Item -* Item -* Un autre item - -ou - -+ Item -+ Item -+ Encore un item - -ou - -- Item -- Item -- Un dernier item - -<!-- les Listes Ordonnées sont générées via un nombre suivi d'un point --> - -1. Item un -2. Item deux -3. Item trois - -<!-- Vous pouvez même vous passer de tout numéroter, et Markdown générera -les bons chiffres. Ceci dit, cette variante perd en clarté.--> - -1. Item un -1. Item deux -1. Item trois -<!-- ( cette liste sera interprétée de la même façon que celle au dessus ) --> - -<!-- Vous pouvez également utiliser des sous-listes --> - -1. Item un -2. Item deux -3. Item trois -* Sub-item -* Sub-item -4. Item quatre - -<!-- Il y a même des "listes de Taches". Elles génèrent des champs HTML -de type checkbox. --> - -Les [ ] ci dessous, n'ayant pas de [ x ], -deviendront des cases à cocher HTML non-cochées. - -- [ ] Première tache à réaliser. -- [ ] Une autre chose à faire. -La case suivante sera une case à cocher HTML cochée. -- [x] Ça ... c'est fait! - -<!-- les Blocs de Code --> -<!-- Pour marquer du texte comme étant du code, il suffit de commencer -chaque ligne en tapant 4 espaces (ou un Tab) --> - - echo "Ça, c'est du Code!"; - var Ça = "aussi !"; - -<!-- L'indentation par tab ou série de quatre espaces -fonctionne aussi à l'intérieur du bloc de code --> - - my_array.each do |item| - puts item - end - -<!-- Des bouts de code en mode 'inline' s'ajoutent en les entourant de ` --> - -La fonction `run()` ne vous oblige pas à aller courir! - -<!-- Via GitHub Flavored Markdown, vous pouvez utiliser -des syntaxes spécifiques --> - -\`\`\`ruby -<!-- mais enlevez les backslashes quand vous faites ça, -gardez juste ```ruby ( ou nom de la syntaxe correspondant à votre code )--> -def foobar -puts "Hello world!" -end -\`\`\` <!-- pareil, pas de backslashes, juste ``` en guise de fin --> - -<-- Pas besoin d'indentation pour le code juste au dessus, de plus, GitHub -va utiliser une coloration syntaxique pour le langage indiqué après les ``` --> - -<!-- Ligne Horizontale (<hr />) --> -<!-- Pour en insérer une, utilisez trois ou plusieurs astérisques ou tirets, -avec ou sans espaces entre chaque un. --> - -*** ---- -- - - -**************** - -<!-- Liens --> -<!-- Une des fonctionnalités sympathiques du Markdown est la facilité -d'ajouter des liens. Le texte du lien entre [ ], l'url entre ( ), -et voilà l'travail. ---> - -[Clic moi!](http://test.com/) - -<!-- -Pour ajouter un attribut Title, collez le entre guillemets, avec le lien. ---> - -[Clic moi!](http://test.com/ "Lien vers Test.com") - -<!-- les Liens Relatifs marchent aussi --> - -[En avant la musique](/music/). - -<!-- Les liens façon "références" sont eux aussi disponibles en Markdown --> - -[Cliquez ici][link1] pour plus d'information! -[Regardez aussi par ici][foobar] si vous voulez. - -[link1]: http://test.com/ "Cool!" -[foobar]: http://foobar.biz/ "Alright!" - -<!-- Le titre peut aussi être entouré de guillemets simples, -entre parenthèses ou absent. Les références peuvent être placées -un peu où vous voulez dans le document, et les identifiants -(link1, foobar, ...) quoi que ce soit tant qu'ils sont uniques --> - -<!-- Il y a également le "nommage implicite" qui transforme le texte du lien - en identifiant --> - -[Ceci][] est un lien. - -[ceci]: http://ceciestunlien.com/ - -<!-- mais ce n'est pas beaucoup utilisé. --> - -<!-- Images --> -<!-- Pour les images, la syntaxe est identique aux liens, sauf que précédée - d'un point d'exclamation! --> - - - -<!-- Là aussi, on peut utiliser le mode "références" --> - -![Ceci est l'attribut ALT de l'image][monimage] - -[monimage]: relative/urls/cool/image.jpg "si vous voulez un titre, c'est ici." - -<!-- Divers --> -<!-- Liens Automatiques --> - -<http://testwebsite.com/> est équivalent à : -[http://testwebsite.com/](http://testwebsite.com/) - -<!-- Liens Automatiques pour emails --> - -<foo@bar.com> - -<!-- Escaping --> -Il suffit de précéder les caractères spécifiques à ignorer par des backslash \ - -Pour taper *ce texte* entouré d'astérisques mais pas en italique : -Tapez \*ce texte\*. - -<!-- Tableaux --> -<!-- les Tableaux ne sont disponibles que dans le GitHub Flavored Markdown - et c'est ce n'est pas super agréable d'utilisation. - Mais si vous en avez besoin : - --> - -| Col1 | Col2 | Col3 | -| :----------- | :------: | ------------: | -| Alignement Gauche | Centé | Alignement Droite | -| bla | bla | bla | - -<!-- ou bien, pour un résultat équivalent : --> - -Col 1 | Col2 | Col3 -:-- | :-: | --: -Ough que c'est moche | svp | arrêtez - -<!-- Fin! --> - -``` - -Pour plus d'information : - consultez [ici](http://daringfireball.net/projects/markdown/syntax) le post officiel de Jhon Gruber à propos de la syntaxe, - et [là](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet) la superbe cheatsheet de Adam Pritchard. diff --git a/fr-fr/php.html.markdown b/fr-fr/php-fr.html.markdown index 823630bd..45a02d75 100644 --- a/fr-fr/php.html.markdown +++ b/fr-fr/php-fr.html.markdown @@ -6,10 +6,11 @@ contributors: - ["Trismegiste", "https://github.com/Trismegiste"] translators: - ["Pascal Boutin", "http://pboutin.net/"] + - ["Julien M'Poy", "https://github.com/groovytron"] lang: fr-fr --- -This document describes PHP 5+. +Ce document décrit PHP 5+. ```php // Le code PHP doit être placé à l'intérieur de balises '<?php' @@ -48,7 +49,7 @@ Hello World Again! // Un nom de variable valide commence par une lettre ou un souligné, // suivi de n'importe quelle lettre, nombre ou de soulignés. -// Les valeurs booléenes ne sont pas sensibles à la casse +// Les valeurs booléennes ne sont pas sensibles à la casse $boolean = true; // ou TRUE ou True $boolean = false; // ou FALSE ou False @@ -84,30 +85,30 @@ $number /= $float; // Divise et assigne le quotient à $number $sgl_quotes = '$String'; // => '$String' // Évitez les guillemets sauf pour inclure le contenu d'une autre variable -$dbl_quotes = "This is a $sgl_quotes."; // => 'This is a $String.' +$dbl_quotes = "Ceci est une $sgl_quotes."; // => 'Ceci est une $String.' // Les caractères spéciaux sont seulement échappés avec des guillemets -$escaped = "This contains a \t tab character."; -$unescaped = 'This just contains a slash and a t: \t'; +$escaped = "Ceci contient \t une tabulation."; +$unescaped = 'Ceci contient juste un slash et un t: \t'; // En cas de besoin, placez la variable dans des accolades -$money = "I have $${number} in the bank."; +$money = "J'ai $${number} sur mon compte en banque."; // Depuis PHP 5.3, Nowdoc peut être utilisé pour faire des chaînes // multi-lignes non-interprétées $nowdoc = <<<'END' -Multi line -string +String +mutli-lignes END; // Heredoc peut être utilisé pour faire des chaînes multi-lignes interprétées $heredoc = <<<END -Multi line $sgl_quotes +multi-lignes END; // La concaténation de chaînes se fait avec un . -echo 'This string ' . 'is concatenated'; +echo 'Cette string ' . 'est concatenée'; // => 'Cette string est concaténée' /******************************** @@ -122,7 +123,7 @@ echo 'This string ' . 'is concatenated'; define("FOO", "something"); // on peut accéder à une constante en utilisant directement son nom -echo 'This outputs '.FOO; +echo 'Ceci affiche ' . FOO; /******************************** @@ -149,6 +150,14 @@ $array[] = 'Four'; // Retrait d'un élément du tableau unset($array[3]); +// Depuis PHP 7, il est possible de déclarer des tableaux constants en +// utilisant 'define'. +define('ANIMAUX', [ + 'chien', + 'chat', + 'oiseau', +]); + /******************************** * Affichage */ @@ -159,11 +168,13 @@ echo('Hello World!'); print('Hello World!'); // Pareil à "écho" -// Pour écho, vous n'avez pas besoin des parenthèses +// 'echo' et 'print' sont des language constructs. +// Il n'ont pas besoin de parenthèses car ils sont traités comme +// des opérateurs unaires. echo 'Hello World!'; -print 'Hello World!'; // Pour print non plus +print 'Hello World!'; -$paragraph = 'paragraph'; +$paragraph = 'paragraphe'; echo 100; // Affichez un scalaire directement echo $paragraph; // ou des variables @@ -202,7 +213,8 @@ $b = '0'; $c = '1'; $d = '1'; -// assert affiche un avertissement dans son argument n'est pas vrai +// assert affiche un avertissement quand l'expression booléenne passée +// en argument n'est pas vraie. // Ces comparaisons vont toujours être vraies, même si leurs // types ne sont pas les mêmes. @@ -315,7 +327,7 @@ if ($x === '0') { switch ($x) { case '0': print 'Les switch font du transtypage implicite'; - break; // Il est important de déclaré un 'break', sinon les cas + break; // Il est important de déclarer un 'break', sinon les cas // 'two' et 'three' seront évalués case 'two': case 'three': @@ -390,9 +402,10 @@ function my_function () { echo my_function(); // => "Hello" -// Les noms de fonction débutent par le symbole $ -// Un nom de variable valide commence par une lettre ou un souligné, +// Un nom de fonction valide commence par une lettre ou un souligné, // suivi de n'importe quelle lettre, nombre ou de soulignés. +// Les noms des arguments d'une fonction doivent respecter le même format que +// celui des variables. function add ($x, $y = 1) { // $y est facultatif et sa valeur par défaut est 1 $result = $x + $y; @@ -519,7 +532,7 @@ class MyClass public static function myStaticMethod() { - print 'I am static'; + print 'Je suis static'; } } @@ -527,7 +540,7 @@ class MyClass echo MyClass::MY_CONST; // Outputs 'value'; echo MyClass::$staticVar; // Retourne 'static'; -MyClass::myStaticMethod(); // Retourne 'I am static'; +MyClass::myStaticMethod(); // Retourne 'Je suis static'; // On peut instancier une classe en utilisant le mot clé 'new' $my_class = new MyClass('An instance property'); @@ -584,7 +597,7 @@ echo $x->property; // Va utiliser la méthode __get() $x->property = 'Something'; // Va utiliser la méthode __set() // Les classes peuvent être abstraites (en utilisant le mot clé 'abstract'), ou -// elle peuvent implémenter une interface (en utilisant le mot clé 'implement'). +// elle peuvent implémenter une interface (en utilisant le mot clé 'implements'). // Une interface peut être déclarée avec le mot clé 'interface' @@ -637,6 +650,35 @@ class SomeOtherClass implements InterfaceOne, InterfaceTwo } } +// Il est possible de déclarer des classes internes anonymes depuis PHP 7 + +interface Logger { + public function log(string $msg); +} + +class Application { + private $logger; + + public function getLogger(): Logger { + return $this->logger; + } + + public function setLogger(Logger $logger) { + $this->logger = $logger; + } +} + +$app = new Application; + +$app->setLogger(new class implements Logger { + public function log(string $msg) { + echo $msg; + } +}); + +var_dump($app->getLogger()); // => 'object(class@anonymous)#2 (0) {}' + + /******************************** * Espaces de noms (namespaces) */ diff --git a/fr-fr/pyqt-fr.html.markdown b/fr-fr/pyqt-fr.html.markdown new file mode 100644 index 00000000..6da9a380 --- /dev/null +++ b/fr-fr/pyqt-fr.html.markdown @@ -0,0 +1,85 @@ +--- +category: tool +tool: PyQT +filename: learnpyqt-fr.py +contributors: + - ["Nathan Hughes", "https://github.com/sirsharpest"] +translators: + - ["DevHugo", "http://twitter.com/devhugo"] +lang: fr-fr +--- + +**Qt** est un framework très connu pour le développement de logiciel cross-platform qui peuvent être lancé sur différents systèmes avec de petit ou aucun changement dans le code, tout en ayant la puissance et la vitesse des applications natives. Bien que **Qt** ait été écrit à l'origine en *C++*. + + +Ceci est une adaptation de l'intro C++ à QT par [Aleksey Kholovchuk](https://github.com/vortexxx192 +), certains exemples du code doivent avoir la même fonctionnalité, +cette version ayant juste été faite en utilisant pyqt! + +```python +import sys +from PyQt4 import QtGui + +def window(): + # Création de l'objet application + app = QtGui.QApplication(sys.argv) + # Création d'un widget où notre label sera placé + w = QtGui.QWidget() + # Ajout d'un label au widget + b = QtGui.QLabel(w) + # Assignation de texte au label + b.setText("Hello World!") + # Assignation des tailles et des informations de placement + w.setGeometry(100, 100, 200, 50) + b.move(50, 20) + # Assignation d'un nom à notre fenêtre + w.setWindowTitle("PyQt") + # Affichage de la fenêtre + w.show() + # Exécution de l'application + sys.exit(app.exec_()) + +if __name__ == '__main__': + window() + +``` + +Pour obtenir certaines des fonctionnalités les plus avancées de **pyqt** nous devons commencer par chercher à construire des éléments supplémentaires. +Ici nous voyons comment introduire une boîte de dialogue popup, utile pour demander une confirmation à un utilisateur ou fournir des informations. + +```Python +import sys +from PyQt4.QtGui import * +from PyQt4.QtCore import * + + +def window(): + app = QApplication(sys.argv) + w = QWidget() + # Creation d'un bouton attaché au widget w + b = QPushButton(w) + b.setText("Press me") + b.move(50, 50) + # Dire à b d'appeler cette fonction quand il est cliqué + # remarquez l'absence de "()" sur l'appel de la fonction + b.clicked.connect(showdialog) + w.setWindowTitle("PyQt Dialog") + w.show() + sys.exit(app.exec_()) + +# Cette fonction devrait créer une fenêtre de dialogue avec un bouton +# qui attend d'être cliqué puis quitte le programme +def showdialog(): + d = QDialog() + b1 = QPushButton("ok", d) + b1.move(50, 50) + d.setWindowTitle("Dialog") + # Cette modalité dit au popup de bloquer le parent pendant qu'il est actif + d.setWindowModality(Qt.ApplicationModal) + # En cliquant je voudrais que tout le processus se termine + b1.clicked.connect(sys.exit) + d.exec_() + +if __name__ == '__main__': + window() +``` diff --git a/fr-fr/scala.html.markdown b/fr-fr/scala-fr.html.markdown index c6a61745..c6a61745 100644 --- a/fr-fr/scala.html.markdown +++ b/fr-fr/scala-fr.html.markdown diff --git a/fr-fr/vim.html.markdown b/fr-fr/vim-fr.html.markdown index b2f1d24d..b2f1d24d 100644 --- a/fr-fr/vim.html.markdown +++ b/fr-fr/vim-fr.html.markdown diff --git a/fsharp.html.markdown b/fsharp.html.markdown index bbf477ba..59461eed 100644 --- a/fsharp.html.markdown +++ b/fsharp.html.markdown @@ -34,7 +34,7 @@ let myFloat = 3.14 let myString = "hello" // note that no types needed // ------ Lists ------ -let twoToFive = [2; 3; 4; 5] // Square brackets create a list with +let twoToFive = [2; 3; 4; 5] // Square brackets create a list with // semicolon delimiters. let oneToFive = 1 :: twoToFive // :: creates list with new 1st element // The result is [1; 2; 3; 4; 5] @@ -53,7 +53,8 @@ add 2 3 // Now run the function. // to define a multiline function, just use indents. No semicolons needed. let evens list = - let isEven x = x % 2 = 0 // Define "isEven" as a sub function + let isEven x = x % 2 = 0 // Define "isEven" as a sub function. Note + // that equality operator is single char "=". List.filter isEven list // List.filter is a library function // with two parameters: a boolean function // and a list to work on @@ -306,7 +307,7 @@ module DataTypeExamples = // ------------------------------------ // Union types (aka variants) have a set of choices - // Only case can be valid at a time. + // Only one case can be valid at a time. // ------------------------------------ // Use "type" with bar/pipe to define a union type diff --git a/git.html.markdown b/git.html.markdown index 582f8863..aa96c90a 100644 --- a/git.html.markdown +++ b/git.html.markdown @@ -26,11 +26,11 @@ Version control is a system that records changes to a file(s), over time. ### Centralized Versioning vs. Distributed Versioning -* Centralized version control focuses on synchronizing, tracking, and backing +* Centralized version control focuses on synchronizing, tracking, and backing up files. -* Distributed version control focuses on sharing changes. Every change has a +* Distributed version control focuses on sharing changes. Every change has a unique id. -* Distributed systems have no defined structure. You could easily have a SVN +* Distributed systems have no defined structure. You could easily have a SVN style, centralized system, with git. [Additional Information](http://git-scm.com/book/en/Getting-Started-About-Version-Control) @@ -57,7 +57,7 @@ A git repository is comprised of the .git directory & working tree. ### .git Directory (component of repository) -The .git directory contains all the configurations, logs, branches, HEAD, and +The .git directory contains all the configurations, logs, branches, HEAD, and more. [Detailed List.](http://gitready.com/advanced/2009/03/23/whats-inside-your-git-directory.html) @@ -68,15 +68,15 @@ referred to as your working directory. ### Index (component of .git dir) -The Index is the staging area in git. It's basically a layer that separates -your working tree from the Git repository. This gives developers more power +The Index is the staging area in git. It's basically a layer that separates +your working tree from the Git repository. This gives developers more power over what gets sent to the Git repository. ### Commit -A git commit is a snapshot of a set of changes, or manipulations to your -Working Tree. For example, if you added 5 files, and removed 2 others, these -changes will be contained in a commit (or snapshot). This commit can then be +A git commit is a snapshot of a set of changes, or manipulations to your +Working Tree. For example, if you added 5 files, and removed 2 others, these +changes will be contained in a commit (or snapshot). This commit can then be pushed to other repositories, or not! ### Branch @@ -91,13 +91,13 @@ functionality to mark release points (v1.0, and so on) ### HEAD and head (component of .git dir) -HEAD is a pointer that points to the current branch. A repository only has 1 -*active* HEAD. -head is a pointer that points to any commit. A repository can have any number +HEAD is a pointer that points to the current branch. A repository only has 1 +*active* HEAD. +head is a pointer that points to any commit. A repository can have any number of heads. ### Stages of Git -* Modified - Changes have been made to a file but file has not been committed +* Modified - Changes have been made to a file but file has not been committed to Git Database yet * Staged - Marks a modified file to go into your next commit snapshot * Committed - Files have been committed to the Git Database @@ -111,7 +111,7 @@ to Git Database yet ### init -Create an empty Git repository. The Git repository's settings, stored +Create an empty Git repository. The Git repository's settings, stored information, and more is stored in a directory (a folder) named ".git". ```bash @@ -179,7 +179,7 @@ $ git help status ### add -To add files to the staging area/index. If you do not `git add` new files to +To add files to the staging area/index. If you do not `git add` new files to the staging area/index, they will not be included in commits! ```bash @@ -201,7 +201,7 @@ working directory/repo. ### branch -Manage your branches. You can view, edit, create, delete branches using this +Manage your branches. You can view, edit, create, delete branches using this command. ```bash @@ -250,7 +250,7 @@ $ git push origin --tags ### checkout -Updates all files in the working tree to match the version in the index, or +Updates all files in the working tree to match the version in the index, or specified tree. ```bash @@ -269,7 +269,7 @@ $ git checkout -b newBranch ### clone Clones, or copies, an existing repository into a new directory. It also adds -remote-tracking branches for each branch in the cloned repo, which allows you +remote-tracking branches for each branch in the cloned repo, which allows you to push to a remote branch. ```bash @@ -285,7 +285,7 @@ $ git clone -b master-cn https://github.com/adambard/learnxinyminutes-docs.git - ### commit -Stores the current contents of the index in a new "commit." This commit +Stores the current contents of the index in a new "commit." This commit contains the changes made and a message created by the user. ```bash @@ -401,11 +401,11 @@ Pulls from a repository and merges it with another branch. $ git pull origin master # By default, git pull will update your current branch -# by merging in new changes from its remote-tracking branch +# by merging in new changes from its remote-tracking branch $ git pull # Merge in changes from remote branch and rebase -# branch commits onto your local repo, like: "git fetch <remote> <branch>, git +# branch commits onto your local repo, like: "git fetch <remote> <branch>, git # rebase <remote>/<branch>" $ git pull origin master --rebase ``` @@ -421,7 +421,7 @@ Push and merge changes from a branch to a remote & branch. $ git push origin master # By default, git push will push and merge changes from -# the current branch to its remote-tracking branch +# the current branch to its remote-tracking branch $ git push # To link up current local branch with a remote branch, add -u flag: @@ -432,7 +432,7 @@ $ git push ### stash -Stashing takes the dirty state of your working directory and saves it on a +Stashing takes the dirty state of your working directory and saves it on a stack of unfinished changes that you can reapply at any time. Let's say you've been doing some work in your git repo, but you want to pull @@ -464,7 +464,7 @@ nothing to commit, working directory clean ``` You can see what "hunks" you've stashed so far using `git stash list`. -Since the "hunks" are stored in a Last-In-First-Out stack, our most recent +Since the "hunks" are stored in a Last-In-First-Out stack, our most recent change will be at top. ```bash @@ -495,7 +495,7 @@ Now you're ready to get back to work on your stuff! ### rebase (caution) -Take all changes that were committed on one branch, and replay them onto +Take all changes that were committed on one branch, and replay them onto another branch. *Do not rebase commits that you have pushed to a public repo*. @@ -510,7 +510,7 @@ $ git rebase master experimentBranch ### reset (caution) Reset the current HEAD to the specified state. This allows you to undo merges, -pulls, commits, adds, and more. It's a great command but also dangerous if you +pulls, commits, adds, and more. It's a great command but also dangerous if you don't know what you are doing. ```bash @@ -535,7 +535,7 @@ $ git reset --hard 31f2bb1 Reflog will list most of the git commands you have done for a given time period, default 90 days. -This give you the chance to reverse any git commands that have gone wrong +This give you the chance to reverse any git commands that have gone wrong (for instance, if a rebase has broken your application). You can do this: @@ -558,8 +558,8 @@ ed8ddf2 HEAD@{4}: rebase -i (pick): pythonstatcomp spanish translation (#1748) ### revert -Revert can be used to undo a commit. It should not be confused with reset which -restores the state of a project to a previous point. Revert will add a new +Revert can be used to undo a commit. It should not be confused with reset which +restores the state of a project to a previous point. Revert will add a new commit which is the inverse of the specified commit, thus reverting it. ```bash @@ -604,3 +604,5 @@ $ git rm /pather/to/the/file/HelloWorld.c * [Pro Git](http://www.git-scm.com/book/en/v2) * [An introduction to Git and GitHub for Beginners (Tutorial)](http://product.hubspot.com/blog/git-and-github-tutorial-for-beginners) + +* [The New Boston tutorial to Git covering basic commands and workflow](https://www.youtube.com/playlist?list=PL6gx4Cwl9DGAKWClAD_iKpNC0bGHxGhcx) diff --git a/go.html.markdown b/go.html.markdown index e5263cf6..ae99535b 100644 --- a/go.html.markdown +++ b/go.html.markdown @@ -15,15 +15,15 @@ contributors: --- Go was created out of the need to get work done. It's not the latest trend -in computer science, but it is the newest fastest way to solve real-world +in programming language theory, but it is a way to solve real-world problems. -It has familiar concepts of imperative languages with static typing. +It draws concepts from imperative languages with static typing. It's fast to compile and fast to execute, it adds easy-to-understand -concurrency to leverage today's multi-core CPUs, and has features to -help with large-scale programming. +concurrency because multi-core CPUs are now common, and it's used successfully +in large codebases (~100 million loc at Google, Inc.). -Go comes with a great standard library and an enthusiastic community. +Go comes with a good standard library and a sizeable community. ```go // Single line comment @@ -48,7 +48,7 @@ import ( // executable program. Love it or hate it, Go uses brace brackets. func main() { // Println outputs a line to stdout. - // Qualify it with the package name, fmt. + // It comes from the package fmt. fmt.Println("Hello world!") // Call another function within this package. @@ -180,7 +180,7 @@ func learnFlowControl() { if true { fmt.Println("told ya") } - // Formatting is standardized by the command line command "go fmt." + // Formatting is standardized by the command line command "go fmt". if false { // Pout. } else { @@ -277,7 +277,8 @@ func sentenceFactory(mystring string) func(before, after string) string { } func learnDefer() (ok bool) { - // Deferred statements are executed just before the function returns. + // A defer statement pushes a function call onto a list. The list of saved + // calls is executed AFTER the surrounding function returns. defer fmt.Println("deferred statements execute in reverse (LIFO) order.") defer fmt.Println("\nThis line is being printed first because") // Defer is commonly used to close a file, so the function closing the diff --git a/haskell.html.markdown b/haskell.html.markdown index 266cf11b..90d47c27 100644 --- a/haskell.html.markdown +++ b/haskell.html.markdown @@ -124,6 +124,9 @@ last [1..5] -- 5 fst ("haskell", 1) -- "haskell" snd ("haskell", 1) -- 1 +-- pair element accessing does not work on n-tuples (i.e. triple, quadruple, etc) +snd ("snd", "can't touch this", "da na na na") -- error! see function below + ---------------------------------------------------- -- 3. Functions ---------------------------------------------------- @@ -159,8 +162,8 @@ fib 1 = 1 fib 2 = 2 fib x = fib (x - 1) + fib (x - 2) --- Pattern matching on tuples: -foo (x, y) = (x + 1, y + 2) +-- Pattern matching on tuples +sndOfTriple (_, y, _) = y -- use a wild card (_) to bypass naming unused value -- Pattern matching on lists. Here `x` is the first element -- in the list, and `xs` is the rest of the list. We can write @@ -203,11 +206,11 @@ foo = (4*) . (10+) foo 5 -- 60 -- fixing precedence --- Haskell has an operator called `$`. This operator applies a function --- to a given parameter. In contrast to standard function application, which --- has highest possible priority of 10 and is left-associative, the `$` operator +-- Haskell has an operator called `$`. This operator applies a function +-- to a given parameter. In contrast to standard function application, which +-- has highest possible priority of 10 and is left-associative, the `$` operator -- has priority of 0 and is right-associative. Such a low priority means that --- the expression on its right is applied as the parameter to the function on its left. +-- the expression on its right is applied as a parameter to the function on its left. -- before even (fib 7) -- false @@ -223,7 +226,7 @@ even . fib $ 7 -- false -- 5. Type signatures ---------------------------------------------------- --- Haskell has a very strong type system, and every valid expression has a type. +-- Haskell has a very strong type system, and every valid expression has a type. -- Some basic types: 5 :: Integer diff --git a/haxe.html.markdown b/haxe.html.markdown index df2a1e78..afb9d1a3 100644 --- a/haxe.html.markdown +++ b/haxe.html.markdown @@ -770,19 +770,18 @@ class UsingExample { ``` We're still only scratching the surface here of what Haxe can do. For a formal -overview of all Haxe features, checkout the [online -manual](http://haxe.org/manual), the [online API](http://api.haxe.org/), and -"haxelib", the [haxe library repo] (http://lib.haxe.org/). +overview of all Haxe features, see the [manual](https://haxe.org/manual) and +the [API docs](https://api.haxe.org/). For a comprehensive directory of available +third-party Haxe libraries, see [Haxelib](https://lib.haxe.org/). For more advanced topics, consider checking out: -* [Abstract types](http://haxe.org/manual/abstracts) -* [Macros](http://haxe.org/manual/macros), and [Compiler Macros](http://haxe.org/manual/macros_compiler) -* [Tips and Tricks](http://haxe.org/manual/tips_and_tricks) - - -Finally, please join us on [the mailing list](https://groups.google.com/forum/#!forum/haxelang), on IRC [#haxe on -freenode](http://webchat.freenode.net/), or on -[Google+](https://plus.google.com/communities/103302587329918132234). +* [Abstract types](https://haxe.org/manual/types-abstract.html) +* [Macros](https://haxe.org/manual/macro.html) +* [Compiler Features](https://haxe.org/manual/cr-features.html) +Finally, please join us on [the Haxe forum](https://community.haxe.org/), +on IRC [#haxe on +freenode](http://webchat.freenode.net/), or on the +[Haxe Gitter chat](https://gitter.im/HaxeFoundation/haxe). diff --git a/hre.csv b/hre.csv new file mode 100644 index 00000000..eab43cc4 --- /dev/null +++ b/hre.csv @@ -0,0 +1 @@ +Ix,Dynasty,Name,Birth,Death,Coronation 1,Coronation 2,Ceased to be Emperor
N/A,Carolingian,Charles I,2 April 742,28 January 814,25 December 800,N/A,28 January 814
N/A,Carolingian,Louis I,778,20 June 840,11 September 813,5 October 816,20 June 840
N/A,Carolingian,Lothair I,795,29 September 855,5 April 823,N/A,29 September 855
N/A,Carolingian,Louis II,825,12 August 875,15 June 844,18 May 872,12 August 875
N/A,Carolingian,Charles II,13 June 823,6 October 877,29 December 875,N/A,6 October 877
N/A,Carolingian,Charles III,13 June 839,13 January 888,12 February 881,N/A,11 November 887
N/A,Widonid,Guy III,835,12 December 894,21 February 891,N/A,12 December 894
N/A,Widonid,Lambert I,880,15 October 898,30 April 892,N/A,15 October 898
N/A,Carolingian,Arnulph,850,8 December 899,22 February 896,N/A,8 December 899
N/A,Bosonid,Louis III,880,5 June 928,22 February 901,N/A,21 July 905
N/A,Unruoching,Berengar I,845,7 April 924,December 915,N/A,7 April 924
1,Ottonian,Otto I,23 November 912,7 May 973,2 February 962,N/A,7 May 973
2,Ottonian,Otto II,955,7 December 983,25 December 967,N/A,7 December 983
3,Ottonian,Otto III,980,23 January 1002,21 May 996,N/A,23 January 1002
4,Ottonian,Henry II,6 May 973,13 July 1024,14 February 1014,N/A,13 July 1024
5,Salian,Conrad II,990,4 June 1039,26 March 1027,N/A,4 June 1039
6,Salian,Henry III,29 October 1017,5 October 1056,25 December 1046,N/A,5 October 1056
7,Salian,Henry IV,11 November 1050,7 August 1106,31 March 1084,N/A,December 1105
8,Salian,Henry V,8 November 1086,23 May 1125,13 April 1111,N/A,23 May 1125
9,Supplinburg,Lothair III,9 June 1075,4 December 1137,4 June 1133,N/A,4 December 1137
10,Staufen,Frederick I,1122,10 June 1190,18 June 1155,N/A,10 June 1190
11,Staufen,Henry VI,November 1165,28 September 1197,14 April 1191,N/A,28 September 1197
12,Welf,Otto IV,1175,19 May 1218,4 October 1209,N/A,1215
13,Staufen,Frederick II,26 December 1194,13 December 1250,22 November 1220,N/A,13 December 1250
14,Luxembourg,Henry VII,1275,24 August 1313,29 June 1312,N/A,24 August 1313
15,Wittelsbach,Louis IV,1 April 1282,11 October 1347,17 January 1328,N/A,11 October 1347
16,Luxembourg,Charles IV,14 May 1316,29 November 1378,5 April 1355,N/A,29 November 1378
17,Luxembourg,Sigismund,14 February 1368,9 December 1437,31 May 1433,N/A,9 December 1437
18,Habsburg,Frederick III,21 September 1415,19 August 1493,19 March 1452,N/A,19 August 1493
19,Habsburg,Maximilian I,22 March 1459,12 January 1519,N/A,N/A,12 January 1519
20,Habsburg,Charles V,24 February 1500,21 September 1558,February 1530,N/A,16 January 1556
21,Habsburg,Ferdinand I,10 March 1503,25 July 1564,N/A,N/A,25 July 1564
22,Habsburg,Maximilian II,31 July 1527,12 October 1576,N/A,N/A,12 October 1576
23,Habsburg,Rudolph II,18 July 1552,20 January 1612,30 June 1575,N/A,20 January 1612
24,Habsburg,Matthias,24 February 1557,20 March 1619,23 January 1612,N/A,20 March 1619
25,Habsburg,Ferdinand II,9 July 1578,15 February 1637,10 March 1619,N/A,15 February 1637
26,Habsburg,Ferdinand III,13 July 1608,2 April 1657,18 November 1637,N/A,2 April 1657
27,Habsburg,Leopold I,9 June 1640,5 May 1705,6 March 1657,N/A,5 May 1705
28,Habsburg,Joseph I,26 July 1678,17 April 1711,1 May 1705,N/A,17 April 1711
29,Habsburg,Charles VI,1 October 1685,20 October 1740,22 December 1711,N/A,20 October 1740
30,Wittelsbach,Charles VII,6 August 1697,20 January 1745,12 February 1742,N/A,20 January 1745
31,Lorraine,Francis I,8 December 1708,18 August 1765,N/A,N/A,18 August 1765
32,Habsburg-Lorraine,Joseph II,13 March 1741,20 February 1790,19 August 1765,N/A,20 February 1790
33,Habsburg-Lorraine,Leopold II,5 May 1747,1 March 1792,N/A,N/A,1 March 1792
34,Habsburg-Lorraine,Francis II,12 February 1768,2 March 1835,4 March 1792,N/A,6 August 1806
\ No newline at end of file diff --git a/html.html.markdown b/html.html.markdown index 6516e5dd..4d225aca 100644 --- a/html.html.markdown +++ b/html.html.markdown @@ -1,31 +1,47 @@ --- language: html -filename: learnhtml.html +filename: learnhtml.txt contributors: - ["Christophe THOMAS", "https://github.com/WinChris"] translators: - ["Robert Steed", "https://github.com/robochat"] --- -HTML stands for HyperText Markup Language. +HTML stands for HyperText Markup Language. + It is a language which allows us to write pages for the world wide web. -It is a markup language, it enables us to write webpages using code to indicate how text and data should be displayed. -In fact, html files are simple text files. -What is this markup? It is a method of organising the page's data by surrounding it with opening tags and closing tags. -This markup serves to give significance to the text that it encloses. -Like other computer languages, HTML has many versions. Here we will talk about HTML5. +It is a markup language, it enables us to write webpages using code to indicate +how text and data should be displayed. In fact, html files are simple text +files. + +What is this markup? It is a method of organising the page's data by +surrounding it with opening tags and closing tags. This markup serves to give +significance to the text that it encloses. Like other computer languages, HTML +has many versions. Here we will talk about HTML5. -**NOTE :** You can test the different tags and elements as you progress through the tutorial on a site like [codepen](http://codepen.io/pen/) in order to see their effects, understand how they work and familiarise yourself with the language. -This article is concerned principally with HTML syntax and some useful tips. +**NOTE :** You can test the different tags and elements as you progress through +the tutorial on a site like [codepen](http://codepen.io/pen/) in order to see +their effects, understand how they work and familiarise yourself with the +language. This article is concerned principally with HTML syntax and some +useful tips. ```html <!-- Comments are enclosed like this line! --> +<!-- + Comments + can + span + multiple + lines! +--> + <!-- #################### The Tags #################### --> - + <!-- Here is an example HTML file that we are going to analyse. --> + <!doctype html> <html> <head> @@ -33,7 +49,9 @@ This article is concerned principally with HTML syntax and some useful tips. </head> <body> <h1>Hello, world!</h1> - <a href = "http://codepen.io/anon/pen/xwjLbZ">Come look at what this shows</a> + <a href="http://codepen.io/anon/pen/xwjLbZ"> + Come look at what this shows + </a> <p>This is a paragraph.</p> <p>This is another paragraph.</p> <ul> @@ -44,7 +62,9 @@ This article is concerned principally with HTML syntax and some useful tips. </body> </html> -<!-- An HTML file always starts by indicating to the browser that the page is HTML. --> +<!-- + An HTML file always starts by indicating to the browser that the page is HTML. +--> <!doctype html> <!-- After this, it starts by opening an <html> tag. --> @@ -58,10 +78,17 @@ This article is concerned principally with HTML syntax and some useful tips. <!-- Inside (between the opening and closing tags <html></html>), we find: --> <!-- A header defined by <head> (it must be closed with </head>). --> -<!-- The header contains some description and additional information which are not displayed; this is metadata. --> +<!-- + The header contains some description and additional information which are not + displayed; this is metadata. +--> <head> - <title>My Site</title><!-- The tag <title> indicates to the browser the title to show in browser window's title bar and tab name. --> + <!-- + The tag <title> indicates to the browser the title to show in browser + window's title bar and tab name. + --> + <title>My Site</title> </head> <!-- After the <head> section, we find the tag - <body> --> @@ -69,13 +96,28 @@ This article is concerned principally with HTML syntax and some useful tips. <!-- We must fill the body with the content to be displayed. --> <body> - <h1>Hello, world!</h1> <!-- The h1 tag creates a title. --> - <!-- There are also subtitles to <h1> from the most important (h2) to the most precise (h6). --> - <a href = "http://codepen.io/anon/pen/xwjLbZ">Come look at what this shows</a> <!-- a hyperlink to the url given by the attribute href="" --> - <p>This is a paragraph.</p> <!-- The tag <p> lets us include text in the html page. --> + <!-- The h1 tag creates a title. --> + <h1>Hello, world!</h1> + <!-- + There are also subtitles to <h1> from the most important (h2) to the most + precise (h6). + --> + + <!-- a hyperlink to the url given by the attribute href="" --> + <a href="http://codepen.io/anon/pen/xwjLbZ"> + Come look at what this shows + </a> + + <!-- The tag <p> lets us include text in the html page. --> + <p>This is a paragraph.</p> <p>This is another paragraph.</p> - <ul> <!-- The tag <ul> creates a bullet list. --> - <!-- To have a numbered list instead we would use <ol> giving 1. for the first element, 2. for the second, etc. --> + + <!-- The tag <ul> creates a bullet list. --> + <!-- + To have a numbered list instead we would use <ol> giving 1. for the first + element, 2. for the second, etc. + --> + <ul> <li>This is an item in a non-enumerated list (bullet list)</li> <li>This is another item</li> <li>And this is the last item on the list</li> @@ -86,21 +128,33 @@ This article is concerned principally with HTML syntax and some useful tips. <!-- But it is possible to add many additional types of HTML tags. --> -<!-- To insert an image. --> -<img src="http://i.imgur.com/XWG0O.gif"/> <!-- The source of the image is indicated using the attribute src="" --> -<!-- The source can be an URL or even path to a file on your computer. --> +<!-- The <img /> tag is used to insert an image. --> +<!-- + The source of the image is indicated using the attribute src="" + The source can be an URL or even path to a file on your computer. +--> +<img src="http://i.imgur.com/XWG0O.gif"/> <!-- It is also possible to create a table. --> -<table> <!-- We open a <table> element. --> - <tr> <!-- <tr> allows us to create a row. --> - <th>First Header</th> <!-- <th> allows us to give a title to a table column. --> +<!-- We open a <table> element. --> +<table> + + <!-- <tr> allows us to create a row. --> + <tr> + + <!-- <th> allows us to give a title to a table column. --> + <th>First Header</th> <th>Second Header</th> </tr> + <tr> - <td>first row, first column</td> <!-- <td> allows us to create a table cell. --> + + <!-- <td> allows us to create a table cell. --> + <td>first row, first column</td> <td>first row, second column</td> </tr> + <tr> <td>second row, first column</td> <td>second row, second column</td> @@ -111,9 +165,10 @@ This article is concerned principally with HTML syntax and some useful tips. ## Usage -HTML is written in files ending with `.html` or `.htm`. The mime type is `text/html`. +HTML is written in files ending with `.html` or `.htm`. The mime type is +`text/html`. -## To Learn More +## To Learn More * [wikipedia](https://en.wikipedia.org/wiki/HTML) * [HTML tutorial](https://developer.mozilla.org/en-US/docs/Web/HTML) diff --git a/hu-hu/python-hu.html.markdown b/hu-hu/python-hu.html.markdown new file mode 100644 index 00000000..9b55f8e2 --- /dev/null +++ b/hu-hu/python-hu.html.markdown @@ -0,0 +1,816 @@ +--- +language: python +contributors: + - ["Louie Dinh", "http://ldinh.ca"] + - ["Amin Bandali", "https://aminb.org"] + - ["Andre Polykanine", "https://github.com/Oire"] + - ["evuez", "http://github.com/evuez"] + - ["asyne", "https://github.com/justblah"] + - ["habi", "http://github.com/habi"] +translators: + - ["Tamás Diószegi", "https://github.com/ditam"] +filename: learnpython-hu.py +lang: hu-hu +--- + +A Python nyelvet Guido Van Rossum alkotta meg a 90-es évek elején. Manapság az +egyik legnépszerűbb programozási nyelv. Én a tiszta szintaxisa miatt szerettem +bele. Tulajdonképpen futtatható pszeudokód. + +Szívesen fogadok visszajelzéseket! Elérsz itt: [@louiedinh](http://twitter.com/louiedinh) +vagy pedig a louiedinh [kukac] [google email szolgáltatása] címen. + +Figyelem: ez a leírás a Python 2.7 verziójára vonatkozok, illetve +általánosságban a 2.x verziókra. A Python 2.7 azonban már csak 2020-ig lesz +támogatva, ezért kezdőknek ajánlott, hogy a Python 3-mal kezdjék az +ismerkedést. A Python 3.x verzióihoz a [Python 3 bemutató](http://learnxinyminutes.com/docs/python3/) +ajánlott. + +Lehetséges olyan Python kódot írni, ami egyszerre kompatibilis a 2.7 és a 3.x +verziókkal is, a Python [`__future__` imports](https://docs.python.org/2/library/__future__.html) használatával. +A `__future__` import használata esetén Python 3-ban írhatod a kódot, ami +Python 2 alatt is futni fog, így ismét a fenti Python 3 bemutató ajánlott. + +```python + +# Az egysoros kommentek kettőskereszttel kezdődnek + +""" Többsoros stringeket három darab " közé + fogva lehet írni, ezeket gyakran használják + több soros kommentként. +""" + +#################################################### +# 1. Egyszerű adattípusok és operátorok +#################################################### + +# Használhatsz számokat +3 # => 3 + +# Az alapműveletek meglepetésektől mentesek +1 + 1 # => 2 +8 - 1 # => 7 +10 * 2 # => 20 +35 / 5 # => 7 + +# Az osztás kicsit trükkös. Egész osztást végez, és a hányados alsó egész része +# lesz az eredmény +5 / 2 # => 2 + +# Az osztás kijavításához a (lebegőpontos) float típust kell használnunk +2.0 # Ez egy float +11.0 / 4.0 # => 2.75 áh... máris jobb + +# Az egész osztás a negatív számok esetén is az alsó egész részt eredményezi +5 // 3 # => 1 +5.0 // 3.0 # => 1.0 # floatok esetén is +-5 // 3 # => -2 +-5.0 // 3.0 # => -2.0 + +# Ha importáljuk a division modult (ld. 6. Modulok rész), +# akkor a '/' jellel pontos osztást tudunk végezni. +from __future__ import division + +11 / 4 # => 2.75 ...sima osztás +11 // 4 # => 2 ...egész osztás + +# Modulo művelet +7 % 3 # => 1 + +# Hatványozás (x az y. hatványra) +2 ** 4 # => 16 + +# A precedencia zárójelekkel befolyásolható +(1 + 3) * 2 # => 8 + +# Logikai operátorok +# Megjegyzés: az "and" és "or" csak kisbetűkkel helyes +True and False # => False +False or True # => True + +# A logikai operátorok egészeken is használhatóak +0 and 2 # => 0 +-5 or 0 # => -5 +0 == False # => True +2 == True # => False +1 == True # => True + +# Negálni a not kulcsszóval lehet +not True # => False +not False # => True + +# Egyenlőségvizsgálat == +1 == 1 # => True +2 == 1 # => False + +# Egyenlőtlenség != +1 != 1 # => False +2 != 1 # => True + +# További összehasonlítások +1 < 10 # => True +1 > 10 # => False +2 <= 2 # => True +2 >= 2 # => True + +# Az összehasonlítások láncolhatóak! +1 < 2 < 3 # => True +2 < 3 < 2 # => False + +# Stringeket " vagy ' jelek közt lehet megadni +"Ez egy string." +'Ez egy másik string.' + +# A stringek összeadhatóak! +"Hello " + "world!" # => "Hello world!" +# '+' jel nélkül is összeadhatóak +"Hello " "world!" # => "Hello world!" + +# ... illetve szorozhatóak +"Hello" * 3 # => "HelloHelloHello" + +# Kezelhető karakterek indexelhető listájaként +"This is a string"[0] # => 'T' + +# A string hosszát a len függvény adja meg +len("This is a string") # => 16 + +# String formázáshoz a % jel használható +# A Python 3.1-gyel a % már deprecated jelölésű, és később eltávolításra fog +# kerülni, de azért jó tudni, hogyan működik. +x = 'alma' +y = 'citrom' +z = "A kosárban levő elemek: %s és %s" % (x, y) + +# A string formázás újabb módja a format metódus használatával történik. +# Jelenleg ez a javasolt megoldás. +"{} egy {} szöveg".format("Ez", "helytartó") +"A {0} pedig {1}".format("string", "formázható") +# Ha nem akarsz számolgatni, nevesíthetőek a pozíciók. +"{name} kedvence a {food}".format(name="Bob", food="lasagna") + +# None egy objektum +None # => None + +# A None-nal való összehasonlításhoz ne használd a "==" jelet, +# használd az "is" kulcsszót helyette +"etc" is None # => False +None is None # => True + +# Az 'is' operátor objektum egyezést vizsgál. +# Primitív típusok esetén ez nem túl hasznos, +# objektumok esetén azonban annál inkább. + +# Bármilyen objektum használható logikai kontextusban. +# A következő értékek hamis-ra értékelődnek ki (ún. "falsey" értékek): +# - None +# - bármelyik szám típus 0 értéke (pl. 0, 0L, 0.0, 0j) +# - üres sorozatok (pl. '', (), []) +# - üres konténerek (pl., {}, set()) +# - egyes felhasználó által definiált osztályok példányai bizonyos szabályok szerint, +# ld: https://docs.python.org/2/reference/datamodel.html#object.__nonzero__ +# +# Minden egyéb érték "truthy" (a bool() függvénynek átadva igazra értékelődnek ki) +bool(0) # => False +bool("") # => False + + +#################################################### +# 2. Változók és kollekciók +#################################################### + +# Létezik egy print utasítás +print "I'm Python. Nice to meet you!" # => I'm Python. Nice to meet you! + +# Így lehet egyszerűen bemenetet kérni a konzolról: +input_string_var = raw_input( + "Enter some data: ") # Visszatér a megadott stringgel +input_var = input("Enter some data: ") # Kiértékeli a bemenetet python kódként +# Vigyázat: a fentiek miatt az input() metódust körültekintően kell használni +# Megjegyzés: Python 3-ban az input() már deprecated, és a raw_input() lett input()-ra átnevezve + +# A változókat nem szükséges a használat előtt deklarálni +some_var = 5 # Konvenció szerint a névben kisbetu_es_alulvonas +some_var # => 5 + +# Érték nélküli változóra hivatkozás hibát dob. +# Lásd a Control Flow szekciót a kivételkezelésről. +some_other_var # name error hibát dob + +# az if használható kifejezésként +# a C nyelv '?:' ternáris operátorával egyenértékűen +"yahoo!" if 3 > 2 else 2 # => "yahoo!" + +# A listákban sorozatok tárolhatóak +li = [] +# Már inicializáláskor megadhatóak elemek +other_li = [4, 5, 6] + +# A lista végére az append metódus rak új elemet +li.append(1) # li jelenleg [1] +li.append(2) # li jelenleg [1, 2] +li.append(4) # li jelenleg [1, 2, 4] +li.append(3) # li jelenleg [1, 2, 4, 3] +# A végéről a pop metódus távolít el elemet +li.pop() # => 3 és li jelenleg [1, 2, 4] +# Rakjuk vissza +li.append(3) # li jelenleg [1, 2, 4, 3], újra. + +# A lista elemeket tömb indexeléssel lehet hivatkozni +li[0] # => 1 +# A már inicializált értékekhez a = jellel lehet új értéket rendelni +li[0] = 42 +li[0] # => 42 +li[0] = 1 # csak visszaállítjuk az eredeti értékére +# Így is lehet az utolsó elemre hivatkozni +li[-1] # => 3 + +# A túlindexelés eredménye IndexError +li[4] # IndexError hibát dob + +# A lista részeit a slice szintaxissal lehet kimetszeni +# (Matekosoknak ez egy zárt/nyitott intervallum.) +li[1:3] # => [2, 4] +# A lista eleje kihagyható így +li[2:] # => [4, 3] +# Kihagyható a vége +li[:3] # => [1, 2, 4] +# Minden második elem kiválasztása +li[::2] # =>[1, 4] +# A lista egy másolata, fordított sorrendben +li[::-1] # => [3, 4, 2, 1] +# A fentiek kombinációival bonyolultabb slice parancsok is képezhetőek +# li[start:end:step] + +# Listaelemek a "del" paranccsal törölhetőek +del li[2] # li jelenleg [1, 2, 3] + +# A listák összeadhatóak +li + other_li # => [1, 2, 3, 4, 5, 6] +# Megjegyzés: az eredeti li és other_li értékei változatlanok + +# Összefőzhetőek (konkatenálhatóak) az "extend()" paranccsal +li.extend(other_li) # li jelenleg [1, 2, 3, 4, 5, 6] + +# Egy elem első előfordulásának eltávolítása +li.remove(2) # li jelenleg [1, 3, 4, 5, 6] +li.remove(2) # ValueError hibát dob, mivel a 2 nem szerepel már a listában + +# Elemek beszúrhatóak tetszőleges helyre +li.insert(1, 2) # li jelenleg [1, 2, 3, 4, 5, 6], ismét + +# Egy elem első előfordulási helye +li.index(2) # => 1 +li.index(7) # ValueError hibát dob, mivel a 7 nem szerepel a listában + +# Egy listában egy elem előfordulása az "in" szóval ellenőrizhető +1 in li # => True + +# A lista hossza a "len()" függvénnyel +len(li) # => 6 + +# Az N-esek ("tuple") hasonlítanak a listákhoz, de nem módosíthatóak +tup = (1, 2, 3) +tup[0] # => 1 +tup[0] = 3 # TypeError hibát dob + +# Az összes lista-műveletet ezeken is használható +len(tup) # => 3 +tup + (4, 5, 6) # => (1, 2, 3, 4, 5, 6) +tup[:2] # => (1, 2) +2 in tup # => True + +# Az N-esek (és listák) kicsomagolhatóak külön változókba +a, b, c = (1, 2, 3) # az a így 1, a b 2 és a c pedig 3 +d, e, f = 4, 5, 6 # a zárójel elhagyható +# Ha elhagyod a zárójeleket, alapértelmezés szerint tuple képződik +g = 4, 5, 6 # => (4, 5, 6) +# Nézd, milyen egyszerű két értéket megcserélni +e, d = d, e # d most már 5 és az e 4 + +# A Dictionary típusokban hozzárendelések (kulcs-érték párok) tárolhatók +empty_dict = {} +# Ez pedig rögtön értékekkel van inicializálva +filled_dict = {"one": 1, "two": 2, "three": 3} + +# Egy dictionary értékei [] jelek közt indexelhetőek +filled_dict["one"] # => 1 + +# A "keys()" metódus visszatér a kulcsok listájával +filled_dict.keys() # => ["three", "two", "one"] +# Megjegyzés: egy dictionary párjainak sorrendje nem garantált +# Lehet, hogy már a fenti példán is más sorrendben kaptad meg az elemeket. + +# Az értékek listája a "values()" metódussal kérhető le +filled_dict.values() # => [3, 2, 1] +# ld. a fenti megjegyzést az elemek sorrendjéről. + +# Az összes kulcs-érték pár megkapható N-esek listájaként az "items()" metódussal +filled_dict.items() # => [("one", 1), ("two", 2), ("three", 3)] + +# Az "in" kulcssszóval ellenőrizhető, hogy egy kulcs szerepel-e a dictionary-ben +"one" in filled_dict # => True +1 in filled_dict # => False + +# Nem létező kulcs hivatkozása KeyError hibát dob +filled_dict["four"] # KeyError + +# A "get()" metódus használatával elkerülhető a KeyError +filled_dict.get("one") # => 1 +filled_dict.get("four") # => None +# A metódusnak megadható egy alapértelmezett visszatérési érték is, hiányzó értékek esetén +filled_dict.get("one", 4) # => 1 +filled_dict.get("four", 4) # => 4 +# Megjegyzés: ettől még filled_dict.get("four") => None +# (vagyis a get nem állítja be az alapértelmezett értéket a dictionary-ben) + +# A kulcsokhoz értékek a listákhoz hasonló szintaxissal rendelhetőek: +filled_dict["four"] = 4 # ez után filled_dict["four"] => 4 + +# A "setdefault()" metódus csak akkor állít be egy értéket, ha az adott kulcshoz még nem volt más megadva +filled_dict.setdefault("five", 5) # filled_dict["five"] beállítva 5-re +filled_dict.setdefault("five", 6) # filled_dict["five"] még mindig 5 + +# Egy halmaz ("set") olyan, mint egy lista, de egy elemet csak egyszer tárolhat +empty_set = set() +# Inicializáljuk ezt a halmazt néhány elemmel +some_set = set([1, 2, 2, 3, 4]) # some_set jelenleg set([1, 2, 3, 4]) + +# A sorrend itt sem garantált, még ha néha rendezettnek is tűnhet +another_set = set([4, 3, 2, 2, 1]) # another_set jelenleg set([1, 2, 3, 4]) + +# Python 2.7 óta már {} jelek közt is lehet halmazt definiálni +filled_set = {1, 2, 2, 3, 4} # => {1, 2, 3, 4} + +# Új halmaz-elemek hozzáadása +filled_set.add(5) # filled_set is now {1, 2, 3, 4, 5} + +# Halmaz metszés a & operátorral +other_set = {3, 4, 5, 6} +filled_set & other_set # => {3, 4, 5} + +# Halmaz unió | operátorral +filled_set | other_set # => {1, 2, 3, 4, 5, 6} + +# Halmaz különbség - +{1, 2, 3, 4} - {2, 3, 5} # => {1, 4} + +# Szimmetrikus differencia ^ +{1, 2, 3, 4} ^ {2, 3, 5} # => {1, 4, 5} + +# Vizsgáljuk, hogy a bal oldali halmaz magában foglalja-e a jobb oldalit +{1, 2} >= {1, 2, 3} # => False + +# Vizsgáljuk, hogy a bal oldali halmaz részhalmaza-e a jobb oldalinak +{1, 2} <= {1, 2, 3} # => True + +# Halmazbeli elemek jelenléte az in kulcssszóval vizsgálható +2 in filled_set # => True +10 in filled_set # => False + + +#################################################### +# 3. Control Flow +#################################################### + +# Legyen egy változónk +some_var = 5 + +# Ez egy if elágazás. A behúzás mértéke (az indentáció) jelentéssel bír a nyelvben! +# Ez a kód ezt fogja kiírni: "some_var kisebb 10-nél" +if some_var > 10: + print "some_var nagyobb, mint 10." +elif some_var < 10: # Az elif kifejezés nem kötelező az if szerkezetben. + print "some_var kisebb 10-nél" +else: # Ez sem kötelező. + print "some_var kereken 10." + +""" +For ciklusokkal végigiterálhatunk listákon +a kimenet: + A(z) kutya emlős + A(z) macska emlős + A(z) egér emlős +""" +for animal in ["kutya", "macska", "egér"]: + # A {0} kifejezéssel formázzuk a stringet, ld. korábban. + print "A(z) {0} emlős".format(animal) + +""" +"range(number)" visszatér számok listájával 0-től number-ig +a kimenet: + 0 + 1 + 2 + 3 +""" +for i in range(4): + print i + +""" +"range(lower, upper)" visszatér a lower és upper közti számok listájával +a kimenet: + 4 + 5 + 6 + 7 +""" +for i in range(4, 8): + print i + +""" +A while ciklus a feltétel hamissá válásáig fut. +a kimenet: + 0 + 1 + 2 + 3 +""" +x = 0 +while x < 4: + print x + x += 1 # Rövidítés az x = x + 1 kifejezésre + +# A kivételek try/except blokkokkal kezelhetőek + +# Python 2.6-tól felfele: +try: + # A "raise" szóval lehet hibát dobni + raise IndexError("Ez egy index error") +except IndexError as e: + pass # A pass egy üres helytartó művelet. Itt hívnánk a hibakezelő kódunkat. +except (TypeError, NameError): + pass # Ha szükséges, egyszerre több hiba típus is kezelhető +else: # Az except blokk után opcionálisan megadható + print "Minden rendben!" # Csak akkor fut le, ha fentebb nem voltak hibák +finally: # Mindenképpen lefut + print "Itt felszabadíthatjuk az erőforrásokat például" + +# Az erőforrások felszabadításához try/finally helyett a with használható +with open("myfile.txt") as f: + for line in f: + print line + + +#################################################### +# 4. Függvények +#################################################### + +# A "def" szóval hozhatunk létre új függvényt +def add(x, y): + print "x is {0} and y is {1}".format(x, y) + return x + y # A return szóval tudunk értékeket visszaadni + + +# Így hívunk függvényt paraméterekkel +add(5, 6) # => a konzol kimenet "x is 5 and y is 6", a visszatérési érték 11 + +# Nevesített paraméterekkel (ún. "keyword arguments") is hívhatunk egy függvényt +add(y=6, x=5) # Ez esetben a sorrendjük nem számít + + +# Változó számú paramétert fogadó függvény így definiálható. +# A * használatával a paramétereket egy N-esként kapjuk meg. +def varargs(*args): + return args + + +varargs(1, 2, 3) # => (1, 2, 3) + + +# Változó számú nevesített paramétert fogadó függvény is megadható, +# a ** használatával a paramétereket egy dictionary-ként kapjuk meg +def keyword_args(**kwargs): + return kwargs + + +# Nézzük meg, mi történik +keyword_args(big="foot", loch="ness") # => {"big": "foot", "loch": "ness"} + + +# A két módszer egyszerre is használható +def all_the_args(*args, **kwargs): + print args + print kwargs + + +""" +all_the_args(1, 2, a=3, b=4) kimenete: + (1, 2) + {"a": 3, "b": 4} +""" + +# Függvények hívásakor a fenti args és kwargs módszerek inverze használható +# A * karakter kifejt egy listát külön paraméterekbe, a ** egy dictionary-t nevesített paraméterekbe. +args = (1, 2, 3, 4) +kwargs = {"a": 3, "b": 4} +all_the_args(*args) # egyenértékű: foo(1, 2, 3, 4) +all_the_args(**kwargs) # egyenértékű: foo(a=3, b=4) +all_the_args(*args, **kwargs) # egyenértékű: foo(1, 2, 3, 4, a=3, b=4) + + +# A fenti arg és kwarg paraméterek továbbadhatóak egyéb függvényeknek, +# a * illetve ** operátorokkal kifejtve +def pass_all_the_args(*args, **kwargs): + all_the_args(*args, **kwargs) + print varargs(*args) + print keyword_args(**kwargs) + + +# Függvény scope +x = 5 + + +def set_x(num): + # A lokális x változó nem ugyanaz, mint a globális x + x = num # => 43 + print x # => 43 + + +def set_global_x(num): + global x + print x # => 5 + x = num # a globális x-et 6-ra állítjuk + print x # => 6 + + +set_x(43) +set_global_x(6) + + +# A pythonban a függvény elsőrendű (ún. "first class") típus +def create_adder(x): + def adder(y): + return x + y + + return adder + + +add_10 = create_adder(10) +add_10(3) # => 13 + +# Névtelen függvények is definiálhatóak +(lambda x: x > 2)(3) # => True +(lambda x, y: x ** 2 + y ** 2)(2, 1) # => 5 + +# Léteznek beépített magasabb rendű függvények +map(add_10, [1, 2, 3]) # => [11, 12, 13] +map(max, [1, 2, 3], [4, 2, 1]) # => [4, 2, 3] + +filter(lambda x: x > 5, [3, 4, 5, 6, 7]) # => [6, 7] + +# A listaképző kifejezések ("list comprehensions") jól használhatóak a map és filter függvényekkel +[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] +[x for x in [3, 4, 5, 6, 7] if x > 5] # => [6, 7] + +# halmaz és dictionary képzők is léteznek +{x for x in 'abcddeef' if x in 'abc'} # => {'a', 'b', 'c'} +{x: x ** 2 for x in range(5)} # => {0: 0, 1: 1, 2: 4, 3: 9, 4: 16} + + +#################################################### +# 5. Osztályok +#################################################### + +# Az object osztály egy alosztályát képezzük +class Human(object): + # Osztály szintű mező: az osztály összes példányában azonos + species = "H. sapiens" + + # Ez a függvény meghívódik az osztály példányosításakor. + # Megjegyzés: a dupla aláhúzás a név előtt és után egy konvenció a python + # előre definiált, a nyelv által belsőleg használt, de a felhasználó által + # is látható objektumok és mezők neveire. + # Ne vezessünk be új, ilyen elnevezési sémát használó neveket! + def __init__(self, name): + # A paramétert értékül adjuk a példány name attribútumának + self.name = name + + # Inicializálunk egy mezőt + self.age = 0 + + # Példány metódus. Minden metódus első paramétere a "self", a példány maga + def say(self, msg): + return "{0}: {1}".format(self.name, msg) + + # Egy osztálymetódus az osztály összes példány közt meg van osztva. + # Hívásukkor az első paraméter mindig a hívó osztály. + @classmethod + def get_species(cls): + return cls.species + + # Egy statikus metódus osztály és példányreferencia nélkül hívódik + @staticmethod + def grunt(): + return "*grunt*" + + # Egy property jelölésű függvény olyan, mint egy getter. + # Használatával az age mező egy csak-olvasható attribútummá válik. + @property + def age(self): + return self._age + + # Így lehet settert megadni egy mezőhöz + @age.setter + def age(self, age): + self._age = age + + # Így lehet egy mező törlését engedélyezni + @age.deleter + def age(self): + del self._age + + +# Példányosítsuk az osztályt +i = Human(name="Ian") +print i.say("hi") # kimenet: "Ian: hi" + +j = Human("Joel") +print j.say("hello") # kimenet: "Joel: hello" + +# Hívjuk az osztály metódusunkat +i.get_species() # => "H. sapiens" + +# Változtassuk meg az osztály szintű attribútumot +Human.species = "H. neanderthalensis" +i.get_species() # => "H. neanderthalensis" +j.get_species() # => "H. neanderthalensis" + +# Hívjuk meg a statikus metódust +Human.grunt() # => "*grunt*" + +# Adjunk új értéket a mezőnek +i.age = 42 + +# Kérjük le a mező értékét +i.age # => 42 + +# Töröljük a mezőt +del i.age +i.age # => AttributeError hibát dob + +#################################################### +# 6. Modulok +#################################################### + +# Modulokat így lehet importálni +import math + +print math.sqrt(16) # => 4 + +# Lehetséges csak bizonyos függvényeket importálni egy modulból +from math import ceil, floor + +print ceil(3.7) # => 4.0 +print floor(3.7) # => 3.0 + +# Egy modul összes függvénye is importálható +# Vigyázat: ez nem ajánlott. +from math import * + +# A modulok nevei lerövidíthetőek +import math as m + +math.sqrt(16) == m.sqrt(16) # => True +# Meggyőződhetünk róla, hogy a függvények valóban azonosak +from math import sqrt + +math.sqrt == m.sqrt == sqrt # => True + +# A Python modulok egyszerű fájlok. +# Írhatsz sajátot és importálhatod is. +# A modul neve azonos a tartalmazó fájl nevével. + +# Így lehet megtekinteni, milyen mezőket és függvényeket definiál egy modul. +import math + +dir(math) + + +# Ha van egy math.py nevű Python scripted a jelenleg futó scripttel azonos +# mappában, a math.py fájl lesz betöltve a beépített Python modul helyett. +# A lokális mappa prioritást élvez a beépített könyvtárak felett. + + +#################################################### +# 7. Haladóknak +#################################################### + +# Generátorok +# Egy generátor értékeket "generál" amikor kérik, a helyett, hogy előre eltárolná őket. + +# A következő metódus (ez még NEM egy generátor) megduplázza a kapott iterable elemeit, +# és eltárolja őket. Nagy méretű iterable esetén ez nagyon sok helyet foglalhat! +def double_numbers(iterable): + double_arr = [] + for i in iterable: + double_arr.append(i + i) + return double_arr + + +# A következő kód futtatásakor az összes szám kétszeresét kiszámítanánk, és visszaadnánk +# ezt a nagy listát a ciklus vezérléséhez. +for value in double_numbers(range(1000000)): # `test_non_generator` + print value + if value > 5: + break + + +# Használjunk inkább egy generátort, ami "legenerálja" a soron következő elemet, +# amikor azt kérik tőle +def double_numbers_generator(iterable): + for i in iterable: + yield i + i + + +# A lenti kód mindig csak a soron következő számot generálja a logikai vizsgálat előtt. +# Így amikor az érték eléri a > 5 határt, megszakítjuk a ciklust, és a lista számainak +# nagy részénél megspóroltuk a duplázás műveletet (ez sokkal gyorsabb így!). +for value in double_numbers_generator(xrange(1000000)): # `test_generator` + print value + if value > 5: + break + +# Feltűnt, hogy a `test_non_generator` esetén `range`, a `test_generator` esetén +# pedig `xrange` volt a segédfüggvény neve? Ahogy `double_numbers_generator` a +# generátor változata a `double_numbers` függvénynek, úgy az `xrange` a `range` +# generátor megfelelője, csak akkor generálja le a következő számot, amikor kérjük +# - esetünkben a ciklus következő iterációjakor + +# A lista képzéshez hasonlóan generátor képzőket is használhatunk +# ("generator comprehensions"). +values = (-x for x in [1, 2, 3, 4, 5]) +for x in values: + print(x) # kimenet: -1 -2 -3 -4 -5 + +# Egy generátor összes generált elemét listaként is elkérhetjük: +values = (-x for x in [1, 2, 3, 4, 5]) +gen_to_list = list(values) +print(gen_to_list) # => [-1, -2, -3, -4, -5] + +# Dekorátorok +# A dekorátor egy magasabb rendű függvény, aminek bemenete és kimenete is egy függvény. +# A lenti egyszerű példában az add_apples dekorátor a dekorált get_fruits függvény +# kimenetébe beszúrja az 'Apple' elemet. +def add_apples(func): + def get_fruits(): + fruits = func() + fruits.append('Apple') + return fruits + return get_fruits + +@add_apples +def get_fruits(): + return ['Banana', 'Mango', 'Orange'] + +# A kimenet tartalmazza az 'Apple' elemet: +# Banana, Mango, Orange, Apple +print ', '.join(get_fruits()) + +# Ebben a példában a beg dekorátorral látjuk el a say függvényt. +# Beg meghívja say-t. Ha a say_please paraméter igaz, akkor +# megváltoztatja az eredmény mondatot. +from functools import wraps + + +def beg(target_function): + @wraps(target_function) + def wrapper(*args, **kwargs): + msg, say_please = target_function(*args, **kwargs) + if say_please: + return "{} {}".format(msg, "Please! I am poor :(") + return msg + + return wrapper + + +@beg +def say(say_please=False): + msg = "Can you buy me a beer?" + return msg, say_please + + +print say() # Can you buy me a beer? +print say(say_please=True) # Can you buy me a beer? Please! I am poor :( +``` + +## Még több érdekel? + +### Ingyenes online tartalmak + +* [Automate the Boring Stuff with Python](https://automatetheboringstuff.com) +* [Learn Python The Hard Way](http://learnpythonthehardway.org/book/) +* [Dive Into Python](http://www.diveintopython.net/) +* [The Official Docs](http://docs.python.org/2/) +* [Hitchhiker's Guide to Python](http://docs.python-guide.org/en/latest/) +* [Python Module of the Week](http://pymotw.com/2/) +* [A Crash Course in Python for Scientists](http://nbviewer.ipython.org/5920182) +* [First Steps With Python](https://realpython.com/learn/python-first-steps/) +* [LearnPython](http://www.learnpython.org/) +* [Fullstack Python](https://www.fullstackpython.com/) + +### Könyvek + +* [Programming Python](http://www.amazon.com/gp/product/0596158106/ref=as_li_qf_sp_asin_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596158106&linkCode=as2&tag=homebits04-20) +* [Dive Into Python](http://www.amazon.com/gp/product/1441413022/ref=as_li_tf_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1441413022&linkCode=as2&tag=homebits04-20) +* [Python Essential Reference](http://www.amazon.com/gp/product/0672329786/ref=as_li_tf_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0672329786&linkCode=as2&tag=homebits04-20) diff --git a/id-id/bf-id.html.markdown b/id-id/bf-id.html.markdown new file mode 100644 index 00000000..bf2f6a09 --- /dev/null +++ b/id-id/bf-id.html.markdown @@ -0,0 +1,86 @@ +--- +language: bf +filename: brainfuck-id.bf +contributors: + - ["Prajit Ramachandran", "http://prajitr.github.io/"] + - ["Mathias Bynens", "http://mathiasbynens.be/"] +translators: + - ["Muhammad Rifqi Fatchurrahman", "http://muhrifqii.github.io/"] +lang: id-id +--- + +Brainfuck (tidak dalam huruf kapital kecuali pada awal kalimat) adalah sebuah +bahasa pemrograman Turing-complete yang sangat minim yang hanya memiliki 8 perintah. + +Anda bisa mencoba brainfuck pada browser dengan menggunakan [brainfuck-visualizer](http://fatiherikli.github.io/brainfuck-visualizer/). + +```bf +Karakter apapun selain "><+-.,[]" (tanda kutip tidak termasuk) diabaikan. + +Brainfuck direpresentasikan dengan sebuah array yang memiliki 30,000 cell yang +diinisialisasi dengan nol dan pointer data yang menunjuk ke current cell. + +Terdapat delapan perintah: ++ : Menaikkan nilai pada current cell sebesar satu. +- : Menurunkan nilai pada current cell sebesar satu. +> : Menggeser pointer data ke cell selanjutnya (cell sebelah kanan). +< : Menggeser pointer data ke cell sebelumnya (cell sebelah kiri). +. : Mencetak nilai ASCII pada current cell (misal 65 = 'A'). +, : Membaca sebuah karakter masukan tunggal ke dalam current cell. +[ : Jika nilai pada current cell bernilai nol, lewati hingga mencapai ] yang sesuai. + Jika tidak, pindah ke instruksi berikutnya. +] : Jika nilai pada current cell bernilai nol, pindah ke instruksi berikutnya. + Jika tidak, mundur pada instruksi hingga mencapai [ yang sesuai. + +[ dan ] membentuk sebuah rekursi while. Tentu saja mereka harus seimbang. + +Mari kita lihat beberapa program brainfuck dasar. + +++++++ [ > ++++++++++ < - ] > +++++ . + +Program ini mencetak huruf 'A'. Mula-mula, cell #1 dinaikkan ke 6. +Cell #1 akan digunakan untuk rekursi. Lalu, masuk ke rekursi ([) dan pindah +ke cell #2. Cell #2 dinaikkan 10 kali, mundur ke cell #1, dan menurunkan +cell #1. Rekursi ini berlangsung 6 kali (melakukan 6 penurunan nilai untuk +cell #1 hingga mencapai 0, di titik mana dia melewati hingga mencapai ] dan +terus berlanjut). + +Pada titik ini, kita berada pada cell #1, yang memiliki nilai 0, sedangkan cell #2 +memiliki sebuah nilai 60. Kita berpindah ke cell #2, menaikkan nilai 5 kali, memunculkan +nilai 65, lalu cetak nilai pada cell #2. 65 adalah 'A' pada ASCII, jadi 'A' +dicetak ke terminal. + +, [ > + < - ] > . + +Program ini membaca sebuah karakter dari masukan user dan menyalin karakternya ke +cell #1. Setelah itu rekursi dimulai. Geser ke cell #2, menaikkan nilai pada cell #2, +mundur ke cell #1, dan menurunkan nilai pada cell #1. Hal ini berlanjut sampai cell #1 +bernilai 0, dan cell #2 menyimpan nilai lama dari cell #1. Karena kita berada di cell #1 +saat ujung rekursi, geser ke cell #2, lalu cetak nilai dalam bentuk ASCII. + +Perlu diingat bahwa spasi itu murni untuk memudahkan membaca. Anda bisa +menuliskannya dengan mudah seperti: + +,[>+<-]>. + +Coba dan cari tahu apa yang program ini lakukan: + +,>,< [ > [ >+ >+ << -] >> [- << + >>] <<< -] >> + +Program ini menerima dua buah angka sebagai input, lalu mengalikannya. + +Intinya adalah membaca dua masukan. Lalu mulai pada rekursi terluar yang +kondisinya pada cell #1. Lalu pindah ke cell #2, dan mulai rekursi terdalam +yang kondisinya ada pada cell #2, menaikkan nilai pada cell #3. Namun, +ada suatu masalah: Pada akhir dari rekursi terdalam, cell #2 bernilai nol. +Pada kasus tersebut, rekursi terdalam tidak dapat bekerja lagi mulai setelah ini. +Untuk menyelesaikan masalah tersebut, kita juga menaikkan cell #4, dan menyalin +ulang cell #4 ke cell #2. Maka cell #3 adalah hasilnya. +``` + +Dan itulah brainfuck. Tidak terlalu sulit kan? Hanya untuk iseng-iseng, anda +bisa menuliskan porgram brainfuck anda sendiri, atau anda bisa menuliskan interpreter +brainfuck pada bahasa lain. Interpreternya tidak begitu sulit untuk diimplementasikan, +tapi jika anda seorang masokis, cobalah menulis sebuah interpreter brainfuck... dalam +brainfuck. + diff --git a/id-id/markdown.html.markdown b/id-id/markdown.html.markdown index 06ad1092..1ff1963b 100644 --- a/id-id/markdown.html.markdown +++ b/id-id/markdown.html.markdown @@ -13,7 +13,7 @@ Markdown dibuat oleh John Gruber pada tahun 2004. Tujuannya untuk menjadi syntax Beri masukan sebanyak-banyaknya! / Jangan sungkan untuk melakukan fork dan pull request! -```markdown +```md <!-- Markdown adalah superset dari HTML, jadi setiap berkas HTML adalah markdown yang valid, ini berarti kita dapat menggunakan elemen HTML dalam markdown, seperti elemen komentar, dan ia tidak akan terpengaruh parser markdown. Namun, jika Anda membuat diff --git a/it-it/asciidoc-it.html.markdown b/it-it/asciidoc-it.html.markdown new file mode 100644 index 00000000..47a57349 --- /dev/null +++ b/it-it/asciidoc-it.html.markdown @@ -0,0 +1,135 @@ +--- +language: asciidoc +contributors: + - ["Ryan Mavilia", "http://unoriginality.rocks/"] + - ["Abel Salgado Romero", "https://twitter.com/abelsromero"] +translators: + - ["Ale46", "https://github.com/ale46"] +lang: it-it +filename: asciidoc-it.md +--- + +AsciiDoc è un linguaggio di markup simile a Markdown e può essere usato per qualsiasi cosa, dai libri ai blog. Creato nel 2002 da Stuart Rackman, questo linguaggio è semplice ma permette un buon numero di personalizzazioni. + +Intestazione Documento + +Le intestazioni sono opzionali e possono contenere linee vuote. Deve avere almeno una linea vuota rispetto al contenuto. + +Solo titolo + +``` += Titolo documento + +Prima frase del documento. +``` + +Titolo ed Autore + +``` += Titolo documento +Primo Ultimo <first.last@learnxinyminutes.com> + +Inizio del documento +``` + +Autori multipli + +``` += Titolo Documento +John Doe <john@go.com>; Jane Doe<jane@yo.com>; Black Beard <beardy@pirate.com> + +Inizio di un documento con autori multipli. +``` + +Linea di revisione (richiede una linea autore) + +``` += Titolo documento V1 +Potato Man <chip@crunchy.com> +v1.0, 2016-01-13 + +Questo articolo sulle patatine sarà divertente. +``` + +Paragrafi + +``` +Non hai bisogno di nulla di speciale per i paragrafi. + +Aggiungi una riga vuota tra i paragrafi per separarli. + +Per creare una riga vuota aggiungi un + +e riceverai una interruzione di linea! +``` + +Formattazione Testo + +``` +_underscore crea corsivo_ +*asterischi per il grassetto* +*_combinali per maggiore divertimento_* +`usa i ticks per indicare il monospazio` +`*spaziatura fissa in grassetto*` +``` + +Titoli di sezione + +``` += Livello 0 (può essere utilizzato solo nell'intestazione del documento) + +== Livello 1 <h2> + +=== Livello 2 <h3> + +==== Livello 3 <h4> + +===== Livello 4 <h5> + +``` + +Liste + +Per creare un elenco puntato, utilizzare gli asterischi. + +``` +* foo +* bar +* baz +``` + +Per creare un elenco numerato usa i periodi. + +``` +. item 1 +. item 2 +. item 3 +``` + +È possibile nidificare elenchi aggiungendo asterischi o periodi aggiuntivi fino a cinque volte. + +``` +* foo 1 +** foo 2 +*** foo 3 +**** foo 4 +***** foo 5 + +. foo 1 +.. foo 2 +... foo 3 +.... foo 4 +..... foo 5 +``` + +## Ulteriori letture + +Esistono due strumenti per elaborare i documenti AsciiDoc: + +1. [AsciiDoc](http://asciidoc.org/): implementazione Python originale, disponibile nelle principali distribuzioni Linux. Stabile e attualmente in modalità di manutenzione. +2. [Asciidoctor](http://asciidoctor.org/): implementazione alternativa di Ruby, utilizzabile anche da Java e JavaScript. In fase di sviluppo attivo, mira ad estendere la sintassi AsciiDoc con nuove funzionalità e formati di output. + +I seguenti collegamenti sono relativi all'implementazione di `Asciidoctor`: + +* [Markdown - AsciiDoc comparazione sintassi](http://asciidoctor.org/docs/user-manual/#comparison-by-example): confronto affiancato di elementi di Markdown e AsciiDoc comuni. +* [Per iniziare](http://asciidoctor.org/docs/#get-started-with-asciidoctor): installazione e guide rapide per il rendering di documenti semplici. +* [Asciidoctor Manuale Utente](http://asciidoctor.org/docs/user-manual/): manuale completo con riferimento alla sintassi, esempi, strumenti di rendering, tra gli altri. diff --git a/it-it/c++-it.html.markdown b/it-it/c++-it.html.markdown index b4f9c50e..449aebfb 100644 --- a/it-it/c++-it.html.markdown +++ b/it-it/c++-it.html.markdown @@ -1130,7 +1130,6 @@ compl 4 // Effettua il NOT bit-a-bit ``` Letture consigliate: -Un riferimento aggiornato del linguaggio può essere trovato qui -<http://cppreference.com/w/cpp> - -Risorse addizionali possono essere trovate qui <http://cplusplus.com> +* Un riferimento aggiornato del linguaggio può essere trovato qui [CPP Reference](http://cppreference.com/w/cpp). +* Risorse addizionali possono essere trovate qui [CPlusPlus](http://cplusplus.com). +* Un tutorial che copre le basi del linguaggio e l'impostazione dell'ambiente di codifica è disponibile su [TheChernoProject - C ++](https://www.youtube.com/playlist?list=PLlrATfBNZ98dudnM48yfGUldqGD0S4FFb). diff --git a/it-it/dynamic-programming-it.html.markdown b/it-it/dynamic-programming-it.html.markdown new file mode 100644 index 00000000..9c7bd9b6 --- /dev/null +++ b/it-it/dynamic-programming-it.html.markdown @@ -0,0 +1,55 @@ +--- +category: Algorithms & Data Structures +name: Dynamic Programming +contributors: + - ["Akashdeep Goel", "http://github.com/akashdeepgoel"] +translators: + - ["Ale46", "https://github.com/ale46"] +lang: it-it +--- + +# Programmazione dinamica + +## Introduzione + +La programmazione dinamica è una tecnica potente utilizzata per risolvere una particolare classe di problemi, come vedremo. L'idea è molto semplice, se hai risolto un problema con l'input dato, salva il risultato come riferimento futuro, in modo da evitare di risolvere nuovamente lo stesso problema. + +Ricordate sempre! +"Chi non ricorda il passato è condannato a ripeterlo" + +## Modi per risolvere questi problemi + +1. *Top-Down* : Inizia a risolvere il problema specifico suddividendolo. Se vedi che il problema è già stato risolto, rispondi semplicemente con la risposta già salvata. Se non è stato risolto, risolvilo e salva la risposta. Di solito è facile da pensare e molto intuitivo. Questo è indicato come Memoization. + +2. *Bottom-Up* : Analizza il problema e vedi l'ordine in cui i sotto-problemi sono risolti e inizia a risolvere dal sottoproblema banale, verso il problema dato. In questo processo, è garantito che i sottoproblemi vengono risolti prima di risolvere il problema. Si parla di programmazione dinamica. + +## Esempio di programmazione dinamica + +Il problema di "Longest Increasing Subsequence" consiste nel trovare la sottosequenza crescente più lunga di una determinata sequenza. Data una sequenza `S= {a1 , a2 , a3, a4, ............., an-1, an }` dobbiamo trovare il sottoinsieme più lungo tale che per tutti gli `j` e gli `i`, `j<i` nel sotto-insieme `aj<ai`. +Prima di tutto dobbiamo trovare il valore delle sottosequenze più lunghe (LSi) ad ogni indice i con l'ultimo elemento della sequenza che è ai. Quindi il più grande LSi sarebbe la sottosequenza più lunga nella sequenza data. Per iniziare LSi viene inizializzato ad 1, dato che ai è un element della sequenza (Ultimo elemento). Quindi per tutti gli `j` tale che `j<i` e `aj<ai`, troviamo il più grande LSj e lo aggiungiamo a LSi. Quindi l'algoritmo richiede un tempo di *O(n2)*. + +Pseudo-codice per trovare la lunghezza della sottosequenza crescente più lunga: +Questa complessità degli algoritmi potrebbe essere ridotta usando una migliore struttura dei dati piuttosto che una matrice. La memorizzazione dell'array predecessore e della variabile come `largest_sequences_so_far` e il suo indice farebbero risparmiare molto tempo. + +Un concetto simile potrebbe essere applicato nel trovare il percorso più lungo nel grafico aciclico diretto. + +```python +for i=0 to n-1 + LS[i]=1 + for j=0 to i-1 + if (a[i] > a[j] and LS[i]<LS[j]) + LS[i] = LS[j]+1 +for i=0 to n-1 + if (largest < LS[i]) +``` + +### Alcuni famosi problemi DP + +- Floyd Warshall Algorithm - Tutorial e Codice sorgente in C del programma: [http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs---floyd-warshall-algorithm-with-c-program-source-code]() +- Integer Knapsack Problem - Tutorial e Codice sorgente in C del programma: [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---the-integer-knapsack-problem]() +- Longest Common Subsequence - Tutorial e Codice sorgente in C del programma: [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---longest-common-subsequence]() + + +## Risorse online + +* [codechef](https://www.codechef.com/wiki/tutorial-dynamic-programming) diff --git a/it-it/go-it.html.markdown b/it-it/go-it.html.markdown index e005f2dc..797f6b0b 100644 --- a/it-it/go-it.html.markdown +++ b/it-it/go-it.html.markdown @@ -26,14 +26,14 @@ Aggiunge la concorrenza in maniera diretta e semplice da capire, per far forza sulle CPU multi-core di oggigiorno. Presenta caratteristiche utili per la programmazione in larga scala. -Go comes with a great standard library and an enthusiastic community. +Go include un'ottima libreria standard e ha una community entusiasta. ```go // Commento su riga singola /* Commento su riga multipla */ -// In cima a ogni file è necessario specificare il package. +// In cima ad ogni file è necessario specificare il package. // Main è un package speciale che identifica un eseguibile anziché una libreria. package main @@ -65,19 +65,19 @@ func oltreIlCiaoMondo() { x = 3 // Assegnazione di una variabile. // E' possibile la dichiarazione "rapida" := per inferire il tipo, dichiarare e assegnare contemporaneamente. y := 4 - // Una funzione che ritorna due valori. - somma, prod := imparaMoltepliciValoriDiRitorno(x, y) + // Una funzione che restituisce due valori. + somma, prod := imparaMoltepliciValoriRestituiti(x, y) fmt.Println("somma:", somma, "prodotto:", prod) // Semplice output. imparaTipi() // < y minuti, devi imparare ancora! } /* <- commento su righe multiple -Le funzioni possono avere parametri e ritornare (molteplici!) valori. -Qua, x e y sono gli argomenti, mentre somma e prod sono i valori ritornati. +Le funzioni possono avere parametri e restituire (molteplici!) valori. +In questo esempio, x e y sono gli argomenti, mentre somma e prod sono i valori restituiti. Da notare il fatto che x e somma vengono dichiarati come interi. */ -func imparaMoltepliciValoriDiRitorno(x, y int) (somma, prod int) { - return x + y, x * y // Ritorna due valori. +func imparaMoltepliciValoriRestituiti(x, y int) (somma, prod int) { + return x + y, x * y // Restituisce due valori. } // Ecco alcuni tipi presenti in Go @@ -86,7 +86,7 @@ func imparaTipi() { str := "Impara il Go!" // Tipo stringa. s2 := `Una stringa letterale -puo' includere andata a capo.` // Sempre di tipo stringa. +può includere andata a capo.` // Sempre di tipo stringa. // Stringa letterale non ASCII. I sorgenti Go sono in UTF-8. g := 'Σ' // Il tipo runa, alias per int32, è costituito da un code point unicode. @@ -144,20 +144,20 @@ puo' includere andata a capo.` // Sempre di tipo stringa. imparaControlloDiFlusso() // Torniamo in carreggiata. } -// In Go è possibile associare dei nomi ai valori di ritorno di una funzione. -// Assegnare un nome al tipo di dato ritornato permette di fare return in vari +// In Go è possibile associare dei nomi ai valori restituiti da una funzione. +// Assegnare un nome al tipo di dato restituito permette di fare return in vari // punti all'interno del corpo della funzione, ma anche di usare return senza -// specificare in modo esplicito che cosa ritornare. -func imparaValoriDiRitornoConNome(x, y int) (z int) { +// specificare in modo esplicito che cosa restituire. +func imparaValoriRestituitiConNome(x, y int) (z int) { z = x * y return // z è implicito, perchè compare nella definizione di funzione. } // Go è dotato di garbage collection. Ha i puntatori, ma non l'aritmetica dei -// puntatori. Puoi fare errori coi puntatori a nil, ma non puoi direttamente -// incrementare un puntatore. +// puntatori. Puoi commettere errori a causa di puntatori nulli, ma non puoi +// incrementare un puntatore direttamente. func imparaLaMemoria() (p, q *int) { - // I valori di ritorno (con nome) p e q sono puntatori a int. + // I valori restituiti (con nome) p e q sono puntatori a int. p = new(int) // La funzione new si occupa di allocare memoria. // L'int allocato viene inizializzato a 0, dunque p non è più nil. s := make([]int, 20) // Alloca 20 int come un singolo blocco di memoria. @@ -207,14 +207,14 @@ func imparaControlloDiFlusso() { } // x == 42 qua. - // Il for è l'unica istruzione per ciclare in Go, ma ha varie forme. + // Il for è l'unica istruzione per i loop in Go, ma ha varie forme. for { // Ciclo infinito. break // Scherzavo. continue // Non si arriva qua. } - // Puoi usare range per ciclare su un vettore, slice, stringa, mappa o canale. - // range ritorna uno (per i canali) o due valori (vettore, slice, stringa, mappa). + // Puoi usare range per iterare lungo un vettore, slice, stringa, mappa o canale. + // range restituisce uno (per i canali) o due valori (vettore, slice, stringa, mappa). for chiave, valore := range map[string]int{"uno": 1, "due": 2, "tre": 3} { // per ogni coppia dentro la mappa, stampa chiave e valore fmt.Printf("chiave=%s, valore=%d\n", chiave, valore) @@ -236,7 +236,7 @@ func imparaControlloDiFlusso() { // Inoltre le funzioni letterali possono essere definite e chiamate // inline, col ruolo di parametri di funzione, a patto che: // a) la funzione letterale venga chiamata subito (), - // b) il valore ritornato è in accordo con il tipo dell'argomento. + // b) il valore restituito è in accordo con il tipo dell'argomento. fmt.Println("Somma e raddoppia due numeri: ", func(a, b int) int { return (a + b) * 2 @@ -247,7 +247,7 @@ func imparaControlloDiFlusso() { goto amore amore: - imparaFabbricaDiFunzioni() // Una funzione che ritorna un'altra funzione è divertente! + imparaFabbricaDiFunzioni() // Una funzione che restituisce un'altra funzione è divertente! imparaDefer() // Un tour veloce di una parola chiave importante. imparaInterfacce() // Arriva la roba buona! } @@ -270,12 +270,13 @@ func fabbricaDiFrasi(miaStringa string) func(prima, dopo string) string { } func imparaDefer() (ok bool) { - // Le istruzioni dette "deferred" (rinviate) sono eseguite - // appena prima che la funzione ritorni. + // La parola chiave "defer" inserisce una funzione in una lista. + // La lista contenente tutte le chiamate a funzione viene eseguita DOPO + // il return finale della funzione che le circonda. defer fmt.Println("le istruzioni 'deferred' sono eseguite in ordine inverso (LIFO).") defer fmt.Println("\nQuesta riga viene stampata per prima perché") // defer viene usato di solito per chiudere un file, così la funzione che - // chiude il file viene messa vicino a quella che lo apre. + // chiude il file, preceduta da "defer", viene messa vicino a quella che lo apre. return true } diff --git a/it-it/html-it.html.markdown b/it-it/html-it.html.markdown index 471019a1..8f7391a2 100644 --- a/it-it/html-it.html.markdown +++ b/it-it/html-it.html.markdown @@ -1,6 +1,6 @@ --- language: html -filename: learnhtml-it.html +filename: learnhtml-it.txt contributors: - ["Christophe THOMAS", "https://github.com/WinChris"] translators: @@ -112,7 +112,7 @@ Questo articolo riguarda principalmente la sintassi HTML ed alcuni suggerimenti ## Uso -HTML è scritto in files che finiscono con `.html`. +HTML è scritto in files che finiscono con `.html` o `.htm`. Il "MIME type" è `text/html`. ## Per saperne di più diff --git a/it-it/java-it.html.markdown b/it-it/java-it.html.markdown index 54602cff..1669816e 100644 --- a/it-it/java-it.html.markdown +++ b/it-it/java-it.html.markdown @@ -17,14 +17,14 @@ concorrente, basato su classi e adatto a svariati scopi. ```java // I commenti su singola linea incominciano con // /* -I commenti su piu' linee invece sono cosi' +I commenti su più linee invece sono così */ /** -I commenti per la documentazione JavaDoc si fanno cosi'. +I commenti per la documentazione JavaDoc si fanno così. Vengono usati per descrivere una classe o alcuni suoi attributi. */ -// Per importare la classe ArrayList conenuta nel package java.util +// Per importare la classe ArrayList contenuta nel package java.util import java.util.ArrayList; // Per importare tutte le classi contenute nel package java.security import java.security.*; @@ -48,7 +48,7 @@ public class LearnJava { System.out.print("Ciao "); System.out.print("Mondo "); - // Per stampare del testo formattato, si puo' usare System.out.printf + // Per stampare del testo formattato, si può usare System.out.printf System.out.printf("pi greco = %.5f", Math.PI); // => pi greco = 3.14159 /////////////////////////////////////// @@ -60,7 +60,7 @@ public class LearnJava { */ // Per dichiarare una variabile basta fare <tipoDato> <nomeVariabile> int fooInt; - // Per dichiarare piu' di una variabile dello lo stesso tipo si usa: + // Per dichiarare più di una variabile dello lo stesso tipo si usa: // <tipoDato> <nomeVariabile1>, <nomeVariabile2>, <nomeVariabile3> int fooInt1, fooInt2, fooInt3; @@ -71,7 +71,7 @@ public class LearnJava { // Per inizializzare una variabile si usa // <tipoDato> <nomeVariabile> = <valore> int fooInt = 1; - // Per inizializzare piu' di una variabile dello lo stesso tipo + // Per inizializzare più di una variabile dello lo stesso tipo // si usa <tipoDato> <nomeVariabile1>, <nomeVariabile2>, <nomeVariabile3> = <valore> int fooInt1, fooInt2, fooInt3; fooInt1 = fooInt2 = fooInt3 = 1; @@ -94,7 +94,7 @@ public class LearnJava { // Long - intero con segno a 64 bit (in complemento a 2) // (-9,223,372,036,854,775,808 <= long <= 9,223,372,036,854,775,807) long fooLong = 100000L; - // L viene usato per indicare che il valore e' di tipo Long; + // L viene usato per indicare che il valore è di tipo Long; // altrimenti il valore viene considerato come intero. // Nota: Java non dispone di interi senza segno. @@ -102,14 +102,14 @@ public class LearnJava { // Float - Numero in virgola mobile a 32 bit con precisione singola (IEEE 754) // 2^-149 <= float <= (2-2^-23) * 2^127 float fooFloat = 234.5f; - // f o F indicano the la variabile e' di tipo float; + // f o F indicano the la variabile è di tipo float; // altrimenti il valore viene considerato come double. // Double - Numero in virgola mobile a 64 bit con precisione doppia (IEEE 754) // 2^-1074 <= x <= (2-2^-52) * 2^1023 double fooDouble = 123.4; - // Boolean - Puo' assumere il valore vero (true) o falso (false) + // Boolean - Può assumere il valore vero (true) o falso (false) boolean fooBoolean = true; boolean barBoolean = false; @@ -118,26 +118,26 @@ public class LearnJava { // Le variabili precedute da final possono essere inizializzate una volta sola, final int HOURS_I_WORK_PER_WEEK = 9001; - // pero' e' possibile dichiararle e poi inizializzarle in un secondo momento. + // però è possibile dichiararle e poi inizializzarle in un secondo momento. final double E; E = 2.71828; // BigInteger - Interi a precisione arbitraria // - // BigInteger e' un tipo di dato che permette ai programmatori di - // gestire interi piu' grandi di 64 bit. Internamente, le variabili + // BigInteger è un tipo di dato che permette ai programmatori di + // gestire interi più grandi di 64 bit. Internamente, le variabili // di tipo BigInteger vengono memorizzate come un vettore di byte e // vengono manipolate usando funzioni dentro la classe BigInteger. // - // Una variabile di tipo BigInteger puo' essere inizializzata usando + // Una variabile di tipo BigInteger può essere inizializzata usando // un array di byte oppure una stringa. BigInteger fooBigInteger = new BigDecimal(fooByteArray); // BigDecimal - Numero con segno, immutabile, a precisione arbitraria // - // Una variabile di tipo BigDecimal e' composta da due parti: un intero + // Una variabile di tipo BigDecimal è composta da due parti: un intero // a precisione arbitraria detto 'non scalato', e un intero a 32 bit // che rappresenta la 'scala', ovvero la potenza di 10 con cui // moltiplicare l'intero non scalato. @@ -158,9 +158,9 @@ public class LearnJava { // Stringhe String fooString = "Questa e' la mia stringa!"; - // \n e' un carattere di escape che rappresenta l'andare a capo + // \n è un carattere di escape che rappresenta l'andare a capo String barString = "Stampare su una nuova riga?\nNessun problema!"; - // \t e' un carattere di escape che aggiunge un tab + // \t è un carattere di escape che aggiunge un tab String bazString = "Vuoi aggiungere un tab?\tNessun problema!"; System.out.println(fooString); System.out.println(barString); @@ -168,7 +168,7 @@ public class LearnJava { // Vettori // La dimensione di un array deve essere decisa in fase di - // istanziazione. Per dichiarare un array si puo' fare in due modi: + // istanziazione. Per dichiarare un array si può fare in due modi: // <tipoDato>[] <nomeVariabile> = new <tipoDato>[<dimensioneArray>]; // <tipoDato> <nomeVariabile>[] = new <tipoDato>[<dimensioneArray>]; int[] intArray = new int[10]; @@ -189,8 +189,8 @@ public class LearnJava { System.out.println("intArray @ 1: " + intArray[1]); // => 1 // Ci sono altri tipo di dato interessanti. - // ArrayList - Simili ai vettori, pero' offrono altre funzionalita', - // e la loro dimensione puo' essere modificata. + // ArrayList - Simili ai vettori, però offrono altre funzionalità, + // e la loro dimensione può essere modificata. // LinkedList - Si tratta di una lista linkata doppia, e come tale // implementa tutte le operazioni del caso. // Map - Un insieme di oggetti che fa corrispondere delle chiavi @@ -207,7 +207,7 @@ public class LearnJava { int i1 = 1, i2 = 2; // Dichiarazone multipla in contemporanea - // L'aritmetica e' lineare. + // L'aritmetica è lineare. System.out.println("1+2 = " + (i1 + i2)); // => 3 System.out.println("2-1 = " + (i2 - i1)); // => 1 System.out.println("2*1 = " + (i2 * i1)); // => 2 @@ -253,7 +253,7 @@ public class LearnJava { /////////////////////////////////////// System.out.println("\n->Strutture di controllo"); - // La dichiarazione dell'If e'' C-like. + // La dichiarazione dell'If è C-like. int j = 10; if (j == 10){ System.out.println("Io vengo stampato"); @@ -328,18 +328,18 @@ public class LearnJava { System.out.println("Risultato del costrutto switch: " + stringaMese); // Condizioni brevi - // Si puo' usare l'operatore '?' per un rapido assegnamento + // Si può usare l'operatore '?' per un rapido assegnamento // o per operazioni logiche. // Si legge: - // Se (condizione) e' vera, usa <primo valore>, altrimenti usa <secondo valore> + // Se (condizione) è vera, usa <primo valore>, altrimenti usa <secondo valore> int foo = 5; String bar = (foo < 10) ? "A" : "B"; System.out.println("Se la condizione e' vera stampa A: "+bar); - // Stampa A, perche' la condizione e' vera. + // Stampa A, perché la condizione è vera. ///////////////////////////////////////// - // Convertire i tipi di tati e Typcasting + // Convertire i tipi di dati e Typecasting ///////////////////////////////////////// // Convertire tipi di dati @@ -397,16 +397,16 @@ class Bicicletta { // Variabili della bicicletta public int cadenza; - // Public: Puo' essere richiamato da qualsiasi classe + // Public: Può essere richiamato da qualsiasi classe private int velocita; - // Private: e'' accessibile solo dalla classe dove e'' stato inizializzato + // Private: è accessibile solo dalla classe dove è stato inizializzato protected int ingranaggi; - // Protected: e'' visto sia dalla classe che dalle sottoclassi + // Protected: è visto sia dalla classe che dalle sottoclassi String nome; - // default: e'' accessibile sono all'interno dello stesso package + // default: è accessibile sono all'interno dello stesso package // I costruttori vengono usati per creare variabili - // Questo e'' un costruttore + // Questo è un costruttore public Bicicletta() { ingranaggi = 1; cadenza = 50; @@ -414,7 +414,7 @@ class Bicicletta { nome = "Bontrager"; } - // Questo e'' un costruttore che richiede parametri + // Questo è un costruttore che richiede parametri public Bicicletta(int cadenza, int velocita, int ingranaggi, String nome) { this.ingranaggi = ingranaggi; this.cadenza = cadenza; @@ -469,7 +469,7 @@ class Bicicletta { } } // Fine classe bicicletta -// PennyFarthing e'' una sottoclasse della bicicletta +// PennyFarthing è una sottoclasse della bicicletta class PennyFarthing extends Bicicletta { // (Sono quelle biciclette con un unica ruota enorme // Non hanno ingranaggi.) @@ -481,7 +481,7 @@ class PennyFarthing extends Bicicletta { // Bisogna contrassegnre un medodo che si sta riscrivendo // con una @annotazione - // Per saperne di piu' sulle annotazioni + // Per saperne di più sulle annotazioni // Vedi la guida: http://docs.oracle.com/javase/tutorial/java/annotations/ @Override public void setIngranaggi(int ingranaggi) { @@ -518,8 +518,8 @@ class Frutta implements Commestibile, Digestibile { } } -//In Java si puo' estendere solo una classe, ma si possono implementare -//piu' interfaccie, per esempio: +//In Java si può estendere solo una classe, ma si possono implementare +//più interfaccie, per esempio: class ClasseEsempio extends AltraClasse implements PrimaInterfaccia, SecondaInterfaccia { public void MetodoPrimaInterfaccia() { diff --git a/it-it/jquery-it.html.markdown b/it-it/jquery-it.html.markdown new file mode 100644 index 00000000..811c5c3a --- /dev/null +++ b/it-it/jquery-it.html.markdown @@ -0,0 +1,131 @@ +--- +category: tool +tool: jquery +contributors: + - ["Sawyer Charles", "https://github.com/xssc"] +filename: jquery-it.js +translators: + - ["Ale46", "https://github.com/ale46"] +lang: it-it +--- + +jQuery è una libreria JavaScript che ti aiuta a "fare di più, scrivendo meno". Rende molte attività comuni di JavaScript più facili da scrivere. jQuery è utilizzato da molte grandi aziende e sviluppatori in tutto il mondo. Rende AJAX, gestione degli eventi, manipolazione dei documenti e molto altro, più facile e veloce. + +Visto che jQuery è una libreria JavaScript dovresti prima [imparare JavaScript](https://learnxinyminutes.com/docs/javascript/) + +```js + + +/////////////////////////////////// +// 1. Selettori + +// I selettori in jQuery vengono utilizzati per selezionare un elemento +var page = $(window); // Seleziona l'intera finestra + +// I selettori possono anche essere selettori CSS +var paragraph = $('p'); // Seleziona tutti gli elementi del paragrafo +var table1 = $('#table1'); // Seleziona elemento con id 'table1' +var squares = $('.square'); // Seleziona tutti gli elementi con la classe 'square' +var square_p = $('p.square') // Seleziona i paragrafi con la classe 'square' + + +/////////////////////////////////// +// 2. Eventi ed effetti +// jQuery è molto bravo a gestire ciò che accade quando un evento viene attivato +// Un evento molto comune è l'evento "pronto" sul documento +// Puoi usare il metodo 'ready' per aspettare che l'elemento abbia finito di caricare +$(document).ready(function(){ + // Il codice non verrà eseguito fino a quando il documento non verrà caricato +}); +// Puoi anche usare funzioni definite +function onAction() { + // Questo viene eseguito quando l'evento viene attivato +} +$('#btn').click(onAction); // Invoca onAction al click + +// Alcuni altri eventi comuni sono: +$('#btn').dblclick(onAction); // Doppio click +$('#btn').hover(onAction); // Al passaggio del mouse +$('#btn').focus(onAction); // Al focus +$('#btn').blur(onAction); // Focus perso +$('#btn').submit(onAction); // Al submit +$('#btn').select(onAction); // Quando un elemento è selezionato +$('#btn').keydown(onAction); // Quando un tasto è premuto (ma non rilasciato) +$('#btn').keyup(onAction); // Quando viene rilasciato un tasto +$('#btn').keypress(onAction); // Quando viene premuto un tasto +$('#btn').mousemove(onAction); // Quando il mouse viene spostato +$('#btn').mouseenter(onAction); // Il mouse entra nell'elemento +$('#btn').mouseleave(onAction); // Il mouse lascia l'elemento + + +// Questi possono anche innescare l'evento invece di gestirlo +// semplicemente non passando alcun parametro +$('#btn').dblclick(); // Innesca il doppio click sull'elemento + +// Puoi gestire più eventi mentre usi il selettore solo una volta +$('#btn').on( + {dblclick: myFunction1} // Attivato con doppio clic + {blur: myFunction1} // Attivato al blur +); + +// Puoi spostare e nascondere elementi con alcuni metodi di effetto +$('.table').hide(); // Nascondi gli elementi + +// Nota: chiamare una funzione in questi metodi nasconderà comunque l'elemento +$('.table').hide(function(){ + // Elemento nascosto quindi funzione eseguita +}); + +// È possibile memorizzare selettori in variabili +var tables = $('.table'); + +// Alcuni metodi di manipolazione dei documenti di base sono: +tables.hide(); // Nascondi elementi +tables.show(); // Mostra elementi +tables.toggle(); // Cambia lo stato nascondi/mostra +tables.fadeOut(); // Fades out +tables.fadeIn(); // Fades in +tables.fadeToggle(); // Fades in o out +tables.fadeTo(0.5); // Dissolve in opacità (tra 0 e 1) +tables.slideUp(); // Scorre verso l'alto +tables.slideDown(); // Scorre verso il basso +tables.slideToggle(); // Scorre su o giù + +// Tutti i precedenti prendono una velocità (millisecondi) e la funzione di callback +tables.hide(1000, myFunction); // nasconde l'animazione per 1 secondo quindi esegue la funzione + +// fadeTo ha un'opacità richiesta come secondo parametro +tables.fadeTo(2000, 0.1, myFunction); // esegue in 2 sec. il fade sino ad una opacità di 0.1 opacity e poi la funzione + +// Puoi ottenere un effetti più avanzati con il metodo animate +tables.animate({margin-top:"+=50", height: "100px"}, 500, myFunction); +// Il metodo animate accetta un oggetto di css e valori con cui terminare, +// parametri opzionali per affinare l'animazione, +// e naturalmente la funzione di callback + +/////////////////////////////////// +// 3. Manipolazione + +// Questi sono simili agli effetti ma possono fare di più +$('div').addClass('taming-slim-20'); // Aggiunge la classe taming-slim-20 a tutti i div + +// Metodi di manipolazione comuni +$('p').append('Hello world'); // Aggiunge alla fine dell'elemento +$('p').attr('class'); // Ottiene l'attributo +$('p').attr('class', 'content'); // Imposta l'attributo +$('p').hasClass('taming-slim-20'); // Restituisce vero se ha la classe +$('p').height(); // Ottiene l'altezza dell'elemento o imposta l'altezza + + +// Per molti metodi di manipolazione, ottenere informazioni su un elemento +// restituirà SOLO il primo elemento corrispondente +$('p').height(); // Ottiene solo la prima altezza del tag 'p' + +// È possibile utilizzare each per scorrere tutti gli elementi +var heights = []; +$('p').each(function() { + heights.push($(this).height()); // Aggiunge tutte le altezze del tag 'p' all'array +}); + + +``` diff --git a/it-it/markdown.html.markdown b/it-it/markdown.html.markdown index 44801747..b0a123f1 100644 --- a/it-it/markdown.html.markdown +++ b/it-it/markdown.html.markdown @@ -28,7 +28,7 @@ Markdown varia nelle sue implementazioni da un parser all'altro. Questa guida ce ## Elementi HTML Markdown è un superset di HTML, quindi ogni file HTML è a sua volta un file Markdown valido. -```markdown +```md <!-- Questo significa che possiamo usare elementi di HTML in Markdown, come per esempio i commenti, e questi non saranno modificati dal parser di Markdown. State attenti però, se inserite un elemento HTML nel vostro file Markdown, non potrete usare la sua sintassi @@ -39,7 +39,7 @@ all'interno del contenuto dell'elemento. --> Potete creare gli elementi HTML da `<h1>` a `<h6>` facilmente, basta che inseriate un egual numero di caratteri cancelletto (#) prima del testo che volete all'interno dell'elemento -```markdown +```md # Questo è un <h1> ## Questo è un <h2> ### Questo è un <h3> @@ -49,7 +49,7 @@ Potete creare gli elementi HTML da `<h1>` a `<h6>` facilmente, basta che inseria ``` Markdown inoltre fornisce due alternative per indicare gli elementi h1 e h2 -```markdown +```md Questo è un h1 ============== @@ -60,7 +60,7 @@ Questo è un h2 ## Stili di testo semplici Il testo può essere stilizzato in corsivo o grassetto usando markdown -```markdown +```md *Questo testo è in corsivo.* _Come pure questo._ @@ -74,12 +74,12 @@ __Come pure questo.__ In Github Flavored Markdown, che è utilizzato per renderizzare i file markdown su Github, è presente anche lo stile barrato: -```markdown +```md ~~Questo testo è barrato.~~ ``` ## Paragrafi -```markdown +```md I paragrafi sono una o più linee di testo adiacenti separate da una o più righe vuote. Questo è un paragrafo. Sto scrivendo in un paragrafo, non è divertente? @@ -93,7 +93,7 @@ Qui siamo nel paragrafo 3! Se volete inserire l'elemento HTML `<br />`, potete terminare la linea con due o più spazi e poi iniziare un nuovo paragrafo. -```markdown +```md Questa frase finisce con due spazi (evidenziatemi per vederli). C'è un <br /> sopra di me! @@ -101,7 +101,7 @@ C'è un <br /> sopra di me! Le citazioni sono semplici da inserire, basta usare il carattere >. -```markdown +```md > Questa è una citazione. Potete > mandare a capo manualmente le linee e inserire un `>` prima di ognuna, oppure potete usare una sola linea e lasciare che vada a capo automaticamente. > Non c'è alcuna differenza, basta che iniziate ogni riga con `>`. @@ -115,7 +115,7 @@ Le citazioni sono semplici da inserire, basta usare il carattere >. ## Liste Le liste non ordinate possono essere inserite usando gli asterischi, il simbolo più o dei trattini -```markdown +```md * Oggetto * Oggetto * Altro oggetto @@ -135,7 +135,7 @@ oppure Le liste ordinate invece, sono inserite con un numero seguito da un punto. -```markdown +```md 1. Primo oggetto 2. Secondo oggetto 3. Terzo oggetto @@ -143,7 +143,7 @@ Le liste ordinate invece, sono inserite con un numero seguito da un punto. Non dovete nemmeno mettere i numeri nell'ordine giusto, markdown li visualizzerà comunque nell'ordine corretto, anche se potrebbe non essere una buona idea. -```markdown +```md 1. Primo oggetto 1. Secondo oggetto 1. Terzo oggetto @@ -152,7 +152,7 @@ Non dovete nemmeno mettere i numeri nell'ordine giusto, markdown li visualizzer Potete inserire anche sotto liste -```markdown +```md 1. Primo oggetto 2. Secondo oggetto 3. Terzo oggetto @@ -163,7 +163,7 @@ Potete inserire anche sotto liste Sono presenti anche le task list. In questo modo è possibile creare checkbox in HTML. -```markdown +```md I box senza la 'x' sono checkbox HTML ancora da completare. - [ ] Primo task da completare. - [ ] Secondo task che deve essere completato. @@ -174,14 +174,14 @@ Il box subito sotto è una checkbox HTML spuntata. Potete inserire un estratto di codice (che utilizza l'elemento `<code>`) indentando una linea con quattro spazi oppure con un carattere tab. -```markdown +```md Questa è una linea di codice Come questa ``` Potete inoltre inserire un altro tab (o altri quattro spazi) per indentare il vostro codice -```markdown +```md my_array.each do |item| puts item end @@ -189,7 +189,7 @@ Potete inoltre inserire un altro tab (o altri quattro spazi) per indentare il vo Codice inline può essere inserito usando il carattere backtick ` -```markdown +```md Giovanni non sapeva neppure a cosa servisse la funzione `go_to()`! ``` @@ -205,7 +205,7 @@ Se usate questa sintassi, il testo non richiederà di essere indentato, inoltre ## Linea orizzontale Le linee orizzontali (`<hr/>`) sono inserite facilmente usanto tre o più asterischi o trattini, con o senza spazi. -```markdown +```md *** --- - - - @@ -215,24 +215,24 @@ Le linee orizzontali (`<hr/>`) sono inserite facilmente usanto tre o più asteri ## Links Una delle funzionalità migliori di markdown è la facilità con cui si possono inserire i link. Mettete il testo da visualizzare fra parentesi quadre [] seguite dall'url messo fra parentesi tonde () -```markdown +```md [Cliccami!](http://test.com/) ``` Potete inoltre aggiungere al link un titolo mettendolo fra doppi apici dopo il link -```markdown +```md [Cliccami!](http://test.com/ "Link a Test.com") ``` La sintassi funziona anche con i path relativi. -```markdown +```md [Vai a musica](/music/). ``` Markdown supporta inoltre anche la possibilità di aggiungere i link facendo riferimento ad altri punti del testo. -```markdown +```md [Apri questo link][link1] per più informazioni! [Guarda anche questo link][foobar] se ti va. @@ -242,7 +242,7 @@ Markdown supporta inoltre anche la possibilità di aggiungere i link facendo rif l titolo può anche essere inserito in apici singoli o in parentesi, oppure omesso interamente. Il riferimento può essere inserito in un punto qualsiasi del vostro documento e l'identificativo del riferimento può essere lungo a piacere a patto che sia univoco. Esiste anche un "identificativo implicito" che vi permette di usare il testo del link come id. -```markdown +```md [Questo][] è un link. [Questo]: http://thisisalink.com/ @@ -252,13 +252,13 @@ Ma non è comunemente usato. ## Immagini Le immagini sono inserite come i link ma con un punto esclamativo inserito prima delle parentesi quadre! -```markdown +```md  ``` E la modalità a riferimento funziona esattamente come ci si aspetta -```markdown +```md ![Questo è il testo alternativo.][myimage] [myimage]: relative/urls/cool/image.jpg "Se vi serve un titolo, lo mettete qui" @@ -266,25 +266,25 @@ E la modalità a riferimento funziona esattamente come ci si aspetta ## Miscellanea ### Auto link -```markdown +```md <http://testwebsite.com/> è equivalente ad [http://testwebsite.com/](http://testwebsite.com/) ``` ### Auto link per le email -```markdown +```md <foo@bar.com> ``` ### Caratteri di escaping -```markdown +```md Voglio inserire *questo testo circondato da asterischi* ma non voglio che venga renderizzato in corsivo, quindi lo inserirò così: \*questo testo è circondato da asterischi\*. ``` ### Combinazioni di tasti In Github Flavored Markdown, potete utilizzare il tag `<kbd>` per raffigurare i tasti della tastiera. -```markdown +```md Il tuo computer è crashato? Prova a premere <kbd>Ctrl</kbd>+<kbd>Alt</kbd>+<kbd>Canc</kbd> ``` @@ -292,7 +292,7 @@ Il tuo computer è crashato? Prova a premere ### Tabelle Le tabelle sono disponibili solo in Github Flavored Markdown e sono leggeremente complesse, ma se proprio volete inserirle fate come segue: -```markdown +```md | Col1 | Col2 | Col3 | | :------------------- | :------: | -----------------: | | Allineato a sinistra | Centrato | Allineato a destra | @@ -300,7 +300,7 @@ Le tabelle sono disponibili solo in Github Flavored Markdown e sono leggeremente ``` oppure, per lo stesso risultato -```markdown +```md Col 1 | Col2 | Col3 :-- | :-: | --: È una cosa orrenda | fatela | finire in fretta diff --git a/it-it/matlab-it.html.markdown b/it-it/matlab-it.html.markdown index 8d6d4385..38be8848 100644 --- a/it-it/matlab-it.html.markdown +++ b/it-it/matlab-it.html.markdown @@ -199,8 +199,7 @@ size(A) % ans = 3 3 A(1, :) =[] % Rimuove la prima riga della matrice A(:, 1) =[] % Rimuove la prima colonna della matrice -transpose(A) % Traspone la matrice, equivale a: -A one +transpose(A) % Traspone la matrice, equivale a: A.' ctranspose(A) % Trasposizione hermitiana della matrice % (ovvero il complesso coniugato di ogni elemento della matrice trasposta) diff --git a/it-it/pcre-it.html.markdown b/it-it/pcre-it.html.markdown new file mode 100644 index 00000000..68233858 --- /dev/null +++ b/it-it/pcre-it.html.markdown @@ -0,0 +1,80 @@ +--- +language: PCRE +filename: pcre-it.txt +contributors: + - ["Sachin Divekar", "http://github.com/ssd532"] +translators: + - ["Christian Grasso", "https://grasso.io"] +lang: it-it +--- + +Un'espressione regolare (regex o regexp in breve) è una speciale stringa +utilizzata per definire un pattern, ad esempio per cercare una sequenza di +caratteri; ad esempio, `/^[a-z]+:/` può essere usato per estrarre `http:` +dall'URL `http://github.com/`. + +PCRE (Perl Compatible Regular Expressions) è una libreria per i regex in C. +La sintassi utilizzata per le espressioni è molto simile a quella di Perl, da +cui il nome. Si tratta di una delle sintassi più diffuse per la scrittura di +regex. + +Esistono due tipi di metacaratteri (caratteri con una funzione speciale): +* Caratteri riconosciuti ovunque tranne che nelle parentesi quadre +``` + \ carattere di escape + ^ cerca all'inizio della stringa (o della riga, in modalità multiline) + $ cerca alla fine della stringa (o della riga, in modalità multiline) + . qualsiasi carattere eccetto le newline + [ inizio classe di caratteri + | separatore condizioni alternative + ( inizio subpattern + ) fine subpattern + ? quantificatore "0 o 1" + * quantificatore "0 o più" + + quantificatore "1 o più" + { inizio quantificatore numerico +``` + +* Caratteri riconosciuti nelle parentesi quadre +``` + \ carattere di escape + ^ nega la classe se è il primo carattere + - indica una serie di caratteri + [ classe caratteri POSIX (se seguita dalla sintassi POSIX) + ] termina la classe caratteri + +``` + +PCRE fornisce inoltre delle classi di caratteri predefinite: +``` + \d cifra decimale + \D NON cifra decimale + \h spazio vuoto orizzontale + \H NON spazio vuoto orizzontale + \s spazio + \S NON spazio + \v spazio vuoto verticale + \V NON spazio vuoto verticale + \w parola + \W "NON parola" +``` + +## Esempi + +Utilizzeremo la seguente stringa per i nostri test: +``` +66.249.64.13 - - [18/Sep/2004:11:07:48 +1000] "GET /robots.txt HTTP/1.0" 200 468 "-" "Googlebot/2.1" +``` +Si tratta di una riga di log del web server Apache. + +| Regex | Risultato | Commento | +| :---- | :-------------- | :------ | +| `GET` | GET | Cerca esattamente la stringa "GET" (case sensitive) | +| `\d+.\d+.\d+.\d+` | 66.249.64.13 | `\d+` identifica uno o più (quantificatore `+`) numeri [0-9], `\.` identifica il carattere `.` | +| `(\d+\.){3}\d+` | 66.249.64.13 | `(\d+\.){3}` cerca il gruppo (`\d+\.`) esattamente 3 volte. | +| `\[.+\]` | [18/Sep/2004:11:07:48 +1000] | `.+` identifica qualsiasi carattere, eccetto le newline; `.` indica un carattere qualsiasi | +| `^\S+` | 66.249.64.13 | `^` cerca all'inizio della stringa, `\S+` identifica la prima stringa di caratteri diversi dallo spazio | +| `\+[0-9]+` | +1000 | `\+` identifica il carattere `+`. `[0-9]` indica una cifra da 0 a 9. L'espressione è equivalente a `\+\d+` | + +## Altre risorse +[Regex101](https://regex101.com/) - tester per le espressioni regolari diff --git a/it-it/pyqt-it.html.markdown b/it-it/pyqt-it.html.markdown new file mode 100644 index 00000000..855a0c75 --- /dev/null +++ b/it-it/pyqt-it.html.markdown @@ -0,0 +1,85 @@ +--- +category: tool +tool: PyQT +filename: learnpyqt.py +contributors: + - ["Nathan Hughes", "https://github.com/sirsharpest"] +translators: + - ["Ale46", "https://github.com/ale46"] +lang: it-it +--- + +**Qt** è un framework ampiamente conosciuto per lo sviluppo di software multipiattaforma che può essere eseguito su varie piattaforme software e hardware con modifiche minime o nulle nel codice, pur avendo la potenza e la velocità delle applicazioni native. Sebbene **Qt** sia stato originariamente scritto in *C++*. + + +Questo è un adattamento sull'introduzione di C ++ a QT di [Aleksey Kholovchuk] (https://github.com/vortexxx192 +), alcuni degli esempi di codice dovrebbero avere la stessa funzionalità +che avrebbero se fossero fatte usando pyqt! + +```python +import sys +from PyQt4 import QtGui + +def window(): + # Crea un oggetto applicazione + app = QtGui.QApplication(sys.argv) + # Crea un widget in cui verrà inserita la nostra etichetta + w = QtGui.QWidget() + # Aggiungi un'etichetta al widget + b = QtGui.QLabel(w) + # Imposta del testo per l'etichetta + b.setText("Ciao Mondo!") + # Fornisce informazioni su dimensioni e posizionamento + w.setGeometry(100, 100, 200, 50) + b.move(50, 20) + # Dai alla nostra finestra un bel titolo + w.setWindowTitle("PyQt") + # Visualizza tutto + w.show() + # Esegui ciò che abbiamo chiesto, una volta che tutto è stato configurato + sys.exit(app.exec_()) + +if __name__ == '__main__': + window() + +``` + +Per ottenere alcune delle funzionalità più avanzate in **pyqt**, dobbiamo iniziare a cercare di creare elementi aggiuntivi. +Qui mostriamo come creare una finestra popup di dialogo, utile per chiedere all'utente di confermare una decisione o fornire informazioni + +```Python +import sys +from PyQt4.QtGui import * +from PyQt4.QtCore import * + + +def window(): + app = QApplication(sys.argv) + w = QWidget() + # Crea un pulsante e allegalo al widget w + b = QPushButton(w) + b.setText("Premimi") + b.move(50, 50) + # Indica a b di chiamare questa funzione quando si fa clic + # notare la mancanza di "()" sulla chiamata di funzione + b.clicked.connect(showdialog) + w.setWindowTitle("PyQt Dialog") + w.show() + sys.exit(app.exec_()) + +# Questa funzione dovrebbe creare una finestra di dialogo con un pulsante +# che aspetta di essere cliccato e quindi esce dal programma +def showdialog(): + d = QDialog() + b1 = QPushButton("ok", d) + b1.move(50, 50) + d.setWindowTitle("Dialog") + # Questa modalità dice al popup di bloccare il genitore, mentre è attivo + d.setWindowModality(Qt.ApplicationModal) + # Al click vorrei che l'intero processo finisse + b1.clicked.connect(sys.exit) + d.exec_() + +if __name__ == '__main__': + window() +``` diff --git a/it-it/python3-it.html.markdown b/it-it/python3-it.html.markdown new file mode 100644 index 00000000..04f78cff --- /dev/null +++ b/it-it/python3-it.html.markdown @@ -0,0 +1,1016 @@ +--- +language: python3 +filename: learnpython3-it.py +contributors: + - ["Louie Dinh", "http://pythonpracticeprojects.com"] + - ["Steven Basart", "http://github.com/xksteven"] + - ["Andre Polykanine", "https://github.com/Oire"] + - ["Zachary Ferguson", "http://github.com/zfergus2"] + - ["evuez", "http://github.com/evuez"] + - ["Rommel Martinez", "https://ebzzry.io"] +translators: + - ["Draio", "http://github.com/Draio/"] + - ["Ale46", "http://github.com/Ale46/"] + - ["Tommaso Pifferi", "http://github.com/neslinesli93/"] +lang: it-it +--- + +Python è stato creato da Guido Van Rossum agli inizi degli anni 90. Oggi è uno dei più popolari linguaggi esistenti. Mi sono innamorato di Python per la sua chiarezza sintattica. E' sostanzialmente pseudocodice eseguibile. + +Feedback sono altamente apprezzati! Potete contattarmi su [@louiedinh](http://twitter.com/louiedinh) oppure [at] [google's email service] + +Nota: Questo articolo è riferito a Python 3 in modo specifico. Se volete avete la necessità di utilizzare Python 2.7 potete consultarla [qui](https://learnxinyminutes.com/docs/it-it/python-it/) + +```python + +# I commenti su una sola linea iniziano con un cancelletto + + +""" Più stringhe possono essere scritte + usando tre ", e sono spesso usate + come documentazione +""" + +#################################################### +## 1. Tipi di dati primitivi ed Operatori +#################################################### + +# Ci sono i numeri +3 # => 3 + +# La matematica è quello che vi aspettereste +1 + 1 # => 2 +8 - 1 # => 7 +10 * 2 # => 20 +35 / 5 # => 7.0 + +# Risultato della divisione intera troncata sia in positivo che in negativo +5 // 3 # => 1 +5.0 // 3.0 # => 1.0 # works on floats too +-5 // 3 # => -2 +-5.0 // 3.0 # => -2.0 + +# Il risultato di una divisione è sempre un numero decimale (float) +10.0 / 3 # => 3.3333333333333335 + +# Operazione Modulo +7 % 3 # => 1 + +# Elevamento a potenza (x alla y-esima potenza) +2**3 # => 8 + +# Forzare le precedenze con le parentesi +(1 + 3) * 2 # => 8 + +# I valori booleani sono primitive del linguaggio (nota la maiuscola) +True +False + +# nega con not +not True # => False +not False # => True + +# Operatori Booleani +# Nota "and" e "or" sono case-sensitive +True and False # => False +False or True # => True + +# Note sull'uso di operatori Bool con interi +# False è 0 e True è 1 +# Non confonderti tra bool(ints) e le operazioni bitwise and/or (&,|) +0 and 2 # => 0 +-5 or 0 # => -5 +0 == False # => True +2 == True # => False +1 == True # => True +-5 != False != True #=> True + +# Uguaglianza è == +1 == 1 # => True +2 == 1 # => False + +# Disuguaglianza è != +1 != 1 # => False +2 != 1 # => True + +# Altri confronti +1 < 10 # => True +1 > 10 # => False +2 <= 2 # => True +2 >= 2 # => True + +# I confronti possono essere concatenati! +1 < 2 < 3 # => True +2 < 3 < 2 # => False + +# ('is' vs. '==') +# 'is' controlla se due variabili si riferiscono allo stesso oggetto +# '==' controlla se gli oggetti puntati hanno lo stesso valore. +a = [1, 2, 3, 4] # a punta ad una nuova lista [1, 2, 3, 4] +b = a # b punta a ciò a cui punta a +b is a # => True, a e b puntano allo stesso oggeto +b == a # => True, gli oggetti di a e b sono uguali +b = [1, 2, 3, 4] # b punta ad una nuova lista [1, 2, 3, 4] +b is a # => False, a e b non puntano allo stesso oggetto +b == a # => True, gli oggetti di a e b sono uguali + +# Le stringhe sono create con " o ' +"Questa è una stringa." +'Anche questa è una stringa.' + +# Anche le stringhe possono essere sommate! Ma cerca di non farlo. +"Hello " + "world!" # => "Hello world!" +# Le stringhe (ma non le variabili contenenti stringhe) possono essere +# sommate anche senza '+' +"Hello " "world!" # => "Hello world!" + +# Una stringa può essere considerata come una lista di caratteri +"Questa è una stringa"[0] # => 'Q' + +# Puoi conoscere la lunghezza di una stringa +len("Questa è una stringa") # => 20 + +# .format può essere usato per formattare le stringhe, in questo modo: +"{} possono essere {}".format("Le stringhe", "interpolate") # => "Le stringhe possono essere interpolate" + +# Puoi ripetere gli argomenti di formattazione per risparmiare un po' di codice +"{0} be nimble, {0} be quick, {0} jump over the {1}".format("Jack", "candle stick") +# => "Jack be nimble, Jack be quick, Jack jump over the candle stick" + +# Puoi usare dei nomi se non vuoi contare gli argomenti +"{nome} vuole mangiare {cibo}".format(nome="Bob", cibo="le lasagne") # => "Bob vuole mangiare le lasagne" + +# Se il tuo codice Python 3 necessita di eseguire codice Python 2.x puoi ancora +# utilizzare il vecchio stile di formattazione: +"%s possono essere %s nel %s modo" % ("Le stringhe", "interpolate", "vecchio") # => "Le stringhe possono essere interpolate nel vecchio modo" + +# None è un oggetto +None # => None + +# Non usare il simbolo di uguaglianza "==" per comparare oggetti a None +# Usa "is" invece +"etc" is None # => False +None is None # => True + +# None, 0, e stringhe/liste/dizionari/tuple vuoti vengono considerati +# falsi (False). Tutti gli altri valori sono considerati veri (True). +bool(0) # => False +bool("") # => False +bool([]) # => False +bool({}) # => False +bool(()) # => False + +#################################################### +## 2. Variabili e Collections +#################################################### + +# Python ha una funzione per scrivere (sul tuo schermo) +print("Sono Python. Piacere di conoscerti!") # => Sono Python. Piacere di conoscerti! + +# Di default la funzione print() scrive e va a capo aggiungendo un carattere +# newline alla fine della stringa. È possibile utilizzare l'argomento opzionale +# end per cambiare quest'ultimo carattere aggiunto. +print("Hello, World", end="!") # => Hello, World! + +# Un modo semplice per ricevere dati in input dalla riga di comando +variabile_stringa_input = input("Inserisci del testo: ") # Restituisce i dati letti come stringa +# Nota: Nelle precedenti vesioni di Python, il metodo input() +# era chiamato raw_input() + +# Non c'è bisogno di dichiarare una variabile per assegnarle un valore +# Come convenzione, per i nomi delle variabili, si utilizzano i caratteri +# minuscoli separati, se necessario, da underscore +some_var = 5 +some_var # => 5 + +# Accedendo ad una variabile non precedentemente assegnata genera un'eccezione. +# Dai un'occhiata al Control Flow per imparare di più su come gestire +# le eccezioni. +some_unknown_var # Genera un errore di nome + +# if può essere usato come un'espressione +# È l'equivalente dell'operatore ternario in C +"yahoo!" if 3 > 2 else 2 # => "yahoo!" + +# Le liste immagazzinano sequenze +li = [] +# Puoi partire con una lista pre-riempita +other_li = [4, 5, 6] + +# Aggiungere alla fine di una lista con append +li.append(1) # li ora è [1] +li.append(2) # li ora è [1, 2] +li.append(4) # li ora è [1, 2, 4] +li.append(3) # li ora è [1, 2, 4, 3] +# Rimuovi dalla fine della lista con pop +li.pop() # => 3 e li ora è [1, 2, 4] +# Rimettiamolo a posto +li.append(3) # li ora è [1, 2, 4, 3] di nuovo. + +# Accedi ad una lista come faresti con un array +li[0] # => 1 +# Guarda l'ultimo elemento +li[-1] # => 3 + +# Guardare al di fuori dei limiti genera un IndexError +li[4] # Genera IndexError + +# Puoi guardare gli intervalli con la sintassi slice (a fetta). +# (E' un intervallo chiuso/aperto per voi tipi matematici.) +li[1:3] # => [2, 4] +# Ometti l'inizio +li[2:] # => [4, 3] +# Ometti la fine +li[:3] # => [1, 2, 4] +# Seleziona ogni seconda voce +li[::2] # =>[1, 4] +# Copia al contrario della lista +li[::-1] # => [3, 4, 2, 1] +# Usa combinazioni per fare slices avanzate +# li[inizio:fine:passo] + +# Crea una copia (one layer deep copy) usando la sintassi slices +li2 = li[:] # => li2 = [1, 2, 4, 3] ma (li2 is li) risulterà falso. + +# Rimuovi arbitrariamente elementi da una lista con "del" +del li[2] # li è ora [1, 2, 3] + +# Rimuove la prima occorrenza di un elemento +li.remove(2) # Ora li è [1, 3, 4, 5, 6] +li.remove(2) # Emette un ValueError, poichè 2 non è contenuto nella lista + +# Inserisce un elemento all'indice specificato +li.insert(1, 2) # li è di nuovo [1, 2, 3, 4, 5, 6] + + Ritorna l'indice della prima occorrenza dell'elemento fornito +li.index(2) # => 1 +li.index(7) # Emette un ValueError, poichè 7 non è contenuto nella lista + +# Puoi sommare le liste +# Nota: i valori per li e per other_li non vengono modificati. +li + other_li # => [1, 2, 3, 4, 5, 6] + +# Concatena le liste con "extend()" +li.extend(other_li) # Adesso li è [1, 2, 3, 4, 5, 6] + +# Controlla l'esistenza di un valore in una lista con "in" +1 in li # => True + +# Esamina la lunghezza con "len()" +len(li) # => 6 + + +# Le tuple sono come le liste ma immutabili. +tup = (1, 2, 3) +tup[0] # => 1 +tup[0] = 3 # Genera un TypeError + +# Note that a tuple of length one has to have a comma after the last element but +# tuples of other lengths, even zero, do not. +type((1)) # => <class 'int'> +type((1,)) # => <class 'tuple'> +type(()) # => <class 'tuple'> + +# Puoi fare tutte queste cose da lista anche sulle tuple +len(tup) # => 3 +tup + (4, 5, 6) # => (1, 2, 3, 4, 5, 6) +tup[:2] # => (1, 2) +2 in tup # => True + +# Puoi scompattare le tuple (o liste) in variabili +a, b, c = (1, 2, 3) # a è ora 1, b è ora 2 e c è ora 3 +d, e, f = 4, 5, 6 # puoi anche omettere le parentesi +# Le tuple sono create di default se non usi le parentesi +g = 4, 5, 6 # => (4, 5, 6) +# Guarda come è facile scambiare due valori +e, d = d, e # d è ora 5 ed e è ora 4 + +# I dizionari memorizzano insiemi di dati indicizzati da nomi arbitrari (chiavi) +empty_dict= {} +# Questo è un dizionario pre-caricato +filled_dict = {"uno": 1, "due": 2, "tre": 3} + +# Nota: le chiavi dei dizionari devono essere di tipo immutabile. Questo per +# assicurare che le chiavi possano essere convertite in calori hash costanti +# per un risposta più veloce. +invalid_dict = {[1,2,3]: "123"} # => Emette un TypeError: unhashable type: 'list' +valid_dict = {(1,2,3):[1,2,3]} # I valori, invece, possono essere di qualunque tipo + +# Accedi ai valori indicando la chiave tra [] +filled_dict["uno"] # => 1 + +# Puoi ottenere tutte le chiavi di un dizionario con "keys()" +# (come oggetto iterabile). Per averle in formato lista è necessario +# utilizzare list(). +# Nota - Nei dizionari l'ordine delle chiavi non è garantito. +# Il tuo risultato potrebbe non essere uguale a questo. +list(filled_dict.keys()) # => ["tre", "due", "uno"] + + +# Puoi ottenere tutti i valori di un dizionario con "values()" +# (come oggetto iterabile). +# Anche in questo caso, er averle in formato lista, è necessario utilizzare list() +# Anche in questo caso, come per le chiavi, l'ordine non è garantito +list(filled_dict.values()) # => [3, 2, 1] + +# Controlla l'esistenza delle chiavi in un dizionario con "in" +"uno" in filled_dict # => True +1 in filled_dict # => False + +# Cercando una chiave non esistente genera un KeyError +filled_dict["quattro"] # KeyError + +# Usa il metodo "get()" per evitare KeyError +filled_dict.get("uno") # => 1 +filled_dict.get("quattro") # => None +# Il metodo get supporta un argomento di default quando il valore è mancante +filled_dict.get("uno", 4) # => 1 +filled_dict.get("quattro", 4) # => 4 + + +# "setdefault()" inserisce un valore per una chiave in un dizionario +# solo se la chiave data non è già presente +filled_dict.setdefault("cinque", 5) # filled_dict["cinque"] viene impostato a 5 +filled_dict.setdefault("cinque", 6) # filled_dict["cinque"] rimane 5 + +# Aggiungere una coppia chiave->valore a un dizionario +filled_dict.update({"quattro":4}) # => {"uno": 1, "due": 2, "tre": 3, "quattro": 4} +filled_dict["quattro"] = 4 # un altro modo pe aggiungere a un dizionario + +# Rimuovi una chiave da un dizionario con del +del filled_dict["uno"] # Rimuove la chiave "uno" dal dizionario + +# Da Python 3.5 puoi anche usare ulteriori opzioni di spacchettamento +{'a': 1, **{'b': 2}} # => {'a': 1, 'b': 2} +{'a': 1, **{'a': 2}} # => {'a': 2} + +# I set sono come le liste ma non possono contenere doppioni +empty_set = set() +# Inizializza un "set()" con un dei valori. Sì, sembra un dizionario. +some_set = {1, 1, 2, 2, 3, 4} # set_nuovo è {1, 2, 3, 4} + +# Come le chiavi di un dizionario, gli elementi di un set devono essere +# di tipo immutabile +invalid_set = {[1], 1} # => Genera un "TypeError: unhashable type: 'list'"" +valid_set = {(1,), 1} + +# Aggiungere uno o più elementi ad un set +some_set.add(5) # some_set ora è {1, 2, 3, 4, 5} + +# Fai intersezioni su un set con & +other_set = {3, 4, 5, 6} +some_set & other_set # => {3, 4, 5} + +# Fai unioni su set con | +some_set | other_set # => {1, 2, 3, 4, 5, 6} + +# Fai differenze su set con - +{1, 2, 3, 4} - {2, 3, 5} # => {1, 4} + +# Effettua la differenza simmetrica con ^ +{1, 2, 3, 4} ^ {2, 3, 5} # => {1, 4, 5} + +# Controlla se il set a sinistra contiene quello a destra +{1, 2} >= {1, 2, 3} # => False + +# Controlla se il set a sinistra è un sottoinsieme di quello a destra +{1, 2} <= {1, 2, 3} # => True + +# Controlla l'esistenza in un set con in +2 in some_set # => True +10 in some_set # => False + + + +#################################################### +## 3. Control Flow e oggetti Iterabili +#################################################### + +# Dichiariamo una variabile +some_var = 5 + +# Questo è un controllo if. L'indentazione è molto importante in python! +# Come convenzione si utilizzano quattro spazi, non la tabulazione. +# Il seguente codice stampa "some_var è minore di 10" +if some_var > 10: + print("some_var è maggiore di 10") +elif some_var < 10: # La clausolo elif è opzionale + print("some_var è minore di 10") +else: # Anche else è opzionale + print("some_var è 10.") + +""" +I cicli for iterano sulle liste, cioè ripetono un codice per ogni elemento +di una lista. +Il seguente codice scriverà: + cane è un mammifero + gatto è un mammifero + topo è un mammifero +""" +for animale in ["cane", "gatto", "topo"]: + # Puoi usare format() per interpolare le stringhe formattate. + print("{} è un mammifero".format(animale)) + +""" +"range(numero)" restituisce una lista di numeri da zero al numero dato +Il seguente codice scriverà: + 0 + 1 + 2 + 3 +""" +for i in range(4): + print(i) + +""" +"range(lower, upper)" restituisce una lista di numeri dal più piccolo (lower) +al più grande (upper). +Il seguente codice scriverà: + 4 + 5 + 6 + 7 +""" +for i in range(4, 8): + print(i) + +""" +"range(lower, upper, step)" rrestituisce una lista di numeri dal più piccolo +(lower) al più grande (upper), incrementando del valore step. +Se step non è indicato, avrà come valore di default 1. +Il seguente codice scriverà: + 4 + 6 +""" +for i in range(4, 8, 2): + print(i) +""" + +I cicli while vengono eseguiti finchè una condizione viene a mancare +Il seguente codice scriverà: + 0 + 1 + 2 + 3 +""" +x = 0 +while x < 4: + print(x) + x += 1 # Forma compatta per x = x + 1 + +# Gestione delle eccezioni con un blocco try/except +try: + # Usa "raise" per generare un errore + raise IndexError("Questo è un IndexError") +except IndexError as e: + pass # Pass è solo una non-operazione. Solitamente vorrai rimediare all'errore. +except (TypeError, NameError): + pass # Eccezioni multiple possono essere gestite tutte insieme, se necessario. +else: # Clausola opzionale al blocco try/except. Deve essere dopo tutti i blocchi except + print("Tutto ok!") # Viene eseguita solo se il codice dentro try non genera eccezioni +finally: # Eseguito sempre + print("Possiamo liberare risorse qui") + +# Se ti serve solo un try/finally, per liberare risorse, puoi usare il metodo with +with open("myfile.txt") as f: + for line in f: + print(line) + +# In Python qualunque oggetto in grado di essere trattato come una +# sequenza è definito un oggetto Iterable (itarabile). +# L'oggetto restituito da una funzione range è un iterabile. + +filled_dict = {"uno": 1, "due": 2, "tre": 3} +our_iterable = filled_dict.keys() +print(our_iterable) # => dict_keys(['uno', 'due', 'tre']). +# Questo è un oggetto che implementa la nostra interfaccia Iterable. + +# È possibile utilizzarlo con i loop: +for i in our_iterable: + print(i) # Scrive uno, due, tre + +# Tuttavia non possiamo recuperarne i valori tramite indice. +our_iterable[1] # Genera un TypeError + +# Un oggetto iterabile è in grado di generare un iteratore +our_iterator = iter(our_iterable) + +# L'iteratore è un oggetto che ricorda il suo stato mentro lo si "attraversa" +# Possiamo accedere al successivo elemento con "next()". +next(our_iterator) # => "uno" + +# Mantiene il suo stato mentro eseguiamo l'iterazione +next(our_iterator) # => "due" +next(our_iterator) # => "tre" + +# Dopo che un iteratore ha restituito tutti i suoi dati, genera +# un'eccezione StopIteration +next(our_iterator) # Raises StopIteration + +# Puoi prendere tutti gli elementi di un iteratore utilizzando list(). +list(filled_dict.keys()) # => Returns ["one", "two", "three"] + + + +#################################################### +## 4. Funzioni +#################################################### + +# Usa "def" per creare nuove funzioni +def aggiungi(x, y): + print("x è {} e y è {}".format(x, y)) // Scrive i valori formattati in una stringa + return x + y # Restituisce la somma dei valori con il metodo return + +# Chiamare funzioni con parametri +aggiungi(5, 6) # => scrive "x è 5 e y è 6" e restituisce 11 + +# Un altro modo per chiamare funzioni è con parole chiave come argomenti +aggiungi(y=6, x=5) # In questo modo non è necessario rispettare l'ordine degli argomenti + +# Puoi definire funzioni che accettano un numero non definito di argomenti +def varargs(*args): + return args + +varargs(1, 2, 3) # => (1, 2, 3) + +# Puoi definire funzioni che accettano un numero variabile di parole chiave +# come argomento, che saranno interpretati come un dizionario usando ** +def keyword_args(**kwargs): + return kwargs + +# Chiamiamola per vedere cosa succede +keyword_args(big="foot", loch="ness") # => {"big": "foot", "loch": "ness"} + + +# Puoi farle entrambi in una volta, se ti va +def all_the_args(*args, **kwargs): + print(args) + print(kwargs) +""" +all_the_args(1, 2, a=3, b=4) stampa: + (1, 2) + {"a": 3, "b": 4} +""" + +# Quando chiami funzioni, puoi fare l'opposto di args/kwargs! +# Usa * per sviluppare gli argomenti posizionale ed usa ** per +# espandere gli argomenti parola chiave +args = (1, 2, 3, 4) +kwargs = {"a": 3, "b": 4} +all_the_args(*args) # equivalente a foo(1, 2, 3, 4) +all_the_args(**kwargs) # equivalente a foo(a=3, b=4) +all_the_args(*args, **kwargs) # equivalente a foo(1, 2, 3, 4, a=3, b=4) + + +# Restituire valori multipli (with tuple assignments) +def swap(x, y): + return y, x # Restituisce valori multipli come tupla senza parentesi + # (Nota: le parentesi sono state escluse ma possono essere messe) + +x = 1 +y = 2 +x, y = swap(x, y) # => x = 2, y = 1 +# (x, y) = swap(x,y) # Le parentesi sono state escluse ma possono essere incluse. + +# Funzioni - Visibilità delle variabili (variable scope) +x = 5 + +def set_x(num): + # La variabile locale x non è la variabile globale x + x = num # => 43 + print(x) # => 43 + +def set_global_x(num): + global x + print(x) # => 5 + x = num # la variabile globable x è ora 6 + print(x) # => 6 + +set_x(43) +set_global_x(6) + + +# Python ha "first class functions" +def create_adder(x): + def adder(y): + return x + y + return adder + +add_10 = create_adder(10) +add_10(3) # => 13 + +# Ci sono anche funzioni anonime +(lambda x: x > 2)(3) # => True +(lambda x, y: x ** 2 + y ** 2)(2, 1) # => 5 + +# È possibile creare "mappe" e "filtri" +list(map(add_10, [1, 2, 3])) # => [11, 12, 13] +list(map(max, [1, 2, 3], [4, 2, 1])) # => [4, 2, 3] + +list(filter(lambda x: x > 5, [3, 4, 5, 6, 7])) # => [6, 7] + +# Possiamo usare le "list comprehensions" per mappe e filtri +# Le "list comprehensions" memorizzano l'output come una lista che può essere +# di per sé una lista annidata +[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] +[x for x in [3, 4, 5, 6, 7] if x > 5] # => [6, 7] + +# Puoi fare anche la comprensione di set e dizionari +{x for x in 'abcddeef' if x not in 'abc'} # => {'d', 'e', 'f'} +{x: x**2 for x in range(5)} # => {0: 0, 1: 1, 2: 4, 3: 9, 4: 16} + + +#################################################### +## 5. Modules +#################################################### + +# Puoi importare moduli +import math +print(math.sqrt(16)) # => 4.0 + +# Puoi ottenere specifiche funzione da un modulo +from math import ceil, floor +print(ceil(3.7)) # => 4.0 +print(floor(3.7)) # => 3.0 + +# Puoi importare tutte le funzioni da un modulo +# Attenzione: questo non è raccomandato +from math import * + +# Puoi abbreviare i nomi dei moduli +import math as m +math.sqrt(16) == m.sqrt(16) # => True + + +# I moduli di Python sono normali file python. Ne puoi +# scrivere di tuoi ed importarli. Il nome del modulo +# è lo stesso del nome del file. + +# Potete scoprire quali funzioni e attributi +# sono definiti in un modulo +import math +dir(math) + +# Se nella cartella corrente hai uno script chiamato math.py, +# Python caricherà quello invece del modulo math. +# Questo succede perchè la cartella corrente ha priorità +# sulle librerie standard di Python + +# Se hai uno script Python chiamato math.py nella stessa +# cartella del tua script, Python caricherà quello al posto del +# comune modulo math. +# Questo accade perché la cartella locale ha la priorità +# sulle librerie built-in di Python. + + +#################################################### +## 6. Classes +#################################################### + +# Usiamo l'istruzione "class" per creare una classe +class Human: + + # Un attributo della classe. E' condiviso tra tutte le istanze delle classe + species = "H. sapiens" + + # Si noti che i doppi underscore iniziali e finali denotano gli oggetti o + # attributi utilizzati da Python ma che vivono nel namespace controllato + # dall'utente + # Metodi, oggetti o attributi come: __init__, __str__, __repr__, etc. sono + # chiamati metodi speciali (o talvolta chiamati "dunder methods"). + # Non dovresti inventare tali nomi da solo. + + def __init__(self, name): + # Assegna l'argomento all'attributo name dell'istanza + self.name = name + + # Inizializza una proprietà + self._age = 0 + + # Un metodo dell'istanza. Tutti i metodi prendo "self" come primo argomento + def say(self, msg): + print("{name}: {message}".format(name=self.name, message=msg)) + + # Un altro metodo dell'istanza + def sing(self): + return 'yo... yo... microphone check... one two... one two...' + + # Un metodo della classe è condiviso fra tutte le istanze + # Sono chiamati con la classe chiamante come primo argomento + @classmethod + def get_species(cls): + return cls.species + + # Un metodo statico è chiamato senza classe o istanza di riferimento + @staticmethod + def grunt(): + return "*grunt*" + + # Una property è come un metodo getter. + # Trasforma il metodo age() in un attributo in sola lettura, che ha + # lo stesso nome + # In Python non c'è bisogno di scrivere futili getter e setter. + @property + def age(self): + return self._age + + # Questo metodo permette di modificare una property + @age.setter + def age(self, age): + self._age = age + + # Questo metodo permette di cancellare una property + @age.deleter + def age(self): + del self._age + +# Quando l'interprete Python legge un sorgente esegue tutto il suo codice. +# Questo controllo su __name__ assicura che questo blocco di codice venga +# eseguito solo quando questo modulo è il programma principale. + +if __name__ == '__main__': + # Crea un'istanza della classe + i = Human(name="Ian") + i.say("hi") # "Ian: hi" + j = Human("Joel") + j.say("hello") # "Joel: hello" + # i e j sono istanze del tipo Human, o in altre parole sono oggetti Human + + # Chiama un metodo della classe + i.say(i.get_species()) # "Ian: H. sapiens" + # Cambia l'attributo condiviso + Human.species = "H. neanderthalensis" + i.say(i.get_species()) # => "Ian: H. neanderthalensis" + j.say(j.get_species()) # => "Joel: H. neanderthalensis" + + # Chiama un metodo statico + print(Human.grunt()) # => "*grunt*" + + # Non è possibile chiamare il metodo statico con l'istanza dell'oggetto + # poiché i.grunt() metterà automaticamente "self" (l'oggetto i) + # come argomento + print(i.grunt()) # => TypeError: grunt() takes 0 positional arguments but 1 was given + + # Aggiorna la property (age) di questa istanza + i.age = 42 + # Leggi la property + i.say(i.age) # => "Ian: 42" + j.say(j.age) # => "Joel: 0" + # Cancella la property + del i.age + i.age # => questo genererà un AttributeError + + +#################################################### +## 6.1 Ereditarietà (Inheritance) +#################################################### + +# L'ereditarietà consente di definire nuove classi figlio che ereditano metodi e +# variabili dalla loro classe genitore. + +# Usando la classe Human definita sopra come classe base o genitore, possiamo +# definire una classe figlia, Superhero, che erediterà le variabili di classe +# come "species", "name" e "age", così come i metodi, come "sing" e "grunt", +# dalla classe Human, ma potrà anche avere le sue proprietà uniche. + +# Per importare le funzioni da altri file usa il seguente formato +# from "nomefile-senza-estensione" import "funzione-o-classe" + +from human import Human + +# Specificare le classi genitore come parametri della definizione della classe +class Superhero(Human): + + # Se la classe figlio deve ereditare tutte le definizioni del genitore + # senza alcuna modifica, puoi semplicemente usare la parola chiave "pass" + # (e nient'altro) + + #Le classi figlio possono sovrascrivere gli attributi dei loro genitori + species = 'Superhuman' + + # Le classi figlie ereditano automaticamente il costruttore della classe + # genitore, inclusi i suoi argomenti, ma possono anche definire ulteriori + # argomenti o definizioni e sovrascrivere i suoi metodi (compreso il + # costruttore della classe). + # Questo costruttore eredita l'argomento "nome" dalla classe "Human" e + # aggiunge gli argomenti "superpowers" e "movie": + + def __init__(self, name, movie=False, + superpowers=["super strength", "bulletproofing"]): + + # aggiungi ulteriori attributi della classe + self.fictional = True + self.movie = movie + self.superpowers = superpowers + + # La funzione "super" ti consente di accedere ai metodi della classe + # genitore che sono stati sovrascritti dalla classe figlia, + # in questo caso il metodo __init__. + # Il seguente codice esegue il costruttore della classe genitore: + super().__init__(name) + + # Sovrascrivere il metodo "sing" + def sing(self): + return 'Dun, dun, DUN!' + + # Aggiungi un ulteriore metodo dell'istanza + def boast(self): + for power in self.superpowers: + print("I wield the power of {pow}!".format(pow=power)) + + +if __name__ == '__main__': + sup = Superhero(name="Tick") + + # Controllo del tipo di istanza + if isinstance(sup, Human): + print('I am human') + if type(sup) is Superhero: + print('I am a superhero') + + # Ottieni il "Method Resolution search Order" usato sia da getattr () + # che da super (). Questo attributo è dinamico e può essere aggiornato + print(Superhero.__mro__) # => (<class '__main__.Superhero'>, + # => <class 'human.Human'>, <class 'object'>) + + # Esegui il metodo principale ma utilizza il proprio attributo di classe + print(sup.get_species()) # => Superhuman + + # Esegui un metodo che è stato sovrascritto + print(sup.sing()) # => Dun, dun, DUN! + + # Esegui un metodo di Human + sup.say('Spoon') # => Tick: Spoon + + # Esegui un metodo che esiste solo in Superhero + sup.boast() # => I wield the power of super strength! + # => I wield the power of bulletproofing! + + # Attributo di classe ereditato + sup.age = 31 + print(sup.age) # => 31 + + # Attributo che esiste solo in Superhero + print('Am I Oscar eligible? ' + str(sup.movie)) + +#################################################### +## 6.2 Ereditarietà multipla +#################################################### + +# Un'altra definizione di classe +# bat.py +class Bat: + + species = 'Baty' + + def __init__(self, can_fly=True): + self.fly = can_fly + + # Questa classe ha anche un metodo "say" + def say(self, msg): + msg = '... ... ...' + return msg + + # E anche un suo metodo personale + def sonar(self): + return '))) ... (((' + +if __name__ == '__main__': + b = Bat() + print(b.say('hello')) + print(b.fly) + +# Definizione di classe che eredita da Superhero e Bat +# superhero.py +from superhero import Superhero +from bat import Bat + +# Definisci Batman come classe figlia che eredita sia da Superhero che da Bat +class Batman(Superhero, Bat): + + def __init__(self, *args, **kwargs): + # In genere per ereditare gli attributi devi chiamare super: + # super(Batman, self).__init__(*args, **kwargs) + # Ma qui abbiamo a che fare con l'ereditarietà multipla, e super() + # funziona solo con la successiva classe nell'elenco MRO. + # Quindi, invece, chiamiamo esplicitamente __init__ per tutti gli + # antenati. L'uso di *args e **kwargs consente di passare in modo + # pulito gli argomenti, con ciascun genitore che "sbuccia un + # livello della cipolla". + Superhero.__init__(self, 'anonymous', movie=True, + superpowers=['Wealthy'], *args, **kwargs) + Bat.__init__(self, *args, can_fly=False, **kwargs) + # sovrascrivere il valore per l'attributo name + self.name = 'Sad Affleck' + + def sing(self): + return 'nan nan nan nan nan batman!' + + +if __name__ == '__main__': + sup = Batman() + + # Ottieni il "Method Resolution search Order" utilizzato da getattr() e super(). + # Questo attributo è dinamico e può essere aggiornato + print(Batman.__mro__) # => (<class '__main__.Batman'>, + # => <class 'superhero.Superhero'>, + # => <class 'human.Human'>, + # => <class 'bat.Bat'>, <class 'object'>) + + # Esegui il metodo del genitore ma utilizza il proprio attributo di classe + print(sup.get_species()) # => Superhuman + + # Esegui un metodo che è stato sovrascritto + print(sup.sing()) # => nan nan nan nan nan batman! + + # Esegui un metodo da Human, perché l'ordine di ereditarietà è importante + sup.say('I agree') # => Sad Affleck: I agree + + # Esegui un metodo che esiste solo nel 2o antenato + print(sup.sonar()) # => ))) ... ((( + + # Attributo di classe ereditato + sup.age = 100 + print(sup.age) # => 100 + + # Attributo ereditato dal secondo antenato il cui valore predefinito + # è stato ignorato. + print('Can I fly? ' + str(sup.fly)) # => Can I fly? False + + + +#################################################### +## 7. Advanced +#################################################### + +# I generatori ti aiutano a creare codice pigro (lazy code). +# Codice che darà un risultato solo quando sarà "valutato" +def double_numbers(iterable): + for i in iterable: + yield i + i + +# I generatori sono efficienti in termini di memoria perché caricano +# solo i dati necessari per elaborare il valore successivo nell'iterabile. +# Ciò consente loro di eseguire operazioni su intervalli di valori +# altrimenti proibitivi. +# NOTA: `range` sostituisce` xrange` in Python 3. +for i in double_numbers(range(1, 900000000)): # `range` is a generator. + print(i) + if i >= 30: + break + +# Proprio come è possibile creare una "list comprehension", è possibile +# creare anche delle "generator comprehensions". +values = (-x for x in [1,2,3,4,5]) +for x in values: + print(x) # prints -1 -2 -3 -4 -5 to console/terminal + +# Puoi anche trasmettere una "generator comprehensions" direttamente +# ad un elenco. +values = (-x for x in [1,2,3,4,5]) +gen_to_list = list(values) +print(gen_to_list) # => [-1, -2, -3, -4, -5] + + +# Decoratori +# In questo esempio "beg" avvolge/wrappa "say". +# Se say_please è True, cambierà il messaggio restituito. +from functools import wraps + +def beg(target_function): + @wraps(target_function) + def wrapper(*args, **kwargs): + msg, say_please = target_function(*args, **kwargs) + if say_please: + return "{} {}".format(msg, "Per favore! Sono povero :(") + return msg + + return wrapper + + +@beg +def say(say_please=False): + msg = "Puoi comprarmi una birra?" + return msg, say_please + + +print(say()) # Puoi comprarmi una birra? +print(say(say_please=True)) # Puoi comprarmi una birra? Per favore! Sono povero :( +``` + +## Pronto per qualcosa di più? + +### Gratis Online + +* [Automate the Boring Stuff with Python](https://automatetheboringstuff.com) +* [Ideas for Python Projects](http://pythonpracticeprojects.com) +* [The Official Docs](http://docs.python.org/3/) +* [Hitchhiker's Guide to Python](http://docs.python-guide.org/en/latest/) +* [Python Course](http://www.python-course.eu/index.php) +* [First Steps With Python](https://realpython.com/learn/python-first-steps/) +* [A curated list of awesome Python frameworks, libraries and software](https://github.com/vinta/awesome-python) +* [30 Python Language Features and Tricks You May Not Know About](http://sahandsaba.com/thirty-python-language-features-and-tricks-you-may-not-know.html) +* [Official Style Guide for Python](https://www.python.org/dev/peps/pep-0008/) +* [Python 3 Computer Science Circles](http://cscircles.cemc.uwaterloo.ca/) +* [Dive Into Python 3](http://www.diveintopython3.net/index.html) +* [A Crash Course in Python for Scientists](http://nbviewer.jupyter.org/gist/anonymous/5924718) diff --git a/it-it/qt-it.html.markdown b/it-it/qt-it.html.markdown new file mode 100644 index 00000000..4543818f --- /dev/null +++ b/it-it/qt-it.html.markdown @@ -0,0 +1,161 @@ +--- +category: tool +tool: Qt Framework +language: c++ +filename: learnqt.cpp +contributors: + - ["Aleksey Kholovchuk", "https://github.com/vortexxx192"] +translators: + - ["Ale46", "https://gihub.com/ale46"] +lang: it-it +--- + +**Qt** è un framework ampiamente conosciuto per lo sviluppo di software multipiattaforma che può essere eseguito su varie piattaforme software e hardware con modifiche minime o nulle nel codice, pur avendo la potenza e la velocità delle applicazioni native. Sebbene **Qt** sia stato originariamente scritto in *C++*, ci sono diversi porting in altri linguaggi: *[PyQt](https://learnxinyminutes.com/docs/pyqt/)*, *QtRuby*, *PHP-Qt*, etc. + +**Qt** è ottimo per la creazione di applicazioni con interfaccia utente grafica (GUI). Questo tutorial descrive come farlo in *C++*. + +```c++ +/* + * Iniziamo classicamente + */ + +// tutte le intestazioni dal framework Qt iniziano con la lettera maiuscola 'Q' +#include <QApplication> +#include <QLineEdit> + +int main(int argc, char *argv[]) { + // crea un oggetto per gestire le risorse a livello di applicazione + QApplication app(argc, argv); + + // crea un widget di campo di testo e lo mostra sullo schermo + QLineEdit lineEdit("Hello world!"); + lineEdit.show(); + + // avvia il ciclo degli eventi dell'applicazione + return app.exec(); +} +``` + +La parte relativa alla GUI di **Qt** riguarda esclusivamente *widget* e le loro *connessioni*. + +[LEGGI DI PIÙ SUI WIDGET](http://doc.qt.io/qt-5/qtwidgets-index.html) + +```c++ +/* + * Creiamo un'etichetta e un pulsante. + * Un'etichetta dovrebbe apparire quando si preme un pulsante. + * + * Il codice Qt parla da solo. + */ + +#include <QApplication> +#include <QDialog> +#include <QVBoxLayout> +#include <QPushButton> +#include <QLabel> + +int main(int argc, char *argv[]) { + QApplication app(argc, argv); + + QDialog dialogWindow; + dialogWindow.show(); + + // add vertical layout + QVBoxLayout layout; + dialogWindow.setLayout(&layout); + + QLabel textLabel("Grazie per aver premuto quel pulsante"); + layout.addWidget(&textLabel); + textLabel.hide(); + + QPushButton button("Premimi"); + layout.addWidget(&button); + + // mostra l'etichetta nascosta quando viene premuto il pulsante + QObject::connect(&button, &QPushButton::pressed, + &textLabel, &QLabel::show); + + return app.exec(); +} +``` + +Si noti la parte relativa a *QObject::connect*. Questo metodo viene utilizzato per connettere *SEGNALI* di un oggetto agli *SLOTS* di un altro. + +**I SEGNALI** vengono emessi quando certe cose accadono agli oggetti, come il segnale *premuto* che viene emesso quando l'utente preme sull'oggetto QPushButton. + +**Gli slot** sono *azioni* che potrebbero essere eseguite in risposta ai segnali ricevuti. + +[LEGGI DI PIÙ SU SLOT E SEGNALI](http://doc.qt.io/qt-5/signalsandslots.html) + + +Successivamente, impariamo che non possiamo solo usare i widget standard, ma estendere il loro comportamento usando l'ereditarietà. Creiamo un pulsante e contiamo quante volte è stato premuto. A tale scopo definiamo la nostra classe *CounterLabel*. Deve essere dichiarato in un file separato a causa dell'architettura Qt specifica. + +```c++ +// counterlabel.hpp + +#ifndef COUNTERLABEL +#define COUNTERLABEL + +#include <QLabel> + +class CounterLabel : public QLabel { + Q_OBJECT // Macro definite da Qt che devono essere presenti in ogni widget personalizzato + +public: + CounterLabel() : counter(0) { + setText("Il contatore non è stato ancora aumentato"); // metodo di QLabel + } + +public slots: + // azione che verrà chiamata in risposta alla pressione del pulsante + void increaseCounter() { + setText(QString("Valore contatore: %1").arg(QString::number(++counter))); + } + +private: + int counter; +}; + +#endif // COUNTERLABEL +``` + +```c++ +// main.cpp +// Quasi uguale all'esempio precedente + +#include <QApplication> +#include <QDialog> +#include <QVBoxLayout> +#include <QPushButton> +#include <QString> +#include "counterlabel.hpp" + +int main(int argc, char *argv[]) { + QApplication app(argc, argv); + + QDialog dialogWindow; + dialogWindow.show(); + + QVBoxLayout layout; + dialogWindow.setLayout(&layout); + + CounterLabel counterLabel; + layout.addWidget(&counterLabel); + + QPushButton button("Premimi ancora una volta"); + layout.addWidget(&button); + QObject::connect(&button, &QPushButton::pressed, + &counterLabel, &CounterLabel::increaseCounter); + + return app.exec(); +} +``` + +Questo è tutto! Ovviamente, il framework Qt è molto più grande della parte che è stata trattata in questo tutorial, quindi preparatevi a leggere e fare pratica. + +## Ulteriori letture + +- [Qt 4.8 tutorials](http://doc.qt.io/qt-4.8/tutorials.html) +- [Qt 5 tutorials](http://doc.qt.io/qt-5/qtexamplesandtutorials.html) + +Buona fortuna e buon divertimento! diff --git a/it-it/rst-it.html.markdown b/it-it/rst-it.html.markdown index 8947c738..a834e899 100644 --- a/it-it/rst-it.html.markdown +++ b/it-it/rst-it.html.markdown @@ -6,10 +6,12 @@ contributors: - ["Andre Polykanine", "https://github.com/Oire"] translators: - ["Ale46", "https://github.com/Ale46"] + - ["Chris54721", "https://chris54721.net"] lang: it-it --- -RST è un formato di file formalmente creato dalla comunità Python per scrivere documentazione (e quindi fa parte di Docutils). +RST (Restructured Text) è un formato di file inizialmente creato dalla comunità Python +per la documentazione (per questo motivo appartiene a Docutils). I file RST sono semplici file di testo con una sintassi leggera (in confronto all'HTML). @@ -23,7 +25,7 @@ Per usare Restructured Text, sarà necessario installare [Python](http://www.pyt $ easy_install docutils ``` -O se il tuo sistema ha `pip`, puoi usare anche lui: +Oppure, se hai `pip` installato sul tuo sistema: ```bash $ pip install docutils @@ -32,7 +34,7 @@ $ pip install docutils ## Sintassi del file -Un semplice esempio della sintassi del file: +Ecco un semplice esempio della sintassi RST: ``` .. Le righe che iniziano con due punti sono comandi speciali. Ma se non è possibile trovare alcun comando, la riga viene considerata come un commento @@ -41,16 +43,16 @@ Un semplice esempio della sintassi del file: I titoli principali sono scritti utilizzando caratteri di uguale, sopra e sotto =============================================================================== -Si noti che devono esistere tanti caratteri di uguale quanti sono i caratteri del titolo. +Si noti che devono esserci tanti caratteri di uguale quanti caratteri del titolo. -Anche il titolo è sottolineato con caratteri di uguale -====================================================== +Anche i titoli normali usano caratteri di uguale, ma solo sotto +=============================================================== -Sottotitoli con i trattini --------------------------- +I sottotitoli usano i trattini +------------------------------ -E sotto-sottotitoli con tildi -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +E i sotto-sottotitoli le tildi +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Puoi inserire il testo in *corsivo* o in **grassetto**, puoi "contrassegnare" il testo come codice con un doppio apice ``: `` print () ``. @@ -60,13 +62,13 @@ Le liste sono semplici come in Markdown: - Secondo elemento - Sottoelemento -o +oppure * Primo elemento * Secondo elemento * Sottoelemento -Le tabelle sono davvero facili da scrivere: +Le tabelle sono molto semplici da inserire: =========== ======== Stato Capitale @@ -75,22 +77,21 @@ Francia Parigi Giappone Tokio =========== ======== -Le tabelle più complesse possono essere fatte facilmente (colonne e/o righe unite) ma ti suggerisco di leggere il documento completo per questo :) +Anche le tabelle più complesse possono essere inserite facilmente (colonne e/o righe unite) ma ti suggerisco di leggere la documentazione completa per questo :) Esistono diversi modi per creare collegamenti: -- Aggiungendo un underscore dopo una parola: Github_ e aggiungendo l'URL di destinazione dopo il testo (questo modo ha il vantaggio di non inserire URL non necessari all'interno del testo leggibile). +- Aggiungendo un underscore dopo una parola: Github_ e aggiungendo l'URL di destinazione dopo il testo (questo metodo ha il vantaggio di non inserire URL non necessari all'interno del testo leggibile). - Digitando un URL completo: https://github.com/ (verrà automaticamente convertito in un collegamento) -- Facendo un collegamento simile a Markdown: `Github <https://github.com/>`_ . +- Utilizzando una sintassi simile a Markdown: `Github <https://github.com/>`_ . .. _Github https://github.com/ ``` - ## Come usarlo -RST viene fornito con docutils che dispone di `rst2html`, per esempio: +RST viene fornito con docutils, che dispone di `rst2html`, per esempio: ```bash $ rst2html miofile.rst output.html diff --git a/it-it/ruby-it.html.markdown b/it-it/ruby-it.html.markdown new file mode 100644 index 00000000..295bf28a --- /dev/null +++ b/it-it/ruby-it.html.markdown @@ -0,0 +1,653 @@ +--- +language: ruby +filename: learnruby-it.rb +contributors: + - ["David Underwood", "http://theflyingdeveloper.com"] + - ["Joel Walden", "http://joelwalden.net"] + - ["Luke Holder", "http://twitter.com/lukeholder"] + - ["Tristan Hume", "http://thume.ca/"] + - ["Nick LaMuro", "https://github.com/NickLaMuro"] + - ["Marcos Brizeno", "http://www.about.me/marcosbrizeno"] + - ["Ariel Krakowski", "http://www.learneroo.com"] + - ["Dzianis Dashkevich", "https://github.com/dskecse"] + - ["Levi Bostian", "https://github.com/levibostian"] + - ["Rahil Momin", "https://github.com/iamrahil"] + - ["Gabriel Halley", "https://github.com/ghalley"] + - ["Persa Zula", "http://persazula.com"] + - ["Jake Faris", "https://github.com/farisj"] + - ["Corey Ward", "https://github.com/coreyward"] +translators: + - ["abonte", "https://github.com/abonte"] +lang: it-it +--- + +```ruby +# Questo è un commento + +# In Ruby, (quasi) tutto è un oggetto. +# Questo include i numeri... +3.class #=> Integer + +# ...stringhe... +"Hello".class #=> String + +# ...e anche i metodi! +"Hello".method(:class).class #=> Method + +# Qualche operazione aritmetica di base +1 + 1 #=> 2 +8 - 1 #=> 7 +10 * 2 #=> 20 +35 / 5 #=> 7 +2 ** 5 #=> 32 +5 % 3 #=> 2 + +# Bitwise operators +3 & 5 #=> 1 +3 | 5 #=> 7 +3 ^ 5 #=> 6 + +# L'aritmetica è solo zucchero sintattico +# per chiamare il metodo di un oggetto +1.+(3) #=> 4 +10.* 5 #=> 50 +100.methods.include?(:/) #=> true + +# I valori speciali sono oggetti +nil # equivalente a null in altri linguaggi +true # vero +false # falso + +nil.class #=> NilClass +true.class #=> TrueClass +false.class #=> FalseClass + +# Uguaglianza +1 == 1 #=> true +2 == 1 #=> false + +# Disuguaglianza +1 != 1 #=> false +2 != 1 #=> true + +# nil è l'unico valore, oltre a false, che è considerato 'falso' +!!nil #=> false +!!false #=> false +!!0 #=> true +!!"" #=> true + +# Altri confronti +1 < 10 #=> true +1 > 10 #=> false +2 <= 2 #=> true +2 >= 2 #=> true + +# Operatori di confronto combinati (ritorna '1' quando il primo argomento è più +# grande, '-1' quando il secondo argomento è più grande, altrimenti '0') +1 <=> 10 #=> -1 +10 <=> 1 #=> 1 +1 <=> 1 #=> 0 + +# Operatori logici +true && false #=> false +true || false #=> true + +# Ci sono versioni alternative degli operatori logici con meno precedenza. +# Sono usati come costrutti per il controllo di flusso per concatenare +# insieme statement finché uno di essi ritorna true o false. + +# `do_something_else` chiamato solo se `do_something` ha successo. +do_something() and do_something_else() +# `log_error` è chiamato solo se `do_something` fallisce. +do_something() or log_error() + +# Interpolazione di stringhe + +placeholder = 'usare l\'interpolazione di stringhe' +"Per #{placeholder} si usano stringhe con i doppi apici" +#=> "Per usare l'interpolazione di stringhe si usano stringhe con i doppi apici" + +# E' possibile combinare le stringhe usando `+`, ma non con gli altri tipi +'hello ' + 'world' #=> "hello world" +'hello ' + 3 #=> TypeError: can't convert Fixnum into String +'hello ' + 3.to_s #=> "hello 3" +"hello #{3}" #=> "hello 3" + +# ...oppure combinare stringhe e operatori +'ciao ' * 3 #=> "ciao ciao ciao " + +# ...oppure aggiungere alla stringa +'ciao' << ' mondo' #=> "ciao mondo" + +# Per stampare a schermo e andare a capo +puts "Sto stampando!" +#=> Sto stampando! +#=> nil + +# Per stampare a schermo senza andare a capo +print "Sto stampando!" +#=> Sto stampando! => nil + +# Variabili +x = 25 #=> 25 +x #=> 25 + +# Notare che l'assegnamento ritorna il valore assegnato. +# Questo significa che è possibile effettuare assegnamenti multipli: +x = y = 10 #=> 10 +x #=> 10 +y #=> 10 + +# Per convenzione si usa lo snake_case per i nomi delle variabili +snake_case = true + +# Usare nomi delle variabili descrittivi +path_to_project_root = '/buon/nome/' +m = '/nome/scadente/' + +# I simboli sono immutabili, costanti riusabili rappresentati internamente da +# un valore intero. Sono spesso usati al posto delle stringhe per comunicare +# specifici e significativi valori. + +:pendente.class #=> Symbol + +stato = :pendente + +stato == :pendente #=> true + +stato == 'pendente' #=> false + +stato == :approvato #=> false + +# Le stringhe possono essere convertite in simboli e viceversa: +status.to_s #=> "pendente" +"argon".to_sym #=> :argon + +# Arrays + +# Questo è un array +array = [1, 2, 3, 4, 5] #=> [1, 2, 3, 4, 5] + +# Gli array possono contenere diversi tipi di elementi +[1, 'hello', false] #=> [1, "hello", false] + +# Gli array possono essere indicizzati +# Dall'inizio... +array[0] #=> 1 +array.first #=> 1 +array[12] #=> nil + + +# ...o dalla fine... +array[-1] #=> 5 +array.last #=> 5 + +# With a start index and length +# ...o con un indice di inzio e la lunghezza... +array[2, 3] #=> [3, 4, 5] + +# ...oppure con un intervallo. +array[1..3] #=> [2, 3, 4] + +# Invertire l'ordine degli elementi di un array +a = [1,2,3] +a.reverse! #=> [3,2,1] + +# Come per l'aritmetica, l'accesso tramite [var] +# è solo zucchero sintattico +# per chiamare il metodo '[]'' di un oggetto +array.[] 0 #=> 1 +array.[] 12 #=> nil + +# Si può aggiungere un elemento all'array così +array << 6 #=> [1, 2, 3, 4, 5, 6] +# oppure così +array.push(6) #=> [1, 2, 3, 4, 5, 6] + +# Controllare se un elemento esiste in un array +array.include?(1) #=> true + +# Hash è un dizionario con coppie di chiave e valore +# Un hash è denotato da parentesi graffe: +hash = { 'colore' => 'verde', 'numero' => 5 } + +hash.keys #=> ['colore', 'numero'] + +# E' possibile accedere all'hash tramite chiave: +hash['colore'] #=> 'verde' +hash['numero'] #=> 5 + +# Accedere all'hash con una chiave che non esiste ritorna nil: +hash['nothing here'] #=> nil + +# Quando si usano simboli come chiavi di un hash, si possono utilizzare +# queste sintassi: + +hash = { :defcon => 3, :action => true } +hash.keys #=> [:defcon, :action] +# oppure +hash = { defcon: 3, action: true } +hash.keys #=> [:defcon, :action] + +# Controllare l'esistenza di una chiave o di un valore in un hash +new_hash.key?(:defcon) #=> true +new_hash.value?(3) #=> true + +# Suggerimento: sia gli array che gli hash sono enumerabili! +# Entrambi possiedono metodi utili come each, map, count e altri. + +# Strutture di controllo + +#Condizionali +if true + 'if statement' +elsif false + 'else if, opzionale' +else + 'else, opzionale' +end + +#Cicli +# In Ruby, i tradizionali cicli `for` non sono molto comuni. Questi semplici +# cicli, invece, sono implementati con un enumerable, usando `each`: +(1..5).each do |contatore| + puts "iterazione #{contatore}" +end + +# Esso è equivalente a questo ciclo, il quale è inusuale da vedere in Ruby: +for contatore in 1..5 + puts "iterazione #{contatore}" +end + +# Il costrutto `do |variable| ... end` è chiamato 'blocco'. I blocchi +# sono simili alle lambda, funzioni anonime o closure che si trovano in altri +# linguaggi di programmazione. Essi possono essere passati come oggetti, +# chiamati o allegati come metodi. +# +# Il metodo 'each' di un intervallo (range) esegue il blocco una volta +# per ogni elemento dell'intervallo. +# Al blocco è passato un contatore come parametro. + +# E' possibile inglobare il blocco fra le parentesi graffe +(1..5).each { |contatore| puts "iterazione #{contatore}" } + +# Il contenuto delle strutture dati può essere iterato usando "each". +array.each do |elemento| + puts "#{elemento} è parte dell'array" +end +hash.each do |chiave, valore| + puts "#{chiave} è #{valore}" +end + +# If you still need an index you can use 'each_with_index' and define an index +# variable +# Se comunque si vuole un indice, si può usare "each_with_index" e definire +# una variabile che contiene l'indice +array.each_with_index do |elemento, indice| + puts "#{elemento} è il numero #{index} nell'array" +end + +contatore = 1 +while contatore <= 5 do + puts "iterazione #{contatore}" + contatore += 1 +end +#=> iterazione 1 +#=> iterazione 2 +#=> iterazione 3 +#=> iterazione 4 +#=> iterazione 5 + +# Esistono in Ruby ulteriori funzioni per fare i cicli, +# come per esempio 'map', 'reduce', 'inject' e altri. +# Nel caso di 'map', esso prende l'array sul quale si sta iterando, esegue +# le istruzioni definite nel blocco, e ritorna un array completamente nuovo. +array = [1,2,3,4,5] +doubled = array.map do |elemento| + elemento * 2 +end +puts doubled +#=> [2,4,6,8,10] +puts array +#=> [1,2,3,4,5] + +# Costrutto "case" +grade = 'B' + +case grade +when 'A' + puts 'Way to go kiddo' +when 'B' + puts 'Better luck next time' +when 'C' + puts 'You can do better' +when 'D' + puts 'Scraping through' +when 'F' + puts 'You failed!' +else + puts 'Alternative grading system, eh?' +end +#=> "Better luck next time" + +# 'case' può usare anche gli intervalli +grade = 82 +case grade +when 90..100 + puts 'Hooray!' +when 80...90 + puts 'OK job' +else + puts 'You failed!' +end +#=> "OK job" + +# Gestione delle eccezioni +begin + # codice che può sollevare un eccezione + raise NoMemoryError, 'Esaurita la memoria.' +rescue NoMemoryError => exception_variable + puts 'NoMemoryError è stato sollevato.', exception_variable +rescue RuntimeError => other_exception_variable + puts 'RuntimeError è stato sollvato.' +else + puts 'Questo viene eseguito se nessuna eccezione è stata sollevata.' +ensure + puts 'Questo codice viene sempre eseguito a prescindere.' +end + +# Metodi + +def double(x) + x * 2 +end + +# Metodi (e blocchi) ritornano implicitamente il valore dell'ultima istruzione +double(2) #=> 4 + +# Le parentesi sono opzionali dove l'interpolazione è inequivocabile +double 3 #=> 6 + +double double 3 #=> 12 + +def sum(x, y) + x + y +end + +# Gli argomenit dei metodi sono separati dalla virgola +sum 3, 4 #=> 7 + +sum sum(3, 4), 5 #=> 12 + +# yield +# Tutti i metodi hanno un implicito e opzionale parametro del blocco. +# Esso può essere chiamato con la parola chiave 'yield'. + +def surround + puts '{' + yield + puts '}' +end + +surround { puts 'hello world' } + +# { +# hello world +# } + +# I blocchi possono essere convertiti in 'proc', il quale racchiude il blocco +# e gli permette di essere passato ad un altro metodo, legato ad uno scope +# differente o modificato. Questo è molto comune nella lista parametri del +# metodo, dove è frequente vedere il parametro '&block' in coda. Esso accetta +# il blocco, se ne è stato passato uno, e lo converte in un 'Proc'. +# Qui la denominazione è una convenzione; funzionerebbe anche con '&ananas'. +def guests(&block) + block.class #=> Proc + block.call(4) +end + +# Il metodo 'call' del Proc è simile allo 'yield' quando è presente un blocco. +# Gli argomenti passati a 'call' sono inoltrati al blocco come argomenti: + +guests { |n| "You have #{n} guests." } +# => "You have 4 guests." + +# L'operatore splat ("*") converte una lista di argomenti in un array +def guests(*array) + array.each { |guest| puts guest } +end + +# Destrutturazione + +# Ruby destruttura automaticamente gli array in assegnamento +# a variabili multiple: +a, b, c = [1, 2, 3] +a #=> 1 +b #=> 2 +c #=> 3 + +# In alcuni casi si usa l'operatore splat ("*") per destrutturare +# un array in una lista. +classifica_concorrenti = ["John", "Sally", "Dingus", "Moe", "Marcy"] + +def migliore(primo, secondo, terzo) + puts "I vincitori sono #{primo}, #{secondo}, e #{terzo}." +end + +migliore *classifica_concorrenti.first(3) +#=> I vincitori sono John, Sally, e Dingus. + +# The splat operator can also be used in parameters: +def migliore(primo, secondo, terzo, *altri) + puts "I vincitori sono #{primo}, #{secondo}, e #{terzo}." + puts "C'erano altri #{altri.count} partecipanti." +end + +migliore *classifica_concorrenti +#=> I vincitori sono John, Sally, e Dingus. +#=> C'erano altri 2 partecipanti. + +# Per convenzione, tutti i metodi che ritornano un booleano terminano +# con un punto interrogativo +5.even? #=> false +5.odd? #=> true + +# Per convenzione, se il nome di un metodo termina con un punto esclamativo, +# esso esegue qualcosa di distruttivo. Molti metodi hanno una versione con '!' +# per effettuare una modifiche, e una versione senza '!' che ritorna +# una versione modificata. +nome_azienda = "Dunder Mifflin" +nome_azienda.upcase #=> "DUNDER MIFFLIN" +nome_azienda #=> "Dunder Mifflin" +# Questa volta modifichiamo nome_azienda +nome_azienda.upcase! #=> "DUNDER MIFFLIN" +nome_azienda #=> "DUNDER MIFFLIN" + +# Classi + +# Definire una classe con la parola chiave class +class Umano + + # Una variabile di classe. E' condivisa da tutte le istance di questa classe. + @@specie = 'H. sapiens' + + # Inizializzatore di base + def initialize(nome, eta = 0) + # Assegna il valore dell'argomento alla variabile dell'istanza "nome" + @nome = nome + # Se l'età non è fornita, verrà assegnato il valore di default indicato + # nella lista degli argomenti + @eta = eta + end + + # Metodo setter di base + def nome=(nome) + @nome = nome + end + + # Metodo getter di base + def nome + @nome + end + + # Le funzionalità di cui sopra posso essere incapsulate usando + # il metodo attr_accessor come segue + attr_accessor :nome + + # Getter/setter possono anche essere creati individualmente + attr_reader :nome + attr_writer :nome + + # Un metodo della classe usa 'self' per distinguersi dai metodi dell'istanza. + # Può essere richimato solo dalla classe, non dall'istanza. + def self.say(msg) + puts msg + end + + def specie + @@specie + end +end + + +# Instanziare una classe +jim = Umano.new('Jim Halpert') + +dwight = Umano.new('Dwight K. Schrute') + +# Chiamiamo qualche metodo +jim.specie #=> "H. sapiens" +jim.nome #=> "Jim Halpert" +jim.nome = "Jim Halpert II" #=> "Jim Halpert II" +jim.nome #=> "Jim Halpert II" +dwight.specie #=> "H. sapiens" +dwight.nome #=> "Dwight K. Schrute" + +# Chiamare un metodo della classe +Umano.say('Ciao') #=> "Ciao" + +# La visibilità della variabile (variable's scope) è determinata dal modo +# in cui le viene assegnato il nome. +# Variabili che iniziano con $ hanno uno scope globale +$var = "Sono una variabile globale" +defined? $var #=> "global-variable" + +# Variabili che inziano con @ hanno a livello dell'istanza +@var = "Sono una variabile dell'istanza" +defined? @var #=> "instance-variable" + +# Variabili che iniziano con @@ hanno una visibilità a livello della classe +@@var = "Sono una variabile della classe" +defined? @@var #=> "class variable" + +# Variabili che iniziano con una lettera maiuscola sono costanti +Var = "Sono una costante" +defined? Var #=> "constant" + +# Anche una classe è un oggetto in ruby. Quindi la classe può avere +# una variabile dell'istanza. Le variabili della classe sono condivise +# fra la classe e tutti i suoi discendenti. + +# Classe base +class Umano + @@foo = 0 + + def self.foo + @@foo + end + + def self.foo=(value) + @@foo = value + end +end + +# Classe derivata +class Lavoratore < Umano +end + +Umano.foo #=> 0 +Lavoratore.foo #=> 0 + +Umano.foo = 2 #=> 2 +Lavoratore.foo #=> 2 + +# La variabile dell'istanza della classe non è condivisa dai discendenti. + +class Umano + @bar = 0 + + def self.bar + @bar + end + + def self.bar=(value) + @bar = value + end +end + +class Dottore < Umano +end + +Umano.bar #=> 0 +Dottore.bar #=> nil + +module EsempioModulo + def foo + 'foo' + end +end + +# Includere moduli vincola i suoi metodi all'istanza della classe. +# Estendere moduli vincola i suoi metodi alla classe stessa. +class Persona + include EsempioModulo +end + +class Libro + extend EsempioModulo +end + +Persona.foo #=> NoMethodError: undefined method `foo' for Person:Class +Persona.new.foo #=> 'foo' +Libro.foo #=> 'foo' +Libro.new.foo #=> NoMethodError: undefined method `foo' + +# Callbacks sono eseguiti quand si include o estende un modulo +module ConcernExample + def self.included(base) + base.extend(ClassMethods) + base.send(:include, InstanceMethods) + end + + module ClassMethods + def bar + 'bar' + end + end + + module InstanceMethods + def qux + 'qux' + end + end +end + +class Something + include ConcernExample +end + +Something.bar #=> 'bar' +Something.qux #=> NoMethodError: undefined method `qux' +Something.new.bar #=> NoMethodError: undefined method `bar' +Something.new.qux #=> 'qux' +``` + +## Ulteriori risorse + +- [Learn Ruby by Example with Challenges](http://www.learneroo.com/modules/61/nodes/338) - Una variante di questa guida con esercizi nel browser. +- [An Interactive Tutorial for Ruby](https://rubymonk.com/) - Imparare Ruby attraverso una serie di tutorial interattivi. +- [Official Documentation](http://ruby-doc.org/core) +- [Ruby from other languages](https://www.ruby-lang.org/en/documentation/ruby-from-other-languages/) +- [Programming Ruby](http://www.amazon.com/Programming-Ruby-1-9-2-0-Programmers/dp/1937785491/) - Una passata [edizione libera](http://ruby-doc.com/docs/ProgrammingRuby/) è disponibile online. +- [Ruby Style Guide](https://github.com/bbatsov/ruby-style-guide) - A community-driven Ruby coding style guide. +- [Try Ruby](http://tryruby.org) - Imparare le basi del linguaggio di programmazion Ruby, interattivamente nel browser. diff --git a/it-it/toml-it.html.markdown b/it-it/toml-it.html.markdown new file mode 100644 index 00000000..99082048 --- /dev/null +++ b/it-it/toml-it.html.markdown @@ -0,0 +1,276 @@ +---
+language: toml
+filename: learntoml-it.toml
+contributors:
+ - ["Alois de Gouvello", "https://github.com/aloisdg"]
+translators:
+ - ["Christian Grasso", "https://grasso.io"]
+lang: it-it
+---
+
+TOML è l'acronimo di _Tom's Obvious, Minimal Language_. È un linguaggio per la
+serializzazione di dati, progettato per i file di configurazione.
+
+È un'alternativa a linguaggi come YAML e JSON, che punta ad essere più leggibile
+per le persone. Allo stesso tempo, TOML può essere utilizzato in modo abbastanza
+semplice nella maggior parte dei linguaggi di programmazione, in quanto è
+progettato per essere tradotto senza ambiguità in una hash table.
+
+Tieni presente che TOML è ancora in fase di sviluppo, e la sua specifica non è
+ancora stabile. Questo documento utilizza TOML 0.4.0.
+
+```toml
+# I commenti in TOML sono fatti così.
+
+################
+# TIPI SCALARI #
+################
+
+# Il nostro oggetto root (corrispondente all'intero documento) sarà una mappa,
+# anche chiamata dizionario, hash o oggetto in altri linguaggi.
+
+# La key, il simbolo di uguale e il valore devono trovarsi sulla stessa riga,
+# eccetto per alcuni tipi di valori.
+key = "value"
+stringa = "ciao"
+numero = 42
+float = 3.14
+boolean = true
+data = 1979-05-27T07:32:00-08:00
+notazScientifica = 1e+12
+"puoi utilizzare le virgolette per la key" = true # Puoi usare " oppure '
+"la key può contenere" = "lettere, numeri, underscore e trattini"
+
+############
+# Stringhe #
+############
+
+# Le stringhe possono contenere solo caratteri UTF-8 validi.
+# Possiamo effettuare l'escape dei caratteri, e alcuni hanno delle sequenze
+# di escape compatte. Ad esempio, \t corrisponde al TAB.
+stringaSemplice = "Racchiusa tra virgolette. \"Usa il backslash per l'escape\"."
+
+stringaMultiriga = """
+Racchiusa da tre virgolette doppie all'inizio e
+alla fine - consente di andare a capo."""
+
+stringaLiteral = 'Virgolette singole. Non consente di effettuare escape.'
+
+stringaMultirigaLiteral = '''
+Racchiusa da tre virgolette singole all'inizio e
+alla fine - consente di andare a capo.
+Anche in questo caso non si può fare escape.
+Il primo ritorno a capo viene eliminato.
+ Tutti gli altri spazi aggiuntivi
+ vengono mantenuti.
+'''
+
+# Per i dati binari è consigliabile utilizzare Base64 e
+# gestirli manualmente dall'applicazione.
+
+##########
+# Interi #
+##########
+
+## Gli interi possono avere o meno un segno (+, -).
+## Non si possono inserire zero superflui all'inizio.
+## Non è possibile inoltre utilizzare valori numerici
+## non rappresentabili con una sequenza di cifre.
+int1 = +42
+int2 = 0
+int3 = -21
+
+## Puoi utilizzare gli underscore per migliorare la leggibilità.
+## Fai attenzione a non inserirne due di seguito.
+int4 = 5_349_221
+int5 = 1_2_3_4_5 # VALIDO, ma da evitare
+
+#########
+# Float #
+#########
+
+# I float permettono di rappresentare numeri decimali.
+flt1 = 3.1415
+flt2 = -5e6
+flt3 = 6.626E-34
+
+###########
+# Boolean #
+###########
+
+# I valori boolean (true/false) devono essere scritti in minuscolo.
+bool1 = true
+bool2 = false
+
+############
+# Data/ora #
+############
+
+data1 = 1979-05-27T07:32:00Z # Specifica RFC 3339/ISO 8601 (UTC)
+data2 = 1979-05-26T15:32:00+08:00 # RFC 3339/ISO 8601 con offset
+
+######################
+# TIPI DI COLLECTION #
+######################
+
+#########
+# Array #
+#########
+
+array1 = [ 1, 2, 3 ]
+array2 = [ "Le", "virgole", "sono", "delimitatori" ]
+array3 = [ "Non", "unire", "tipi", "diversi" ]
+array4 = [ "tutte", 'le stringhe', """hanno lo stesso""", '''tipo''' ]
+array5 = [
+ "Gli spazi vuoti", "sono", "ignorati"
+]
+
+###########
+# Tabelle #
+###########
+
+# Le tabelle (o hash table o dizionari) sono collection di coppie key/value.
+# Iniziano con un nome tra parentesi quadre su una linea separata.
+# Le tabelle vuote (senza alcun valore) sono valide.
+[tabella]
+
+# Tutti i valori che si trovano sotto il nome della tabella
+# appartengono alla tabella stessa (finchè non ne viene creata un'altra).
+# L'ordine di questi valori non è garantito.
+[tabella-1]
+key1 = "una stringa"
+key2 = 123
+
+[tabella-2]
+key1 = "un'altra stringa"
+key2 = 456
+
+# Utilizzando i punti è possibile creare delle sottotabelle.
+# Ogni parte suddivisa dai punti segue le regole delle key per il nome.
+[tabella-3."sotto.tabella"]
+key1 = "prova"
+
+# Ecco l'equivalente JSON della tabella precedente:
+# { "tabella-3": { "sotto.tabella": { "key1": "prova" } } }
+
+# Gli spazi non vengono considerati, ma è consigliabile
+# evitare di usare spazi superflui.
+[a.b.c] # consigliato
+[ d.e.f ] # identico a [d.e.f]
+
+# Non c'è bisogno di creare le tabelle superiori per creare una sottotabella.
+# [x] queste
+# [x.y] non
+# [x.y.z] servono
+[x.y.z.w] # per creare questa tabella
+
+# Se non è stata già creata prima, puoi anche creare
+# una tabella superiore più avanti.
+[a.b]
+c = 1
+
+[a]
+d = 2
+
+# Non puoi definire una key o una tabella più di una volta.
+
+# ERRORE
+[a]
+b = 1
+
+[a]
+c = 2
+
+# ERRORE
+[a]
+b = 1
+
+[a.b]
+c = 2
+
+# I nomi delle tabelle non possono essere vuoti.
+[] # NON VALIDO
+[a.] # NON VALIDO
+[a..b] # NON VALIDO
+[.b] # NON VALIDO
+[.] # NON VALIDO
+
+##################
+# Tabelle inline #
+##################
+
+tabelleInline = { racchiuseData = "{ e }", rigaSingola = true }
+punto = { x = 1, y = 2 }
+
+####################
+# Array di tabelle #
+####################
+
+# Un array di tabelle può essere creato utilizzando due parentesi quadre.
+# Tutte le tabelle con questo nome saranno elementi dell'array.
+# Gli elementi vengono inseriti nell'ordine in cui si trovano.
+
+[[prodotti]]
+nome = "array di tabelle"
+sku = 738594937
+tabelleVuoteValide = true
+
+[[prodotti]]
+
+[[prodotti]]
+nome = "un altro item"
+sku = 284758393
+colore = "grigio"
+
+# Puoi anche creare array di tabelle nested. Le sottotabelle con doppie
+# parentesi quadre apparterranno alla tabella più vicina sopra di esse.
+
+[[frutta]]
+ nome = "mela"
+
+ [frutto.geometria]
+ forma = "sferica"
+ nota = "Sono una proprietà del frutto"
+
+ [[frutto.colore]]
+ nome = "rosso"
+ nota = "Sono un oggetto di un array dentro mela"
+
+ [[frutto.colore]]
+ nome = "verde"
+ nota = "Sono nello stesso array di rosso"
+
+[[frutta]]
+ nome = "banana"
+
+ [[frutto.colore]]
+ nome = "giallo"
+ nota = "Anche io sono un oggetto di un array, ma dentro banana"
+```
+
+Ecco l'equivalente JSON dell'ultima tabella:
+
+```json
+{
+ "frutta": [
+ {
+ "nome": "mela",
+ "geometria": { "forma": "sferica", "nota": "..."},
+ "colore": [
+ { "nome": "rosso", "nota": "..." },
+ { "nome": "verde", "nota": "..." }
+ ]
+ },
+ {
+ "nome": "banana",
+ "colore": [
+ { "nome": "giallo", "nota": "..." }
+ ]
+ }
+ ]
+}
+```
+
+### Altre risorse
+
++ [Repository ufficiale di TOML](https://github.com/toml-lang/toml)
diff --git a/it-it/typescript-it.html.markdown b/it-it/typescript-it.html.markdown new file mode 100644 index 00000000..b78705c5 --- /dev/null +++ b/it-it/typescript-it.html.markdown @@ -0,0 +1,227 @@ +--- +language: TypeScript +contributors: + - ["Philippe Vlérick", "https://github.com/pvlerick"] +translators: + - ["Christian Grasso", "https://grasso.io"] +filename: learntypescript-it.ts +lang: it-it +--- + +TypeScript è un linguaggio basato su JavaScript che punta a rendere il codice +più scalabile introducendo concetti quali le classi, i moduli, le interface, +e i generics. +Poichè TypeScript è un superset di JavaScript, è possibile sfruttare le sue +funzionalità anche in progetti esistenti: il codice JavaScript valido è anche +valido in TypeScript. Il compilatore di TypeScript genera codice JavaScript. + +Questo articolo si concentrerà solo sulle funzionalità aggiuntive di TypeScript. + +Per testare il compilatore, puoi utilizzare il +[Playground](http://www.typescriptlang.org/Playground), dove potrai scrivere +codice TypeScript e visualizzare l'output in JavaScript. + +```ts +// TypeScript ha tre tipi di base +let completato: boolean = false; +let righe: number = 42; +let nome: string = "Andrea"; + +// Il tipo può essere omesso se è presente un assegnamento a scalari/literal +let completato = false; +let righe = 42; +let nome = "Andrea"; + +// Il tipo "any" indica che la variabile può essere di qualsiasi tipo +let qualsiasi: any = 4; +qualsiasi = "oppure una stringa"; +qualsiasi = false; // o magari un boolean + +// Usa la keyword "const" per le costanti +const numeroViteGatti = 9; +numeroViteGatti = 1; // Errore + +// Per gli array, puoi usare l'apposito tipo o la versione con i generics +let lista: number[] = [1, 2, 3]; +let lista: Array<number> = [1, 2, 3]; + +// Per le enumerazioni: +enum Colore { Rosso, Verde, Blu }; +let c: Colore = Colore.Verde; + +// Infine, "void" viene utilizzato per le funzioni che non restituiscono valori +function avviso(): void { + alert("Sono un piccolo avviso fastidioso!"); +} + +// Le funzioni supportano la sintassi "a freccia" (lambda) e supportano la type +// inference, cioè per scalari/literal non c'è bisogno di specificare il tipo + +// Tutte le seguenti funzioni sono equivalenti, e il compilatore genererà +// lo stesso codice JavaScript per ognuna di esse +let f1 = function (i: number): number { return i * i; } +// Type inference +let f2 = function (i: number) { return i * i; } +// Sintassi lambda +let f3 = (i: number): number => { return i * i; } +// Sintassi lambda + type inference +let f4 = (i: number) => { return i * i; } +// Sintassi lambda + type inference + sintassi abbreviata (senza return) +let f5 = (i: number) => i * i; + +// Le interfacce sono strutturali, e qualunque oggetto con le stesse proprietà +// di un'interfaccia è compatibile con essa +interface Persona { + nome: string; + // Proprietà opzionale, indicata con "?" + anni?: number; + // Funzioni + saluta(): void; +} + +// Oggetto che implementa l'interfaccia Persona +// È una Persona valida poichè implementa tutta le proprietà non opzionali +let p: Persona = { nome: "Bobby", saluta: () => { } }; +// Naturalmente può avere anche le proprietà opzionali: +let pValida: Persona = { nome: "Bobby", anni: 42, saluta: () => { } }; +// Questa invece NON è una Persona, poichè il tipo di "anni" è sbagliato +let pNonValida: Persona = { nome: "Bobby", anni: true }; + +// Le interfacce possono anche descrivere una funzione +interface SearchFunc { + (source: string, subString: string): boolean; +} +// I nomi dei parametri non sono rilevanti: vengono controllati solo i tipi +let ricerca: SearchFunc; +ricerca = function (src: string, sub: string) { + return src.search(sub) != -1; +} + +// Classi - i membri sono pubblici di default +class Punto { + // Proprietà + x: number; + + // Costruttore - in questo caso la keyword "public" può generare in automatico + // il codice per l'inizializzazione di una variabile. + // In questo esempio, verrà creata la variabile y in modo identico alla x, ma + // con meno codice. Sono supportati anche i valori di default. + constructor(x: number, public y: number = 0) { + this.x = x; + } + + // Funzioni + dist() { return Math.sqrt(this.x * this.x + this.y * this.y); } + + // Membri statici + static origine = new Point(0, 0); +} + +// Le classi possono anche implementare esplicitamente delle interfacce. +// Il compilatore restituirà un errore nel caso in cui manchino delle proprietà. +class PersonaDiRiferimento implements Persona { + nome: string + saluta() {} +} + +let p1 = new Punto(10, 20); +let p2 = new Punto(25); // y = 0 + +// Inheritance +class Punto3D extends Punto { + constructor(x: number, y: number, public z: number = 0) { + super(x, y); // La chiamata esplicita a super è obbligatoria + } + + // Sovrascrittura + dist() { + let d = super.dist(); + return Math.sqrt(d * d + this.z * this.z); + } +} + +// Moduli - "." può essere usato come separatore per i sottomoduli +module Geometria { + export class Quadrato { + constructor(public lato: number = 0) { } + + area() { + return Math.pow(this.lato, 2); + } + } +} + +let s1 = new Geometria.Quadrato(5); + +// Alias locale per un modulo +import G = Geometria; + +let s2 = new G.Quadrato(10); + +// Generics +// Classi +class Tuple<T1, T2> { + constructor(public item1: T1, public item2: T2) { + } +} + +// Interfacce +interface Pair<T> { + item1: T; + item2: T; +} + +// E funzioni +let pairToTuple = function <T>(p: Pair<T>) { + return new Tuple(p.item1, p.item2); +}; + +let tuple = pairToTuple({ item1: "hello", item2: "world" }); + +// Interpolazione con le template string (definite con i backtick) +let nome = 'Tyrone'; +let saluto = `Ciao ${name}, come stai?` +// Possono anche estendersi su più righe +let multiriga = `Questo è un esempio +di stringa multiriga.`; + +// La keyword "readonly" rende un membro di sola lettura +interface Persona { + readonly nome: string; + readonly anni: number; +} + +var p1: Persona = { nome: "Tyrone", anni: 42 }; +p1.anni = 25; // Errore, p1.anni è readonly + +var p2 = { nome: "John", anni: 60 }; +var p3: Person = p2; // Ok, abbiamo creato una versione readonly di p2 +p3.anni = 35; // Errore, p3.anni è readonly +p2.anni = 45; // Compila, ma cambia anche p3.anni per via dell'aliasing! + +class Macchina { + readonly marca: string; + readonly modello: string; + readonly anno = 2018; + + constructor() { + // Possiamo anche assegnare nel constructor + this.marca = "Marca sconosciuta"; + this.modello = "Modello sconosciuto"; + } +} + +let numeri: Array<number> = [0, 1, 2, 3, 4]; +let altriNumeri: ReadonlyArray<number> = numbers; +altriNumeri[5] = 5; // Errore, gli elementi sono readonly +altriNumeri.push(5); // Errore, il metodo push non esiste (modifica l'array) +altriNumeri.length = 3; // Errore, length è readonly +numeri = altriNumeri; // Errore, i metodi di modifica non esistono +``` + +## Altre risorse + * [Sito ufficiale di TypeScript](http://www.typescriptlang.org/) + * [Specifica di TypeScript](https://github.com/Microsoft/TypeScript/blob/master/doc/spec.md) + * [Anders Hejlsberg - Introducing TypeScript su Channel 9](http://channel9.msdn.com/posts/Anders-Hejlsberg-Introducing-TypeScript) + * [TypeScript su GitHub](https://github.com/Microsoft/TypeScript) + * [Definitely Typed - definizioni per le librerie](http://definitelytyped.org/) diff --git a/java.html.markdown b/java.html.markdown index 7b59b085..ca0b04c2 100644 --- a/java.html.markdown +++ b/java.html.markdown @@ -11,6 +11,7 @@ contributors: - ["Michael Dähnert", "https://github.com/JaXt0r"] - ["Rob Rose", "https://github.com/RobRoseKnows"] - ["Sean Nam", "https://github.com/seannam"] + - ["Shawn M. Hanes", "https://github.com/smhanes15"] filename: LearnJava.java --- @@ -44,8 +45,6 @@ import java.util.ArrayList; // Import all classes inside of java.security package import java.security.*; -// Each .java file contains one outer-level public class, with the same name -// as the file. public class LearnJava { // In order to run a java program, it must have a main method as an entry @@ -173,7 +172,7 @@ public class LearnJava { // Char - A single 16-bit Unicode character char fooChar = 'A'; - // final variables can't be reassigned to another object, + // final variables can't be reassigned, final int HOURS_I_WORK_PER_WEEK = 9001; // but they can be initialized later. final double E; @@ -280,7 +279,7 @@ public class LearnJava { // LinkedLists - Implementation of doubly-linked list. All of the // operations perform as could be expected for a // doubly-linked list. - // Maps - A set of objects that map keys to values. Map is + // Maps - A mapping of key Objects to value Objects. Map is // an interface and therefore cannot be instantiated. // The type of keys and values contained in a Map must // be specified upon instantiation of the implementing @@ -289,10 +288,16 @@ public class LearnJava { // HashMaps - This class uses a hashtable to implement the Map // interface. This allows the execution time of basic // operations, such as get and insert element, to remain - // constant even for large sets. - // TreeMap - This class is a sorted tree structure. It implements a red - // black tree and sorts the entries based on the key value or - // the comparator provided while creating the object + // constant-amortized even for large sets. + // TreeMap - A Map that is sorted by its keys. Each modification + // maintains the sorting defined by either a Comparator + // supplied at instantiation, or comparisons of each Object + // if they implement the Comparable interface. + // Failure of keys to implement Comparable combined with failure to + // supply a Comparator will throw ClassCastExceptions. + // Insertion and removal operations take O(log(n)) time + // so avoid using this data structure unless you are taking + // advantage of the sorting. /////////////////////////////////////// // Operators @@ -306,7 +311,7 @@ public class LearnJava { System.out.println("2-1 = " + (i2 - i1)); // => 1 System.out.println("2*1 = " + (i2 * i1)); // => 2 System.out.println("1/2 = " + (i1 / i2)); // => 0 (int/int returns int) - System.out.println("1/2 = " + (i1 / (double)i2)); // => 0.5 + System.out.println("1/2.0 = " + (i1 / (double)i2)); // => 0.5 // Modulo System.out.println("11%3 = "+(11 % 3)); // => 2 @@ -703,15 +708,21 @@ public class ExampleClass extends ExampleClassParent implements InterfaceOne, // // Method declarations // } -// Marking a class as abstract means that it contains at least one abstract -// method that must be defined in a child class. Similar to interfaces, abstract -// classes cannot be instantiated, but instead must be extended and the abstract -// methods defined. Different from interfaces, abstract classes can contain a -// mixture of concrete and abstract methods. Methods in an interface cannot -// have a body, unless the method is static, and variables are final by default, -// unlike an abstract class. Also abstract classes CAN have the "main" method. +// Abstract Classes cannot be instantiated. +// Abstract classes may define abstract methods. +// Abstract methods have no body and are marked abstract +// Non-abstract child classes must @Override all abstract methods +// from their super-classes. +// Abstract classes can be useful when combining repetitive logic +// with customised behavior, but as Abstract classes require +// inheritance, they violate "Composition over inheritance" +// so consider other approaches using composition. +// https://en.wikipedia.org/wiki/Composition_over_inheritance + public abstract class Animal { + private int age; + public abstract void makeSound(); // Method can have a body @@ -722,17 +733,12 @@ public abstract class Animal age = 30; } - // No need to initialize, however in an interface - // a variable is implicitly final and hence has - // to be initialized. - private int age; - public void printAge() { System.out.println(age); } - // Abstract classes can have main function. + // Abstract classes can have main method. public static void main(String[] args) { System.out.println("I am abstract"); @@ -853,6 +859,108 @@ public class EnumTest { // The enum body can include methods and other fields. // You can see more at https://docs.oracle.com/javase/tutorial/java/javaOO/enum.html +// Getting Started with Lambda Expressions +// +// New to Java version 8 are lambda expressions. Lambdas are more commonly found +// in functional programming languages, which means they are methods which can +// be created without belonging to a class, passed around as if it were itself +// an object, and executed on demand. +// +// Final note, lambdas must implement a functional interface. A functional +// interface is one which has only a single abstract method declared. It can +// have any number of default methods. Lambda expressions can be used as an +// instance of that functional interface. Any interface meeting the requirements +// is treated as a functional interface. You can read more about interfaces +// above. +// +import java.util.Map; +import java.util.HashMap; +import java.util.function.*; +import java.security.SecureRandom; + +public class Lambdas { + public static void main(String[] args) { + // Lambda declaration syntax: + // <zero or more parameters> -> <expression body or statement block> + + // We will use this hashmap in our examples below. + Map<String, String> planets = new HashMap<>(); + planets.put("Mercury", "87.969"); + planets.put("Venus", "224.7"); + planets.put("Earth", "365.2564"); + planets.put("Mars", "687"); + planets.put("Jupiter", "4,332.59"); + planets.put("Saturn", "10,759"); + planets.put("Uranus", "30,688.5"); + planets.put("Neptune", "60,182"); + + // Lambda with zero parameters using the Supplier functional interface + // from java.util.function.Supplier. The actual lambda expression is + // what comes after numPlanets =. + Supplier<String> numPlanets = () -> Integer.toString(planets.size()); + System.out.format("Number of Planets: %s\n\n", numPlanets.get()); + + // Lambda with one parameter and using the Consumer functional interface + // from java.util.function.Consumer. This is because planets is a Map, + // which implements both Collection and Iterable. The forEach used here, + // found in Iterable, applies the lambda expression to each member of + // the Collection. The default implementation of forEach behaves as if: + /* + for (T t : this) + action.accept(t); + */ + + // The actual lambda expression is the parameter passed to forEach. + planets.keySet().forEach((p) -> System.out.format("%s\n", p)); + + // If you are only passing a single argument, then the above can also be + // written as (note absent parentheses around p): + planets.keySet().forEach(p -> System.out.format("%s\n", p)); + + // Tracing the above, we see that planets is a HashMap, keySet() returns + // a Set of its keys, forEach applies each element as the lambda + // expression of: (parameter p) -> System.out.format("%s\n", p). Each + // time, the element is said to be "consumed" and the statement(s) + // referred to in the lambda body is applied. Remember the lambda body + // is what comes after the ->. + + // The above without use of lambdas would look more traditionally like: + for (String planet : planets.keySet()) { + System.out.format("%s\n", planet); + } + + // This example differs from the above in that a different forEach + // implementation is used: the forEach found in the HashMap class + // implementing the Map interface. This forEach accepts a BiConsumer, + // which generically speaking is a fancy way of saying it handles + // the Set of each Key -> Value pairs. This default implementation + // behaves as if: + /* + for (Map.Entry<K, V> entry : map.entrySet()) + action.accept(entry.getKey(), entry.getValue()); + */ + + // The actual lambda expression is the parameter passed to forEach. + String orbits = "%s orbits the Sun in %s Earth days.\n"; + planets.forEach((K, V) -> System.out.format(orbits, K, V)); + + // The above without use of lambdas would look more traditionally like: + for (String planet : planets.keySet()) { + System.out.format(orbits, planet, planets.get(planet)); + } + + // Or, if following more closely the specification provided by the + // default implementation: + for (Map.Entry<String, String> planet : planets.entrySet()) { + System.out.format(orbits, planet.getKey(), planet.getValue()); + } + + // These examples cover only the very basic use of lambdas. It might not + // seem like much or even very useful, but remember that a lambda can be + // created as an object that can later be passed as parameters to other + // methods. + } +} ``` ## Further Reading diff --git a/javascript.html.markdown b/javascript.html.markdown index 85c8a52d..ecaf02c5 100644 --- a/javascript.html.markdown +++ b/javascript.html.markdown @@ -103,7 +103,7 @@ false; // ... which works with more than just strings "1, 2, " + 3; // = "1, 2, 3" -"Hello " + ["world", "!"] // = "Hello world,!" +"Hello " + ["world", "!"]; // = "Hello world,!" // and are compared with < and > "a" < "b"; // = true @@ -180,6 +180,24 @@ myArray.length; // = 4 // Add/Modify at specific index myArray[3] = "Hello"; +// Add and remove element from front or back end of an array +myArray.unshift(3); // Add as the first element +someVar = myArray.shift(); // Remove first element and return it +myArray.push(3); // Add as the last element +someVar = myArray.pop(); // Remove last element and return it + +// Join all elements of an array with semicolon +var myArray0 = [32,false,"js",12,56,90]; +myArray0.join(";") // = "32;false;js;12;56;90" + +// Get subarray of elements from index 1 (include) to 4 (exclude) +myArray0.slice(1,4); // = [false,"js",12] + +// Remove 4 elements starting from index 2, and insert there strings +// "hi","wr" and "ld"; return removed subarray +myArray0.splice(2,4,"hi","wr","ld"); // = ["js",12,56,90] +// myArray0 === [32,false,"hi","wr","ld"] + // JavaScript's objects are equivalent to "dictionaries" or "maps" in other // languages: an unordered collection of key-value pairs. var myObj = {key1: "Hello", key2: "World"}; @@ -222,7 +240,7 @@ while (true){ var input; do { input = getInput(); -} while (!isValid(input)) +} while (!isValid(input)); // The `for` loop is the same as C and Java: // initialization; continue condition; iteration. @@ -248,6 +266,15 @@ for (var x in person){ description += person[x] + " "; } // description = 'Paul Ken 18 ' +// The for/of statement allows iteration over iterable objects (including the built-in String, +// Array, e.g. the Array-like arguments or NodeList objects, TypedArray, Map and Set, +// and user-defined iterables). +var myPets = ""; +var pets = ["cat", "dog", "hamster", "hedgehog"]; +for (var pet of pets){ + myPets += pet + " "; +} // myPets = 'cat dog hamster hedgehog ' + // && is logical and, || is logical or if (house.size == "big" && house.colour == "blue"){ house.contains = "bear"; @@ -293,7 +320,7 @@ myFunction("foo"); // = "FOO" // automatic semicolon insertion. Watch out for this when using Allman style. function myFunction(){ return // <- semicolon automatically inserted here - {thisIsAn: 'object literal'} + {thisIsAn: 'object literal'}; } myFunction(); // = undefined @@ -388,7 +415,7 @@ myFunc(); // = undefined // through `this`, even if it wasn't attached when it was defined. var myOtherFunc = function(){ return this.myString.toUpperCase(); -} +}; myObj.myOtherFunc = myOtherFunc; myObj.myOtherFunc(); // = "HELLO WORLD!" @@ -397,7 +424,7 @@ myObj.myOtherFunc(); // = "HELLO WORLD!" var anotherFunc = function(s){ return this.myString + s; -} +}; anotherFunc.call(myObj, " And Hello Moon!"); // = "Hello World! And Hello Moon!" // The `apply` function is nearly identical, but takes an array for an argument @@ -420,7 +447,7 @@ boundFunc(" And Hello Saturn!"); // = "Hello World! And Hello Saturn!" // `bind` can also be used to partially apply (curry) a function. -var product = function(a, b){ return a * b; } +var product = function(a, b){ return a * b; }; var doubler = product.bind(this, 2); doubler(8); // = 16 @@ -430,11 +457,11 @@ doubler(8); // = 16 var MyConstructor = function(){ this.myNumber = 5; -} +}; myNewObj = new MyConstructor(); // = {myNumber: 5} myNewObj.myNumber; // = 5 -// Unlike most other popular object-oriented languages, JavaScript has no +// Unlike most other popular object-oriented languages, JavaScript has no // concept of 'instances' created from 'class' blueprints; instead, JavaScript // combines instantiation and inheritance into a single concept: a 'prototype'. @@ -451,7 +478,7 @@ var myObj = { var myPrototype = { meaningOfLife: 42, myFunc: function(){ - return this.myString.toLowerCase() + return this.myString.toLowerCase(); } }; @@ -515,7 +542,7 @@ MyConstructor.prototype = { }; var myNewObj2 = new MyConstructor(); myNewObj2.getMyNumber(); // = 5 -myNewObj2.myNumber = 6 +myNewObj2.myNumber = 6; myNewObj2.getMyNumber(); // = 6 // Built-in types like strings and numbers also have constructors that create @@ -540,7 +567,7 @@ if (new Number(0)){ // you can actually add functionality to a string, for instance. String.prototype.firstCharacter = function(){ return this.charAt(0); -} +}; "abc".firstCharacter(); // = "a" // This fact is often used in "polyfilling", which is implementing newer @@ -556,7 +583,7 @@ if (Object.create === undefined){ // don't overwrite it if it exists Constructor.prototype = proto; // then use it to create a new, appropriately-prototyped object return new Constructor(); - } + }; } ``` @@ -582,13 +609,13 @@ of the language. [Eloquent Javascript][8] by Marijn Haverbeke is an excellent JS book/ebook with attached terminal -[Eloquent Javascript - The Annotated Version][9] by Gordon Zhu is also a great -derivative of Eloquent Javascript with extra explanations and clarifications for -some of the more complicated examples. - [Javascript: The Right Way][10] is a guide intended to introduce new developers to JavaScript and help experienced developers learn more about its best practices. +[Javascript:Info][11] is a modern javascript tutorial covering the basics (core language and working with a browser) +as well as advanced topics with concise explanations. + + In addition to direct contributors to this article, some content is adapted from Louie Dinh's Python tutorial on this site, and the [JS Tutorial][7] on the Mozilla Developer Network. @@ -602,5 +629,5 @@ Mozilla Developer Network. [6]: http://www.amazon.com/gp/product/0596805527/ [7]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript [8]: http://eloquentjavascript.net/ -[9]: http://watchandcode.com/courses/eloquent-javascript-the-annotated-version [10]: http://jstherightway.org/ +[11]: https://javascript.info/ diff --git a/jquery.html.markdown b/jquery.html.markdown index 9326c74b..a1673c10 100644 --- a/jquery.html.markdown +++ b/jquery.html.markdown @@ -104,7 +104,7 @@ tables.animate({margin-top:"+=50", height: "100px"}, 500, myFunction); // 3. Manipulation // These are similar to effects but can do more -$('div').addClass('taming-slim-20'); // Adds class taming-slim-20 to all div +$('div').addClass('taming-slim-20'); // Adds class taming-slim-20 to all div // Common manipulation methods $('p').append('Hello world'); // Adds to end of element @@ -126,3 +126,7 @@ $('p').each(function() { ``` + +## Further Reading + +* [Codecademy - jQuery](https://www.codecademy.com/learn/learn-jquery) A good introduction to jQuery in a "learn by doing it" format. diff --git a/json.html.markdown b/json.html.markdown index cd42d42d..322c7a47 100644 --- a/json.html.markdown +++ b/json.html.markdown @@ -81,3 +81,5 @@ Supported data types: ## Further Reading * [JSON.org](http://json.org) All of JSON beautifully explained using flowchart-like graphics. + +* [JSON Tutorial](https://www.youtube.com/watch?v=wI1CWzNtE-M) A concise introduction to JSON. diff --git a/julia.html.markdown b/julia.html.markdown index 85033aa6..2fe05c49 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -2,17 +2,18 @@ language: Julia contributors: - ["Leah Hanson", "http://leahhanson.us"] - - ["Pranit Bauva", "http://github.com/pranitbauva1997"] + - ["Pranit Bauva", "https://github.com/pranitbauva1997"] + - ["Daniel YC Lin", "https://github.com/dlintw"] filename: learnjulia.jl --- Julia is a new homoiconic functional language focused on technical computing. -While having the full power of homoiconic macros, first-class functions, and low-level control, Julia is as easy to learn and use as Python. +While having the full power of homoiconic macros, first-class functions, +and low-level control, Julia is as easy to learn and use as Python. -This is based on Julia 0.4. - -```ruby +This is based on Julia 1.0.0 +```julia # Single line comments start with a hash (pound) symbol. #= Multiline comments can be written by putting '#=' before the text and '=#' @@ -26,38 +27,38 @@ This is based on Julia 0.4. # Everything in Julia is an expression. # There are several basic types of numbers. -3 # => 3 (Int64) -3.2 # => 3.2 (Float64) -2 + 1im # => 2 + 1im (Complex{Int64}) -2//3 # => 2//3 (Rational{Int64}) +typeof(3) # => Int64 +typeof(3.2) # => Float64 +typeof(2 + 1im) # => Complex{Int64} +typeof(2 // 3) # => Rational{Int64} # All of the normal infix operators are available. -1 + 1 # => 2 -8 - 1 # => 7 -10 * 2 # => 20 -35 / 5 # => 7.0 -5 / 2 # => 2.5 # dividing an Int by an Int always results in a Float -div(5, 2) # => 2 # for a truncated result, use div -5 \ 35 # => 7.0 -2 ^ 2 # => 4 # power, not bitwise xor -12 % 10 # => 2 +1 + 1 # => 2 +8 - 1 # => 7 +10 * 2 # => 20 +35 / 5 # => 7.0 +10 / 2 # => 5.0 # dividing integers always results in a Float64 +div(5, 2) # => 2 # for a truncated result, use div +5 \ 35 # => 7.0 +2^2 # => 4 # power, not bitwise xor +12 % 10 # => 2 # Enforce precedence with parentheses -(1 + 3) * 2 # => 8 +(1 + 3) * 2 # => 8 # Bitwise Operators -~2 # => -3 # bitwise not -3 & 5 # => 1 # bitwise and -2 | 4 # => 6 # bitwise or -2 $ 4 # => 6 # bitwise xor -2 >>> 1 # => 1 # logical shift right -2 >> 1 # => 1 # arithmetic shift right -2 << 1 # => 4 # logical/arithmetic shift left - -# You can use the bits function to see the binary representation of a number. -bits(12345) +~2 # => -3 # bitwise not +3 & 5 # => 1 # bitwise and +2 | 4 # => 6 # bitwise or +xor(2, 4) # => 6 # bitwise xor +2 >>> 1 # => 1 # logical shift right +2 >> 1 # => 1 # arithmetic shift right +2 << 1 # => 4 # logical/arithmetic shift left + +# Use the bitstring function to see the binary representation of a number. +bitstring(12345) # => "0000000000000000000000000000000000000000000000000011000000111001" -bits(12345.0) +bitstring(12345.0) # => "0100000011001000000111001000000000000000000000000000000000000000" # Boolean values are primitives @@ -65,70 +66,70 @@ true false # Boolean operators -!true # => false -!false # => true -1 == 1 # => true -2 == 1 # => false -1 != 1 # => false -2 != 1 # => true -1 < 10 # => true -1 > 10 # => false -2 <= 2 # => true -2 >= 2 # => true +!true # => false +!false # => true +1 == 1 # => true +2 == 1 # => false +1 != 1 # => false +2 != 1 # => true +1 < 10 # => true +1 > 10 # => false +2 <= 2 # => true +2 >= 2 # => true # Comparisons can be chained -1 < 2 < 3 # => true -2 < 3 < 2 # => false +1 < 2 < 3 # => true +2 < 3 < 2 # => false # Strings are created with " "This is a string." -# Julia has several types of strings, including ASCIIString and UTF8String. -# More on this in the Types section. - # Character literals are written with ' 'a' -# Some strings can be indexed like an array of characters -"This is a string"[1] # => 'T' # Julia indexes from 1 -# However, this is will not work well for UTF8 strings, -# so iterating over strings is recommended (map, for loops, etc). +# Strings are UTF8 encoded. Only if they contain only ASCII characters can +# they be safely indexed. +ascii("This is a string")[1] +# => 'T': ASCII/Unicode U+0054 (category Lu: Letter, uppercase) +# Julia indexes from 1 +# Otherwise, iterating over strings is recommended (map, for loops, etc). # $ can be used for string interpolation: "2 + 2 = $(2 + 2)" # => "2 + 2 = 4" # You can put any Julia expression inside the parentheses. -# Another way to format strings is the printf macro. -@printf "%d is less than %f" 4.5 5.3 # 5 is less than 5.300000 +# Another way to format strings is the printf macro from the stdlib Printf. +using Printf +@printf "%d is less than %f\n" 4.5 5.3 # => 5 is less than 5.300000 # Printing is easy -println("I'm Julia. Nice to meet you!") +println("I'm Julia. Nice to meet you!") # => I'm Julia. Nice to meet you! # String can be compared lexicographically "good" > "bye" # => true "good" == "good" # => true -"1 + 2 = 3" == "1 + 2 = $(1+2)" # => true +"1 + 2 = 3" == "1 + 2 = $(1 + 2)" # => true #################################################### ## 2. Variables and Collections #################################################### # You don't declare variables before assigning to them. -some_var = 5 # => 5 -some_var # => 5 +someVar = 5 # => 5 +someVar # => 5 # Accessing a previously unassigned variable is an error try - some_other_var # => ERROR: some_other_var not defined + someOtherVar # => ERROR: UndefVarError: someOtherVar not defined catch e println(e) end # Variable names start with a letter or underscore. # After that, you can use letters, digits, underscores, and exclamation points. -SomeOtherVar123! = 6 # => 6 +SomeOtherVar123! = 6 # => 6 # You can also use certain unicode characters -☃ = 8 # => 8 +☃ = 8 # => 8 # These are especially handy for mathematical notation 2 * π # => 6.283185307179586 @@ -147,250 +148,280 @@ SomeOtherVar123! = 6 # => 6 # functions are sometimes called mutating functions or in-place functions. # Arrays store a sequence of values indexed by integers 1 through n: -a = Int64[] # => 0-element Int64 Array +a = Int64[] # => 0-element Array{Int64,1} # 1-dimensional array literals can be written with comma-separated values. -b = [4, 5, 6] # => 3-element Int64 Array: [4, 5, 6] -b = [4; 5; 6] # => 3-element Int64 Array: [4, 5, 6] -b[1] # => 4 -b[end] # => 6 +b = [4, 5, 6] # => 3-element Array{Int64,1}: [4, 5, 6] +b = [4; 5; 6] # => 3-element Array{Int64,1}: [4, 5, 6] +b[1] # => 4 +b[end] # => 6 # 2-dimensional arrays use space-separated values and semicolon-separated rows. -matrix = [1 2; 3 4] # => 2x2 Int64 Array: [1 2; 3 4] +matrix = [1 2; 3 4] # => 2×2 Array{Int64,2}: [1 2; 3 4] -# Arrays of a particular Type -b = Int8[4, 5, 6] # => 3-element Int8 Array: [4, 5, 6] +# Arrays of a particular type +b = Int8[4, 5, 6] # => 3-element Array{Int8,1}: [4, 5, 6] # Add stuff to the end of a list with push! and append! -push!(a,1) # => [1] -push!(a,2) # => [1,2] -push!(a,4) # => [1,2,4] -push!(a,3) # => [1,2,4,3] -append!(a,b) # => [1,2,4,3,4,5,6] +push!(a, 1) # => [1] +push!(a, 2) # => [1,2] +push!(a, 4) # => [1,2,4] +push!(a, 3) # => [1,2,4,3] +append!(a, b) # => [1,2,4,3,4,5,6] # Remove from the end with pop -pop!(b) # => 6 and b is now [4,5] +pop!(b) # => 6 +b # => [4,5] # Let's put it back -push!(b,6) # b is now [4,5,6] again. +push!(b, 6) # => [4,5,6] +b # => [4,5,6] -a[1] # => 1 # remember that Julia indexes from 1, not 0! +a[1] # => 1 # remember that Julia indexes from 1, not 0! # end is a shorthand for the last index. It can be used in any # indexing expression -a[end] # => 6 +a[end] # => 6 -# we also have shift and unshift -shift!(a) # => 1 and a is now [2,4,3,4,5,6] -unshift!(a,7) # => [7,2,4,3,4,5,6] +# we also have popfirst! and pushfirst! +popfirst!(a) # => 1 +a # => [2,4,3,4,5,6] +pushfirst!(a, 7) # => [7,2,4,3,4,5,6] +a # => [7,2,4,3,4,5,6] # Function names that end in exclamations points indicate that they modify # their argument. -arr = [5,4,6] # => 3-element Int64 Array: [5,4,6] -sort(arr) # => [4,5,6]; arr is still [5,4,6] -sort!(arr) # => [4,5,6]; arr is now [4,5,6] +arr = [5,4,6] # => 3-element Array{Int64,1}: [5,4,6] +sort(arr) # => [4,5,6] +arr # => [5,4,6] +sort!(arr) # => [4,5,6] +arr # => [4,5,6] # Looking out of bounds is a BoundsError try - a[0] # => ERROR: BoundsError() in getindex at array.jl:270 - a[end+1] # => ERROR: BoundsError() in getindex at array.jl:270 + a[0] + # => ERROR: BoundsError: attempt to access 7-element Array{Int64,1} at + # index [0] + # => Stacktrace: + # => [1] getindex(::Array{Int64,1}, ::Int64) at .\array.jl:731 + # => [2] top-level scope at none:0 + # => [3] ... + # => in expression starting at ...\LearnJulia.jl:180 + a[end + 1] + # => ERROR: BoundsError: attempt to access 7-element Array{Int64,1} at + # index [8] + # => Stacktrace: + # => [1] getindex(::Array{Int64,1}, ::Int64) at .\array.jl:731 + # => [2] top-level scope at none:0 + # => [3] ... + # => in expression starting at ...\LearnJulia.jl:188 catch e println(e) end # Errors list the line and file they came from, even if it's in the standard -# library. If you built Julia from source, you can look in the folder base -# inside the julia folder to find these files. +# library. You can look in the folder share/julia inside the julia folder to +# find these files. # You can initialize arrays from ranges -a = [1:5;] # => 5-element Int64 Array: [1,2,3,4,5] +a = [1:5;] # => 5-element Array{Int64,1}: [1,2,3,4,5] +a2 = [1:5] # => 1-element Array{UnitRange{Int64},1}: [1:5] # You can look at ranges with slice syntax. -a[1:3] # => [1, 2, 3] -a[2:end] # => [2, 3, 4, 5] +a[1:3] # => [1, 2, 3] +a[2:end] # => [2, 3, 4, 5] # Remove elements from an array by index with splice! arr = [3,4,5] -splice!(arr,2) # => 4 ; arr is now [3,5] +splice!(arr, 2) # => 4 +arr # => [3,5] # Concatenate lists with append! b = [1,2,3] -append!(a,b) # Now a is [1, 2, 3, 4, 5, 1, 2, 3] +append!(a, b) # => [1, 2, 3, 4, 5, 1, 2, 3] +a # => [1, 2, 3, 4, 5, 1, 2, 3] # Check for existence in a list with in -in(1, a) # => true +in(1, a) # => true # Examine the length with length -length(a) # => 8 +length(a) # => 8 # Tuples are immutable. -tup = (1, 2, 3) # => (1,2,3) # an (Int64,Int64,Int64) tuple. +tup = (1, 2, 3) # => (1,2,3) +typeof(tup) # => Tuple{Int64,Int64,Int64} tup[1] # => 1 -try: - tup[1] = 3 # => ERROR: no method setindex!((Int64,Int64,Int64),Int64,Int64) +try + tup[1] = 3 + # => ERROR: MethodError: no method matching + # setindex!(::Tuple{Int64,Int64,Int64}, ::Int64, ::Int64) catch e println(e) end -# Many list functions also work on tuples +# Many array functions also work on tuples length(tup) # => 3 -tup[1:2] # => (1,2) -in(2, tup) # => true +tup[1:2] # => (1,2) +in(2, tup) # => true # You can unpack tuples into variables -a, b, c = (1, 2, 3) # => (1,2,3) # a is now 1, b is now 2 and c is now 3 +a, b, c = (1, 2, 3) # => (1,2,3) +a # => 1 +b # => 2 +c # => 3 # Tuples are created even if you leave out the parentheses -d, e, f = 4, 5, 6 # => (4,5,6) +d, e, f = 4, 5, 6 # => (4,5,6) +d # => 4 +e # => 5 +f # => 6 # A 1-element tuple is distinct from the value it contains (1,) == 1 # => false -(1) == 1 # => true +(1) == 1 # => true # Look how easy it is to swap two values -e, d = d, e # => (5,4) # d is now 5 and e is now 4 - +e, d = d, e # => (5,4) +d # => 5 +e # => 4 # Dictionaries store mappings -empty_dict = Dict() # => Dict{Any,Any}() +emptyDict = Dict() # => Dict{Any,Any} with 0 entries # You can create a dictionary using a literal -filled_dict = Dict("one"=> 1, "two"=> 2, "three"=> 3) -# => Dict{ASCIIString,Int64} +filledDict = Dict("one" => 1, "two" => 2, "three" => 3) +# => Dict{String,Int64} with 3 entries: +# => "two" => 2, "one" => 1, "three" => 3 # Look up values with [] -filled_dict["one"] # => 1 +filledDict["one"] # => 1 # Get all keys -keys(filled_dict) -# => KeyIterator{Dict{ASCIIString,Int64}}(["three"=>3,"one"=>1,"two"=>2]) +keys(filledDict) +# => Base.KeySet for a Dict{String,Int64} with 3 entries. Keys: +# => "two", "one", "three" # Note - dictionary keys are not sorted or in the order you inserted them. # Get all values -values(filled_dict) -# => ValueIterator{Dict{ASCIIString,Int64}}(["three"=>3,"one"=>1,"two"=>2]) +values(filledDict) +# => Base.ValueIterator for a Dict{String,Int64} with 3 entries. Values: +# => 2, 1, 3 # Note - Same as above regarding key ordering. # Check for existence of keys in a dictionary with in, haskey -in(("one" => 1), filled_dict) # => true -in(("two" => 3), filled_dict) # => false -haskey(filled_dict, "one") # => true -haskey(filled_dict, 1) # => false +in(("one" => 1), filledDict) # => true +in(("two" => 3), filledDict) # => false +haskey(filledDict, "one") # => true +haskey(filledDict, 1) # => false # Trying to look up a non-existent key will raise an error try - filled_dict["four"] # => ERROR: key not found: four in getindex at dict.jl:489 + filledDict["four"] # => ERROR: KeyError: key "four" not found catch e println(e) end # Use the get method to avoid that error by providing a default value -# get(dictionary,key,default_value) -get(filled_dict,"one",4) # => 1 -get(filled_dict,"four",4) # => 4 +# get(dictionary, key, defaultValue) +get(filledDict, "one", 4) # => 1 +get(filledDict, "four", 4) # => 4 # Use Sets to represent collections of unordered, unique values -empty_set = Set() # => Set{Any}() +emptySet = Set() # => Set(Any[]) # Initialize a set with values -filled_set = Set([1,2,2,3,4]) # => Set{Int64}(1,2,3,4) +filledSet = Set([1, 2, 2, 3, 4]) # => Set([4, 2, 3, 1]) # Add more values to a set -push!(filled_set,5) # => Set{Int64}(5,4,2,3,1) +push!(filledSet, 5) # => Set([4, 2, 3, 5, 1]) # Check if the values are in the set -in(2, filled_set) # => true -in(10, filled_set) # => false +in(2, filledSet) # => true +in(10, filledSet) # => false # There are functions for set intersection, union, and difference. -other_set = Set([3, 4, 5, 6]) # => Set{Int64}(6,4,5,3) -intersect(filled_set, other_set) # => Set{Int64}(3,4,5) -union(filled_set, other_set) # => Set{Int64}(1,2,3,4,5,6) -setdiff(Set([1,2,3,4]),Set([2,3,5])) # => Set{Int64}(1,4) - +otherSet = Set([3, 4, 5, 6]) # => Set([4, 3, 5, 6]) +intersect(filledSet, otherSet) # => Set([4, 3, 5]) +union(filledSet, otherSet) # => Set([4, 2, 3, 5, 6, 1]) +setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set([4, 1]) #################################################### ## 3. Control Flow #################################################### # Let's make a variable -some_var = 5 +someVar = 5 # Here is an if statement. Indentation is not meaningful in Julia. -if some_var > 10 - println("some_var is totally bigger than 10.") -elseif some_var < 10 # This elseif clause is optional. - println("some_var is smaller than 10.") +if someVar > 10 + println("someVar is totally bigger than 10.") +elseif someVar < 10 # This elseif clause is optional. + println("someVar is smaller than 10.") else # The else clause is optional too. - println("some_var is indeed 10.") + println("someVar is indeed 10.") end # => prints "some var is smaller than 10" - # For loops iterate over iterables. # Iterable types include Range, Array, Set, Dict, and AbstractString. -for animal=["dog", "cat", "mouse"] +for animal = ["dog", "cat", "mouse"] println("$animal is a mammal") # You can use $ to interpolate variables or expression into strings end -# prints: -# dog is a mammal -# cat is a mammal -# mouse is a mammal +# => dog is a mammal +# => cat is a mammal +# => mouse is a mammal # You can use 'in' instead of '='. for animal in ["dog", "cat", "mouse"] println("$animal is a mammal") end -# prints: -# dog is a mammal -# cat is a mammal -# mouse is a mammal +# => dog is a mammal +# => cat is a mammal +# => mouse is a mammal -for a in Dict("dog"=>"mammal","cat"=>"mammal","mouse"=>"mammal") - println("$(a[1]) is a $(a[2])") +for pair in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal") + from, to = pair + println("$from is a $to") end -# prints: -# dog is a mammal -# cat is a mammal -# mouse is a mammal +# => mouse is a mammal +# => cat is a mammal +# => dog is a mammal -for (k,v) in Dict("dog"=>"mammal","cat"=>"mammal","mouse"=>"mammal") +for (k, v) in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal") println("$k is a $v") end -# prints: -# dog is a mammal -# cat is a mammal -# mouse is a mammal +# => mouse is a mammal +# => cat is a mammal +# => dog is a mammal # While loops loop while a condition is true -x = 0 -while x < 4 - println(x) - x += 1 # Shorthand for x = x + 1 +let x = 0 + while x < 4 + println(x) + x += 1 # Shorthand for x = x + 1 + end end -# prints: -# 0 -# 1 -# 2 -# 3 +# => 0 +# => 1 +# => 2 +# => 3 # Handle exceptions with a try/catch block try - error("help") + error("help") catch e - println("caught it $e") + println("caught it $e") end # => caught it ErrorException("help") - #################################################### ## 4. Functions #################################################### # The keyword 'function' creates new functions -#function name(arglist) -# body... -#end +# function name(arglist) +# body... +# end function add(x, y) println("x is $x and y is $y") @@ -398,15 +429,17 @@ function add(x, y) x + y end -add(5, 6) # => 11 after printing out "x is 5 and y is 6" +add(5, 6) +# => x is 5 and y is 6 +# => 11 # Compact assignment of functions -f_add(x, y) = x + y # => "f (generic function with 1 method)" -f_add(3, 4) # => 7 +f_add(x, y) = x + y # => f_add (generic function with 1 method) +f_add(3, 4) # => 7 # Function can also return multiple values as tuple -f(x, y) = x + y, x - y -f(3, 4) # => (7, -1) +fn(x, y) = x + y, x - y # => fn (generic function with 1 method) +fn(3, 4) # => (7, -1) # You can define functions that take a variable number of # positional arguments @@ -416,54 +449,56 @@ function varargs(args...) end # => varargs (generic function with 1 method) -varargs(1,2,3) # => (1,2,3) +varargs(1, 2, 3) # => (1,2,3) # The ... is called a splat. # We just used it in a function definition. # It can also be used in a function call, # where it will splat an Array or Tuple's contents into the argument list. -add([5,6]...) # this is equivalent to add(5,6) +add([5,6]...) # this is equivalent to add(5,6) -x = (5,6) # => (5,6) -add(x...) # this is equivalent to add(5,6) +x = (5, 6) # => (5,6) +add(x...) # this is equivalent to add(5,6) # You can define functions with optional positional arguments -function defaults(a,b,x=5,y=6) +function defaults(a, b, x=5, y=6) return "$a $b and $x $y" end +# => defaults (generic function with 3 methods) -defaults('h','g') # => "h g and 5 6" -defaults('h','g','j') # => "h g and j 6" -defaults('h','g','j','k') # => "h g and j k" +defaults('h', 'g') # => "h g and 5 6" +defaults('h', 'g', 'j') # => "h g and j 6" +defaults('h', 'g', 'j', 'k') # => "h g and j k" try - defaults('h') # => ERROR: no method defaults(Char,) - defaults() # => ERROR: no methods defaults() + defaults('h') # => ERROR: MethodError: no method matching defaults(::Char) + defaults() # => ERROR: MethodError: no method matching defaults() catch e println(e) end # You can define functions that take keyword arguments -function keyword_args(;k1=4,name2="hello") # note the ; - return Dict("k1"=>k1,"name2"=>name2) +function keyword_args(;k1=4, name2="hello") # note the ; + return Dict("k1" => k1, "name2" => name2) end +# => keyword_args (generic function with 1 method) -keyword_args(name2="ness") # => ["name2"=>"ness","k1"=>4] -keyword_args(k1="mine") # => ["k1"=>"mine","name2"=>"hello"] -keyword_args() # => ["name2"=>"hello","k1"=>4] +keyword_args(name2="ness") # => ["name2"=>"ness", "k1"=>4] +keyword_args(k1="mine") # => ["name2"=>"hello", "k1"=>"mine"] +keyword_args() # => ["name2"=>"hello", "k1"=>4] # You can combine all kinds of arguments in the same function -function all_the_args(normal_arg, optional_positional_arg=2; keyword_arg="foo") - println("normal arg: $normal_arg") - println("optional arg: $optional_positional_arg") - println("keyword arg: $keyword_arg") +function all_the_args(normalArg, optionalPositionalArg=2; keywordArg="foo") + println("normal arg: $normalArg") + println("optional arg: $optionalPositionalArg") + println("keyword arg: $keywordArg") end +# => all_the_args (generic function with 2 methods) -all_the_args(1, 3, keyword_arg=4) -# prints: -# normal arg: 1 -# optional arg: 3 -# keyword arg: 4 +all_the_args(1, 3, keywordArg=4) +# => normal arg: 1 +# => optional arg: 3 +# => keyword arg: 4 # Julia has first class functions function create_adder(x) @@ -472,14 +507,16 @@ function create_adder(x) end return adder end +# => create_adder (generic function with 1 method) # This is "stabby lambda syntax" for creating anonymous functions -(x -> x > 2)(3) # => true +(x -> x > 2)(3) # => true # This function is identical to create_adder implementation above. function create_adder(x) y -> x + y end +# => create_adder (generic function with 1 method) # You can also name the internal function, if you want function create_adder(x) @@ -488,18 +525,21 @@ function create_adder(x) end adder end +# => create_adder (generic function with 1 method) -add_10 = create_adder(10) +add_10 = create_adder(10) # => (::getfield(Main, Symbol("#adder#11")){Int64}) + # (generic function with 1 method) add_10(3) # => 13 # There are built-in higher order functions -map(add_10, [1,2,3]) # => [11, 12, 13] -filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] +map(add_10, [1,2,3]) # => [11, 12, 13] +filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] -# We can use list comprehensions for nicer maps -[add_10(i) for i=[1, 2, 3]] # => [11, 12, 13] -[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] +# We can use list comprehensions +[add_10(i) for i = [1, 2, 3]] # => [11, 12, 13] +[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] +[x for x in [3, 4, 5, 6, 7] if x > 5] # => [6, 7] #################################################### ## 5. Types @@ -508,11 +548,11 @@ filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] # Julia has a type system. # Every value has a type; variables do not have types themselves. # You can use the `typeof` function to get the type of a value. -typeof(5) # => Int64 +typeof(5) # => Int64 # Types are first-class values -typeof(Int64) # => DataType -typeof(DataType) # => DataType +typeof(Int64) # => DataType +typeof(DataType) # => DataType # DataType is the type that represents types, including itself. # Types are used for documentation, optimizations, and dispatch. @@ -520,80 +560,76 @@ typeof(DataType) # => DataType # Users can define types # They are like records or structs in other languages. -# New types are defined using the `type` keyword. +# New types are defined using the `struct` keyword. -# type Name +# struct Name # field::OptionalType # ... # end -type Tiger - taillength::Float64 - coatcolor # not including a type annotation is the same as `::Any` +struct Tiger + taillength::Float64 + coatcolor # not including a type annotation is the same as `::Any` end # The default constructor's arguments are the properties # of the type, in the order they are listed in the definition -tigger = Tiger(3.5,"orange") # => Tiger(3.5,"orange") +tigger = Tiger(3.5, "orange") # => Tiger(3.5,"orange") # The type doubles as the constructor function for values of that type -sherekhan = typeof(tigger)(5.6,"fire") # => Tiger(5.6,"fire") +sherekhan = typeof(tigger)(5.6, "fire") # => Tiger(5.6,"fire") # These struct-style types are called concrete types # They can be instantiated, but cannot have subtypes. # The other kind of types is abstract types. # abstract Name -abstract Cat # just a name and point in the type hierarchy +abstract type Cat end # just a name and point in the type hierarchy # Abstract types cannot be instantiated, but can have subtypes. # For example, Number is an abstract type -subtypes(Number) # => 2-element Array{Any,1}: - # Complex{T<:Real} - # Real -subtypes(Cat) # => 0-element Array{Any,1} +subtypes(Number) # => 2-element Array{Any,1}: + # => Complex + # => Real +subtypes(Cat) # => 0-element Array{Any,1} # AbstractString, as the name implies, is also an abstract type -subtypes(AbstractString) # 8-element Array{Any,1}: - # Base.SubstitutionString{T<:AbstractString} - # DirectIndexString - # RepString - # RevString{T<:AbstractString} - # RopeString - # SubString{T<:AbstractString} - # UTF16String - # UTF8String - -# Every type has a super type; use the `super` function to get it. +subtypes(AbstractString) # => 4-element Array{Any,1}: + # => String + # => SubString + # => SubstitutionString + # => Test.GenericString + +# Every type has a super type; use the `supertype` function to get it. typeof(5) # => Int64 -super(Int64) # => Signed -super(Signed) # => Integer -super(Integer) # => Real -super(Real) # => Number -super(Number) # => Any -super(super(Signed)) # => Real -super(Any) # => Any +supertype(Int64) # => Signed +supertype(Signed) # => Integer +supertype(Integer) # => Real +supertype(Real) # => Number +supertype(Number) # => Any +supertype(supertype(Signed)) # => Real +supertype(Any) # => Any # All of these type, except for Int64, are abstract. -typeof("fire") # => ASCIIString -super(ASCIIString) # => DirectIndexString -super(DirectIndexString) # => AbstractString -# Likewise here with ASCIIString +typeof("fire") # => String +supertype(String) # => AbstractString +# Likewise here with String +supertype(SubString) # => AbstractString # <: is the subtyping operator -type Lion <: Cat # Lion is a subtype of Cat - mane_color - roar::AbstractString +struct Lion <: Cat # Lion is a subtype of Cat + maneColor + roar::AbstractString end # You can define more constructors for your type # Just define a function of the same name as the type # and call an existing constructor to get a value of the correct type -Lion(roar::AbstractString) = Lion("green",roar) +Lion(roar::AbstractString) = Lion("green", roar) # This is an outer constructor because it's outside the type definition -type Panther <: Cat # Panther is also a subtype of Cat - eye_color - Panther() = new("green") - # Panthers will only have this constructor, and no default constructor. +struct Panther <: Cat # Panther is also a subtype of Cat + eyeColor + Panther() = new("green") + # Panthers will only have this constructor, and no default constructor. end # Using inner constructors, like Panther does, gives you control # over how values of the type can be created. @@ -611,35 +647,36 @@ end # Definitions for Lion, Panther, Tiger function meow(animal::Lion) - animal.roar # access type properties using dot notation + animal.roar # access type properties using dot notation end function meow(animal::Panther) - "grrr" + "grrr" end function meow(animal::Tiger) - "rawwwr" + "rawwwr" end # Testing the meow function -meow(tigger) # => "rawwr" -meow(Lion("brown","ROAAR")) # => "ROAAR" +meow(tigger) # => "rawwwr" +meow(Lion("brown", "ROAAR")) # => "ROAAR" meow(Panther()) # => "grrr" # Review the local type hierarchy -issubtype(Tiger,Cat) # => false -issubtype(Lion,Cat) # => true -issubtype(Panther,Cat) # => true +Tiger <: Cat # => false +Lion <: Cat # => true +Panther <: Cat # => true # Defining a function that takes Cats function pet_cat(cat::Cat) - println("The cat says $(meow(cat))") + println("The cat says $(meow(cat))") end +# => pet_cat (generic function with 1 method) -pet_cat(Lion("42")) # => prints "The cat says 42" +pet_cat(Lion("42")) # => The cat says 42 try - pet_cat(tigger) # => ERROR: no method pet_cat(Tiger,) + pet_cat(tigger) # => ERROR: MethodError: no method matching pet_cat(::Tiger) catch e println(e) end @@ -649,130 +686,179 @@ end # In Julia, all of the argument types contribute to selecting the best method. # Let's define a function with more arguments, so we can see the difference -function fight(t::Tiger,c::Cat) - println("The $(t.coatcolor) tiger wins!") +function fight(t::Tiger, c::Cat) + println("The $(t.coatcolor) tiger wins!") end # => fight (generic function with 1 method) -fight(tigger,Panther()) # => prints The orange tiger wins! -fight(tigger,Lion("ROAR")) # => prints The orange tiger wins! +fight(tigger, Panther()) # => The orange tiger wins! +fight(tigger, Lion("ROAR")) # => The orange tiger wins! # Let's change the behavior when the Cat is specifically a Lion -fight(t::Tiger,l::Lion) = println("The $(l.mane_color)-maned lion wins!") +fight(t::Tiger, l::Lion) = println("The $(l.maneColor)-maned lion wins!") # => fight (generic function with 2 methods) -fight(tigger,Panther()) # => prints The orange tiger wins! -fight(tigger,Lion("ROAR")) # => prints The green-maned lion wins! +fight(tigger, Panther()) # => The orange tiger wins! +fight(tigger, Lion("ROAR")) # => The green-maned lion wins! # We don't need a Tiger in order to fight -fight(l::Lion,c::Cat) = println("The victorious cat says $(meow(c))") +fight(l::Lion, c::Cat) = println("The victorious cat says $(meow(c))") # => fight (generic function with 3 methods) -fight(Lion("balooga!"),Panther()) # => prints The victorious cat says grrr +fight(Lion("balooga!"), Panther()) # => The victorious cat says grrr try - fight(Panther(),Lion("RAWR")) # => ERROR: no method fight(Panther,Lion) -catch + fight(Panther(), Lion("RAWR")) + # => ERROR: MethodError: no method matching fight(::Panther, ::Lion) + # => Closest candidates are: + # => fight(::Tiger, ::Lion) at ... + # => fight(::Tiger, ::Cat) at ... + # => fight(::Lion, ::Cat) at ... + # => ... +catch e + println(e) end # Also let the cat go first -fight(c::Cat,l::Lion) = println("The cat beats the Lion") -# => Warning: New definition -# fight(Cat,Lion) at none:1 -# is ambiguous with -# fight(Lion,Cat) at none:2. -# Make sure -# fight(Lion,Lion) -# is defined first. -#fight (generic function with 4 methods) +fight(c::Cat, l::Lion) = println("The cat beats the Lion") +# => fight (generic function with 4 methods) # This warning is because it's unclear which fight will be called in: -fight(Lion("RAR"),Lion("brown","rarrr")) # => prints The victorious cat says rarrr +try + fight(Lion("RAR"), Lion("brown", "rarrr")) + # => ERROR: MethodError: fight(::Lion, ::Lion) is ambiguous. Candidates: + # => fight(c::Cat, l::Lion) in Main at ... + # => fight(l::Lion, c::Cat) in Main at ... + # => Possible fix, define + # => fight(::Lion, ::Lion) + # => ... +catch e + println(e) +end # The result may be different in other versions of Julia -fight(l::Lion,l2::Lion) = println("The lions come to a tie") -fight(Lion("RAR"),Lion("brown","rarrr")) # => prints The lions come to a tie +fight(l::Lion, l2::Lion) = println("The lions come to a tie") +# => fight (generic function with 5 methods) +fight(Lion("RAR"), Lion("brown", "rarrr")) # => The lions come to a tie # Under the hood # You can take a look at the llvm and the assembly code generated. -square_area(l) = l * l # square_area (generic function with 1 method) +square_area(l) = l * l # square_area (generic function with 1 method) -square_area(5) #25 +square_area(5) # => 25 # What happens when we feed square_area an integer? -code_native(square_area, (Int32,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 # Prologue - # push RBP - # mov RBP, RSP - # Source line: 1 - # movsxd RAX, EDI # Fetch l from memory? - # imul RAX, RAX # Square l and store the result in RAX - # pop RBP # Restore old base pointer - # ret # Result will still be in RAX - -code_native(square_area, (Float32,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # Source line: 1 - # vmulss XMM0, XMM0, XMM0 # Scalar single precision multiply (AVX) - # pop RBP - # ret - -code_native(square_area, (Float64,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # Source line: 1 - # vmulsd XMM0, XMM0, XMM0 # Scalar double precision multiply (AVX) - # pop RBP - # ret - # +code_native(square_area, (Int32,), syntax = :intel) + # .text + # ; Function square_area { + # ; Location: REPL[116]:1 # Prologue + # push rbp + # mov rbp, rsp + # ; Function *; { + # ; Location: int.jl:54 + # imul ecx, ecx # Square l and store the result in ECX + # ;} + # mov eax, ecx + # pop rbp # Restore old base pointer + # ret # Result will still be in EAX + # nop dword ptr [rax + rax] + # ;} + +code_native(square_area, (Float32,), syntax = :intel) + # .text + # ; Function square_area { + # ; Location: REPL[116]:1 + # push rbp + # mov rbp, rsp + # ; Function *; { + # ; Location: float.jl:398 + # vmulss xmm0, xmm0, xmm0 # Scalar single precision multiply (AVX) + # ;} + # pop rbp + # ret + # nop word ptr [rax + rax] + # ;} + +code_native(square_area, (Float64,), syntax = :intel) + # .text + # ; Function square_area { + # ; Location: REPL[116]:1 + # push rbp + # mov rbp, rsp + # ; Function *; { + # ; Location: float.jl:399 + # vmulsd xmm0, xmm0, xmm0 # Scalar double precision multiply (AVX) + # ;} + # pop rbp + # ret + # nop word ptr [rax + rax] + # ;} + # Note that julia will use floating point instructions if any of the # arguments are floats. # Let's calculate the area of a circle circle_area(r) = pi * r * r # circle_area (generic function with 1 method) -circle_area(5) # 78.53981633974483 - -code_native(circle_area, (Int32,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # Source line: 1 - # vcvtsi2sd XMM0, XMM0, EDI # Load integer (r) from memory - # movabs RAX, 4593140240 # Load pi - # vmulsd XMM1, XMM0, QWORD PTR [RAX] # pi * r - # vmulsd XMM0, XMM0, XMM1 # (pi * r) * r - # pop RBP - # ret - # - -code_native(circle_area, (Float64,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # movabs RAX, 4593140496 - # Source line: 1 - # vmulsd XMM1, XMM0, QWORD PTR [RAX] - # vmulsd XMM0, XMM1, XMM0 - # pop RBP - # ret - # +circle_area(5) # 78.53981633974483 + +code_native(circle_area, (Int32,), syntax = :intel) + # .text + # ; Function circle_area { + # ; Location: REPL[121]:1 + # push rbp + # mov rbp, rsp + # ; Function *; { + # ; Location: operators.jl:502 + # ; Function *; { + # ; Location: promotion.jl:314 + # ; Function promote; { + # ; Location: promotion.jl:284 + # ; Function _promote; { + # ; Location: promotion.jl:261 + # ; Function convert; { + # ; Location: number.jl:7 + # ; Function Type; { + # ; Location: float.jl:60 + # vcvtsi2sd xmm0, xmm0, ecx # Load integer (r) from memory + # movabs rax, 497710928 # Load pi + # ;}}}}} + # ; Function *; { + # ; Location: float.jl:399 + # vmulsd xmm1, xmm0, qword ptr [rax] # pi * r + # vmulsd xmm0, xmm1, xmm0 # (pi * r) * r + # ;}} + # pop rbp + # ret + # nop dword ptr [rax] + # ;} + +code_native(circle_area, (Float64,), syntax = :intel) + # .text + # ; Function circle_area { + # ; Location: REPL[121]:1 + # push rbp + # mov rbp, rsp + # movabs rax, 497711048 + # ; Function *; { + # ; Location: operators.jl:502 + # ; Function *; { + # ; Location: promotion.jl:314 + # ; Function *; { + # ; Location: float.jl:399 + # vmulsd xmm1, xmm0, qword ptr [rax] + # ;}}} + # ; Function *; { + # ; Location: float.jl:399 + # vmulsd xmm0, xmm1, xmm0 + # ;} + # pop rbp + # ret + # nop dword ptr [rax + rax] + # ;} ``` ## Further Reading -You can get a lot more detail from [The Julia Manual](http://docs.julialang.org/en/latest/#Manual-1) +You can get a lot more detail from the [Julia Documentation](https://docs.julialang.org/) The best place to get help with Julia is the (very friendly) [Discourse forum](https://discourse.julialang.org/). diff --git a/kdb+.html.markdown b/kdb+.html.markdown index 5ae86a4f..027b6571 100644 --- a/kdb+.html.markdown +++ b/kdb+.html.markdown @@ -76,7 +76,7 @@ floor 3.14159 / => 3 / ...getting the absolute value... abs -3.14159 / => 3.14159 / ...and many other things -/ see http://code.kx.com/wiki/Reference for more +/ see http://code.kx.com/q/ref/card/ for more / q has no operator precedence, everything is evaluated right to left / so results like this might take some getting used to @@ -174,7 +174,7 @@ t - 00:10:00.000 / => 00:50:00.000 d.year / => 2015i d.mm / => 12i d.dd / => 25i -/ see http://code.kx.com/wiki/JB:QforMortals2/atoms#Temporal_Data for more +/ see http://code.kx.com/q4m3/2_Basic_Data_Types_Atoms/#25-temporal-data for more / q also has an infinity value so div by zero will not throw an error 1%0 / => 0w @@ -183,7 +183,7 @@ d.dd / => 25i / And null types for representing missing values 0N / => null int 0n / => null float -/ see http://code.kx.com/wiki/JB:QforMortals2/atoms#Null_Values for more +/ see http://code.kx.com/q4m3/2_Basic_Data_Types_Atoms/#27-nulls for more / q has standard control structures / if is as you might expect (; separates the condition and instructions) @@ -642,7 +642,7 @@ kt upsert ([]name:`Thomas`Chester;age:33 58;height:175 179;sex:`f`m) / => Thomas 32 175 m / Most of the standard SQL joins are present in q-sql, plus a few new friends -/ see http://code.kx.com/wiki/JB:QforMortals2/queries_q_sql#Joins +/ see http://code.kx.com/q4m3/9_Queries_q-sql/#99-joins / the two most important (commonly used) are lj and aj / lj is basically the same as SQL LEFT JOIN @@ -669,7 +669,7 @@ aj[`time`sym;trades;quotes] / => 10:01:04 ge 150 / for each row in the trade table, the last (prevailing) quote (px) for that sym / is joined on. -/ see http://code.kx.com/wiki/JB:QforMortals2/queries_q_sql#Asof_Join +/ see http://code.kx.com/q4m3/9_Queries_q-sql/#998-as-of-joins //////////////////////////////////// ///// Extra/Advanced ////// @@ -689,14 +689,14 @@ first each (1 2 3;4 5 6;7 8 9) / each-left (\:) and each-right (/:) modify a two-argument function / to treat one of the arguments and individual variables instead of a list -1 2 3 +\: 1 2 3 -/ => 2 3 4 -/ => 3 4 5 -/ => 4 5 6 -1 2 3 +/: 1 2 3 -/ => 2 3 4 -/ => 3 4 5 -/ => 4 5 6 +1 2 3 +\: 11 22 33 +/ => 12 23 34 +/ => 13 24 35 +/ => 14 25 36 +1 2 3 +/: 11 22 33 +/ => 12 13 14 +/ => 23 24 25 +/ => 34 35 36 / The true alternatives to loops in q are the adverbs scan (\) and over (/) / their behaviour differs based on the number of arguments the function they @@ -716,7 +716,7 @@ first each (1 2 3;4 5 6;7 8 9) {x + y}/[1 2 3 4 5] / => 15 (only the final result) / There are other adverbs and uses, this is only intended as quick overview -/ http://code.kx.com/wiki/JB:QforMortals2/functions#Adverbs +/ http://code.kx.com/q4m3/6_Functions/#67-adverbs ////// Scripts ////// / q scripts can be loaded from a q session using the "\l" command @@ -756,7 +756,7 @@ select from splayed / (the columns are read from disk on request) / => 1 1 / => 2 2 / => 3 3 -/ see http://code.kx.com/wiki/JB:KdbplusForMortals/contents for more +/ see http://code.kx.com/q4m3/14_Introduction_to_Kdb+/ for more ////// Frameworks ////// / kdb+ is typically used for data capture and analysis. @@ -769,8 +769,8 @@ select from splayed / (the columns are read from disk on request) ## Want to know more? -* [*q for mortals* q language tutorial](http://code.kx.com/wiki/JB:QforMortals2/contents) -* [*kdb for mortals* on disk data tutorial](http://code.kx.com/wiki/JB:KdbplusForMortals/contents) -* [q language reference](http://code.kx.com/wiki/Reference) +* [*q for mortals* q language tutorial](http://code.kx.com/q4m3/) +* [*Introduction to Kdb+* on disk data tutorial](http://code.kx.com/q4m3/14_Introduction_to_Kdb+/) +* [q language reference](http://code.kx.com/q/ref/card/) * [Online training courses](http://training.aquaq.co.uk/) * [TorQ production framework](https://github.com/AquaQAnalytics/TorQ) diff --git a/ko-kr/markdown-kr.html.markdown b/ko-kr/markdown-kr.html.markdown index bfa2a877..397e9f30 100644 --- a/ko-kr/markdown-kr.html.markdown +++ b/ko-kr/markdown-kr.html.markdown @@ -25,7 +25,7 @@ lang: ko-kr ## HTML 요소 HTML은 마크다운의 수퍼셋입니다. 모든 HTML 파일은 유효한 마크다운이라는 것입니다. -```markdown +```md <!--따라서 주석과 같은 HTML 요소들을 마크다운에 사용할 수 있으며, 마크다운 파서에 영향을 받지 않을 것입니다. 하지만 마크다운 파일에서 HTML 요소를 만든다면 그 요소의 안에서는 마크다운 문법을 사용할 수 없습니다.--> @@ -34,7 +34,7 @@ HTML은 마크다운의 수퍼셋입니다. 모든 HTML 파일은 유효한 마 텍스트 앞에 붙이는 우물 정 기호(#)의 갯수에 따라 `<h1>`부터 `<h6>`까지의 HTML 요소를 손쉽게 작성할 수 있습니다. -```markdown +```md # <h1>입니다. ## <h2>입니다. ### <h3>입니다. @@ -43,7 +43,7 @@ HTML은 마크다운의 수퍼셋입니다. 모든 HTML 파일은 유효한 마 ###### <h6>입니다. ``` 또한 h1과 h2를 나타내는 다른 방법이 있습니다. -```markdown +```md h1입니다. ============= @@ -53,7 +53,7 @@ h2입니다. ## 간단한 텍스트 꾸미기 마크다운으로 쉽게 텍스트를 기울이거나 굵게 할 수 있습니다. -```markdown +```md *기울인 텍스트입니다.* _이 텍스트도 같습니다._ @@ -65,14 +65,14 @@ __이 텍스트도 같습니다.__ *__이것도 같습니다.__* ``` 깃헙 전용 마크다운에는 취소선도 있습니다. -```markdown +```md ~~이 텍스트에는 취소선이 그려집니다.~~ ``` ## 문단 문단은 하나 이상의 빈 줄로 구분되는, 한 줄 이상의 인접한 텍스트입니다. -```markdown +```md 문단입니다. 문단에 글을 쓰다니 재밌지 않나요? 이제 두 번째 문단입니다. @@ -83,7 +83,7 @@ __이 텍스트도 같습니다.__ HTML `<br />` 태그를 삽입하고 싶으시다면, 두 개 이상의 띄어쓰기로 문단을 끝내고 새 문단을 시작할 수 있습니다. -```markdown +```md 띄어쓰기 두 개로 끝나는 문단 (마우스로 긁어 보세요). 이 위에는 `<br />` 태그가 있습니다. @@ -91,7 +91,7 @@ HTML `<br />` 태그를 삽입하고 싶으시다면, 두 개 이상의 띄어 인용문은 > 문자로 쉽게 쓸 수 있습니다. -```markdown +```md > 인용문입니다. 수동으로 개행하고서 > 줄마다 `>`를 칠 수도 있고 줄을 길게 쓴 다음에 저절로 개행되게 내버려 둘 수도 있습니다. > `>`로 시작하기만 한다면 차이가 없습니다. @@ -103,7 +103,7 @@ HTML `<br />` 태그를 삽입하고 싶으시다면, 두 개 이상의 띄어 ## 목록 순서가 없는 목록은 별표, 더하기, 하이픈을 이용해 만들 수 있습니다. -```markdown +```md * 이거 * 저거 * 그거 @@ -111,7 +111,7 @@ HTML `<br />` 태그를 삽입하고 싶으시다면, 두 개 이상의 띄어 또는 -```markdown +```md + 이거 + 저거 + 그거 @@ -119,7 +119,7 @@ HTML `<br />` 태그를 삽입하고 싶으시다면, 두 개 이상의 띄어 또는 -```markdown +```md - 이거 - 저거 - 그거 @@ -127,7 +127,7 @@ HTML `<br />` 태그를 삽입하고 싶으시다면, 두 개 이상의 띄어 순서가 있는 목록은 숫자와 마침표입니다. -```markdown +```md 1. 하나 2. 둘 3. 셋 @@ -135,7 +135,7 @@ HTML `<br />` 태그를 삽입하고 싶으시다면, 두 개 이상의 띄어 숫자를 정확히 붙이지 않더라도 제대로 된 순서로 보여주겠지만, 좋은 생각은 아닙니다. -```markdown +```md 1. 하나 1. 둘 1. 셋 @@ -144,7 +144,7 @@ HTML `<br />` 태그를 삽입하고 싶으시다면, 두 개 이상의 띄어 목록 안에 목록이 올 수도 있습니다. -```markdown +```md 1. 하나 2. 둘 3. 셋 @@ -155,7 +155,7 @@ HTML `<br />` 태그를 삽입하고 싶으시다면, 두 개 이상의 띄어 심지어 할 일 목록도 있습니다. HTML 체크박스가 만들어집니다. -```markdown +```md x가 없는 박스들은 체크되지 않은 HTML 체크박스입니다. - [ ] 첫 번째 할 일 - [ ] 두 번째 할 일 @@ -168,13 +168,13 @@ x가 없는 박스들은 체크되지 않은 HTML 체크박스입니다. 띄어쓰기 네 개 혹은 탭 한 개로 줄을 들여씀으로서 (`<code> 요소를 사용하여`) 코드를 나타낼 수 있습니다. -```markdown +```md puts "Hello, world!" ``` 탭을 더 치거나 띄어쓰기를 네 번 더 함으로써 코드를 들여쓸 수 있습니다. -```markdown +```md my_array.each do |item| puts item end @@ -182,7 +182,7 @@ x가 없는 박스들은 체크되지 않은 HTML 체크박스입니다. 인라인 코드는 백틱 문자를 이용하여 나타냅니다. ` -```markdown +```md 철수는 `go_to()` 함수가 뭘 했는지도 몰랐어! ``` @@ -202,7 +202,7 @@ end 수평선(`<hr/>`)은 셋 이상의 별표나 하이픈을 이용해 쉽게 나타낼 수 있습니다. 띄어쓰기가 포함될 수 있습니다. -```markdown +```md *** --- - - - @@ -213,19 +213,19 @@ end 마크다운의 장점 중 하나는 링크를 만들기 쉽다는 것입니다. 대괄호 안에 나타낼 텍스트를 쓰고 괄호 안에 URL을 쓰면 됩니다. -```markdown +```md [클릭](http://test.com/) ``` 괄호 안에 따옴표를 이용해 링크에 제목을 달 수도 있습니다. -```markdown +```md [클릭](http://test.com/ "test.com으로 가기") ``` 상대 경로도 유효합니다. -```markdown +```md [music으로 가기](/music/). ``` @@ -251,7 +251,7 @@ end ## 이미지 이미지는 링크와 같지만 앞에 느낌표가 붙습니다. -```markdown +```md  ``` @@ -264,18 +264,18 @@ end ## 기타 ### 자동 링크 -```markdown +```md <http://testwebsite.com/>와 [http://testwebsite.com/](http://testwebsite.com/)는 동일합니다. ``` ### 이메일 자동 링크 -```markdown +```md <foo@bar.com> ``` ### 탈출 문자 -```markdown +```md *별표 사이에 이 텍스트*를 치고 싶지만 기울이고 싶지는 않다면 이렇게 하시면 됩니다. \*별표 사이에 이 텍스트\*. ``` @@ -284,7 +284,7 @@ end 깃헙 전용 마크다운에서는 `<kbd>` 태그를 이용해 키보드 키를 나타낼 수 있습니다. -```markdown +```md 컴퓨터가 멈췄다면 눌러보세요. <kbd>Ctrl</kbd>+<kbd>Alt</kbd>+<kbd>Del</kbd> ``` @@ -292,14 +292,14 @@ end ### 표 표는 깃헙 전용 마크다운에서만 쓸 수 있고 다소 복잡하지만, 정말 쓰고 싶으시다면 -```markdown +```md | 1열 | 2열 | 3열 | | :--------| :-------: | --------: | | 왼쪽 정렬 | 가운데 정렬 | 오른쪽 정렬 | | 머시기 | 머시기 | 머시기 | ``` 혹은 -```markdown +```md 1열 | 2열 | 3열 :-- | :-: | --: 으악 너무 못생겼어 | 그만 | 둬 diff --git a/kotlin.html.markdown b/kotlin.html.markdown index 0c787d7e..81242bac 100644 --- a/kotlin.html.markdown +++ b/kotlin.html.markdown @@ -65,7 +65,7 @@ fun helloWorld(val name : String) { A template expression starts with a dollar sign ($). */ val fooTemplateString = "$fooString has ${fooString.length} characters" - println(fooTemplateString) // => My String Is Here! has 18 characters + println(fooTemplateString) // => My String Is Here! has 18 characters /* For a variable to hold null it must be explicitly specified as nullable. @@ -175,12 +175,12 @@ fun helloWorld(val name : String) { // Objects can be destructured into multiple variables. val (a, b, c) = fooCopy println("$a $b $c") // => 1 100 4 - + // destructuring in "for" loop for ((a, b, c) in listOf(fooData)) { println("$a $b $c") // => 1 100 4 } - + val mapData = mapOf("a" to 1, "b" to 2) // Map.Entry is destructurable as well for ((key, value) in mapData) { @@ -347,6 +347,8 @@ fun helloWorld(val name : String) { println(EnumExample.A) // => A println(ObjectExample.hello()) // => hello + + testOperator() } // Enum classes are similar to Java enum types. @@ -370,10 +372,81 @@ fun useObject() { val someRef: Any = ObjectExample // we use objects name just as is } + +/* The not-null assertion operator (!!) converts any value to a non-null type and +throws an exception if the value is null. +*/ +var b: String? = "abc" +val l = b!!.length + +/* You can add many custom operations using symbol like +, to particular instance +by overloading the built-in kotlin operator, using "operator" keyword + +below is the sample class to add some operator, and the most basic example +*/ +data class SomeClass(var savedValue: Int = 0) + +// instance += valueToAdd +operator fun SomeClass.plusAssign(valueToAdd: Int) { + this.savedValue += valueToAdd +} + +// -instance +operator fun SomeClass.unaryMinus() = SomeClass(-this.savedValue) + +// ++instance or instance++ +operator fun SomeClass.inc() = SomeClass(this.savedValue + 1) + +// instance * other +operator fun SomeClass.times(other: SomeClass) = + SomeClass(this.savedValue * other.savedValue) + +// an overload for multiply +operator fun SomeClass.times(value: Int) = SomeClass(this.savedValue * value) + +// other in instance +operator fun SomeClass.contains(other: SomeClass) = + other.savedValue == this.savedValue + +// instance[dummyIndex] = valueToSet +operator fun SomeClass.set(dummyIndex: Int, valueToSet: Int) { + this.savedValue = valueToSet + dummyIndex +} + +// instance() +operator fun SomeClass.invoke() { + println("instance invoked by invoker") +} + +/* return type must be Integer, +so that, it can be translated to "returned value" compareTo 0 + +for equality (==,!=) using operator will violates overloading equals function, +since it is already defined in Any class +*/ +operator fun SomeClass.compareTo(other: SomeClass) = + this.savedValue - other.savedValue + +fun testOperator() { + var x = SomeClass(4) + + println(x) // => "SomeClass(savedValue=4)" + x += 10 + println(x) // => "SomeClass(savedValue=14)" + println(-x) // => "SomeClass(savedValue=-14)" + println(++x) // => "SomeClass(savedValue=15)" + println(x * SomeClass(3)) // => "SomeClass(savedValue=45)" + println(x * 2) // => "SomeClass(savedValue=30)" + println(SomeClass(15) in x) // => true + x[2] = 10 + println(x) // => "SomeClass(savedValue=12)" + x() // => "instance invoked by invoker" + println(x >= 15) // => false +} ``` ### Further Reading * [Kotlin tutorials](https://kotlinlang.org/docs/tutorials/) -* [Try Kotlin in your browser](http://try.kotlinlang.org/) +* [Try Kotlin in your browser](https://play.kotlinlang.org/) * [A list of Kotlin resources](http://kotlin.link/) diff --git a/lambda-calculus.html.markdown b/lambda-calculus.html.markdown new file mode 100644 index 00000000..3d080de7 --- /dev/null +++ b/lambda-calculus.html.markdown @@ -0,0 +1,214 @@ +--- +category: Algorithms & Data Structures +name: Lambda Calculus +contributors: + - ["Max Sun", "http://github.com/maxsun"] + - ["Yan Hui Hang", "http://github.com/yanhh0"] +--- + +# Lambda Calculus + +Lambda calculus (λ-calculus), originally created by +[Alonzo Church](https://en.wikipedia.org/wiki/Alonzo_Church), +is the world's smallest programming language. +Despite not having numbers, strings, booleans, or any non-function datatype, +lambda calculus can be used to represent any Turing Machine! + +Lambda calculus is composed of 3 elements: **variables**, **functions**, and +**applications**. + + +| Name | Syntax | Example | Explanation | +|-------------|------------------------------------|-----------|-----------------------------------------------| +| Variable | `<name>` | `x` | a variable named "x" | +| Function | `λ<parameters>.<body>` | `λx.x` | a function with parameter "x" and body "x" | +| Application | `<function><variable or function>` | `(λx.x)a` | calling the function "λx.x" with argument "a" | + +The most basic function is the identity function: `λx.x` which is equivalent to +`f(x) = x`. The first "x" is the function's argument, and the second is the +body of the function. + +## Free vs. Bound Variables: + +- In the function `λx.x`, "x" is called a bound variable because it is both in +the body of the function and a parameter. +- In `λx.y`, "y" is called a free variable because it is never declared before hand. + +## Evaluation: + +Evaluation is done via +[β-Reduction](https://en.wikipedia.org/wiki/Lambda_calculus#Beta_reduction), +which is essentially lexically-scoped substitution. + +When evaluating the +expression `(λx.x)a`, we replace all occurences of "x" in the function's body +with "a". + +- `(λx.x)a` evaluates to: `a` +- `(λx.y)a` evaluates to: `y` + +You can even create higher-order functions: + +- `(λx.(λy.x))a` evaluates to: `λy.a` + +Although lambda calculus traditionally supports only single parameter +functions, we can create multi-parameter functions using a technique called +[currying](https://en.wikipedia.org/wiki/Currying). + +- `(λx.λy.λz.xyz)` is equivalent to `f(x, y, z) = ((x y) z)` + +Sometimes `λxy.<body>` is used interchangeably with: `λx.λy.<body>` + +---- + +It's important to recognize that traditional **lambda calculus doesn't have +numbers, characters, or any non-function datatype!** + +## Boolean Logic: + +There is no "True" or "False" in lambda calculus. There isn't even a 1 or 0. + +Instead: + +`T` is represented by: `λx.λy.x` + +`F` is represented by: `λx.λy.y` + +First, we can define an "if" function `λbtf` that +returns `t` if `b` is True and `f` if `b` is False + +`IF` is equivalent to: `λb.λt.λf.b t f` + +Using `IF`, we can define the basic boolean logic operators: + +`a AND b` is equivalent to: `λab.IF a b F` + +`a OR b` is equivalent to: `λab.IF a T b` + +`a NOT b` is equivalent to: `λa.IF a F T` + +*Note: `IF a b c` is essentially saying: `IF((a b) c)`* + +## Numbers: + +Although there are no numbers in lambda calculus, we can encode numbers using +[Church numerals](https://en.wikipedia.org/wiki/Church_encoding). + +For any number n: <code>n = λf.f<sup>n</sup></code> so: + +`0 = λf.λx.x` + +`1 = λf.λx.f x` + +`2 = λf.λx.f(f x)` + +`3 = λf.λx.f(f(f x))` + +To increment a Church numeral, +we use the successor function `S(n) = n + 1` which is: + +`S = λn.λf.λx.f((n f) x)` + +Using successor, we can define add: + +`ADD = λab.(a S)n` + +**Challenge:** try defining your own multiplication function! + +## Get even smaller: SKI, SK and Iota + +### SKI Combinator Calculus + +Let S, K, I be the following functions: + +`I x = x` + +`K x y = x` + +`S x y z = x z (y z)` + +We can convert an expression in the lambda calculus to an expression +in the SKI combinator calculus: + +1. `λx.x = I` +2. `λx.c = Kc` +3. `λx.(y z) = S (λx.y) (λx.z)` + +Take the church number 2 for example: + +`2 = λf.λx.f(f x)` + +For the inner part `λx.f(f x)`: +``` + λx.f(f x) += S (λx.f) (λx.(f x)) (case 3) += S (K f) (S (λx.f) (λx.x)) (case 2, 3) += S (K f) (S (K f) I) (case 2, 1) +``` + +So: +``` + 2 += λf.λx.f(f x) += λf.(S (K f) (S (K f) I)) += λf.((S (K f)) (S (K f) I)) += S (λf.(S (K f))) (λf.(S (K f) I)) (case 3) +``` + +For the first argument `λf.(S (K f))`: +``` + λf.(S (K f)) += S (λf.S) (λf.(K f)) (case 3) += S (K S) (S (λf.K) (λf.f)) (case 2, 3) += S (K S) (S (K K) I) (case 2, 3) +``` + +For the second argument `λf.(S (K f) I)`: +``` + λf.(S (K f) I) += λf.((S (K f)) I) += S (λf.(S (K f))) (λf.I) (case 3) += S (S (λf.S) (λf.(K f))) (K I) (case 2, 3) += S (S (K S) (S (λf.K) (λf.f))) (K I) (case 1, 3) += S (S (K S) (S (K K) I)) (K I) (case 1, 2) +``` + +Merging them up: +``` + 2 += S (λf.(S (K f))) (λf.(S (K f) I)) += S (S (K S) (S (K K) I)) (S (S (K S) (S (K K) I)) (K I)) +``` + +Expanding this, we would end up with the same expression for the +church number 2 again. + +### SK Combinator Calculus + +The SKI combinator calculus can still be reduced further. We can +remove the I combinator by noting that `I = SKK`. We can substitute +all `I`'s with `SKK`. + +### Iota Combinator + +The SK combinator calculus is still not minimal. Defining: + +``` +ι = λf.((f S) K) +``` + +We have: + +``` +I = ιι +K = ι(ιI) = ι(ι(ιι)) +S = ι(K) = ι(ι(ι(ιι))) +``` + +## For more advanced reading: + +1. [A Tutorial Introduction to the Lambda Calculus](http://www.inf.fu-berlin.de/lehre/WS03/alpi/lambda.pdf) +2. [Cornell CS 312 Recitation 26: The Lambda Calculus](http://www.cs.cornell.edu/courses/cs3110/2008fa/recitations/rec26.html) +3. [Wikipedia - Lambda Calculus](https://en.wikipedia.org/wiki/Lambda_calculus) +4. [Wikipedia - SKI combinator calculus](https://en.wikipedia.org/wiki/SKI_combinator_calculus) +5. [Wikipedia - Iota and Jot](https://en.wikipedia.org/wiki/Iota_and_Jot) diff --git a/latex.html.markdown b/latex.html.markdown index a3866892..874efeeb 100644 --- a/latex.html.markdown +++ b/latex.html.markdown @@ -6,6 +6,7 @@ contributors: - ["Sricharan Chiruvolu", "http://sricharan.xyz"] - ["Ramanan Balakrishnan", "https://github.com/ramananbalakrishnan"] - ["Svetlana Golubeva", "https://attillax.github.io/"] + - ["Oliver Kopp", "http://orcid.org/0000-0001-6962-4290"] filename: learn-latex.tex --- @@ -26,8 +27,8 @@ filename: learn-latex.tex % Next we define the packages the document uses. % If you want to include graphics, colored text, or -% source code from another language file into your document, -% you need to enhance the capabilities of LaTeX. This is done by adding packages. +% source code from another language file into your document, +% you need to enhance the capabilities of LaTeX. This is done by adding packages. % I'm going to include the float and caption packages for figures % and hyperref package for hyperlinks \usepackage{caption} @@ -38,18 +39,18 @@ filename: learn-latex.tex \author{Chaitanya Krishna Ande, Colton Kohnke, Sricharan Chiruvolu \& \\ Svetlana Golubeva} \date{\today} -\title{Learn \LaTeX \hspace{1pt} in Y Minutes!} +\title{Learn \LaTeX{} in Y Minutes!} % Now we're ready to begin the document % Everything before this line is called "The Preamble" -\begin{document} -% if we set the author, date, title fields, we can have LaTeX +\begin{document} +% if we set the author, date, title fields, we can have LaTeX % create a title page for us. \maketitle % If we have sections, we can create table of contents. We have to compile our % document twice to make it appear in right order. -% It is a good practice to separate the table of contents form the body of the +% It is a good practice to separate the table of contents form the body of the % document. To do so we use \newpage command \newpage \tableofcontents @@ -58,14 +59,14 @@ Svetlana Golubeva} % Most research papers have abstract, you can use the predefined commands for this. % This should appear in its logical order, therefore, after the top matter, -% but before the main sections of the body. +% but before the main sections of the body. % This command is available in the document classes article and report. \begin{abstract} - \LaTeX \hspace{1pt} documentation written as \LaTeX! How novel and totally not + \LaTeX{} documentation written as \LaTeX! How novel and totally not my idea! \end{abstract} -% Section commands are intuitive. +% Section commands are intuitive. % All the titles of the sections are added automatically to the table of contents. \section{Introduction} Hello, my name is Colton and together we're going to explore \LaTeX! @@ -74,23 +75,28 @@ Hello, my name is Colton and together we're going to explore \LaTeX! This is the text for another section. I think it needs a subsection. \subsection{This is a subsection} % Subsections are also intuitive. -I think we need another one +I think we need another one. \subsubsection{Pythagoras} Much better now. \label{subsec:pythagoras} % By using the asterisk we can suppress LaTeX's inbuilt numbering. -% This works for other LaTeX commands as well. -\section*{This is an unnumbered section} +% This works for other LaTeX commands as well. +\section*{This is an unnumbered section} However not all sections have to be numbered! \section{Some Text notes} %\section{Spacing} % Need to add more information about space intervals -\LaTeX \hspace{1pt} is generally pretty good about placing text where it should -go. If -a line \\ needs \\ to \\ break \\ you add \textbackslash\textbackslash -\hspace{1pt} to the source code. \\ +\LaTeX{} is generally pretty good about placing text where it should +go. If +a line \\ needs \\ to \\ break \\ you add \textbackslash\textbackslash{} +to the source code. + +Separate paragraphs by empty lines. + +You need to add a dot after abbreviations (if not followed by a comma), because otherwise the spacing after the dot is too large: +E.g., i.e., etc.\ are are such abbreviations. \section{Lists} Lists are one of the easiest things to create in \LaTeX! I need to go shopping @@ -109,18 +115,18 @@ tomorrow, so let's make a grocery list. \section{Math} -One of the primary uses for \LaTeX \hspace{1pt} is to produce academic articles -or technical papers. Usually in the realm of math and science. As such, -we need to be able to add special symbols to our paper! \\ +One of the primary uses for \LaTeX{} is to produce academic articles +or technical papers. Usually in the realm of math and science. As such, +we need to be able to add special symbols to our paper! Math has many symbols, far beyond what you can find on a keyboard; -Set and relation symbols, arrows, operators, and Greek letters to name a few.\\ +Set and relation symbols, arrows, operators, and Greek letters to name a few. Sets and relations play a vital role in many mathematical research papers. -Here's how you state all x that belong to X, $\forall$ x $\in$ X. \\ -% Notice how I needed to add $ signs before and after the symbols. This is -% because when writing, we are in text-mode. -% However, the math symbols only exist in math-mode. +Here's how you state all x that belong to X, $\forall$ x $\in$ X. +% Notice how I needed to add $ signs before and after the symbols. This is +% because when writing, we are in text-mode. +% However, the math symbols only exist in math-mode. % We can enter math-mode from text mode with the $ signs. % The opposite also holds true. Variable can also be rendered in math-mode. % We can also enter math mode with \[\] @@ -128,16 +134,16 @@ Here's how you state all x that belong to X, $\forall$ x $\in$ X. \\ \[a^2 + b^2 = c^2 \] My favorite Greek letter is $\xi$. I also like $\beta$, $\gamma$ and $\sigma$. -I haven't found a Greek letter yet that \LaTeX \hspace{1pt} doesn't know -about! \\ +I haven't found a Greek letter yet that \LaTeX{} doesn't know +about! -Operators are essential parts of a mathematical document: -trigonometric functions ($\sin$, $\cos$, $\tan$), -logarithms and exponentials ($\log$, $\exp$), -limits ($\lim$), etc. -have per-defined LaTeX commands. -Let's write an equation to see how it's done: -$\cos(2\theta) = \cos^{2}(\theta) - \sin^{2}(\theta)$ \\ +Operators are essential parts of a mathematical document: +trigonometric functions ($\sin$, $\cos$, $\tan$), +logarithms and exponentials ($\log$, $\exp$), +limits ($\lim$), etc.\ +have per-defined LaTeX commands. +Let's write an equation to see how it's done: +$\cos(2\theta) = \cos^{2}(\theta) - \sin^{2}(\theta)$ Fractions (Numerator-denominators) can be written in these forms: @@ -146,7 +152,7 @@ $$ ^{10}/_{7} $$ % Relatively complex fractions can be written as % \frac{numerator}{denominator} -$$ \frac{n!}{k!(n - k)!} $$ \\ +$$ \frac{n!}{k!(n - k)!} $$ We can also insert equations in an ``equation environment''. @@ -156,31 +162,31 @@ We can also insert equations in an ``equation environment''. \label{eq:pythagoras} % for referencing \end{equation} % all \begin statements must have an end statement -We can then reference our new equation! +We can then reference our new equation! Eqn.~\ref{eq:pythagoras} is also known as the Pythagoras Theorem which is also -the subject of Sec.~\ref{subsec:pythagoras}. A lot of things can be labeled: +the subject of Sec.~\ref{subsec:pythagoras}. A lot of things can be labeled: figures, equations, sections, etc. Summations and Integrals are written with sum and int commands: % Some LaTeX compilers will complain if there are blank lines % In an equation environment. -\begin{equation} +\begin{equation} \sum_{i=0}^{5} f_{i} -\end{equation} -\begin{equation} +\end{equation} +\begin{equation} \int_{0}^{\infty} \mathrm{e}^{-x} \mathrm{d}x -\end{equation} +\end{equation} \section{Figures} -Let's insert a Figure. Figure placement can get a little tricky. +Let's insert a figure. Figure placement can get a little tricky. I definitely have to lookup the placement options each time. -\begin{figure}[H] % H here denoted the placement option. +\begin{figure}[H] % H here denoted the placement option. \centering % centers the figure on the page % Inserts a figure scaled to 0.8 the width of the page. - %\includegraphics[width=0.8\linewidth]{right-triangle.png} + %\includegraphics[width=0.8\linewidth]{right-triangle.png} % Commented out for compilation purposes. Please use your imagination. \caption{Right triangle with sides $a$, $b$, $c$} \label{fig:right-triangle} @@ -193,7 +199,7 @@ We can also insert Tables in the same way as figures. \caption{Caption for the Table.} % the {} arguments below describe how each row of the table is drawn. % Again, I have to look these up. Each. And. Every. Time. - \begin{tabular}{c|cc} + \begin{tabular}{c|cc} Number & Last Name & First Name \\ % Column rows are separated by & \hline % a horizontal line 1 & Biggus & Dickus \\ @@ -201,37 +207,38 @@ We can also insert Tables in the same way as figures. \end{tabular} \end{table} -\section{Getting \LaTeX \hspace{1pt} to not compile something (i.e. Source Code)} -Let's say we want to include some code into our \LaTeX \hspace{1pt} document, -we would then need \LaTeX \hspace{1pt} to not try and interpret that text and -instead just print it to the document. We do this with a verbatim -environment. +\section{Getting \LaTeX{} to not compile something (i.e.\ Source Code)} +Let's say we want to include some code into our \LaTeX{} document, +we would then need \LaTeX{} to not try and interpret that text and +instead just print it to the document. We do this with a verbatim +environment. % There are other packages that exist (i.e. minty, lstlisting, etc.) % but verbatim is the bare-bones basic one. -\begin{verbatim} +\begin{verbatim} print("Hello World!") - a%b; % look! We can use % signs in verbatim. + a%b; % look! We can use % signs in verbatim. random = 4; #decided by fair random dice roll \end{verbatim} -\section{Compiling} +\section{Compiling} + +By now you're probably wondering how to compile this fabulous document +and look at the glorious glory that is a \LaTeX{} pdf. +(yes, this document actually does compile). -By now you're probably wondering how to compile this fabulous document -and look at the glorious glory that is a \LaTeX \hspace{1pt} pdf. -(yes, this document actually does compile). \\ -Getting to the final document using \LaTeX \hspace{1pt} consists of the following +Getting to the final document using \LaTeX{} consists of the following steps: \begin{enumerate} \item Write the document in plain text (the ``source code''). - \item Compile source code to produce a pdf. + \item Compile source code to produce a pdf. The compilation step looks like this (in Linux): \\ - \begin{verbatim} + \begin{verbatim} > pdflatex learn-latex.tex \end{verbatim} \end{enumerate} -A number of \LaTeX \hspace{1pt}editors combine both Step 1 and Step 2 in the +A number of \LaTeX{} editors combine both Step 1 and Step 2 in the same piece of software. So, you get to see Step 1, but not Step 2 completely. Step 2 is still happening behind the scenes\footnote{In cases, where you use references (like Eqn.~\ref{eq:pythagoras}), you may need to run Step 2 @@ -245,17 +252,17 @@ format you defined in Step 1. \section{Hyperlinks} We can also insert hyperlinks in our document. To do so we need to include the package hyperref into preamble with the command: -\begin{verbatim} +\begin{verbatim} \usepackage{hyperref} \end{verbatim} There exists two main types of links: visible URL \\ -\url{https://learnxinyminutes.com/docs/latex/}, or +\url{https://learnxinyminutes.com/docs/latex/}, or \href{https://learnxinyminutes.com/docs/latex/}{shadowed by text} -% You can not add extra-spaces or special symbols into shadowing text since it +% You can not add extra-spaces or special symbols into shadowing text since it % will cause mistakes during the compilation -This package also produces list of tumbnails in the output pdf document and +This package also produces list of thumbnails in the output pdf document and active links in the table of contents. \section{End} @@ -267,9 +274,8 @@ That's all for now! \begin{thebibliography}{1} % similar to other lists, the \bibitem command can be used to list items % each entry can then be cited directly in the body of the text - \bibitem{latexwiki} The amazing \LaTeX \hspace{1pt} wikibook: {\em -https://en.wikibooks.org/wiki/LaTeX} - \bibitem{latextutorial} An actual tutorial: {\em http://www.latex-tutorial.com} + \bibitem{latexwiki} The amazing \LaTeX{} wikibook: \emph{https://en.wikibooks.org/wiki/LaTeX} + \bibitem{latextutorial} An actual tutorial: \emph{http://www.latex-tutorial.com} \end{thebibliography} % end the document @@ -280,3 +286,4 @@ https://en.wikibooks.org/wiki/LaTeX} * The amazing LaTeX wikibook: [https://en.wikibooks.org/wiki/LaTeX](https://en.wikibooks.org/wiki/LaTeX) * An actual tutorial: [http://www.latex-tutorial.com/](http://www.latex-tutorial.com/) +* A quick guide for learning LaTeX: [Learn LaTeX in 30 minutes](https://www.overleaf.com/learn/latex/Learn_LaTeX_in_30_minutes) diff --git a/lua.html.markdown b/lua.html.markdown index 1e2d4366..32174a81 100644 --- a/lua.html.markdown +++ b/lua.html.markdown @@ -62,6 +62,11 @@ if not aBoolValue then print('twas false') end -- in C/js: ans = aBoolValue and 'yes' or 'no' --> 'no' +-- BEWARE: this only acts as a ternary if the value returned when the condition +-- evaluates to true is not `false` or Nil +iAmNotFalse = (not aBoolValue) and false or true --> true +iAmAlsoNotFalse = (not aBoolValue) and true or false --> true + karlSum = 0 for i = 1, 100 do -- The range includes both ends. karlSum = karlSum + i diff --git a/make.html.markdown b/make.html.markdown index ab128475..45d020e9 100644 --- a/make.html.markdown +++ b/make.html.markdown @@ -2,6 +2,7 @@ language: make
contributors:
- ["Robert Steed", "https://github.com/robochat"]
+ - ["Stephan Fuhrmann", "https://github.com/sfuhrm"]
filename: Makefile
---
@@ -11,7 +12,7 @@ target to the most recent version of the source. Famously written over a weekend by Stuart Feldman in 1976, it is still widely used (particularly
on Unix and Linux) despite many competitors and criticisms.
-There are many varieties of make in existence, however this article
+There are many varieties of make in existence, however this article
assumes that we are using GNU make which is the standard on Linux.
```make
@@ -168,9 +169,9 @@ echo: name2 = Sara # True within the matching rule # Some variables defined automatically by make.
echo_inbuilt:
echo $(CC)
- echo ${CXX)}
+ echo ${CXX}
echo $(FC)
- echo ${CFLAGS)}
+ echo ${CFLAGS}
echo $(CPPFLAGS)
echo ${CXXFLAGS}
echo $(LDFLAGS)
diff --git a/markdown.html.markdown b/markdown.html.markdown index a1f5173b..cf4286e2 100644 --- a/markdown.html.markdown +++ b/markdown.html.markdown @@ -29,7 +29,7 @@ specific to a certain parser. ## HTML Elements Markdown is a superset of HTML, so any HTML file is valid Markdown. -```markdown +```md <!--This means we can use HTML elements in Markdown, such as the comment element, and they won't be affected by a markdown parser. However, if you create an HTML element in your markdown file, you cannot use markdown syntax @@ -41,7 +41,7 @@ within that element's contents.--> You can create HTML elements `<h1>` through `<h6>` easily by prepending the text you want to be in that element by a number of hashes (#). -```markdown +```md # This is an <h1> ## This is an <h2> ### This is an <h3> @@ -51,7 +51,7 @@ text you want to be in that element by a number of hashes (#). ``` Markdown also provides us with two alternative ways of indicating h1 and h2. -```markdown +```md This is an h1 ============= @@ -63,7 +63,7 @@ This is an h2 Text can be easily styled as italic or bold using markdown. -```markdown +```md *This text is in italics.* _And so is this text._ @@ -78,7 +78,7 @@ __And so is this text.__ In GitHub Flavored Markdown, which is used to render markdown files on GitHub, we also have strikethrough: -```markdown +```md ~~This text is rendered with strikethrough.~~ ``` ## Paragraphs @@ -86,7 +86,7 @@ GitHub, we also have strikethrough: Paragraphs are a one or multiple adjacent lines of text separated by one or multiple blank lines. -```markdown +```md This is a paragraph. I'm typing in a paragraph isn't this fun? Now I'm in paragraph 2. @@ -99,7 +99,7 @@ I'm in paragraph three! Should you ever want to insert an HTML `<br />` tag, you can end a paragraph with two or more spaces and then begin a new paragraph. -```markdown +```md I end with two spaces (highlight me to see them). There's a <br /> above me! @@ -107,7 +107,7 @@ There's a <br /> above me! Block quotes are easy and done with the > character. -```markdown +```md > This is a block quote. You can either > manually wrap your lines and put a `>` before every line or you can let your lines get really long and wrap on their own. > It doesn't make a difference so long as they start with a `>`. @@ -121,7 +121,7 @@ Block quotes are easy and done with the > character. ## Lists Unordered lists can be made using asterisks, pluses, or hyphens. -```markdown +```md * Item * Item * Another item @@ -141,7 +141,7 @@ or Ordered lists are done with a number followed by a period. -```markdown +```md 1. Item one 2. Item two 3. Item three @@ -150,7 +150,7 @@ Ordered lists are done with a number followed by a period. You don't even have to label the items correctly and Markdown will still render the numbers in order, but this may not be a good idea. -```markdown +```md 1. Item one 1. Item two 1. Item three @@ -159,7 +159,7 @@ render the numbers in order, but this may not be a good idea. You can also use sublists -```markdown +```md 1. Item one 2. Item two 3. Item three @@ -170,7 +170,7 @@ You can also use sublists There are even task lists. This creates HTML checkboxes. -```markdown +```md Boxes below without the 'x' are unchecked HTML checkboxes. - [ ] First task to complete. - [ ] Second task that needs done @@ -183,7 +183,7 @@ This checkbox below will be a checked HTML checkbox. You can indicate a code block (which uses the `<code>` element) by indenting a line with four spaces or a tab. -```markdown +```md This is code So is this ``` @@ -191,15 +191,15 @@ a line with four spaces or a tab. You can also re-tab (or add an additional four spaces) for indentation inside your code -```markdown +```md my_array.each do |item| puts item end ``` -Inline code can be created using the backtick character ` +Inline code can be created using the backtick character `` ` `` -```markdown +```md John didn't even know what the `go_to()` function did! ``` @@ -220,7 +220,7 @@ highlighting of the language you specify after the \`\`\` Horizontal rules (`<hr/>`) are easily added with three or more asterisks or hyphens, with or without spaces. -```markdown +```md *** --- - - - @@ -232,17 +232,17 @@ hyphens, with or without spaces. One of the best things about markdown is how easy it is to make links. Put the text to display in hard brackets [] followed by the url in parentheses () -```markdown +```md [Click me!](http://test.com/) ``` You can also add a link title using quotes inside the parentheses. -```markdown +```md [Click me!](http://test.com/ "Link to Test.com") ``` Relative paths work too. -```markdown +```md [Go to music](/music/). ``` @@ -269,7 +269,7 @@ But it's not that commonly used. ## Images Images are done the same way as links but with an exclamation point in front! -```markdown +```md  ``` @@ -281,20 +281,20 @@ And reference style works as expected. ## Miscellany ### Auto-links -```markdown +```md <http://testwebsite.com/> is equivalent to [http://testwebsite.com/](http://testwebsite.com/) ``` ### Auto-links for emails -```markdown +```md <foo@bar.com> ``` ### Escaping characters -```markdown +```md I want to type *this text surrounded by asterisks* but I don't want it to be in italics, so I do this: \*this text surrounded by asterisks\*. ``` @@ -304,7 +304,7 @@ in italics, so I do this: \*this text surrounded by asterisks\*. In GitHub Flavored Markdown, you can use a `<kbd>` tag to represent keyboard keys. -```markdown +```md Your computer crashed? Try sending a <kbd>Ctrl</kbd>+<kbd>Alt</kbd>+<kbd>Del</kbd> ``` @@ -313,7 +313,7 @@ Your computer crashed? Try sending a Tables are only available in GitHub Flavored Markdown and are slightly cumbersome, but if you really want it: -```markdown +```md | Col1 | Col2 | Col3 | | :----------- | :------: | ------------: | | Left-aligned | Centered | Right-aligned | @@ -321,7 +321,7 @@ cumbersome, but if you really want it: ``` or, for the same results -```markdown +```md Col 1 | Col2 | Col3 :-- | :-: | --: Ugh this is so ugly | make it | stop diff --git a/matlab.html.markdown b/matlab.html.markdown index 6dc9f697..5790bcc6 100644 --- a/matlab.html.markdown +++ b/matlab.html.markdown @@ -221,11 +221,11 @@ A(1, :) =[] % Delete the first row of the matrix A(:, 1) =[] % Delete the first column of the matrix transpose(A) % Transpose the matrix, which is the same as: -A one -ctranspose(A) % Hermitian transpose the matrix -% (the transpose, followed by taking complex conjugate of each element) -A' % Concise version of complex transpose A.' % Concise version of transpose (without taking complex conjugate) +ctranspose(A) % Hermitian transpose the matrix, which is the same as: +A' % Concise version of complex transpose + % (the transpose, followed by taking complex conjugate of each element) + @@ -374,8 +374,8 @@ disp('Hello World') % Print out a string fprintf % Print to Command Window with more control % Conditional statements (the parentheses are optional, but good style) -if (a > 15) - disp('Greater than 15') +if (a > 23) + disp('Greater than 23') elseif (a == 23) disp('a is 23') else @@ -545,7 +545,7 @@ ans = multiplyLatBy(a,3) % The method can also be called using dot notation. In this case, the object % does not need to be passed to the method. -ans = a.multiplyLatBy(a,1/3) +ans = a.multiplyLatBy(1/3) % Matlab functions can be overloaded to handle objects. % In the method above, we have overloaded how Matlab handles diff --git a/mercurial.html.markdown b/mercurial.html.markdown new file mode 100644 index 00000000..d1cac66c --- /dev/null +++ b/mercurial.html.markdown @@ -0,0 +1,363 @@ +--- +category: tool +tool: hg +contributors: + - ["Will L. Fife", "http://github.com/sarlalian"] +filename: LearnHG.txt +--- + +Mercurial is a free, distributed source control management tool. It offers +you the power to efficiently handle projects of any size while using an +intuitive interface. It is easy to use and hard to break, making it ideal for +anyone working with versioned files. + +## Versioning Concepts + +### What is version control? + +Version control is a system that keeps track fo changes to a set of file(s) +and/or directorie(s) over time. + +### Why Use Mercurial + +* Distributed Architecture - Traditionally version control systems such as CVS +and Subversion are a client server architecture with a central server to +store the revsion history of a project. Mercurial however is a truly +distributed architecture, giving each devloper a full local copy of the +entire development history. It works independently of a central server. + +* Fast - Traditionally version control systems such as CVS and Subversion are a +client server architecture with a central server to store the revsion history +of a project. Mercurial however is a truly distributed architecture, giving +each devloper a full local copy of the entire development history. It works +independently of a central server. + +* Platform Independent - Mercurial was written to be highly platform +independent. Much of Mercurial is written in Python, with small performance +critical parts written in portable C. Binary releases are available for all +major platforms. + +* Extensible - The functionality of Mercurial can be increased with extensions, +either by activating the official ones which are shipped with Mercurial or +downloading some [from the +wiki](https://www.mercurial-scm.org/wiki/UsingExtensions) or by [writing your +own](https://www.mercurial-scm.org/wiki/WritingExtensions). Extensions are +written in Python and can change the workings of the basic commands, add new +commands and access all the core functions of Mercurial. + +* Easy to use - The Mercurial command set is consistent with what subversion +users would expect, so they are likely to feel right at home. Most dangerous +actions are part of extensions that need to be enabled to be used. + +* Open Source - Mercurial is free software licensed under the terms of the [GNU +General Public License Version 2](http://www.gnu.org/licenses/gpl-2.0.txt) or +any later version. + +## Terminology + +| Term | Definition | +| ------------- | ---------------------------------- | +| Repository | A repository is a collection of revisions | +| hgrc | A configuration file which stores the defaults for a repository. | +| revision | A committed changeset: has a REV number | +| changeset | Set of changes saved as diffs | +| diff | Changes between file(s) | +| tag | A named named revision | +| parent(s) | Immediate ancestor(s) of a revison | +| branch | A child of a revision | +| head | A head is a changeset with no child changesets | +| merge | The process of merging two HEADS | +| tip | The latest revision in any branch | +| patch | All of the diffs between two revisions | +| bundle | Patch with permissions and rename support | + +## Commands + +### init + +Create a new repository in the given directory, the settings and stored +information are in a directory named ".hg" + +```bash +$ hg init +``` + +### help + +Will give you access to a very detailed description of each command. + +```bash +# Quickly check what commands are available +$ hg help + +# Get help on a specific command +# hg help <command> +$ hg help add +$ hg help commit +$ hg help init +``` + +### status + +Show the differences between what is on disk and what is committed to the current +branch or tag. + + +```bash +# Will display the status of files +$ hg status + +# Get help on the status subcommand +$ hg help status +``` + +### add + +Will add the specified files to the repository on the next commit + +```bash +# Add a file in the current directory +$ hg add filename.rb + +# Add a file in a sub directory +$ hg add foo/bar/filename.rb + +# Add files by pattern +$ hg add *.rb +``` + +### branch + +Set or show the current branch name + +*Branch names are permanent and global. Use 'hg bookmark' to create a +light-weight bookmark instead. See 'hg help glossary' for more information +about named branches and bookmarks.* + +```bash +# With no argument it shows the current branch name +$ hg branch + +# With a name argument it will change the current branch. +$ hg branch new_branch +marked working directory as branch new_branch +(branches are permanent and global, did you want a bookmark?) +``` + +### tag + +Add one or more tags for the current or given revision + +Tags are used to name particular revisions of the repository and are very +useful to compare different revisions, to go back to significant earlier +versions or to mark branch points as releases, etc. Changing an existing tag +is normally disallowed; use -f/--force to override. + +```bash +# List tags +$ hg tags +tip 2:efc8222cd1fb +v1.0 0:37e9b57123b3 + +# Create a new tag on the current revision +$ hg tag v1.1 + +# Create a tag on a specific revision +$ hg tag -r efc8222cd1fb v1.1.1 +``` + +### clone + +Create a copy of an existing repository in a new directory. + +If no destination directory name is specified, it defaults to the basename of +the source. + +```bash +# Clone a remote repo to a local directory +$ hg clone https://some-mercurial-server.example.com/reponame + +# Clone a local repo to a remote server +$ hg clone . ssh://username@some-mercurial-server.example.com/newrepo + +# Clone a local repo to a local repo +$ hg clone . /tmp/some_backup_dir +``` + +### commit / ci + +Commit changes to the given files into the repository. + +```bash +# Commit with a message +$ hg commit -m 'This is a commit message' + +# Commit all added / removed files in the currrent tree +$ hg commit -A 'Adding and removing all existing files in the tree' + +# amend the parent of the working directory with a new commit that contains the +# changes in the parent in addition to those currently reported by 'hg status', +$ hg commit --amend -m "Correct message" +``` + +### diff + +Show differences between revisions for the specified files using the unified +diff format. + +```bash +# Show the diff between the current directory and a previous revision +$ hg diff -r 10 + +# Show the diff between two previous revisions +$ hg diff -r 30 -r 20 +``` + +### grep + +Search revision history for a pattern in specified files + +```bash +# Search files for a specific phrase +$ hg grep "TODO:" +``` + +### log / history + +Show revision history of entire repository or files. If no revision range is +specified, the default is "tip:0" unless --follow is set, in which case the +working directory parent is used as the starting revision. + +```bash +# Show the history of the entire repository +$ hg log + +# Show the history of a single file +$ hg log myfile.rb + +# Show the revision changes as an ASCII art DAG with the most recent changeset +# at the top. +$ hg log -G +``` + +### merge + +Merge another revision into working directory + +```bash +# Merge changesets to local repository +$ hg merge + +# Merge from a named branch or revision into the current local branch +$ hg merge branchname_or_revision + +# After successful merge, commit the changes +hg commit +``` + +### move / mv / rename + +Rename files; equivalent of copy + remove. Mark dest as copies of sources; +mark sources for deletion. If dest is a directory, copies are put in that +directory. If dest is a file, there can only be one source. + +```bash +# Rename a single file +$ hg mv foo.txt bar.txt + +# Rename a directory +$ hg mv some_directory new_directory +``` + +### pull + +Pull changes from a remote repository to a local one. + +```bash +# List remote paths +$ hg paths +remote1 = http://path/to/remote1 +remote2 = http://path/to/remote2 + +# Pull from remote 1 +$ hg pull remote1 + +# Pull from remote 2 +$ hg pull remote2 +``` + +### push + +Push changesets from the local repository to the specified destination. + +```bash +# List remote paths +$ hg paths +remote1 = http://path/to/remote1 +remote2 = http://path/to/remote2 + +# Pull from remote 1 +$ hg push remote1 + +# Pull from remote 2 +$ hg push remote2 +``` + +### rebase + +Move changeset (and descendants) to a different branch + +Rebase uses repeated merging to graft changesets from one part of history +(the source) onto another (the destination). This can be useful for +linearizing *local* changes relative to a master development tree. + +* Draft the commits back to the source revision. +* -s is the source, ie. what you are rebasing. +* -d is the destination, which is where you are sending it. + +```bash +# Put the commits into draft status +# This will draft all subsequent commits on the relevant branch +$ hg phase --draft --force -r 1206 + +# Rebase from from revision 102 over revision 208 +$ hg rebase -s 102 -d 208 +``` + +### revert + +Restore files to their checkout state. With no revision specified, revert the +specified files or directories to the contents they had in the parent of the +working directory. This restores the contents of files to an unmodified state +and unschedules adds, removes, copies, and renames. If the working directory +has two parents, you must explicitly specify a revision. + +```bash +# Reset a specific file to its checked out state +$ hg revert oops_i_did_it_again.txt + +# Revert a specific file to its checked out state without leaving a .orig file +# around +$ hg revert -C oops_i_did_it_again.txt + +# Revert all changes +$ hg revert -a +``` + +### rm / remove + +Remove the specified files on the next commit. + +```bash +# Remove a spcific file +$ hg remove go_away.txt + +# Remove a group of files by pattern +$ hg remove *.txt +``` + +## Further Information + +* [Learning Mercurial in Workflows](https://www.mercurial-scm.org/guid) +* [Mercurial Quick Start](https://www.mercurial-scm.org/wiki/QuickStart) +* [Mercurial: The Definitive Guide by Bryan O'Sullivan](http://hgbook.red-bean.com/)
\ No newline at end of file diff --git a/mips.html.markdown b/mips.html.markdown new file mode 100644 index 00000000..4134d3fa --- /dev/null +++ b/mips.html.markdown @@ -0,0 +1,366 @@ +--- +language: "MIPS Assembly" +filename: MIPS.asm +contributors: + - ["Stanley Lim", "https://github.com/Spiderpig86"] +--- + +The MIPS (Microprocessor without Interlocked Pipeline Stages) Assembly language +is designed to work with the MIPS microprocessor paradigm designed by J. L. +Hennessy in 1981. These RISC processors are used in embedded systems such as +gateways and routers. + +[Read More](https://en.wikipedia.org/wiki/MIPS_architecture) + +```asm +# Comments are denoted with a '#' + +# Everything that occurs after a '#' will be ignored by the assembler's lexer. + +# Programs typically contain a .data and .text sections + +.data # Section where data is stored in memory (allocated in RAM), similar to + # variables in higher level languages + + # Declarations follow a ( label: .type value(s) ) form of declaration + hello_world: .asciiz "Hello World\n" # Declare a null terminated string + num1: .word 42 # Integers are referred to as words + # (32 bit value) + + arr1: .word 1, 2, 3, 4, 5 # Array of words + arr2: .byte 'a', 'b' # Array of chars (1 byte each) + buffer: .space 60 # Allocates space in the RAM + # (not cleared to 0) + + # Datatype sizes + _byte: .byte 'a' # 1 byte + _halfword: .half 53 # 2 bytes + _word: .word 3 # 4 bytes + _float: .float 3.14 # 4 bytes + _double: .double 7.0 # 8 bytes + + .align 2 # Memory alignment of data, where + # number indicates byte alignment in + # powers of 2. (.align 2 represents + # word alignment since 2^2 = 4 bytes) + +.text # Section that contains instructions + # and program logic +.globl _main # Declares an instruction label as + # global, making it accessible to + # other files + + _main: # MIPS programs execute instructions + # sequentially, where the code under + # this label will be executed firsts + + # Let's print "hello world" + la $a0, hello_world # Load address of string stored in + # memory + li $v0, 4 # Load the syscall value (indicating + # type of functionality) + syscall # Perform the specified syscall with + # the given argument ($a0) + + # Registers (used to hold data during program execution) + # $t0 - $t9 # Temporary registers used for + # intermediate calculations inside + # subroutines (not saved across + # function calls) + + # $s0 - $s7 # Saved registers where values are + # saved across subroutine calls. + # Typically saved in stack + + # $a0 - $a3 # Argument registers for passing in + # arguments for subroutines + # $v0 - $v1 # Return registers for returning + # values to caller function + + # Types of load/store instructions + la $t0, label # Copy the address of a value in + # memory specified by the label into + # register $t0 + lw $t0, label # Copy a word value from memory + lw $t1, 4($s0) # Copy a word value from an address + # stored in a register with an offset + # of 4 bytes (addr + 4) + lb $t2, label # Copy a byte value to the lower order + # portion of the register $t2 + lb $t2, 0($s0) # Copy a byte value from the source + # address in $s0 with offset 0 + # Same idea with 'lh' for halfwords + + sw $t0, label # Store word value into memory address + # mapped by label + sw $t0, 8($s0) # Store word value into address + # specified in $s0 and offset of 8 bytes + # Same idea using 'sb' and 'sh' for bytes and halfwords. 'sa' does not exist + +### Math ### + _math: + # Remember to load your values into a register + lw $t0, num # From the data section + li $t0, 5 # Or from an immediate (constant) + li $t1, 6 + add $t2, $t0, $t1 # $t2 = $t0 + $t1 + sub $t2, $t0, $t1 # $t2 = $t0 - $t1 + mul $t2, $t0, $t1 # $t2 = $t0 * $t1 + div $t2, $t0, $t1 # $t2 = $t0 / $t1 (Might not be + # supported in some versons of MARS) + div $t0, $t1 # Performs $t0 / $t1. Get the quotient + # using 'mflo' and remainder using 'mfhi' + + # Bitwise Shifting + sll $t0, $t0, 2 # Bitwise shift to the left with + # immediate (constant value) of 2 + sllv $t0, $t1, $t2 # Shift left by a variable amount in + # register + srl $t0, $t0, 5 # Bitwise shift to the right (does + # not sign preserve, sign-extends with 0) + srlv $t0, $t1, $t2 # Shift right by a variable amount in + # a register + sra $t0, $t0, 7 # Bitwise arithmetic shift to the right + # (preserves sign) + srav $t0, $t1, $t2 # Shift right by a variable amount + # in a register + + # Bitwise operators + and $t0, $t1, $t2 # Bitwise AND + andi $t0, $t1, 0xFFF # Bitwise AND with immediate + or $t0, $t1, $t2 # Bitwise OR + ori $t0, $t1, 0xFFF # Bitwise OR with immediate + xor $t0, $t1, $t2 # Bitwise XOR + xori $t0, $t1, 0xFFF # Bitwise XOR with immediate + nor $t0, $t1, $t2 # Bitwise NOR + +## BRANCHING ## + _branching: + # The basic format of these branching instructions typically follow <instr> + # <reg1> <reg2> <label> where label is the label we want to jump to if the + # given conditional evaluates to true + # Sometimes it is easier to write the conditional logic backwards, as seen + # in the simple if statement example below + + beq $t0, $t1, reg_eq # Will branch to reg_eq if + # $t0 == $t1, otherwise + # execute the next line + bne $t0, $t1, reg_neq # Branches when $t0 != $t1 + b branch_target # Unconditional branch, will always execute + beqz $t0, req_eq_zero # Branches when $t0 == 0 + bnez $t0, req_neq_zero # Branches when $t0 != 0 + bgt $t0, $t1, t0_gt_t1 # Branches when $t0 > $t1 + bge $t0, $t1, t0_gte_t1 # Branches when $t0 >= $t1 + bgtz $t0, t0_gt0 # Branches when $t0 > 0 + blt $t0, $t1, t0_gt_t1 # Branches when $t0 < $t1 + ble $t0, $t1, t0_gte_t1 # Branches when $t0 <= $t1 + bltz $t0, t0_lt0 # Branches when $t0 < 0 + slt $s0, $t0, $t1 # Instruction that sends a signal when + # $t0 < $t1 with reuslt in $s0 (1 for true) + + # Simple if statement + # if (i == j) + # f = g + h; + # f = f - i; + + # Let $s0 = f, $s1 = g, $s2 = h, $s3 = i, $s4 = j + bne $s3, $s4, L1 # if (i !=j) + add $s0, $s1, $s2 # f = g + h + + L1: + sub $s0, $s0, $s3 # f = f - i + + # Below is an example of finding the max of 3 numbers + # A direct translation in Java from MIPS logic: + # if (a > b) + # if (a > c) + # max = a; + # else + # max = c; + # else + # max = b; + # else + # max = c; + + # Let $s0 = a, $s1 = b, $s2 = c, $v0 = return register + ble $s0, $s1, a_LTE_b # if (a <= b) branch(a_LTE_b) + ble $s0, $s2, max_C # if (a > b && a <=c) branch(max_C) + move $v0, $s1 # else [a > b && a > c] max = a + j done # Jump to the end of the program + + a_LTE_b: # Label for when a <= b + ble $s1, $s2, max_C # if (a <= b && b <= c) branch(max_C) + move $v0, $s1 # if (a <= b && b > c) max = b + j done # Jump to done + + max_C: + move $v0, $s2 # max = c + + done: # End of program + +## LOOPS ## + _loops: + # The basic structure of loops is having an exit condition and a jump + instruction to continue its execution + li $t0, 0 + while: + bgt $t0, 10, end_while # While $t0 is less than 10, keep iterating + addi $t0, $t0, 1 # Increment the value + j while # Jump back to the beginning of the loop + end_while: + + # 2D Matrix Traversal + # Assume that $a0 stores the address of an integer matrix which is 3 x 3 + li $t0, 0 # Counter for i + li $t1, 0 # Counter for j + matrix_row: + bgt $t0, 3, matrix_row_end + + matrix_col: + bgt $t1, 3, matrix_col_end + + # Do stuff + + addi $t1, $t1, 1 # Increment the col counter + matrix_col_end: + + # Do stuff + + addi $t0, $t0, 1 + matrix_row_end: + +## FUNCTIONS ## + _functions: + # Functions are callable procedures that can accept arguments and return + values all denoted with labels, like above + + main: # Programs begin with main func + jal return_1 # jal will store the current PC in $ra + # and then jump to return_1 + + # What if we want to pass in args? + # First we must pass in our parameters to the argument registers + li $a0, 1 + li $a1, 2 + jal sum # Now we can call the function + + # How about recursion? + # This is a bit more work since we need to make sure we save and restore + # the previous PC in $ra since jal will automatically overwrite on each call + li $a0, 3 + jal fact + + li $v0, 10 + syscall + + # This function returns 1 + return_1: + li $v0, 1 # Load val in return register $v0 + jr $ra # Jump back to old PC to continue exec + + + # Function with 2 args + sum: + add $v0, $a0, $a1 + jr $ra # Return + + # Recursive function to find factorial + fact: + addi $sp, $sp, -8 # Allocate space in stack + sw $s0, ($sp) # Store reg that holds current num + sw $ra, 4($sp) # Store previous PC + + li $v0, 1 # Init return value + beq $a0, 0, fact_done # Finish if param is 0 + + # Otherwise, continue recursion + move $s0, $a0 # Copy $a0 to $s0 + sub $a0, $a0, 1 + jal fact + + mul $v0, $s0, $v0 # Multiplication is done + + fact_done: + lw $s0, ($sp) + lw $ra, ($sp) # Restore the PC + addi $sp, $sp, 8 + + jr $ra + +## MACROS ## + _macros: + # Macros are extremly useful for substituting repeated code blocks with a + # single label for better readability + # These are in no means substitutes for functions + # These must be declared before it is used + + # Macro for printing new lines (since these can be very repetitive) + .macro println() + la $a0, newline # New line string stored here + li $v0, 4 + syscall + .end_macro + + println() # Assembler will copy that block of + # code here before running + + # Parameters can be passed in through macros. + # These are denoted by a '%' sign with any name you choose + .macro print_int(%num) + li $v0, 1 + lw $a0, %num + syscall + .end_macro + + li $t0, 1 + print_int($t0) + + # We can also pass in immediates for macros + .macro immediates(%a, %b) + add $t0, %a, %b + .end_macro + + immediates(3, 5) + + # Along with passing in labels + .macro print(%string) + la $a0, %string + li $v0, 4 + syscall + .end_macro + + print(hello_world) + +## ARRAYS ## +.data + list: .word 3, 0, 1, 2, 6 # This is an array of words + char_arr: .asciiz "hello" # This is a char array + buffer: .space 128 # Allocates a block in memory, does + # not automatically clear + # These blocks of memory are aligned + # next each other + +.text + la $s0, list # Load address of list + li $t0, 0 # Counter + li $t1, 5 # Length of the list + + loop: + bgt $t0, $t1, end_loop + + lw $a0, ($s0) + li $v0, 1 + syscall # Print the number + + addi $s0, $s0, 4 # Size of a word is 4 bytes + addi $t0, $t0, 1 # Increment + j loop + end_loop: + +## INCLUDE ## +# You do this to import external files into your program (behind the scenes, +# it really just takes whatever code that is in that file and places it where +# the include statement is) +.include "somefile.asm" + +``` diff --git a/montilang.html.markdown b/montilang.html.markdown new file mode 100644 index 00000000..cceb7aa1 --- /dev/null +++ b/montilang.html.markdown @@ -0,0 +1,233 @@ +--- +language: "montilang" +filename: montilang.ml +contributors: + - ["Leo Whitehead", "https://github.com/lduck11007"] +--- + +MontiLang is a Stack-Oriented concatenative imperative programming language. Its syntax +is roughly based off of forth with similar style for doing arithmetic in [reverse polish notation.](https://en.wikipedia.org/wiki/Reverse_Polish_notation) + +A good way to start with MontiLang is to read the documentation and examples at [montilang.ml](http://montilang.ml), +then download MontiLang or build from source code with the instructions provided. + +``` +/# Monti Reference sheet #/ +/# +Comments are multiline +Nested comments are not supported +#/ +/# Whitespace is all arbitrary, indentation is optional #/ +/# All programming in Monti is done by manipulating the parameter stack +arithmetic and stack operations in MontiLang are similar to FORTH +https://en.wikipedia.org/wiki/Forth_(programming_language) +#/ + +/# in Monti, everything is either a string or a number. Operations treat all numbers +similarly to floats, but anything without a remainder is treated as type int #/ + +/# numbers and strings are added to the stack from left to right #/ + +/# Arithmetic works by manipulating data on the stack #/ + +5 3 + PRINT . /# 8 #/ + +/# 5 and 3 are pushed onto the stack + '+' replaces top 2 items on stack with sum of top 2 items + 'PRINT' prints out the top item on the stack + '.' pops the top item from the stack. + #/ + +6 7 * PRINT . /# 42 #/ +1360 23 - PRINT . /# 1337 #/ +12 12 / PRINT . /# 1 #/ +13 2 % PRINT . /# 1 #/ + +37 NEG PRINT . /# -37 #/ +-12 ABS PRINT . /# 12 #/ +52 23 MAX PRINT . /# 52 #/ +52 23 MIN PRINT . /# 23 #/ + +/# 'PSTACK' command prints the entire stack, 'CLEAR' clears the entire stack #/ + +3 6 8 PSTACK CLEAR /# [3, 6, 8] #/ + +/# Monti comes with some tools for stack manipulation #/ + +2 DUP PSTACK CLEAR /# [2, 2] - Duplicate the top item on the stack#/ +2 6 SWAP PSTACK CLEAR /# [6, 2] - Swap top 2 items on stack #/ +1 2 3 ROT PSTACK CLEAR /# [2, 3, 1] - Rotate top 3 items on stack #/ +2 3 NIP PSTACK CLEAR /# [3] - delete second item from the top of the stack #/ +4 5 6 TRIM PSTACK CLEAR /# [5, 6] - Deletes first item on stack #/ +/# variables are assigned with the syntax 'VAR [name]'#/ +/# When assigned, the variable will take the value of the top item of the stack #/ + +6 VAR six . /# assigns var 'six' to be equal to 6 #/ +3 6 + VAR a . /# assigns var 'a' to be equal to 9 #/ + +/# the length of the stack can be calculated with the statement 'STKLEN' #/ +1 2 3 4 STKLEN PRINT CLEAR /# 4 #/ + +/# strings are defined with | | #/ + +|Hello World!| VAR world . /# sets variable 'world' equal to string 'Hello world! #/ + +/# variables can be called by typing its name. when called, the value of the variable is pushed +to the top of the stack #/ +world PRINT . + +/# with the OUT statement, the top item on the stack can be printed without a newline #/ + +|world!| |Hello, | OUT SWAP PRINT CLEAR + +/# Data types can be converted between strings and integers with the commands 'TOINT' and 'TOSTR'#/ +|5| TOINT PSTACK . /# [5] #/ +45 TOSTR PSTACK . /# ['45'] #/ + +/# User input is taken with INPUT and pushed to the stack. If the top item of the stack is a string, +the string is used as an input prompt #/ + +|What is your name? | INPUT NIP +|Hello, | OUT SWAP PRINT CLEAR + + +/# FOR loops have the syntax 'FOR [condition] [commands] ENDFOR' At the moment, [condition] can +only have the value of an integer. Either by using an integer, or a variable call to an integer. +[commands] will be interpereted the amount of time specified in [condition] #/ +/# E.G: this prints out 1 to 10 #/ + +1 VAR a . +FOR 10 + a PRINT 1 + VAR a +ENDFOR + +/# the syntax for while loops are similar. A number is evaluated as true if it is larger than +0. a string is true if its length > 0. Infinite loops can be used by using literals. +#/ +10 var loop . +WHILE loop + loop print + 1 - var loop +ENDWHILE +/# +this loop would count down from 10. + +IF statements are pretty much the same, but only are executed once. +#/ +IF loop + loop PRINT . +ENDIF + +/# This would only print 'loop' if it is larger than 0 #/ + +/# If you would want to use the top item on the stack as loop parameters, this can be done with the ':' character #/ + +/# eg, if you wanted to print 'hello' 7 times, instead of using #/ + +FOR 7 + |hello| PRINT . +ENDFOR + +/# this could be used #/ +7 +FOR : + |hello| PRINT . +ENDFOR + +/# Equality and inequality statements use the top 2 items on the stack as parameters, and replace the top two items with the output #/ +/# If it is true, the top 2 items are replaced with '1'. If false, with '0'. #/ + +7 3 > PRINT . /# 1 #/ +2 10 > PRINT . /# 0 #/ +5 9 <= PRINT . /# 1 #/ +5 5 == PRINT . /# 1 #/ +5 7 == PRINT . /# 0 #/ +3 8 != PRINT . /# 1 #/ + +/# User defined commands have the syntax of 'DEF [name] [commands] ENDDEF'. #/ +/# eg, if you wanted to define a function with the name of 'printseven' to print '7' 10 times, this could be used #/ + +DEF printseven + FOR 10 + 7 PRINT . + ENDFOR +ENDDEF + +/# to run the defined statement, simply type it and it will be run by the interpereter #/ + +printseven + +/# Montilang supports AND, OR and NOT statements #/ + +1 0 AND PRINT . /# 0 #/ +1 1 AND PRINT . /# 1 #/ +1 0 OR PRINT . /# 1 #/ +0 0 OR PRINT . /# 0 #/ +1 NOT PRINT . /# 0 #/ +0 NOT PRINT . /# 1 #/ + +/# Preprocessor statements are made inbetween '&' characters #/ +/# currently, preprocessor statements can be used to make c++-style constants #/ + +&DEFINE LOOPSTR 20& +/# must have & on either side with no spaces, 'DEFINE' is case sensative. #/ +/# All statements are scanned and replaced before the program is run, regardless of where the statements are placed #/ + +FOR LOOPSTR 7 PRINT . ENDFOR /# Prints '7' 20 times. At run, 'LOOPSTR' in source code is replaced with '20' #/ + +/# Multiple files can be used with the &INCLUDE <filename>& Command that operates similar to c++, where the file specified is tokenized, + and the &INCLUDE statement is replaced with the file #/ + +/# E.G, you can have a program be run through several files. If you had the file 'name.mt' with the following data: + +[name.mt] +|Hello, | OUT . name PRINT . + +a program that asks for your name and then prints it out can be defined as such: #/ + +|What is your name? | INPUT VAR name . &INCLUDE name.mt& + +/# ARRAYS: #/ + +/# arrays are defined with the statement 'ARR' +When called, everything currently in the stack is put into one +array and all items on the stack are replaced with the new array. #/ + +2 3 4 ARR PSTACK . /# [[2, 3, 4]] #/ + +/# the statement 'LEN' adds the length of the last item on the stack to the stack. +This can be used on arrays, as well as strings. #/ + +3 4 5 ARR LEN PRINT . /# 3 #/ + +/# values can be appended to an array with the statement 'APPEND' #/ + +1 2 3 ARR 5 APPEND . PRINT . /# [1, 2, 3, 5] #/ + +/# an array at the top of the stack can be wiped with the statement 'WIPE' #/ +3 4 5 ARR WIPE PRINT . /# [] #/ + +/# The last item of an array can be removed with the statement 'DROP' #/ + +3 4 5 ARR DROP PRINT . /# [3, 4] +/# arrays, like other datatypes can be stored in variables #/ +5 6 7 ARR VAR list . +list PRINT . /# [5, 6, 7] #/ + +/# Values at specific indexes can be changed with the statement 'INSERT <index>' #/ +4 5 6 ARR +97 INSERT 1 . PRINT /# 4, 97, 6 #/ + +/# Values at specific indexes can be deleted with the statement 'DEL <index>' #/ +1 2 3 ARR +DEL 1 PRINT . /# [1, 3] #/ + +/# items at certain indexes of an array can be gotten with the statement 'GET <index>' #/ + +1 2 3 ARR GET 2 PSTACK /# [[1, 2, 3], 3] #/ +``` + +## Extra information + +- [MontiLang.ml](http://montilang.ml/) +- [Github Page](https://github.com/lduck11007/MontiLang) diff --git a/moonscript.html.markdown b/moonscript.html.markdown new file mode 100644 index 00000000..941578e7 --- /dev/null +++ b/moonscript.html.markdown @@ -0,0 +1,570 @@ +--- +language: moonscript +contributors: + - ["RyanSquared", "https://ryansquared.github.io/"] + - ["Job van der Zwan", "https://github.com/JobLeonard"] +filename: moonscript.moon +--- + +MoonScript is a dynamic scripting language that compiles into Lua. It gives +you the power of one of the fastest scripting languages combined with a +rich set of features. + +See [the MoonScript website](https://moonscript.org/) to see official guides on installation for all platforms. + +```moon +-- Two dashes start a comment. Comments can go until the end of the line. +-- MoonScript transpiled to Lua does not keep comments. + +-- As a note, MoonScript does not use 'do', 'then', or 'end' like Lua would and +-- instead uses an indented syntax, much like Python. + +-------------------------------------------------- +-- 1. Assignment +-------------------------------------------------- + +hello = "world" +a, b, c = 1, 2, 3 +hello = 123 -- Overwrites `hello` from above. + +x = 0 +x += 10 -- x = x + 10 + +s = "hello " +s ..= "world" -- s = s .. "world" + +b = false +b and= true or false -- b = b and (true or false) + +-------------------------------------------------- +-- 2. Literals and Operators +-------------------------------------------------- + +-- Literals work almost exactly as they would in Lua. Strings can be broken in +-- the middle of a line without requiring a \. + +some_string = "exa +mple" -- local some_string = "exa\nmple" + +-- Strings can also have interpolated values, or values that are evaluated and +-- then placed inside of a string. + +some_string = "This is an #{some_string}" -- Becomes 'This is an exa\nmple' + +-------------------------------------------------- +-- 2.1. Function Literals +-------------------------------------------------- + +-- Functions are written using arrows: + +my_function = -> -- compiles to `function() end` +my_function() -- calls an empty function + +-- Functions can be called without using parenthesis. Parentheses may still be +-- used to have priority over other functions. + +func_a = -> print "Hello World!" +func_b = -> + value = 100 + print "The value: #{value}" + +-- If a function needs no parameters, it can be called with either `()` or `!`. + +func_a! +func_b() + +-- Functions can use arguments by preceding the arrow with a list of argument +-- names bound by parentheses. + +sum = (x, y)-> x + y -- The last expression is returned from the function. +print sum(5, 10) + +-- Lua has an idiom of sending the first argument to a function as the object, +-- like a 'self' object. Using a fat arrow (=>) instead of a skinny arrow (->) +-- automatically creates a `self` variable. `@x` is a shorthand for `self.x`. + +func = (num)=> @value + num + +-- Default arguments can also be used with function literals: + +a_function = (name = "something", height=100)-> + print "Hello, I am #{name}.\nMy height is #{height}." + +-- Because default arguments are calculated in the body of the function when +-- transpiled to Lua, you can reference previous arguments. + +some_args = (x = 100, y = x + 1000)-> print(x + y) + +-------------------------------------------------- +-- Considerations +-------------------------------------------------- + +-- The minus sign plays two roles, a unary negation operator and a binary +-- subtraction operator. It is recommended to always use spaces between binary +-- operators to avoid the possible collision. + +a = x - 10 -- a = x - 10 +b = x-10 -- b = x - 10 +c = x -y -- c = x(-y) +d = x- z -- d = x - z + +-- When there is no space between a variable and string literal, the function +-- call takes priority over following expressions: + +x = func"hello" + 100 -- func("hello") + 100 +y = func "hello" + 100 -- func("hello" + 100) + +-- Arguments to a function can span across multiple lines as long as the +-- arguments are indented. The indentation can be nested as well. + +my_func 5, -- called as my_func(5, 8, another_func(6, 7, 9, 1, 2), 5, 4) + 8, another_func 6, 7, -- called as + 9, 1, 2, -- another_func(6, 7, 9, 1, 2) + 5, 4 + +-- If a function is used at the start of a block, the indentation can be +-- different than the level of indentation used in a block: + +if func 1, 2, 3, -- called as func(1, 2, 3, "hello", "world") + "hello", + "world" + print "hello" + +-------------------------------------------------- +-- 3. Tables +-------------------------------------------------- + +-- Tables are defined by curly braces, like Lua: + +some_values = {1, 2, 3, 4} + +-- Tables can use newlines instead of commas. + +some_other_values = { + 5, 6 + 7, 8 +} + +-- Assignment is done with `:` instead of `=`: + +profile = { + name: "Bill" + age: 200 + "favorite food": "rice" +} + +-- Curly braces can be left off for `key: value` tables. + +y = type: "dog", legs: 4, tails: 1 + +profile = + height: "4 feet", + shoe_size: 13, + favorite_foods: -- nested table + foo: "ice cream", + bar: "donuts" + +my_function dance: "Tango", partner: "none" -- :( forever alone + +-- Tables constructed from variables can use the same name as the variables +-- by using `:` as a prefix operator. + +hair = "golden" +height = 200 +person = {:hair, :height} + +-- Like in Lua, keys can be non-string or non-numeric values by using `[]`. + +t = + [1 + 2]: "hello" + "hello world": true -- Can use string literals without `[]`. + +-------------------------------------------------- +-- 3.1. Table Comprehensions +-------------------------------------------------- + +-- List Comprehensions + +-- Creates a copy of a list but with all items doubled. Using a star before a +-- variable name or table can be used to iterate through the table's values. + +items = {1, 2, 3, 4} +doubled = [item * 2 for item in *items] +-- Uses `when` to determine if a value should be included. + +slice = [item for item in *items when i > 1 and i < 3] + +-- `for` clauses inside of list comprehensions can be chained. + +x_coords = {4, 5, 6, 7} +y_coords = {9, 2, 3} + +points = [{x,y} for x in *x_coords for y in *y_coords] + +-- Numeric for loops can also be used in comprehensions: + +evens = [i for i=1, 100 when i % 2 == 0] + +-- Table Comprehensions are very similar but use `{` and `}` and take two +-- values for each iteration. + +thing = color: "red", name: "thing", width: 123 +thing_copy = {k, v for k, v in pairs thing} + +-- Tables can be "flattened" from key-value pairs in an array by using `unpack` +-- to return both values, using the first as the key and the second as the +-- value. + +tuples = {{"hello", "world"}, {"foo", "bar"}} +table = {unpack tuple for tuple in *tuples} + +-- Slicing can be done to iterate over only a certain section of an array. It +-- uses the `*` notation for iterating but appends `[start, end, step]`. + +-- The next example also shows that this syntax can be used in a `for` loop as +-- well as any comprehensions. + +for item in *points[1, 10, 2] + print unpack item + +-- Any undesired values can be left off. The second comma is not required if +-- the step is not included. + +words = {"these", "are", "some", "words"} +for word in *words[,3] + print word + +-------------------------------------------------- +-- 4. Control Structures +-------------------------------------------------- + +have_coins = false +if have_coins + print "Got coins" +else + print "No coins" + +-- Use `then` for single-line `if` +if have_coins then "Got coins" else "No coins" + +-- `unless` is the opposite of `if` +unless os.date("%A") == "Monday" + print "It is not Monday!" + +-- `if` and `unless` can be used as expressions +is_tall = (name)-> if name == "Rob" then true else false +message = "I am #{if is_tall "Rob" then "very tall" else "not so tall"}" +print message -- "I am very tall" + +-- `if`, `elseif`, and `unless` can evaluate assignment as well as expressions. +if x = possibly_nil! -- sets `x` to `possibly_nil()` and evaluates `x` + print x + +-- Conditionals can be used after a statement as well as before. This is +-- called a "line decorator". + +is_monday = os.date("%A") == "Monday" +print("It IS Monday!") if isMonday +print("It is not Monday..") unless isMonday +--print("It IS Monday!" if isMonday) -- Not a statement, does not work + +-------------------------------------------------- +-- 4.1 Loops +-------------------------------------------------- + +for i = 1, 10 + print i + +for i = 10, 1, -1 do print i -- Use `do` for single-line loops. + +i = 0 +while i < 10 + continue if i % 2 == 0 -- Continue statement; skip the rest of the loop. + print i + +-- Loops can be used as a line decorator, just like conditionals +print "item: #{item}" for item in *items + +-- Using loops as an expression generates an array table. The last statement +-- in the block is coerced into an expression and added to the table. +my_numbers = for i = 1, 6 do i -- {1, 2, 3, 4, 5, 6} + +-- use `continue` to filter out values +odds = for i in *my_numbers + continue if i % 2 == 0 -- acts opposite to `when` in comprehensions! + i -- Only added to return table if odd + +-- A `for` loop returns `nil` when it is the last statement of a function +-- Use an explicit `return` to generate a table. +print_squared = (t) -> for x in *t do x*x -- returns `nil` +squared = (t) -> return for x in *t do x*x -- returns new table of squares + +-- The following does the same as `(t) -> [i for i in *t when i % 2 == 0]` +-- But list comprehension generates better code and is more readable! + +filter_odds = (t) -> + return for x in *t + if x % 2 == 0 then x else continue +evens = filter_odds(my_numbers) -- {2, 4, 6} + +-------------------------------------------------- +-- 4.2 Switch Statements +-------------------------------------------------- + +-- Switch statements are a shorthand way of writing multiple `if` statements +-- checking against the same value. The value is only evaluated once. + +name = "Dan" + +switch name + when "Dave" + print "You are Dave." + when "Dan" + print "You are not Dave, but Dan." + else + print "You are neither Dave nor Dan." + +-- Switches can also be used as expressions, as well as compare multiple +-- values. The values can be on the same line as the `when` clause if they +-- are only one expression. + +b = 4 +next_even = switch b + when 1 then 2 + when 2, 3 then 4 + when 4, 5 then 6 + else error "I can't count that high! D:" + +-------------------------------------------------- +-- 5. Object Oriented Programming +-------------------------------------------------- + +-- Classes are created using the `class` keyword followed by an identifier, +-- typically written using CamelCase. Values specific to a class can use @ as +-- the identifier instead of `self.value`. + +class Inventory + new: => @items = {} + add_item: (name)=> -- note the use of fat arrow for classes! + @items[name] = 0 unless @items[name] + @items[name] += 1 + +-- The `new` function inside of a class is special because it is called when +-- an instance of the class is created. + +-- Creating an instance of the class is as simple as calling the class as a +-- function. Calling functions inside of the class uses \ to separate the +-- instance from the function it is calling. + +inv = Inventory! +inv\add_item "t-shirt" +inv\add_item "pants" + +-- Values defined in the class - not the new() function - will be shared across +-- all instances of the class. + +class Person + clothes: {} + give_item: (name)=> + table.insert @clothes name + +a = Person! +b = Person! + +a\give_item "pants" +b\give_item "shirt" + +-- prints out both "pants" and "shirt" + +print item for item in *a.clothes + +-- Class instances have a value `.__class` that are equal to the class object +-- that created the instance. + +assert(b.__class == Person) + +-- Variables declared in class body the using the `=` operator are locals, +-- so these "private" variables are only accessible within the current scope. + +class SomeClass + x = 0 + reveal: -> + x += 1 + print x + +a = SomeClass! +b = SomeClass! +print a.x -- nil +a.reveal! -- 1 +b.reveal! -- 2 + +-------------------------------------------------- +-- 5.1 Inheritance +-------------------------------------------------- + +-- The `extends` keyword can be used to inherit properties and methods from +-- another class. + +class Backpack extends Inventory + size: 10 + add_item: (name)=> + error "backpack is full" if #@items > @size + super name -- calls Inventory.add_item with `name`. + +-- Because a `new` method was not added, the `new` method from `Inventory` will +-- be used instead. If we did want to use a constructor while still using the +-- constructor from `Inventory`, we could use the magical `super` function +-- during `new()`. + +-- When a class extends another, it calls the method `__inherited` on the +-- parent class (if it exists). It is always called with the parent and the +-- child object. + +class ParentClass + @__inherited: (child)=> + print "#{@__name} was inherited by #{child.__name}" + a_method: (a, b) => print a .. ' ' .. b + +-- Will print 'ParentClass was inherited by MyClass' + +class MyClass extends ParentClass + a_method: => + super "hello world", "from MyClass!" + assert super == ParentClass + +-------------------------------------------------- +-- 6. Scope +-------------------------------------------------- + +-- All values are local by default. The `export` keyword can be used to +-- declare the variable as a global value. + +export var_1, var_2 +var_1, var_3 = "hello", "world" -- var_3 is local, var_1 is not. + +export this_is_global_assignment = "Hi!" + +-- Classes can also be prefixed with `export` to make them global classes. +-- Alternatively, all CamelCase variables can be exported automatically using +-- `export ^`, and all values can be exported using `export *`. + +-- `do` lets you manually create a scope, for when you need local variables. + +do + x = 5 +print x -- nil + +-- Here we use `do` as an expression to create a closure. + +counter = do + i = 0 + -> + i += 1 + return i + +print counter! -- 1 +print counter! -- 2 + +-- The `local` keyword can be used to define variables +-- before they are assigned. + +local var_4 +if something + var_4 = 1 +print var_4 -- works because `var_4` was set in this scope, not the `if` scope. + +-- The `local` keyword can also be used to shadow an existing variable. + +x = 10 +if false + local x + x = 12 +print x -- 10 + +-- Use `local *` to forward-declare all variables. +-- Alternatively, use `local ^` to forward-declare all CamelCase values. + +local * + +first = -> + second! + +second = -> + print data + +data = {} + +-------------------------------------------------- +-- 6.1 Import +-------------------------------------------------- + +-- Values from a table can be brought to the current scope using the `import` +-- and `from` keyword. Names in the `import` list can be preceded by `\` if +-- they are a module function. + +import insert from table -- local insert = table.insert +import \add from state: 100, add: (value)=> @state + value +print add 22 + +-- Like tables, commas can be excluded from `import` lists to allow for longer +-- lists of imported items. + +import + asdf, gh, jkl + antidisestablishmentarianism + from {} + +-------------------------------------------------- +-- 6.2 With +-------------------------------------------------- + +-- The `with` statement can be used to quickly call and assign values in an +-- instance of a class or object. + +file = with File "lmsi15m.moon" -- `file` is the value of `set_encoding()`. + \set_encoding "utf8" + +create_person = (name, relatives)-> + with Person! + .name = name + \add_relative relative for relative in *relatives +me = create_person "Ryan", {"sister", "sister", "brother", "dad", "mother"} + +with str = "Hello" -- assignment as expression! :D + print "original: #{str}" + print "upper: #{\upper!}" + +-------------------------------------------------- +-- 6.3 Destructuring +-------------------------------------------------- + +-- Destructuring can take arrays, tables, and nested tables and convert them +-- into local variables. + +obj2 = + numbers: {1, 2, 3, 4} + properties: + color: "green" + height: 13.5 + +{numbers: {first, second}, properties: {:color}} = obj2 + +print first, second, color -- 1 2 green + +-- `first` and `second` return [1] and [2] because they are as an array, but +-- `:color` is like `color: color` so it sets itself to the `color` value. + +-- Destructuring can be used in place of `import`. + +{:max, :min, random: rand} = math -- rename math.random to rand + +-- Destructuring can be done anywhere assignment can be done. + +for {left, right} in *{{"hello", "world"}, {"egg", "head"}} + print left, right +``` + +## Additional Resources + +- [Language Guide](https://moonscript.org/reference/) +- [Online Compiler](https://moonscript.org/compiler/) diff --git a/ms-my/clojure-macros-my.html.markdown b/ms-my/clojure-macros-my.html.markdown new file mode 100644 index 00000000..099f376e --- /dev/null +++ b/ms-my/clojure-macros-my.html.markdown @@ -0,0 +1,154 @@ +--- +language: "clojure macros" +filename: learnclojuremacros-ms.clj +contributors: + - ["Adam Bard", "http://adambard.com/"] +translators: + - ["Burhanuddin Baharuddin", "https://github.com/burhanloey"] +lang: ms-my +--- + +Sama seperti Lisp yang lain, sifat Clojure yang mempunyai [homoiconicity](https://en.wikipedia.org/wiki/Homoiconic) +membolehkan anda untuk menggunakan sepenuhnya language ini untuk menulis code yang boleh generate code sendiri yang +dipanggil "macro". Macro memberi cara yang sangat menarik untuk mengubahsuai language mengikut kehendak anda. + +Jaga-jaga. Penggunaan macro boleh dikatakan tidak elok jika digunakan secara berlebihan jika function sahaja sudah mencukupi. +Gunakan macro hanya apabila anda mahu lebih kawalan terhadap sesuatu form. + +Biasakan diri dengan Clojure terlebih dahulu. Pastikan anda memahami semuanya di +[Clojure in Y Minutes](/docs/ms-my/clojure-my/). + +```clojure +;; Define macro menggunakan defmacro. Macro anda akan output list yang boleh +;; dijalankan sebagai code clojure. +;; +;; Macro ini adalah sama seperti (reverse "Hello World") +(defmacro my-first-macro [] + (list reverse "Hello World")) + +;; Lihat hasil macro tersebut menggunakan macroexpand atau macroexpand-1. +;; +;; Pastikan panggilan kepada macro tersebut mempunyai tanda petikan +(macroexpand '(my-first-macro)) +;; -> (#<core$reverse clojure.core$reverse@xxxxxxxx> "Hello World") + +;; Anda boleh menggunakan eval terus kepada macroexpand untuk mendapatkan hasil: +(eval (macroexpand '(my-first-macro))) +; -> (\d \l \o \r \W \space \o \l \l \e \H) + +;; Tetapi anda sepatutnya menggunakan cara yang lebih ringkas, sama seperti panggilan kepada function: +(my-first-macro) ; -> (\d \l \o \r \W \space \o \l \l \e \H) + +;; Anda boleh memudahkan cara untuk membuat macro dengan mengguna tanda petikan +;; untuk membuat list untuk macro: +(defmacro my-first-quoted-macro [] + '(reverse "Hello World")) + +(macroexpand '(my-first-quoted-macro)) +;; -> (reverse "Hello World") +;; Perhatikan yang reverse bukan lagi function tetapi adalah simbol. + +;; Macro boleh mengambil argument. +(defmacro inc2 [arg] + (list + 2 arg)) + +(inc2 2) ; -> 4 + +;; Tetapi jika anda membuat cara yang sama menggunakan tanda petikan, anda akan mendapat error sebab +;; argument tersebut juga akan mempunyai tanda petikan. Untuk mengatasi masalah ini, Clojure memberi +;; cara untuk meletak tanda petikan untuk macro: `. Di dalam `, anda boleh menggunakan ~ untuk mendapatkan scope luaran +(defmacro inc2-quoted [arg] + `(+ 2 ~arg)) + +(inc2-quoted 2) + +;; Anda boleh menggunakan destructuring untuk argument seperti biasa. Gunakan ~@ untuk mengembangkan variable +(defmacro unless [arg & body] + `(if (not ~arg) + (do ~@body))) ; Jangan lupa do! + +(macroexpand '(unless true (reverse "Hello World"))) +;; -> +;; (if (clojure.core/not true) (do (reverse "Hello World"))) + +;; (unless) mengembalikan body jika argument yang pertama adalah false. +;; Jika tidak, (unless) akan memulangkan nil + +(unless true "Hello") ; -> nil +(unless false "Hello") ; -> "Hello" + +;; Jika tidak berhati-hati, macro boleh memeningkan anda dengan mencampuradukkan nama variable +(defmacro define-x [] + '(do + (def x 2) + (list x))) + +(def x 4) +(define-x) ; -> (2) +(list x) ; -> (2) + +;; Untuk mengelakkan masalah ini, gunakan gensym untuk mendapatkan identifier yang berbeza +(gensym 'x) ; -> x1281 (atau yang sama waktu dengannya) + +(defmacro define-x-safely [] + (let [sym (gensym 'x)] + `(do + (def ~sym 2) + (list ~sym)))) + +(def x 4) +(define-x-safely) ; -> (2) +(list x) ; -> (4) + +;; Anda boleh menggunakan # di dalam ` untuk menghasilkan gensym untuk setiap simbol secara automatik +(defmacro define-x-hygienically [] + `(do + (def x# 2) + (list x#))) + +(def x 4) +(define-x-hygienically) ; -> (2) +(list x) ; -> (4) + +;; Kebiasaannya helper function digunakan untuk membuat macro. Jom buat beberapa function untuk +;; membuatkan program boleh memahami inline arithmetic. Saja suka-suka. +(declare inline-2-helper) +(defn clean-arg [arg] + (if (seq? arg) + (inline-2-helper arg) + arg)) + +(defn apply-arg + "Diberi argument [x (+ y)], pulangkan (+ x y)" + [val [op arg]] + (list op val (clean-arg arg))) + +(defn inline-2-helper + [[arg1 & ops-and-args]] + (let [ops (partition 2 ops-and-args)] + (reduce apply-arg (clean-arg arg1) ops))) + +;; Kita boleh test terlebih dahulu tanpa membuat macro +(inline-2-helper '(a + (b - 2) - (c * 5))) ; -> (- (+ a (- b 2)) (* c 5)) + +; Tetapi, kita perlu membuat macro jika kita mahu jalankan code tersebut +(defmacro inline-2 [form] + (inline-2-helper form)) + +(macroexpand '(inline-2 (1 + (3 / 2) - (1 / 2) + 1))) +; -> (+ (- (+ 1 (/ 3 2)) (/ 1 2)) 1) + +(inline-2 (1 + (3 / 2) - (1 / 2) + 1)) +; -> 3 (sepatutnya, 3N, sebab nombor tersebut ditukarkan kepada pecahan rasional menggunakan /) +``` + +### Bacaaan Lanjut + +Writing Macros daripada [Clojure for the Brave and True](http://www.braveclojure.com/) +[http://www.braveclojure.com/writing-macros/](http://www.braveclojure.com/writing-macros/) + +Dokumen rasmi +[http://clojure.org/macros](http://clojure.org/macros) + +Bila perlu guna macro? +[http://dunsmor.com/lisp/onlisp/onlisp_12.html](http://dunsmor.com/lisp/onlisp/onlisp_12.html) diff --git a/ms-my/common-lisp-my.html.markdown b/ms-my/common-lisp-my.html.markdown new file mode 100644 index 00000000..f5914aae --- /dev/null +++ b/ms-my/common-lisp-my.html.markdown @@ -0,0 +1,692 @@ +--- + +language: "Common Lisp" +filename: commonlisp-ms.lisp +contributors: + - ["Paul Nathan", "https://github.com/pnathan"] + - ["Rommel Martinez", "https://ebzzry.io"] +translators: + - ["Burhanuddin Baharuddin", "https://github.com/burhanloey"] +lang: ms-my +--- + +Common Lisp ialah programming language yang general-purpose (boleh digunakan untuk semua benda) dan multi-paradigm (konsep yang pelbagai) sesuai untuk pelbagai kegunaan di dalam +industri aplikasi. Common Lisp biasa digelar sebagai programmable programming language (programming language yang boleh di-program-kan). + +Sumber bacaan yang klasik ialah [Practical Common Lisp](http://www.gigamonkeys.com/book/). Sumber bacaan yang lain dan +yang terbaru ialah [Land of Lisp](http://landoflisp.com/). Buku baru mengenai best practices (amalan terbaik), +[Common Lisp Recipes](http://weitz.de/cl-recipes/), baru sahaja diterbitkan. + + + +```common-lisp + +;;;----------------------------------------------------------------------------- +;;; 0. Syntax +;;;----------------------------------------------------------------------------- + +;;; General form (Bentuk umum) + +;;; Ada dua asas dalam syntax CL: ATOM dan S-EXPRESSION. +;;; Kebiasaannya, gabungan S-expression dipanggil sebagai `forms`. + +10 ; atom; bermaksud seperti yang ditulis iaitu nombor 10 +:thing ; juga atom; bermaksud simbol :thing +t ; juga atom, bermaksud true (ya/betul/benar) +(+ 1 2 3 4) ; s-expression +'(4 :foo t) ; juga s-expression + + +;;; Comment (Komen) + +;;; Comment satu baris bermula dengan semicolon; gunakan empat untuk comment +;;; mengenai file, tiga untuk seksyen penghuraian, dua untuk yang dalam definition, +;;; dan satu untuk satu baris. Sebagai contoh, + +;;;; life.lisp + +;;; Foo bar baz, disebabkan quu quux. Sangat optimum untuk krakaboom dan umph. +;;; Diperlukan oleh function LINULUKO. Ini merepek sahaja kebaboom. + +(defun meaning (life) + "Memulangkan hasil pengiraan makna KEHIDUPAN" + (let ((meh "abc")) + ;; Jalankan krakaboom + (loop :for x :across meh + :collect x))) ; Simpan hasil ke x, kemudian pulangkan + +;;; Komen berbentuk blok, sebaliknya, membenarkan komen untuk bentuk bebas. Komen +;;; tersebut berada di antara #| dan |# + +#| Ini adalah komen berbentuk blok di mana + tulisan boleh ditulis dalam beberapa baris dan + #| + juga boleh dalam bentuk nested (berlapis-lapis)! + |# +|# + + +;;; Environment (benda-benda yang diperlukan untuk program menggunakan Common Lisp) + +;;; Common Lisp ada banyak jenis; kebanyakannya mengikut standard. SBCL +;;; ialah titik permulaan yang baik. Quicklisp boleh digunakan untuk install +;;; library third party. + +;;; CL kebiasaannya digunakan dengan text editor dan Real Eval Print +;;; Loop (REPL) yang dilancarkan dengan serentak. REPL membolehkan kita menjelajah +;;; program secara interaktif semasa program tersebut sedang berjalan secara "live". + + +;;;----------------------------------------------------------------------------- +;;; 1. Datatype primitif dan operator +;;;----------------------------------------------------------------------------- + +;;; Simbol + +'foo ; => FOO Perhatikan simbol menjadi huruf besar secara automatik. + +;;; INTERN menjadikan string sebagai simbol secara manual. + +(intern "AAAA") ; => AAAA +(intern "aaa") ; => |aaa| + +;;; Nombor + +9999999999999999999999 ; integer +#b111 ; binary => 7 +#o111 ; octal => 73 +#x111 ; hexadecimal => 273 +3.14159s0 ; single +3.14159d0 ; double +1/2 ; ratio +#C(1 2) ; complex number + +;;; Function ditulis sebagai (f x y z ...) di mana f ialah function dan +;;; x, y, z, ... adalah argument. + +(+ 1 2) ; => 3 + +;;; Jika anda ingin membuat data sebagai data bukannya function, gunakan QUOTE +;;; untuk mengelakkan data tersebut daripada dikira oleh program + +(quote (+ 1 2)) ; => (+ 1 2) +(quote a) ; => A + +;;; Singkatan untuk QUOTE ialah ' (tanda petikan) + +'(+ 1 2) ; => (+ 1 2) +'a ; => A + +;;; Operasi arithmetic asas + +(+ 1 1) ; => 2 +(- 8 1) ; => 7 +(* 10 2) ; => 20 +(expt 2 3) ; => 8 +(mod 5 2) ; => 1 +(/ 35 5) ; => 7 +(/ 1 3) ; => 1/3 +(+ #C(1 2) #C(6 -4)) ; => #C(7 -2) + +;;; Boolean + +t ; true; semua nilai yang bukan NIL ialah true +nil ; false; termasuklah list yang kosong: () +(not nil) ; => T +(and 0 t) ; => T +(or 0 nil) ; => 0 + +;;; Character + +#\A ; => #\A +#\λ ; => #\GREEK_SMALL_LETTER_LAMDA +#\u03BB ; => #\GREEK_SMALL_LETTER_LAMDA + +;;; String ialah array character yang tidak berubah panjang + +"Hello, world!" +"Benjamin \"Bugsy\" Siegel" ; backslash ialah escape character + +;;; String boleh digabungkan + +(concatenate 'string "Hello, " "world!") ; => "Hello, world!" + +;;; String boleh diperlakukan seperti urutan character + +(elt "Apple" 0) ; => #\A + +;;; FORMAT digunakan untuk output mengikut format, daripada penggubahan string +;;; yang simple sehinggalah loop dan conditional. Argument pertama untuk FORMAT +;;; menentukan ke mana string akan pergi. Jika NIL, FORMAT +;;; akan pulangkan string sebagai data string; jika T, FORMAT akan output +;;; ke standard output, biasanya di screen, kemudian pulangkan NIL. + +(format nil "~A, ~A!" "Hello" "world") ; => "Hello, world!" +(format t "~A, ~A!" "Hello" "world") ; => NIL + + +;;;----------------------------------------------------------------------------- +;;; 2. Variable +;;;----------------------------------------------------------------------------- + +;;; Anda boleh membuat variable global (dynamically scoped) menggunakan DEFVAR dan +;;; DEFPARAMETER. Nama variable boleh guna mana-mana character kecuali: ()",'`;#|\ + +;;; Beza antara DEFVAR dengan DEFPARAMETER ialah DEFVAR tidak akan ubah nilai +;;; variable jika dijalankan semula. Manakala DEFPARAMETER, akan mengubah nilai +;;; jika dijalankan semula. + +;;; Kebiasaannya, variable global diletakkan earmuff (asterisk) pada nama. + +(defparameter *some-var* 5) +*some-var* ; => 5 + +;;; Anda juga boleh menggunakan character unicode. +(defparameter *AΛB* nil) + +;;; Variable yang tidak wujud boleh diakses tetapi akan menyebabkan undefined +;;; behavior. Jangan buat. + +;;; Anda boleh membuat local binding menggunakan LET. Dalam snippet berikut, `me` +;;; terikat dengan "dance with you" hanya dalam (let ...). LET mesti akan pulangkan +;;; nilai `form` yang paling terakhir. + +(let ((me "dance with you")) me) ; => "dance with you" + + +;;;-----------------------------------------------------------------------------; +;;; 3. Struct dan collection +;;;-----------------------------------------------------------------------------; + + +;;; Struct + +(defstruct dog name breed age) +(defparameter *rover* + (make-dog :name "rover" + :breed "collie" + :age 5)) +*rover* ; => #S(DOG :NAME "rover" :BREED "collie" :AGE 5) +(dog-p *rover*) ; => T +(dog-name *rover*) ; => "rover" + +;;; DOG-P, MAKE-DOG, dan DOG-NAME semuanya dibuat oleh DEFSTRUCT secara automatik + + +;;; Pair + +;;; CONS membuat pair. CAR dan CDR pulangkan head (kepala) dan tail (ekor) CONS-pair. + +(cons 'SUBJECT 'VERB) ; => '(SUBJECT . VERB) +(car (cons 'SUBJECT 'VERB)) ; => SUBJECT +(cdr (cons 'SUBJECT 'VERB)) ; => VERB + + +;;; List + +;;; List ialah data structure linked-list, dihasilkan daripada pair CONS dan +;;; berakhir dengan NIL (atau '()) menandakan akhirnya list tersebut + +(cons 1 (cons 2 (cons 3 nil))) ; => '(1 2 3) + +;;; LIST ialah constructor untuk memudahkan penghasilan list + +(list 1 2 3) ; => '(1 2 3) + +;;; Apabila argument pertama untuk CONS ialah atom dan argument kedua ialah +;;; list, CONS akan pulangkan CONS-pair baru dengan argument pertama sebagai +;;; item pertama dan argument kedua sebagai CONS-pair yang lain + +(cons 4 '(1 2 3)) ; => '(4 1 2 3) + +;;; Gunakan APPEND untuk menggabungkan list + +(append '(1 2) '(3 4)) ; => '(1 2 3 4) + +;;; Atau CONCATENATE + +(concatenate 'list '(1 2) '(3 4)) ; => '(1 2 3 4) + +;;; List ialah type utama, jadi ada pelbagai function untuk mengendalikan +;;; list, contohnya: + +(mapcar #'1+ '(1 2 3)) ; => '(2 3 4) +(mapcar #'+ '(1 2 3) '(10 20 30)) ; => '(11 22 33) +(remove-if-not #'evenp '(1 2 3 4)) ; => '(2 4) +(every #'evenp '(1 2 3 4)) ; => NIL +(some #'oddp '(1 2 3 4)) ; => T +(butlast '(subject verb object)) ; => (SUBJECT VERB) + + +;;; Vector + +;;; Vector ialah array yang tidak berubah panjang + +#(1 2 3) ; => #(1 2 3) + +;;; Gunakan CONCATENATE untuk menggabungkan vector + +(concatenate 'vector #(1 2 3) #(4 5 6)) ; => #(1 2 3 4 5 6) + + +;;; Array + +;;; Vector dan string adalah sejenis array. + +;;; 2D array + +(make-array (list 2 2)) ; => #2A((0 0) (0 0)) +(make-array '(2 2)) ; => #2A((0 0) (0 0)) +(make-array (list 2 2 2)) ; => #3A(((0 0) (0 0)) ((0 0) (0 0))) + +;;; Perhatian: nilai awal MAKE-ARRAY adalah bergantung kepada jenis Common Lisp. +;;; Untuk meletakkan nilai awal secara manual: + +(make-array '(2) :initial-element 'unset) ; => #(UNSET UNSET) + +;;; Untuk mengakses element di kedudukan 1, 1, 1: + +(aref (make-array (list 2 2 2)) 1 1 1) ; => 0 + + +;;; Adjustable vector (vector yang boleh berubah) + +;;; Adjustable vector mempunyai rupa yang sama dengan +;;; vector yang tidak berubah panjang. + +(defparameter *adjvec* (make-array '(3) :initial-contents '(1 2 3) + :adjustable t :fill-pointer t)) +*adjvec* ; => #(1 2 3) + +;;; Tambah element baru + +(vector-push-extend 4 *adjvec*) ; => 3 +*adjvec* ; => #(1 2 3 4) + + +;;; Set hanyalah list: + +(set-difference '(1 2 3 4) '(4 5 6 7)) ; => (3 2 1) +(intersection '(1 2 3 4) '(4 5 6 7)) ; => 4 +(union '(1 2 3 4) '(4 5 6 7)) ; => (3 2 1 4 5 6 7) +(adjoin 4 '(1 2 3 4)) ; => (1 2 3 4) + +;;; Tetapi, anda perlukan data structure yang lebih baik untuk digunakan dengan +;;; data set yang sangat banyak + +;;; Kamus dibuat menggunakan hash table. + +;;; Bina hash table + +(defparameter *m* (make-hash-table)) + +;;; Tetapkan nilai + +(setf (gethash 'a *m*) 1) + +;;; Baca nilai + +(gethash 'a *m*) ; => 1, T + +;;; CL boleh memulangkan beberapa nilai (multiple value). + +(values 1 2) ; => 1, 2 + +;;; dan boleh digunakan dengan MULTIPLE-VALUE-BIND untuk bind setiap nilai + +(multiple-value-bind (x y) + (values 1 2) + (list y x)) + +; => '(2 1) + +;;; GETHASH antara contoh function yang memulangkan multiple value. Value +;;; pertama ialah nilai untuk key dalam hash table; jika key tidak +;;; jumpa GETHASH akan pulangkan NIL. + +;;; Value kedua menentukan sama ada key tersebut betul-betul wujud dalam hash +;;; table. Jika key tidak jumpa dalam table value tersebut ialah NIL. Cara ini +;;; membolehkan kita untuk periksa sama ada value untuk key ialah NIL. + +;;; Dapatkan value yang tidak wujud akan pulangkan nil + +(gethash 'd *m*) ;=> NIL, NIL + +;;; Anda boleh menentukan value default untuk key yang tidak wujud + +(gethash 'd *m* :not-found) ; => :NOT-FOUND + +;;; Jom lihat penggunaan multiple return value di dalam code. + +(multiple-value-bind (a b) + (gethash 'd *m*) + (list a b)) +; => (NIL NIL) + +(multiple-value-bind (a b) + (gethash 'a *m*) + (list a b)) +; => (1 T) + + +;;;----------------------------------------------------------------------------- +;;; 3. Function +;;;----------------------------------------------------------------------------- + +;;; Gunakan LAMBDA untuk membuat anonymous function. Function sentiasa memulangkan +;;; value untuk expression terakhir. + +(lambda () "Hello World") ; => #<FUNCTION (LAMBDA ()) {1004E7818B}> + +;;; Gunakan FUNCALL untuk memanggil anonymous function + +(funcall (lambda () "Hello World")) ; => "Hello World" +(funcall #'+ 1 2 3) ; => 6 + +;;; Panggilan kepada FUNCALL juga boleh terjadi apabila lambda tersebut ialah CAR +;;; (yang pertama) untuk list (yang tidak mempunyai tanda petikan) + +((lambda () "Hello World")) ; => "Hello World" +((lambda (val) val) "Hello World") ; => "Hello World" + +;;; FUNCALL digunakan apabila argument sudah diketahui. Jika tidak, gunakan APPLY + +(apply #'+ '(1 2 3)) ; => 6 +(apply (lambda () "Hello World") nil) ; => "Hello World" + +;;; Untuk menamakan sebuah function, guna DEFUN + +(defun hello-world () "Hello World") +(hello-world) ; => "Hello World" + +;;; Simbol () di atas bermaksud list kepada argument + +(defun hello (name) (format nil "Hello, ~A" name)) +(hello "Steve") ; => "Hello, Steve" + +;;; Function boleh ada argument optional (tidak wajib); argument tersebut bernilai +;;; NIL secara default + +(defun hello (name &optional from) + (if from + (format t "Hello, ~A, from ~A" name from) + (format t "Hello, ~A" name))) + +(hello "Jim" "Alpacas") ; => Hello, Jim, from Alpacas + +;;; Nilai default boleh ditetapkan untuk argument tersebut + +(defun hello (name &optional (from "The world")) + (format nil "Hello, ~A, from ~A" name from)) + +(hello "Steve") ; => Hello, Steve, from The world +(hello "Steve" "the alpacas") ; => Hello, Steve, from the alpacas + +;;; Function juga mempunyai keyword argument untuk membolehkan argument diletakkan +;;; tidak mengikut kedudukan + +(defun generalized-greeter (name &key (from "the world") (honorific "Mx")) + (format t "Hello, ~A ~A, from ~A" honorific name from)) + +(generalized-greeter "Jim") +; => Hello, Mx Jim, from the world + +(generalized-greeter "Jim" :from "the alpacas you met last summer" :honorific "Mr") +; => Hello, Mr Jim, from the alpacas you met last summer + + +;;;----------------------------------------------------------------------------- +;;; 4. Kesamaan +;;;----------------------------------------------------------------------------- + +;;; CL mempunyai sistem kesaksamaan yang canggih. Antaranya adalah seperti berikut. + +;;; Untuk nombor, guna `=' +(= 3 3.0) ; => T +(= 2 1) ; => NIL + +;;; Untuk identiti object (lebih kurang) guna EQL +(eql 3 3) ; => T +(eql 3 3.0) ; => NIL +(eql (list 3) (list 3)) ; => NIL + +;;; untuk list, string, dan bit-vector, guna EQUAL +(equal (list 'a 'b) (list 'a 'b)) ; => T +(equal (list 'a 'b) (list 'b 'a)) ; => NIL + + +;;;----------------------------------------------------------------------------- +;;; 5. Control Flow +;;;----------------------------------------------------------------------------- + +;;; Conditional (syarat) + +(if t ; test expression + "this is true" ; then expression + "this is false") ; else expression +; => "this is true" + +;;; Dalam conditional, semua value yang bukan NIL ialah true + +(member 'Groucho '(Harpo Groucho Zeppo)) ; => '(GROUCHO ZEPPO) +(if (member 'Groucho '(Harpo Groucho Zeppo)) + 'yep + 'nope) +; => 'YEP + +;;; Guna COND untuk meletakkan beberapa test +(cond ((> 2 2) (error "wrong!")) + ((< 2 2) (error "wrong again!")) + (t 'ok)) ; => 'OK + +;;; TYPECASE adalah seperti switch tetapi untuk data type value tersebut +(typecase 1 + (string :string) + (integer :int)) +; => :int + + +;;; Loop + +;;; Recursion + +(defun fact (n) + (if (< n 2) + 1 + (* n (fact(- n 1))))) + +(fact 5) ; => 120 + +;;; Iteration + +(defun fact (n) + (loop :for result = 1 :then (* result i) + :for i :from 2 :to n + :finally (return result))) + +(fact 5) ; => 120 + +(loop :for x :across "abc" :collect x) +; => (#\a #\b #\c #\d) + +(dolist (i '(1 2 3 4)) + (format t "~A" i)) +; => 1234 + + +;;;----------------------------------------------------------------------------- +;;; 6. Mutation +;;;----------------------------------------------------------------------------- + +;;; Guna SETF untuk meletakkan nilai baru untuk variable yang sedia ada. Ini sama +;;; seperti contoh hash table di atas. + +(let ((variable 10)) + (setf variable 2)) +; => 2 + +;;; Sebaik-baiknya kurangkan penggunaan destructive function dan elakkan +;;; mutation jika boleh. + + +;;;----------------------------------------------------------------------------- +;;; 7. Class dan object +;;;----------------------------------------------------------------------------- + +;;; Takde dah class untuk haiwan. Jom buat Human-Powered Mechanical +;;; Conveyances (Kenderaan Mekanikal Berkuasa Manusia). + +(defclass human-powered-conveyance () + ((velocity + :accessor velocity + :initarg :velocity) + (average-efficiency + :accessor average-efficiency + :initarg :average-efficiency)) + (:documentation "A human powered conveyance")) + +;;; Argument untuk DEFCLASS, mengikut susunan ialah: +;;; 1. nama class +;;; 2. list untuk superclass +;;; 3. list untuk slot +;;; 4. specifier optional (tidak wajib) + +;;; Apabile list untuk superclass tidak ditetapkan, list yang kosong bermaksud +;;; class standard-object. Ini *boleh* ditukar, kalau anda tahu apa yang anda buat. +;;; Baca Art of the Metaobject Protocol untuk maklumat lebih lanjut. + +(defclass bicycle (human-powered-conveyance) + ((wheel-size + :accessor wheel-size + :initarg :wheel-size + :documentation "Diameter of the wheel.") + (height + :accessor height + :initarg :height))) + +(defclass recumbent (bicycle) + ((chain-type + :accessor chain-type + :initarg :chain-type))) + +(defclass unicycle (human-powered-conveyance) nil) + +(defclass canoe (human-powered-conveyance) + ((number-of-rowers + :accessor number-of-rowers + :initarg :number-of-rowers))) + +;;; Panggilan DESCRIBE kepada class HUMAN-POWERED-CONVEYANCE di REPL akan memberi: + +(describe 'human-powered-conveyance) + +; COMMON-LISP-USER::HUMAN-POWERED-CONVEYANCE +; [symbol] +; +; HUMAN-POWERED-CONVEYANCE names the standard-class #<STANDARD-CLASS +; HUMAN-POWERED-CONVEYANCE>: +; Documentation: +; A human powered conveyance +; Direct superclasses: STANDARD-OBJECT +; Direct subclasses: UNICYCLE, BICYCLE, CANOE +; Not yet finalized. +; Direct slots: +; VELOCITY +; Readers: VELOCITY +; Writers: (SETF VELOCITY) +; AVERAGE-EFFICIENCY +; Readers: AVERAGE-EFFICIENCY +; Writers: (SETF AVERAGE-EFFICIENCY) + +;;; Perhatikan apa yang berlaku. CL memang direka sebagai sistem interaktif. + +;;; Untuk membuat method, jom kira berapa panjang lilitan untuk +;;; roda basikal menggunakan formula: C = d * pi + +(defmethod circumference ((object bicycle)) + (* pi (wheel-size object))) + +;;; Nilai PI memang sudah ada dalam CL + +;;; Katakanlah kita ingin ambil tahu efficiency value (nilai keberkesanan) +;;; rower (pendayung) di dalam canoe (perahu) adalah berbentuk logarithmic. Ini +;;; boleh ditetapkan di dalam constructor/initializer. + +;;; Untuk initialize instance selepas CL sudah siap construct: + +(defmethod initialize-instance :after ((object canoe) &rest args) + (setf (average-efficiency object) (log (1+ (number-of-rowers object))))) + +;;; Kemudian untuk construct sesebuah instance dan periksa purata efficiency... + +(average-efficiency (make-instance 'canoe :number-of-rowers 15)) +; => 2.7725887 + + +;;;----------------------------------------------------------------------------- +;;; 8. Macro +;;;----------------------------------------------------------------------------- + +;;; Macro membolehkan anda untuk menambah syntax language. CL tidak ada +;;; WHILE loop, tetapi, kita boleh mencipta syntax ter. Jika kita buat menggunakan +;;; naluri, kita akan dapat: + +(defmacro while (condition &body body) + "While `condition` is true, `body` is executed. +`condition` is tested prior to each execution of `body`" + (let ((block-name (gensym)) (done (gensym))) + `(tagbody + ,block-name + (unless ,condition + (go ,done)) + (progn + ,@body) + (go ,block-name) + ,done))) + +;;; Jom lihat versi yang lebih high-level: + +(defmacro while (condition &body body) + "While `condition` is true, `body` is executed. +`condition` is tested prior to each execution of `body`" + `(loop while ,condition + do + (progn + ,@body))) + +;;; Namun, dengan compiler yang modern, cara ini tidak diperlukan; form LOOP +;;; compile sama sahaja dan juga mudah dibaca. + +;;; Perhatikan ``` digunakan, sama juga `,` dan `@`. ``` ialah operator jenis quote +;;; yang dipanggil quasiquote; operator tersebut membolehkan penggunaan `,` . +;;; `,` membolehkan variable "di-unquote-kan". @ mengembangkan list. + +;;; GENSYM membuat simbol unik yang pasti tidak wujud di tempat-tempat yang +;;; lain. Ini kerana macro dikembangkan semasa compile dan +;;; nama variable di dalam macro boleh bertembung dengan nama variable yang +;;; digunakan dalam code yang biasa. + +;;; Baca Practical Common Lisp dan On Lisp untuk maklumat lebih lanjut mengenai macro. +``` + + +## Bacaan lanjut + +- [Practical Common Lisp](http://www.gigamonkeys.com/book/) +- [Common Lisp: A Gentle Introduction to Symbolic Computation](https://www.cs.cmu.edu/~dst/LispBook/book.pdf) + + +## Maklumat tambahan + +- [CLiki](http://www.cliki.net/) +- [common-lisp.net](https://common-lisp.net/) +- [Awesome Common Lisp](https://github.com/CodyReichert/awesome-cl) +- [Lisp Lang](http://lisp-lang.org/) + + +## Kredit + +Terima kasih banyak diucapkan kepada ahli Scheme yang membuat permulaan yang sangat +bagus dan mudah untuk diguna pakai untuk Common Lisp. + +- [Paul Khuong](https://github.com/pkhuong) untuk review yang bagus. diff --git a/ms-my/elisp-my.html.markdown b/ms-my/elisp-my.html.markdown new file mode 100644 index 00000000..73dff0f4 --- /dev/null +++ b/ms-my/elisp-my.html.markdown @@ -0,0 +1,347 @@ +--- +language: elisp +contributors: + - ["Bastien Guerry", "https://bzg.fr"] + - ["Saurabh Sandav", "http://github.com/SaurabhSandav"] +translators: + - ["Burhanuddin Baharuddin", "https://github.com/burhanloey"] +lang: ms-my +filename: learn-emacs-lisp-ms.el +--- + +```scheme +;; Ini adalah pengenalan kepada Emacs Lisp dalam masa 15 minit (v0.2d) +;; +;; Mula-mula pastikan anda sudah membaca artikel daripada Peter Norvig ini: +;; http://norvig.com/21-days.html +;; +;; Kemudian install GNU Emacs 24.3: +;; +;; Debian: apt-get install emacs (atau lihat arahan untuk distro anda) +;; OSX: http://emacsformacosx.com/emacs-builds/Emacs-24.3-universal-10.6.8.dmg +;; Windows: http://ftp.gnu.org/gnu/windows/emacs/emacs-24.3-bin-i386.zip +;; +;; Maklumat lanjut boleh didapati di: +;; http://www.gnu.org/software/emacs/#Obtaining + +;; Amaran penting: +;; +;; Tutorial ini tidak akan merosakkan komputer anda melainkan jika anda berasa +;; terlalu marah sehingga anda menghempap komputer anda ke lantai. Kalau begitu, +;; saya dengan ini tidak akan bertanggungjawab terhadap apa-apa. Berseronoklah ya! + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; +;; Buka Emacs. +;; +;; Tekan `q' untuk tutup mesej selamat datang. +;; +;; Sekarang lihat garis kelabu di bahagian bawah window: +;; +;; "*scratch*" ialah nama ruangan untuk anda edit. +;; Ruangan ini disebut sebagai "buffer". +;; +;; Buffer scratch ialah buffer yang default setiap kali Emacs dibuka. +;; Anda bukannya edit file: anda edit buffer yang kemudiannya +;; boleh save ke file. +;; +;; "Lisp interaction (interaksi)" merujuk kepada command yang wujud di sini. +;; +;; Emacs mempunyai beberapa command yang sedia ada dalam setiap buffer, +;; dan sesetengah command yang lain boleh didapati jika sesetengah mode +;; diaktifkan. Di sini kita menggunakan `lisp-interaction-mode', yang +;; mempunyai command untuk menjalankan dan mengendalikan code Elisp. + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; +;; Semicolon akan menjadikan comment sepanjang baris tersebut. +;; +;; Program Elisp mengandungi symbolic expressions ("sexps"): +(+ 2 2) + +;; Symbolic expression di atas dibaca begini "Tambah 2 pada 2". + +;; Sexps dilitupi oleh parentheses, dan boleh dalam bentuk nested (parentheses +;; dalam parentheses): +(+ 2 (+ 1 1)) + +;; Symbolic expression mengandungi atom atau symbolic expression +;; yang lain. Untuk contoh di atas, 1 dan 2 ialah atom, +;; (+ 2 (+ 1 1)) dan (+ 1 1) ialah symbolic expression. + +;; Dengan menggunakan `lisp-interaction-mode', anda boleh evaluate +;; (mendapatkan hasil pengiraan) sexps. Letak cursor selepas parenthesis penutup +;; kemudian tekan control dan j ("C-j"). + +(+ 3 (+ 1 2)) +;; ^ cursor di sini +;; `C-j' => 6 + +;; `C-j' memasukkan jawapan pengiraan ke dalam buffer. + +;; `C-xC-e' memaparkan jawapan yang sama di bahagian bawah Emacs, +;; yang dipanggil "minibuffer". Secara umumnya kita akan menggunakan `C-xC-e', +;; sebab kita tidak mahu memenuhi buffer dengan teks yang tidak penting. + +;; `setq' menyimpan value ke dalam variable: +(setq my-name "Bastien") +;; `C-xC-e' => "Bastien" (terpapar di mini-buffer) + +;; `insert' akan memasukkan "Hello!" di tempat di mana cursor berada: +(insert "Hello!") +;; `C-xC-e' => "Hello!" + +;; Di atas, kita menggunakan `insert' dengan satu argument "Hello!", tetapi +;; kita boleh meletakkan beberapa argument -- di sini kita letak dua: + +(insert "Hello" " world!") +;; `C-xC-e' => "Hello world!" + +;; Anda boleh menggunakan variable selain string: +(insert "Hello, I am " my-name) +;; `C-xC-e' => "Hello, I am Bastien" + +;; Anda boleh menggabungkan sexps untuk membuat function: +(defun hello () (insert "Hello, I am " my-name)) +;; `C-xC-e' => hello + +;; Anda boleh evaluate function: +(hello) +;; `C-xC-e' => Hello, I am Bastien + +;; Parentheses kosong di dalam function bermaksud function tersebut tidak +;; terima argument. Sekarang kita tukar function untuk menerima satu argument. +;; Di sini, argument tersebut dinamakan "name": + +(defun hello (name) (insert "Hello " name)) +;; `C-xC-e' => hello + +;; Sekarang panggil function tersebut dengan string "you" sebagai value +;; untuk argument: +(hello "you") +;; `C-xC-e' => "Hello you" + +;; Yay! + +;; Tarik nafas. + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; +;; Sekarang tukar ke buffer baru dengan nama "*test*" di window yang lain: + +(switch-to-buffer-other-window "*test*") +;; `C-xC-e' +;; => [The screen has two windows and cursor is in the *test* buffer] + +;; Gerakkan mouse ke window atas dan klik kiri untuk pergi balik ke buffer scratch. +;; Cara lain adalah dengan menggunakan `C-xo' (i.e. tekan control-x kemudian +;; tekan o) untuk pergi ke window yang lain. + +;; Anda boleh menggabungkan beberapa sexps menggunakan `progn': +(progn + (switch-to-buffer-other-window "*test*") + (hello "you")) +;; `C-xC-e' +;; => [The screen has two windows and cursor is in the *test* buffer] + +;; Mulai dari sekarang saya tidak akan beritahu anda untuk tekan `C-xC-e' lagi: +;; buat untuk setiap sexp yang akan datang. + +;; Pergi balik ke buffer *scratch* menggunakan mouse atau `C-xo'. + +;; Seelok-eloknya padam buffer tersebut: +(progn + (switch-to-buffer-other-window "*test*") + (erase-buffer) + (hello "there")) + +;; Atau pergi balik ke window lain: +(progn + (switch-to-buffer-other-window "*test*") + (erase-buffer) + (hello "you") + (other-window 1)) + +;; Anda boleh menetapkan value dengan local variable menggunakan `let': +(let ((local-name "you")) + (switch-to-buffer-other-window "*test*") + (erase-buffer) + (hello local-name) + (other-window 1)) + +;; Tidak perlu menggunakan `progn', sebab `let' juga menggabungkan +;; beberapa sexps. + +;; Jom format string: +(format "Hello %s!\n" "visitor") + +;; %s ialah tempat untuk meletakkan string, digantikan dengan "visitor". +;; \n ialah character untuk membuat baris baru. + +;; Jom tukar function kita menggunakan format: +(defun hello (name) + (insert (format "Hello %s!\n" name))) + +(hello "you") + +;; Jom buat function lain menggunakan `let': +(defun greeting (name) + (let ((your-name "Bastien")) + (insert (format "Hello %s!\n\nI am %s." + name ; argument untuk function + your-name ; variable "Bastien" daripada let + )))) + +;; Kemudian evaluate: +(greeting "you") + +;; Sesetengah function adalah interaktif: +(read-from-minibuffer "Enter your name: ") + +;; Function tersebut akan memulangkan kembali apa yang anda masukkan ke prompt. + +;; Jom jadikan function `greeting' untuk prompt nama anda: +(defun greeting (from-name) + (let ((your-name (read-from-minibuffer "Enter your name: "))) + (insert (format "Hello!\n\nI am %s and you are %s." + from-name ; argument untuk function + your-name ; variable daripada let, yang dimasukkan dari prompt + )))) + +(greeting "Bastien") + +;; Jom siapkan function dengan memaparkan result di window yang lain: +(defun greeting (from-name) + (let ((your-name (read-from-minibuffer "Enter your name: "))) + (switch-to-buffer-other-window "*test*") + (erase-buffer) + (insert (format "Hello %s!\n\nI am %s." your-name from-name)) + (other-window 1))) + +;; Test function tersebut: +(greeting "Bastien") + +;; Tarik nafas. + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; +;; Jom simpan senarai nama: +;; Jika anda ingin membuat list(senarai) data, guna ' untuk elak +;; daripada list tersebut evaluate. +(setq list-of-names '("Sarah" "Chloe" "Mathilde")) + +;; Dapatkan elemen pertama daripada list menggunakan `car': +(car list-of-names) + +;; Dapatkan semua elemen kecuali yang pertama menggunakan `cdr': +(cdr list-of-names) + +;; Tambah elemen di awal list menggunakan `push': +(push "Stephanie" list-of-names) + +;; NOTA: `car' dan `cdr' tidak ubah suai list, tetapi `push' ya. +;; Perbezaan ini penting: sesetengah function tiada side-effects (kesan sampingan) +;; (seperti `car') dan yang lain ada side-effect (seperti `push'). + +;; Jom panggil `hello' untuk setiap elemen dalam `list-of-names': +(mapcar 'hello list-of-names) + +;; Tukar `greeting' supaya ucapkan hello kepada semua orang dalam `list-of-names': +(defun greeting () + (switch-to-buffer-other-window "*test*") + (erase-buffer) + (mapcar 'hello list-of-names) + (other-window 1)) + +(greeting) + +;; Ingat lagi function `hello' di atas? Function tersebut mengambil satu +;; argument, iaitu nama. `mapcar' memanggil `hello', kemudian menggunakan setiap +;; nama dalam `list-of-names' sebagai argument untuk function `hello'. + +;; Sekarang kita susun sedikit untuk apa yang terpapar di buffer: + +(defun replace-hello-by-bonjour () + (switch-to-buffer-other-window "*test*") + (goto-char (point-min)) + (while (search-forward "Hello") + (replace-match "Bonjour")) + (other-window 1)) + +;; (goto-char (point-min)) akan pergi ke permulaan buffer. +;; (search-forward "Hello") akan mencari string "Hello". +;; (while x y) evaluate sexp(s) y selagi x masih pulangkan sesuatu. +;; Jika x pulangkan `nil', kita akan keluar daripada while loop. + +(replace-hello-by-bonjour) + +;; Anda akan dapat melihat semua "Hello" dalam buffer *test* +;; ditukarkan dengan "Bonjour". + +;; Anda juga akan dapat error: "Search failed: Hello". +;; +;; Bagi mengelakkan error tersebut, anda perlu beritahu `search-forward' sama ada +;; perlu berhenti mencari pada suatu ketika, dan sama ada perlu diam jika +;; tidak jumpa apa yang dicari: + +;; (search-forward "Hello" nil 't) selesai masalah: + +;; Argument `nil' cakap: carian tidak mengikut kedudukan. +;; Argument `'t' cakap: diam saja jika tidak jumpa apa yang dicari. + +;; Kita guna sexp ini di function berikut, barulah tidak keluar error: + +(defun hello-to-bonjour () + (switch-to-buffer-other-window "*test*") + (erase-buffer) + ;; Ucap hello pada nama-nama dalam `list-of-names' + (mapcar 'hello list-of-names) + (goto-char (point-min)) + ;; Ganti "Hello" dengan "Bonjour" + (while (search-forward "Hello" nil 't) + (replace-match "Bonjour")) + (other-window 1)) + +(hello-to-bonjour) + +;; Jom jadikan nama-nama tersebut bold: + +(defun boldify-names () + (switch-to-buffer-other-window "*test*") + (goto-char (point-min)) + (while (re-search-forward "Bonjour \\(.+\\)!" nil 't) + (add-text-properties (match-beginning 1) + (match-end 1) + (list 'face 'bold))) + (other-window 1)) + +;; Function ini memperkenalkan `re-search-forward': anda mencari menggunakan +;; pattern iaitu "regular expression", bukannya mencari string "Bonjour". + +;; Regular expression tersebut ialah "Bonjour \\(.+\\)!" dan dibaca begini: +;; string "Bonjour ", dan +;; kumpulan | ini ialah \\( ... \\) +;; mana-mana character | ini ialah . +;; yang boleh berulang | ini ialah + +;; dan string "!". + +;; Dah sedia? Test function tersebut! + +(boldify-names) + +;; `add-text-properties' tambah... ciri-ciri teks, seperti face. + +;; OK, kita sudah selesai. Selamat ber-hacking! + +;; Jika anda ingin tahu lebih mengenai variable atau function: +;; +;; C-h v a-variable RET +;; C-h f a-function RET +;; +;; Jika anda ingin membaca manual Emacs Lisp menggunakan Emacs: +;; +;; C-h i m elisp RET +;; +;; Jika ingin membaca pengenalan kepada Emacs Lisp secara online: +;; https://www.gnu.org/software/emacs/manual/html_node/eintr/index.html +``` diff --git a/nim.html.markdown b/nim.html.markdown index 30dfa94f..1e17d8f0 100644 --- a/nim.html.markdown +++ b/nim.html.markdown @@ -15,15 +15,9 @@ Nim is efficient, expressive, and elegant. # Single-line comments start with a # #[ - Multi-line comments begin with a #[ - ... and end with ]# - -They don't care about indentation - - #[ - and they can be nested - ]# - + This is a multiline comment. + In Nim, multiline comments can be nested, beginning with #[ + ... and ending with ]# ]# discard """ diff --git a/nix.html.markdown b/nix.html.markdown index ba122a46..d078395a 100644 --- a/nix.html.markdown +++ b/nix.html.markdown @@ -3,6 +3,7 @@ language: nix filename: learn.nix contributors: - ["Chris Martin", "http://chris-martin.org/"] + - ["Rommel Martinez", "https://ebzzry.io"] --- Nix is a simple functional language developed for the @@ -356,5 +357,5 @@ with builtins; [ * [James Fisher - Nix by example - Part 1: The Nix expression language] (https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55) -* [Susan Potter - Nix Cookbook - Nix By Example] - (http://funops.co/nix-cookbook/nix-by-example/) +* [Rommel Martinez - A Gentle Introduction to the Nix Family] + (https://ebzzry.io/en/nix/#nix) diff --git a/nl-nl/bash-nl.html.markdown b/nl-nl/bash-nl.html.markdown index da47e2a9..af4a8cc8 100644 --- a/nl-nl/bash-nl.html.markdown +++ b/nl-nl/bash-nl.html.markdown @@ -17,8 +17,8 @@ lang: nl-nl filename: LearnBash-nl.sh --- -Bash is de naam van den unix shell, deze wordt gebruikt voor het GNU operating system en is de standaard shell op Linux en Mac OS X. -Bijna alle voorbeelden hier onder kunnen deel uitmaken van een shell script of kunnen uitgevoerd worden in de shell. +Bash is de naam van de unix shell, deze wordt gebruikt voor het GNU operating system en is de standaard shell op Linux en Mac OS X. +Bijna alle voorbeelden hieronder kunnen deel uitmaken van een shell script of kunnen uitgevoerd worden in de shell. [Lees er meer over hier.](http://www.gnu.org/software/bash/manual/bashref.html) @@ -28,23 +28,23 @@ Bijna alle voorbeelden hier onder kunnen deel uitmaken van een shell script of k # het script uitgevoerd moet worden: http://en.wikipedia.org/wiki/Shebang_(Unix) # Zoals je kan zien wordt # gebruikt om een commentaar lijn te starten. -# Simpel hello world voorbeeld: +# Een simpel hello world voorbeeld: echo Hello world! -# Elke command start op een nieuwe lijn, of achter een puntkomma (;): +# Elk commando start op een nieuwe lijn, of achter een puntkomma (;): echo 'Dit is de eerste lijn'; echo 'Dit is de tweede lijn' -# Een varialbe declareren gebeurt op volgende manier: +# Een variabele declareren gebeurt op volgende manier: Variabele="Een string" # Maar niet op deze manier: Variabele = "Een string" -# Bash ziet variable als een commando en zal een error geven omdat dit commando +# Bash ziet variabelen als een commando en zal een error geven omdat dit commando # niet bestaat. # Of op deze manier: Variabele= 'Een string' -# Bash zal 'Een string' zien als een commanda en een error geven omdat het niet +# Bash zal 'Een string' zien als een commando en een error geven omdat het niet # gevonden kan worden. # Variabelen gebruiken: @@ -83,7 +83,7 @@ echo "Wat is uw naam?" read Naam # Merk op dat we geen variabele gedeclareerd hebben echo Hallo, $Naam! -# We hebben ook if structuren +# We hebben ook logische if structuren # Gebruik 'man test' voor meer informatie over condities. if [ $Naam -ne $USER ] then diff --git a/nl-nl/dynamic-programming-nl.html.markdown b/nl-nl/dynamic-programming-nl.html.markdown new file mode 100644 index 00000000..5186a3bf --- /dev/null +++ b/nl-nl/dynamic-programming-nl.html.markdown @@ -0,0 +1,55 @@ +--- +category: Algorithms & Data Structures +name: Dynamic Programming +contributors: + - ["Akashdeep Goel", "http://github.com/akashdeepgoel"] +translators: + - ["Jasper Haasdijk", "https://github.com/jhaasdijk"] +lang: nl-nl +--- + +# Dynamisch Programmeren + +## Introductie + +Dynamisch programmeren is een krachtige techniek die, zoals we zullen zien, gebruikt kan worden om een bepaalde klasse van problemen op te lossen. Het idee is eenvoudig. Als je een oplossing hebt voor een probleem met een bepaalde input, sla dit resultaat dan op. Hiermee kan je voorkomen dat je in de toekomst nog een keer hetzelfde probleem moet gaan oplossen omdat je het resultaat vergeten bent. + +Onthoud altijd! +"Zij die het verleden niet kunnen herinneren, zijn gedoemd het te herhalen." + +## Verschillende aanpakken + +1. *Top-Down* : Oftewel, van boven naar beneden. Begin je oplossing met het afbreken van het probleem in kleine stukken. Kom je een stukje tegen dat je eerder al hebt opgelost, kijk dan enkel naar het opgeslagen antwoord. Kom je een stukje tegen dat je nog niet eerder hebt opgelost, los het op en sla het antwoord op. Deze manier is voor veel mensen de makkelijke manier om erover na te denken, erg intuitief. Deze methode wordt ook wel Memoization genoemd. + +2. *Bottom-Up* : Oftewel, van beneden naar boven. Analyseer het probleem en bekijk de volgorde waarin de sub-problemen opgelost kunnen worden. Begin met het oplossen van de triviale gevallen en maak zodoende de weg naar het gegeven probleem. In dit process is het gegarandeerd dat de sub-problemen eerder worden opgelost dan het gegeven probleem. Deze methode wordt ook wel Dynamisch Programmeren genoemd. + +## Voorbeeld van Dynamisch Programmeren + +Het langst stijgende sequentie probleem is het probleem waarbij je binnen een bepaalde reeks op zoek bent naar het langste aaneengesloten stijgende stuk. Gegeven een reeks `S = {a1 , a2 , a3, a4, ............., an-1, an }` zijn we op zoek naar het langst aaneengesloten stuk zodanig dat voor alle `j` en `i`, `j<i` in de reeks `aj<ai`. + +Ten eerste moeten we de waarde van de langste subreeksen(LSi) op elke index i vinden waar het laatste element van de reeks ai is. Daarna zal LSi het langste subreeks in de gegeven reeks zijn. Om te beginnen heeft LSi de waarde 1 omdat ai een element van de reeks(laatste element) is. Daarna zal voor alle `j` zodanig dat `j<i` en `aj<ai` de grootste LSj gevonden en toegevoegd worden aan LSi. Het algoritme duurt *O(n2)* tijd. + +Pseudo-code voor het vinden van de lengte van de langst stijgende subreeks: +De complexiteit van het algoritme kan worden vermindert door het gebruik van een betere data structuur dan een simpele lijst. Het opslaan van een voorgangers lijst en een variabele als `langste_reeks_dusver` en de index daarvan, kan ook een hoop tijd schelen. + +Een soortgelijk concept kan worden toegepast in het vinden van het langste pad in een gerichte acyclische graaf. + +```python +for i=0 to n-1 + LS[i]=1 + for j=0 to i-1 + if (a[i] > a[j] and LS[i]<LS[j]) + LS[i] = LS[j]+1 +for i=0 to n-1 + if (langste < LS[i]) +``` + +### Enkele beroemde DP problemen + +- Floyd Warshall Algorithm - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs---floyd-warshall-algorithm-with-c-program-source-code]() +- Integer Knapsack Problem - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---the-integer-knapsack-problem]() +- Longest Common Subsequence - Tutorial and C Program source code : [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---longest-common-subsequence]() + +## Online Bronnen + +* [codechef](https://www.codechef.com/wiki/tutorial-dynamic-programming) diff --git a/nl-nl/html-nl.html.markdown b/nl-nl/html-nl.html.markdown new file mode 100644 index 00000000..54c81ed6 --- /dev/null +++ b/nl-nl/html-nl.html.markdown @@ -0,0 +1,98 @@ +--- +language: html +filename: learnhtml-nl.html +contributors: + - ["Christophe THOMAS", "https://github.com/WinChris"] +translators: + - ["Robert Steed", "https://github.com/robochat"] + - ["Jeroen Deviaene", "https://github.com/jerodev"] +lang: nl-nl +--- + +HTML staat voor HyperText Markup Language. +Het is een taal die je toe staat pagina's te maken op het World Wide Web. +Het is een opmaak taal, dit staat de gebruiker toe om webpagina's te maken in code en zo aan te duiden hoe de pagina moet weergegeven worden. +Eigenlijk zijn html files zelfs simpele tekst bestanden. +Wat is deze opmaak? Het is een manier om de structuur en data op de pagina weer te geven met speciale html tags. +Deze tags dienen om de betekenis te geven aan de tekst die het bevat. +Zoals vele computer talen heeft html vele verschillende versies. Hier zullen we HTML5 bespreken. + +**Merk op:** Je kan de verschillende tags en elementen testen terwijl je door de tutorial gaat met een website zoals [codepen](http://codepen.io/pen/), zo kan je de effecten hier van live zien. +Dit artikel gaat vooral over de HTML syntax en enkele handige tips + + +```html +<!-- Commentaren worden toegevoegd zoals deze lijn --> + +<!-- #################### De Tags #################### --> + +<!-- Hier is een voorbeeld HTML bestand dat we zullen analyseren. --> + +<!doctype html> + <html> + <head> + <title>Mijn Website</title> + </head> + <body> + <h1>Hello, world!</h1> + <a href="http://codepen.io/anon/pen/xwjLbZ">Neem een kijkje op deze link</a> + <p>Dit is een paragraaf.</p> + <p>Dit is nog een paragraaf.</p> + <ul> + <li>Dit is een item in een niet genummerde lijst</li> + <li>Dit is nog zo een item</li> + <li>En dit is het laatste item van de lijst</li> + </ul> + </body> + </html> + +<!-- Een HTML bestand start altijd met een tag die aan de browser laat weten dat we HTML gebruiken --> +<!doctype html> + +<!-- Daarna openen we de root van het bestand met de <html> tag --> +<html> + +<!-- Deze tag moet ook gesloten worden op het einde van het bestand --> +</html> + +<!-- Niets mag nog na deze tag komen! --> + +<!-- Binnenin (tussen de html tags <html></html>) vinden we: --> + +<!-- Een header, gedefigneerd door <head> (Deze moet gesloten worden met </head>) --> +<!-- De header bevat beschrijvingen en externe data die niet zichtbaar is op de website; Dit is metadata --> + +<head> + <title>Mijn Website</title><!-- De <title> tag geeft de tekst aan die in de titelbar van de browser moet weergegeven worden. --> +</head> + +<!-- Achter de <head> sectie vinden we bijna altijd <body> --> +<!-- Tot op dit punt is nog niets verschenen in het browser venster. --> +<!-- In de body plaatsen we wat zichtbaar moet zijn in de browser --> + +<body> + <h1>Hello, world!</h1> <!-- De h1 tag maakt een titel. --> + <!-- Er zijn ook sub titels voor <h1> van belangrijk <h2> tot minder belangrijk <h6>. --> + <a href="http://codepen.io/anon/pen/xwjLbZ">Neem een kijkje op deze link</a> <!-- een hyperlink naar de aangegeven link waar op geklikt kan worden in de browser --> + <p>This is a paragraph.</p> <!-- De tag <p> laat ons tekst toevoegen. --> + <p>This is another paragraph.</p> + <ul> <!-- De tag <ul> maakt een lijst met puntjes. --> + <!-- Om een genummerde lijst te hebben gebruik je <ol>, hiermee worden de elementen <li> automatisch genummerd --> + <li>This is an item in a non-enumerated list (bullet list)</li> + <li>This is another item</li> + <li>And this is the last item on the list</li> + </ul> +</body> + +<!-- En dat is het! Zo gemakkelijk is het om een html bestand te maken. --> +``` + +## Gebruik + +HTML wordt altijd opgeslagen in bestanden die eindigen in `.html`. + +## Meer weten + +* [wikipedia](https://nl.wikipedia.org/wiki/HTML) +* [HTML tutorial](https://developer.mozilla.org/en-US/docs/Web/HTML) +* [W3School](http://www.w3schools.com/html/html_intro.asp) diff --git a/nl-nl/markdown-nl.html.markdown b/nl-nl/markdown-nl.html.markdown index 35cc67c5..b5b4681c 100644 --- a/nl-nl/markdown-nl.html.markdown +++ b/nl-nl/markdown-nl.html.markdown @@ -12,7 +12,7 @@ Markdown is gecreëerd door John Gruber in 2004. Het is bedoeld om met een gemak schrijven syntax te zijn die gemakkelijk omgevormd kan worden naar HTML (en op heden verschillende andere formaten) -```markdown +```md <!-- Markdown erft over van HTML, dus ieder HTML bestand is een geldig Markdown bestand. Dit betekend ook dat html elementen gebruikt kunnen worden in Markdown zoals het commentaar element. Echter, als je een html element maakt in een Markdown diff --git a/nl-nl/vim-nl.html.markdown b/nl-nl/vim-nl.html.markdown new file mode 100644 index 00000000..a69c031c --- /dev/null +++ b/nl-nl/vim-nl.html.markdown @@ -0,0 +1,272 @@ +--- +category: tool +tool: vim +contributors: + - ["RadhikaG", "https://github.com/RadhikaG"] +translators: + - ["Rick Haan", "https://github.com/RickHaan"] +filename: learnvim-nl.yaml +lang: nl-nl +--- + +# Vim in het Nederlands + +[Vim](http://www.vim.org) +(Vi IMproved) is een kopie van de populaire vi editor voor Unix. Het is +ontworpen voor snelheid, verhoogde productiviteit en is beschikbaar in de meeste +unix-gebaseerde systemen. Het heeft verscheidene toetscombinaties voor snelle +navigatie en aanpassingen in het doelbestand. + +## De Basis van het navigeren in Vim + +``` Vim + vim <bestandsnaam> # Open <bestandsnaam> in vim + :help <onderwerp> # Open ingebouwde documentatie over <onderwerp> als + deze bestaat + :q # Vim afsluiten + :w # Huidig bestand opslaan + :wq # Huidig bestand opslaan en vim afsluiten + ZZ # Huidig bestand opslaan en vim afsluiten + :x # Huidig bestand opslaan en vim afsluiten, verkorte versie + :q! # Afsluiten zonder opslaan + # ! *forceert* het normale afsluiten met :q + + u # Ongedaan maken + CTRL+R # Opnieuw doen + + h # Ga 1 karakter naar links + j # Ga 1 regel naar beneden + k # Ga 1 regel omhoog + l # Ga 1 karakter naar rechts + + Ctrl+B # Ga 1 volledig scherm terug + Ctrl+F # Ga 1 volledig scherm vooruit + Ctrl+D # Ga 1/2 scherm vooruit + Ctrl+U # Ga 1/2 scherm terug + + # Verplaatsen over de regel + + 0 # Verplaats naar het begin van de regel + $ # Verplaats naar het eind van de regel + ^ # Verplaats naar het eerste niet-lege karakter op de regel + + # Zoeken in de tekst + + /word # Markeert alle voorvallen van 'word' na de cursor + ?word # Markeert alle voorvallen van 'word' voor de cursor + n # Verplaatst de cursor naar het volgende voorval van + de zoekopdracht + N # Verplaatst de cursor naar het vorige voorval van + de zoekopdracht + + :%s/foo/bar/g # Verander 'foo' naar 'bar' op elke regel van het bestand + :s/foo/bar/g # Verander 'foo' naar 'bar' op de huidge regel in + het bestand + :%s/\n/\r/g # Vervang nieuwe regel karakters met nieuwe regel karakters + + # Spring naar karakters + + f<character> # Spring vooruit en land op <character> + t<character> # Spring vooruit en land net voor <character> + + # Bijvoorbeeld, + f< # Spring vooruit en land op < + t< # Spring vooruit en land net voor < + + # Verplaatsen per woord + + w # Ga 1 woord vooruit + b # Ga 1 woord achteruit + e # Ga naar het einde van het huidige woord + + # Andere karakters om mee te verplaatsen + + gg # Ga naar de bovenkant van het bestand + G # Ga naar de onderkant van het bestand + :NUM # Ga naar regel NUM (NUM is elk nummer) + H # Ga naar de bovenkant van het scherm + M # Ga naar het midden van het scherm + L # Ga naar de onderkant van het scherm +``` + +## Help documentatie + +Vim heeft ingebouwde help documentatie dat benaderd kan worden met +`:help <onderwerp>`. Bijvoorbeeld `:help navigation` geeft documentatie weer hoe +door vim te navigeren. `:help` kan ook gebruikt worden zonder onderwerp. Dan wordt de standaard documentatie weergeven die bedoelt is om vim toegankelijker te maken. + +## Modus + +Vim is gebaseerd op het concept van **modus**. + +* Command (opdracht) modus - Vim wordt opgestart in deze mode. Deze mode wordt +gebruikt om opdrachten te geven en te navigeren +* Insert (invoer) modus - Wordt gebruikt voor het aanpassen van het bestand +* Zichtbare (Visual) modus - Wordt gebruikt voor het markeren en bewerken van +tekst +* Ex modus - Wordt gebruikt voor het uitvoeren van opdrachten met `:` + +``` Vim + i # Zet vim in de Command modus voor de cursor positie + a # Zet vim in de Insert modus na de cursor positie (append) + v # Zet vim in de Visual modus + : # Zet vim in de ex modus + <esc> # 'Escapes' vanuit elke modus naar de Command modus + + # Het kopiëren en plakken van tekst + + y # Yank (kopieer) wat geselecteerd is + yy # Yank (kopieer) de huidige regel + d # Verwijder wat geselecteerd is + dd # Verwijder de huidige regel + p # Plak de huidige tekst op de cursor positie + P # Plak de huidige tekst voor de cursor positie + x # Verwijder karakter op cursor positie +``` + +## De 'gramatica' van vim + +Vim kan aangeleerd worden als een set van acties in het 'Verb-Modifier-Noun' +formaat waar: + +Verb (werkwoord) - De uit te voeren actie +Modifier (bijwoord) - Hoe de actie uitgevoerd dient te worden +Noun - Het object waarop de actie uitgevoerd wordt + +Een paar belangrijke voorbeelden van 'Verbs', 'Modifiers', en 'Nouns' zijn: + +``` Vim + # 'Verbs' + + d # Verwijder + c # Verander + y # Kopieer + v # Zichtbaar selecteren + + # 'Modifiers' + + i # Binnen + a # Rondom + NUM # Elk nummer + f # Zoekt iets en selecteerd het + t # Zoekt iets en selecteerd het karakter voor het + / # Vindt een combinatie van tekens vanaf de cursor + ? # Vindt een combinatie van tekens voor de cursor + + # 'Nouns' + + w # Woord + s # Zin + p # Paragraaf + b # Blok + + # Voorbeeld 'zinnen' of opdrachten + + d2w # Verwijder twee woorden + cis # Verander in de zin + yip # Kopiereer in de paragraaf + ct< # Verander naar haakje openen + # Verander de tekst vanaf de huidige positie tot het volgende haakje + openen + d$ # Verwijder tot het einde van de regel +``` + +## Een aantal afkortingen en trucs + +``` Vim + > # Verspring de selectie met 1 blok + < # Verspring de selectie met 1 blok terug + :earlier 15 # Zet het document terug naar de situatie van 15 minuten + geleden + :later 15 # Zet het document in de situatie 15 minuten in de toekomst + (omgekeerde van de vorige opdracht) + ddp # Wissel de positie van opeenvolgende regels. dd daarna p + . # Herhaal de vorige opdracht + :w !sudo tee% # Sla het huidige bestand op als root + :set syntax=c # Stel syntax uitlichten in op 'c' + :sort # Sorteer alle regels + :sort! # Sorteer alle regels omgekeerd + :sort u # Sorteer alle regels en verwijder duplicaten + ~ # Stel letter case in voor geselecteerde tekst + u # Verander de geselecteerde tekst naar kleine letters + U # Verander de geselecteerde tekst naar hoofdletters + + # Fold text + zf # Creeer een vouw op de geslecteerde tekst + zo # Open huidige vouw + zc # Sluit huidige vouw + zR # Open alle vouwen + zM # Sluit alle vouwen +``` + +## Macro's + +Macro's zijn opgeslagen opdrachten. Wanneer je begint met het opnemen van een +macro dan worden **alle** acties opgenomen, totdat je stopt met opnemen. Als de +macro uitgevoerd wordt, worden alle acties in de zelfde volgorde als tijdens het +opnemen uitgevoerd. + +``` Vim + qa # Start met het opnemen van de makro genaamd 'a' + q # Stop met opnemen + @a # Gebruik macro 'a' +``` + +## Configureren van .vimrc + +Het .vimrc bestand kan gebruikt worden voor het opslaan van een +standaardconfiguratie van Vim. Het bestand wordt opgeslagen in de home map van de gebruiker. Hieronder staat een voorbeeld van een .vimrc bestand. + +``` Vim +" Voorbeeld ~/.vimrc +" 2015.10 + +" In te stellen dat Vim niet samenwerkt met Vi +set nocompatible + +" Stel in dat Vim kijkt naar de bestandstype voor syntax uitlichting en +automatish inspringen +filetype indent plugin on + +" Zet inspringen aan +syntax on + +" Betere opdracht regel aanvulling +set wildmenu + +" Gebruik niet hoofdlettergevoelig zoeken. +set ignorecase +set smartcase + +" Gebruik automatisch inspringen +set autoindent + +" Geef regelnummers weer +set number + +" Het aantal zichtbare spatie's per TAB +set tabstop=4 + +" Het aantal spatie's tijdens het aanpassen +set softtabstop=4 + +" Aantal spatie's wanneer (>> en <<) worden gebruikt + +" Maak van TAB's spatie's +set expandtab + +" Gebruik slimme tabs spatie's voor inspringen en uitlijnen +set smarttab +``` + +## Referenties (Engels) + +[Vim | Home](http://www.vim.org/index.php) + +`$ vimtutor` + +[A vim Tutorial and Primer](https://danielmiessler.com/study/vim/) + +[What are the dark corners of Vim your mom never told you about? (Stack Overflow thread)](http://stackoverflow.com/questions/726894/what-are-the-dark-corners-of-vim-your-mom-never-told-you-about) + +[Arch Linux Wiki](https://wiki.archlinux.org/index.php/Vim)
\ No newline at end of file diff --git a/objective-c.html.markdown b/objective-c.html.markdown index 04c4e529..de3884af 100644 --- a/objective-c.html.markdown +++ b/objective-c.html.markdown @@ -731,7 +731,10 @@ if ([myClass conformsToProtocol:@protocol(CarUtilities)]) { /////////////////////////////////////// // Blocks are statements of code, just like a function, that are able to be used as data. // Below is a simple block with an integer argument that returns the argument plus 4. -int (^addUp)(int n); // Declare a variable to store the block. +^(int n) { + return n + 4; +} +int (^addUp)(int n); // Declare a variable to store a block. void (^noParameterBlockVar)(void); // Example variable declaration of block with no arguments. // Blocks have access to variables in the same scope. But the variables are readonly and the // value passed to the block is the value of the variable when the block is created. diff --git a/ocaml.html.markdown b/ocaml.html.markdown index c087216c..74eb7993 100644 --- a/ocaml.html.markdown +++ b/ocaml.html.markdown @@ -375,4 +375,3 @@ sum_int_list t ;; * Visit the official website to get the compiler and read the docs: <http://ocaml.org/> * Try interactive tutorials and a web-based interpreter by OCaml Pro: <http://try.ocamlpro.com/> -* Read "OCaml for the skeptical" course: <http://www2.lib.uchicago.edu/keith/ocaml-class/home.html> diff --git a/opencv.html.markdown b/opencv.html.markdown new file mode 100644 index 00000000..f8763b35 --- /dev/null +++ b/opencv.html.markdown @@ -0,0 +1,144 @@ +--- +category: tool +tool: OpenCV +filename: learnopencv.py +contributors: + - ["Yogesh Ojha", "http://github.com/yogeshojha"] +--- +### Opencv + +OpenCV (Open Source Computer Vision) is a library of programming functions mainly aimed at real-time computer vision. +Originally developed by Intel, it was later supported by Willow Garage then Itseez (which was later acquired by Intel). +Opencv currently supports wide variety of languages like, C++, Python, Java etc + +#### Installation +Please refer to these articles for installation of OpenCV on your computer. + +* Windows Installation Instructions: [https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_setup/py_setup_in_windows/py_setup_in_windows.html#install-opencv-python-in-windows]() +* Mac Installation Instructions (High Sierra): [https://medium.com/@nuwanprabhath/installing-opencv-in-macos-high-sierra-for-python-3-89c79f0a246a]() +* Linux Installation Instructions (Ubuntu 18.04): [https://www.pyimagesearch.com/2018/05/28/ubuntu-18-04-how-to-install-opencv]() + +### Here we will be focusing on python implementation of OpenCV + +```python +# Reading image in OpenCV +import cv2 +img = cv2.imread('cat.jpg') + +# Displaying the image +# imshow() function is used to display the image +cv2.imshow('Image',img) +# Your first arguement is the title of the window and second parameter is image +# If you are getting error, Object Type None, your image path may be wrong. Please recheck the pack to the image +cv2.waitKey(0) +# waitKey() is a keyboard binding function and takes arguement in milliseconds. For GUI events you MUST use waitKey() function. + +# Writing an image +cv2.imwrite('catgray.png',img) +# first arguement is the file name and second is the image + +# Convert image to grayscale +gray_image = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) + +# Capturing Video from Webcam +cap = cv2.VideoCapture(0) +#0 is your camera, if you have multiple camera, you need to enter their id +while(True): + # Capturing frame-by-frame + _, frame = cap.read() + cv2.imshow('Frame',frame) + # When user presses q -> quit + if cv2.waitKey(1) & 0xFF == ord('q'): + break +# Camera must be released +cap.release() + +# Playing Video from file +cap = cv2.VideoCapture('movie.mp4') +while(cap.isOpened()): + _, frame = cap.read() + # Play the video in grayscale + gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) + cv2.imshow('frame',gray) + if cv2.waitKey(1) & 0xFF == ord('q'): + break +cap.release() + +# Drawing The Line in OpenCV +# cv2.line(img,(x,y),(x1,y1),(color->r,g,b->0 to 255),thickness) +cv2.line(img,(0,0),(511,511),(255,0,0),5) + +# Drawing Rectangle +# cv2.rectangle(img,(x,y),(x1,y1),(color->r,g,b->0 to 255),thickness) +# thickness = -1 used for filling the rectangle +cv2.rectangle(img,(384,0),(510,128),(0,255,0),3) + +# Drawing Circle +cv2.circle(img,(xCenter,yCenter), radius, (color->r,g,b->0 to 255), thickness) +cv2.circle(img,(200,90), 100, (0,0,255), -1) + +# Drawing Ellipse +cv2.ellipse(img,(256,256),(100,50),0,0,180,255,-1) + +# Adding Text On Images +cv2.putText(img,"Hello World!!!", (x,y), cv2.FONT_HERSHEY_SIMPLEX, 2, 255) + +# Blending Images +img1 = cv2.imread('cat.png') +img2 = cv2.imread('openCV.jpg') +dst = cv2.addWeighted(img1,0.5,img2,0.5,0) + +# Thresholding image +# Binary Thresholding +_,thresImg = cv2.threshold(img,127,255,cv2.THRESH_BINARY) +# Adaptive Thresholding +adapThres = cv2.adaptiveThreshold(img,255,cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY,11,2) + +# Blur Image +# Gaussian Blur +blur = cv2.GaussianBlur(img,(5,5),0) +# Median Blur +medianBlur = cv2.medianBlur(img,5) + +# Canny Edge Detection +img = cv2.imread('cat.jpg',0) +edges = cv2.Canny(img,100,200) + +# Face Detection using Haar Cascades +# Download Haar Cascades from https://github.com/opencv/opencv/blob/master/data/haarcascades/ +import cv2 +import numpy as np +face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml') +eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml') + +img = cv2.imread('human.jpg') +gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) + +aces = face_cascade.detectMultiScale(gray, 1.3, 5) +for (x,y,w,h) in faces: + cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) + roi_gray = gray[y:y+h, x:x+w] + roi_color = img[y:y+h, x:x+w] + eyes = eye_cascade.detectMultiScale(roi_gray) + for (ex,ey,ew,eh) in eyes: + cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2) + +cv2.imshow('img',img) +cv2.waitKey(0) + +cv2.destroyAllWindows() +# destroyAllWindows() destroys all windows. +# If you wish to destroy specific window pass the exact name of window you created. +``` + +### Further Reading: + +* Download Cascade from [https://github.com/opencv/opencv/blob/master/data/haarcascades]() +* OpenCV drawing Functions [https://docs.opencv.org/2.4/modules/core/doc/drawing_functions.html]() +* An up-to-date language reference can be found at [https://opencv.org]() +* Additional resources may be found at [https://en.wikipedia.org/wiki/OpenCV]() +* Good OpenCv Tutorials + * [https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_tutorials.html]() + * [https://realpython.com/python-opencv-color-spaces]() + * [https://pyimagesearch.com]() + * [https://www.learnopencv.com]() diff --git a/pascal.html.markdown b/pascal.html.markdown new file mode 100644 index 00000000..28dcc10f --- /dev/null +++ b/pascal.html.markdown @@ -0,0 +1,206 @@ +--- +language: Pascal +filename: learnpascal.pas +contributors: + - ["Ganesha Danu", "http://github.com/blinfoldking"] + - ["Keith Miyake", "https://github.com/kaymmm"] +--- + + +>Pascal is an imperative and procedural programming language, which Niklaus Wirth designed in 1968–69 and published in 1970, as a small, efficient language intended to encourage good programming practices using structured programming and data structuring. It is named in honor of the French mathematician, philosopher and physicist Blaise Pascal. +source : [wikipedia](https://en.wikipedia.org/wiki/Pascal_(programming_language)) + + + +to compile and run a pascal program you could use a free pascal compiler. [Download Here](https://www.freepascal.org/) + +```pascal +//Anathomy of a Pascal Program +//this is a comment +{ + this is a + multiline comment +} + +//name of the program +program learn_pascal; //<-- dont forget a semicolon + +const + { + this is where you should declare constant values + } +type + { + this is where you should delcare a custom + data-types + } +var + { + this is where you should declare a variable + } + +//main program area +begin + { + area to declare your instruction + } +end. // End of a main program area should required a "." symbol +``` + +```pascal +//declaring variable +//you can do this +var a:integer; +var b:integer; +//or this +var + a : integer; + b : integer; +//or this +var a,b : integer; +``` + +```pascal +program Learn_More; +//Lets learn about data types and their operations + +const + PI = 3.141592654; + GNU = 'GNU's Not Unix'; + // constants are conventionally named using CAPS + // their values are fixed and cannot be changed during runtime + // holds any standard data type (integer, real, boolean, char, string) + +type + ch_array : array [0..255] of char; + // arrays are new 'types' specifying the length and data type + // this defines a new data type that contains 255 characters + // (this is functionally equivalent to a string[256] variable) + md_array : array of array of integer; + // nested arrays are equivalent to multidimensional arrays + // can define zero (0) length arrays that are dynamically sized + // this is a 2-dimensional array of integers + +//Declaring variables +var + int, c, d : integer; + // three variables that contain integer numbers + // integers are 16-bits and limited to the range [-32,768..32,767] + r : real; + // a variable that contains a real number data types + // reals can range between [3.4E-38..3.4E38] + bool : boolean; + // a variable that contains a Boolean(True/False) value + ch : char; + // a variable that contains a character value + // char variables are stored as 8-bit data types so no UTF + str : string; + // a non-standard variable that contains a string value + // strings are an extension included in most Pascal compilers + // they are stored as an array of char with default length of 255. + s : string[50]; + // a string with maximum length of 50 chars. + // you can specify the length of the string to minimize memory usage + my_str: ch_array; + // you can declare variables of custom types + my_2d : md_array; + // dynamically sized arrays need to be sized before they can be used. + + // additional integer data types + b : byte; // range [0..255] + shi : shortint; // range [-128..127] + smi : smallint; // range [-32,768..32,767] (standard Integer) + w : word; // range [0..65,535] + li : longint; // range [-2,147,483,648..2,147,483,647] + lw : longword; // range [0..4,294,967,295] + c : cardinal; // longword + i64 : int64; // range [-9223372036854775808..9223372036854775807] + qw : qword; // range [0..18,446,744,073,709,551,615] + + // additional real types + rr : real; // range depends on platform (i.e., 8-bit, 16-bit, etc.) + rs : single; // range [1.5E-45..3.4E38] + rd : double; // range [5.0E-324 .. 1.7E308] + re : extended; // range [1.9E-4932..1.1E4932] + rc : comp; // range [-2E64+1 .. 2E63-1] + +Begin + int := 1;// how to assign a value to a variable + r := 3.14; + ch := 'a'; + str := 'apple'; + bool := true; + //pascal is not a case-sensitive language + //arithmethic operation + int := 1 + 1; // int = 2 overwriting the previous assignment + int := int + 1; // int = 2 + 1 = 3; + int := 4 div 2; //int = 2 division operation where result will be floored + int := 3 div 2; //int = 1 + int := 1 div 2; //int = 0 + + bool := true or false; // bool = true + bool := false and true; // bool = false + bool := true xor true; // bool = false + + r := 3 / 2; // a division operator for real + r := int; // can assign an integer to a real variable but not the reverse + + c := str[1]; // assign the first letter of str to c + str := 'hello' + 'world'; //combining strings + + my_str[0] := 'a'; // array assignment needs an index + + setlength(my_2d,10,10); // initialize dynamically sized arrays: 10×10 array + for c := 0 to 9 do // arrays begin at 0 and end at length-1 + for d := 0 to 9 do // for loop counters need to be declared variables + my_2d[c,d] := c * d; + // address multidimensional arrays with a single set of brackets + +End. +``` + +```pascal +program Functional_Programming; + +Var + i, dummy : integer; + +function factorial_recursion(const a: integer) : integer; +{ recursively calculates the factorial of integer parameter a } + +// Declare local variables within the function +// e.g.: +// Var +// local_a : integer; + +Begin + If a >= 1 Then + // return values from functions by assigning a value to the function name + factorial_recursion := a * factorial_recursion(a-1) + Else + factorial_recursion := 1; +End; // terminate a function using a semicolon after the End statement. + +procedure get_integer(var i : integer; dummy : integer); +{ get user input and store it in the integer parameter i. + parameters prefaced with 'var' are variable, meaning their value can change + outside of the parameter. Value parameters (without 'var') like 'dummy' are + static and changes made within the scope of the function/procedure do not + affect the variable passed as a parameter } + +Begin + write('Enter an integer: '); + readln(i); + dummy := 4; // dummy will not change value outside of the procedure +End; + +Begin // main program block + dummy := 3; + get_integer(i, dummy); + writeln(i, '! = ', factorial_recursion(i)); + // outputs i! + writeln('dummy = ', dummy); // always outputs '3' since dummy is unchanged. +End. + +``` + diff --git a/pcre.html.markdown b/pcre.html.markdown index 0b61653d..3e877a35 100644 --- a/pcre.html.markdown +++ b/pcre.html.markdown @@ -63,20 +63,12 @@ We will test our examples on following string `66.249.64.13 - - [18/Sep/2004:11: | Regex | Result | Comment | | :---- | :-------------- | :------ | -| GET | GET | GET matches the characters GET literally (case sensitive) | -| \d+.\d+.\d+.\d+ | 66.249.64.13 | `\d+` match a digit [0-9] one or more times defined by `+` quantifier, `\.` matches `.` literally | -| (\d+\.){3}\d+ | 66.249.64.13 | `(\d+\.){3}` is trying to match group (`\d+\.`) exactly three times. | -| \[.+\] | [18/Sep/2004:11:07:48 +1000] | `.+` matches any character (except newline), `.` is any character | -| ^\S+ | 66.249.64.13 | `^` means start of the line, `\S+` matches any number of non-space characters | -| \+[0-9]+ | +1000 | `\+` matches the character `+` literally. `[0-9]` character class means single number. Same can be achieved using `\+\d+` | - -All these examples can be tried at https://regex101.com/ - -1. Copy the example string in `TEST STRING` section -2. Copy regex code in `Regular Expression` section -3. The web application will show the matching result - +| `GET` | GET | GET matches the characters GET literally (case sensitive) | +| `\d+.\d+.\d+.\d+` | 66.249.64.13 | `\d+` match a digit [0-9] one or more times defined by `+` quantifier, `\.` matches `.` literally | +| `(\d+\.){3}\d+` | 66.249.64.13 | `(\d+\.){3}` is trying to match group (`\d+\.`) exactly three times. | +| `\[.+\]` | [18/Sep/2004:11:07:48 +1000] | `.+` matches any character (except newline), `.` is any character | +| `^\S+` | 66.249.64.13 | `^` means start of the line, `\S+` matches any number of non-space characters | +| `\+[0-9]+` | +1000 | `\+` matches the character `+` literally. `[0-9]` character class means single number. Same can be achieved using `\+\d+` | ## Further Reading - - +[Regex101](https://regex101.com/) - Regular Expression tester and debugger diff --git a/perl6.html.markdown b/perl6.html.markdown index 2821f0d4..04f9c6e3 100644 --- a/perl6.html.markdown +++ b/perl6.html.markdown @@ -1366,7 +1366,7 @@ sub add($a, $b) { $a + $b } say [[&add]] 1, 2, 3; #=> 6 ## * Zip meta-operator -## This one is an infix meta-operator than also can be used as a "normal" +## This one is an infix meta-operator that also can be used as a "normal" ## operator. It takes an optional binary function (by default, it just creates ## a pair), and will pop one value off of each array and call its binary ## function on these until it runs out of elements. It returns an array with @@ -1659,7 +1659,7 @@ sub MAIN($name) { say "Hello, $name !" } ## Usage: ## t.pl <name> -## And since it's a regular Perl 6 sub, you can haz multi-dispatch: +## And since it's a regular Perl 6 sub, you can have multi-dispatch: ## (using a "Bool" for the named argument so that we can do `--replace` ## instead of `--replace=1`) subset File of Str where *.IO.d; # convert to IO object to check the file exists diff --git a/php.html.markdown b/php.html.markdown index f82cea7d..3b18aa60 100644 --- a/php.html.markdown +++ b/php.html.markdown @@ -443,7 +443,7 @@ echo $function_name(1, 2); // => 3 // Or, use call_user_func(callable $callback [, $parameter [, ... ]]); -// You can get the all the parameters passed to a function +// You can get all the parameters passed to a function function parameters() { $numargs = func_num_args(); if ($numargs > 0) { @@ -794,7 +794,7 @@ But I'm ChildClass /********************** * Magic constants -* +* */ // Get current class name. Must be used inside a class declaration. @@ -826,7 +826,7 @@ echo "Current trait is " . __TRAIT__; /********************** * Error Handling -* +* */ // Simple error handling can be done with try catch block @@ -841,7 +841,7 @@ try { try { // Do something -} catch (\Exception $e) { +} catch (Exception $e) { // Handle exception } @@ -871,6 +871,9 @@ and community input. If you're interested in up-to-date best practices, visit [PHP The Right Way](http://www.phptherightway.com/). +A tutorial covering basics of language, setting up coding environment and making +few practical projects at [Codecourse - PHP Basics](https://www.youtube.com/playlist?list=PLfdtiltiRHWHjTPiFDRdTOPtSyYfz3iLW). + If you're coming from a language with good package management, check out [Composer](http://getcomposer.org/). diff --git a/processing.html.markdown b/processing.html.markdown new file mode 100644 index 00000000..fc5dc997 --- /dev/null +++ b/processing.html.markdown @@ -0,0 +1,421 @@ +--- +language: processing +filename: learnprocessing.pde +contributors: + - ["Phone Thant Ko", "http://github.com/phonethantko"] +--- +## Introduction + +Processing is a programming language for creation of digital arts and multimedia content, allowing non-programmers to +learn fundamentals of computer programming in a visual context. +While the language is based on Java language, +its syntax has been largely influenced by both Java and Javascript syntaxes. [See more here](https://processing.org/reference/) +The language is statically typed, and also comes with its official IDE to compile and run the scripts. + +```processing +/* --------- + Comments + --------- +*/ + +// Single-line comment starts with // + +/* + Since Processing is based on Java, + the syntax for its comments are the same as Java (as you may have noticed above)! + Multi-line comments are wrapped as seen here. +*/ + +/* --------------------------------------- + Writing and Running Processing Programs + --------------------------------------- + */ + +// In Processing, your program's entry point is a function named setup() with a void return type. +// Note! The syntax looks strikingly similar to that of C++. +void setup() { + // This prints out the classic output "Hello World!" to the console when run. + println("Hello World!"); // Another language with a semi-column trap, ain't it? +} + +// Normally, we put all the static codes inside the setup() method as the name suggest since it only runs once. +// It can range from setting the background colours, setting the canvas size. +background(color); // setting the background colour +size(width,height,[renderer]); // setting the canvas size with optional parameter defining renderer +// You will see more of them throughout this document. + +// If you want to run the codes indefinitely, it has to be placed in draw() method. +// draw() must exist if you want the code to run continuously and obviously, there can only be one draw() method. +int i = 0; +void draw() { + // This block of code loops forever until stopped + print(i); + i++; // Increment Operator! +} + +// Now that we know how to write the working script and how to run it, +// we will proceed to explore what data types and collections are supported in Processing. + +/* ------------------------ + Datatypes & collections + ------------------------ +*/ + +// According to Processing References, Processing supports 8 primitive datatypes as follows. + +boolean booleanValue = true; // Boolean +byte byteValueOfA = 23; // Byte +char charValueOfA = 'A'; // Char +color colourValueOfWhiteM = color(255, 255, 255); // Colour (Specified using color() method) +color colourValueOfWhiteH = #FFFFFF; // Colour (Specified using hash value) +int intValue = 5; // Integer (Number without decimals) +long longValue = 2147483648L; // "L" is added to the number to mark it as a long +float floatValue = 1.12345; // Float (32-bit floating-point numbers) +double doubleValue = 1.12345D; // Double (64-bit floating-point numbers) + +// NOTE! +// Although datatypes "long" and "double" work in the language, +// processing functions do not use these datatypes, therefore +// they need to be converted into "int" and "float" datatypes respectively, +// using (int) and (float) syntax before passing into a function. + +// There is a whole bunch of default composite datatypes available for use in Processing. +// Primarily, I will brief through the most commonly used ones to save time. + +// String +// While char datatype uses '', String datatype uses "" - double quotes. +String sampleString = "Hello, Processing!"; +// String can be constructed from an array of char datatypes as well. We will discuss array very soon. +char source = {'H', 'E', 'L', 'L', 'O'}; +String stringFromSource = new String(source); // HELLO +// As in Java, strings can be concatenated using the "+" operator. +print("Hello " + "World!"); // Hello World! + +// Array +// Arrays in Processing can hold any datatypes including Objects themselves. +// Since arrays are similar to objects, they must be created with the keyword "new". +int[] intArray = new int[5]; +int[] intArrayWithValues = {1, 2, 3}; // You can also populate with data. + +// ArrayList +// Functions are similar to those of array; arraylists can hold any datatypes. +// The only difference is arraylists resize dynamically, +// as it is a form of resizable-array implementation of the Java "List" interface. +ArrayList<Integer> intArrayList = new ArrayList<Integer>(); + +// Object +// Since it is based on Java, Processing supports object-oriented programming. +// That means you can basically define any datatypes of your own and manipulate them to your needs. +// Of course, a class has to be defined before for the object you want. +// Format --> ClassName InstanceName +SomeRandomClass myObject // then instantiate later +//or +SomeRandomClass myObjectInstantiated = new SomeRandomClass(); + +// Processing comes up with more collections (eg. - Dictionaries and Lists) by default, +// for the simplicity sake, I will leave them out of discussion here. + +/* ------------ + Maths + ------------ +*/ + +// Arithmetic +1 + 1 // 2 +2 - 1 // 0 +2 * 3 // 6 +3 / 2 // 1 +3.0 / 2 // 1.5 +3.0 % 2 // 1.0 + +// Processing also comes with a set of functions that simplify mathematical operations. +float f = sq(3); // f = 9.0 +float p = pow(3, 3); // p = 27.0 +int a = abs(-13) // a = 13 +int r1 = round(3.1); // r1 = 3 +int r2 = round(3.7); // r2 = 4 +float sr = sqrt(25); // sr = 5.0 + +// Vectors +// Processing provides an easy way to implement vectors in its environment using PVector class. +// It can describe a two or three dimensional vector and +// comes with a set of methods which are useful for matrices operations. +// You can find more information on PVector class and its functions here. +// (https://processing.org/reference/PVector.html) + +// Trigonometry +// Processing also supports trigonometric operations by supplying a set of functions. +// sin(), cos(), tan(), asin(), acos(), atan() and also degrees() and radians() for convenient conversion. +// However, those functions take angle in radians as the parameter so it has to be converted beforehand. +float one = sin(PI/2); // one = 1.0 +// As you may have noticed, there exists a set of constants for trigonometric uses; +// PI, HALF_PI, QUARTER_PI and so on... + +/* ------------- + Control Flow + ------------- +*/ + +// Conditional Statements +// If Statements - The same syntax as if statements in Java. +if (author.getAppearance().equals("hot")) { + print("Narcissism at its best!"); +} else { + // You can check for other conditions here. + print("Something is really wrong here!"); +} +// A shortcut for if-else statements can also be used. +int i = 3; +String value = (i > 5) ? "Big" : "Small"; // "Small" + +// Switch-case structure can be used to check multiple conditions more concisely. +int value = 2; +switch(value) { + case 0: + print("Nought!"); // This doesn't get executed. + break; // Jumps to the next statement + case 1: + print("Getting there..."); // This again doesn't get executed. + break; + case 2: + print("Bravo!"); // This line gets executed. + break; + default: + print("Not found!"); // This line gets executed if our value was some other value. + break; +} + +// Iterative statements +// For Statements - Again, the same syntax as in Java +for(int i = 0; i < 5; i ++){ + print(i); // prints from 0 to 4 +} + +// While Statements - Again, nothing new if you are familiar with Java syntax. +int j = 3; +while(j > 0) { + print(j); + j--; // This is important to prevent from the code running indefinitely. +} + +// loop()| noLoop() | redraw() | exit() +// These are more of Processing-specific functions to configure program flow. +loop(); // allows the draw() method to run forever while +noLoop(); // only allows it to run once. +redraw(); // runs the draw() method once more. +exit(); // This stops the program. It is useful for programs with draw() running continuously. +``` +## Drawing with Processing +Since you will have understood the basics of the language by now, we will now look into the best part of Processing; DRAWING. + +```processing + +/* ------ + Shapes + ------ +*/ + +// 2D Shapes + +// Point +point(x, y); // In 2D space +point(x, y, z); // In 3D space +// Draws a point in the coordinate space. + +// Line +line(x1, y1, x2, y2); // In 2D space +line(x1, y1, z1, x2, y2, z2); // In 3D space +// Draws a line connecting two points defined by (x1, y1) and (x2, y2). + +// Triangle +triangle(x1, y1, x2, y2, x3, y3); +// Draws a triangle connecting three points defined by coordinate paramters. + +// Rectangle +rect(a, b, c, d, [r]); // With optional parameter defining the radius of all corners +rect(a, b, c, d, [tl, tr, br, bl]); // With optional set of parameters defining radius of each corner +// Draws a rectangle with {a, b} as a top left coordinate and c and d as width and height respectively. + +// Quad +quad(x, y, x2, y2, x3, y3, x4, y4); +// Draws a quadrilateral with parameters defining coordinates of each corner point. + +// Ellipse +ellipse(x, y, width, height); +// Draws an eclipse at point {x, y} with width and height specified. + +// Arc +arc(x, y, width, height, start, stop, [mode]); +// While the first four parameters are self-explanatory, +// start and end defined the angles the arc starts and ends (in radians). +// Optional parameter [mode] defines the filling; +// PIE gives pie-like outline, CHORD gives the chord-like outline and OPEN is CHORD without strokes + +// Curves +// Processing provides two implementation of curves; using curve() and bezier(). +// Since I plan to keep this simple I won't be discussing any further details. +// However, if you want to implement it in your sketch, here are the references: +// (https://processing.org/reference/curve_.html)(https://processing.org/reference/bezier_.html) + +// 3D Shapes + +// 3D space can be configured by setting "P3D" to the renderer parameter in size() method. +size(width, height, P3D); +// In 3D space, you will have to translate to the particular coordinate to render the 3D shapes. + +// Box +box(size); // Cube with same length defined by size +box(w, h, d); // Box with width, height and depth separately defined + +// Sphere +sphere(radius); // Its size is defined using the radius parameter +// Mechanism behind rendering spheres is implemented by tessellating triangles. +// That said, how much detail being rendered is controlled by function sphereDetail(res) +// More information here: (https://processing.org/reference/sphereDetail_.html) + +// Irregular Shapes +// What if you wanted to draw something that's not made available by Processing's functions? +// You can use beginShape(), endShape(), vertex(x,y) to define shapes by specifying each point. +// More information here: (https://processing.org/reference/beginShape_.html) +// You can also use custom made shapes using PShape class.(https://processing.org/reference/PShape.html) + +/* --------------- + Transformations + --------------- +*/ + +// Transformations are particularly useful to keep track of the coordinate space +// and the vertices of the shapes you have drawn. +// Particularly, matrix stack methods; pushMatrix(), popMatrix() and translate(x,y) +pushMatrix(); // Saves the current coordinate system to the stack +// ... apply all the transformations here ... +popMatrix(); // Restores the saved coordinate system +// Using them, the coordinate system can be preserved and visualized without causing any conflicts. + +// Translate +translate(x, y); // Translates to point{x, y} i.e. - setting origin to that point +translate(x, y, z); // 3D counterpart of the function + +// Rotate +rotate(angle); // Rotate the amount specified by the angle parameter +// It has 3 3D counterparts to perform rotation, each for every dimension, +// namely: rotateX(angle), rotateY(angle), rotateZ(angle) + +// Scale +scale(s); // Scale the coordinate system by either expanding or contracting it. + +/* -------------------- + Styling and Textures + -------------------- +*/ + +// Colours +// As I have discussed earlier, the background colour can be configured using background() function. +// You can define a color object beforehand and then pass it to the function as an argument. +color c = color(255, 255, 255); // WHITE! +// By default, Processing uses RGB colour scheme but it can be configured to HSB using colorMode(). +// Read here: (https://processing.org/reference/colorMode_.html) +background(color); // By now, the background colour should be white. +// You can use fill() function to select the colour for filling the shapes. +// It has to be configured before you start drawing shapes so the colours gets applied. +fill(color(0, 0, 0)); +// If you just want to colour the outlines of the shapes then you can use stroke() function. +stroke(255, 255, 255, 200); // stroke colour set to yellow with transparency set to a lower value. + +// Images +// Processing can render images and use them in several ways. Mostly stored as PImage datatype. +filter(shader); // Processing supports several filter functions for image manipulation. +texture(image); // PImage can be passed into arguments for texture-mapping the shapes. + +``` +If you want to take things further, there are more things Processing is powered for. Rendering models, shaders and whatnot. +There's too much to cover in a short documentation, so I will leave them out here. Shoud you be interested, please check out the references. +```processing +// Before we move on, I will touch a little bit more on how to import libraries +// so you can extend Processing's functionality to another horizon. + +/* ------- + Imports + ------- +*/ + +// The power of Processing can be further visualized when we import libraries and packages into our sketches. +// Import statement can be written as below at the top of the source code. +import processing.something.*; + +``` +## DTC? + +Down To Code? Let's get our hands dirty! + +Let us see an example from openprocessing to visualize how much Processing is capable of within few lines of code. +Copy the code below into your Processing IDE and see the magic. + +```processing + +// Disclaimer: I did not write this program since I currently am occupied with internship and +// this sketch is adapted from openprocessing since it shows something cool with simple codes. +// Retrieved from: (https://www.openprocessing.org/sketch/559769) + +float theta; +float a; +float col; +float num; + +void setup() { + size(600,600); +} + +void draw() { + background(#F2F2F2); + translate(width/2, height/2); + theta = map(sin(millis()/1000.0), -1, 1, 0, PI/6); + + float num=6; + for (int i=0; i<num; i++) { + a =350; + rotate(TWO_PI/num); + branch(a); + } + +} + + + +void branch(float len) { + col=map(len, 0, 90, 150, 255); + fill(col, 0, 74); + stroke (col, 0, 74); + line(0, 0, 0, -len); + ellipse(0, -len, 3, 3); + len *= 0.7; + + + if (len>30) { + pushMatrix(); + translate(0, -30); + rotate(theta); + branch(len); + popMatrix(); + + pushMatrix(); + translate(0, -30); + rotate(-theta); + branch(len); + popMatrix(); + + } +} + +``` + +Processing is easy to learn and is particularly useful to create multimedia contents (even in 3D) without +having to type a lot of codes. It is so simple that you can read through the code and get a rough idea of +the program flow. +However, that does not apply when you introduce external libraries, packages and even your own classes. +(Trust me! Processing projects can get real humongous...) + +## Some useful resources: + + - [Processing Website](http://processing.org) + - [Processing Sketches](http://openprocessing.org) diff --git a/prolog.html.markdown b/prolog.html.markdown index 7a18a144..f7b55ac6 100644 --- a/prolog.html.markdown +++ b/prolog.html.markdown @@ -38,9 +38,9 @@ magicNumber(42). % predicate names must start with lower case letters. We can now use % interactive mode to ask if it is true for different values: -?- magicNumber(7). % True -?- magicNumber(8). % False -?- magicNumber(9). % True +?- magicNumber(7). % True +?- magicNumber(8). % False +?- magicNumber(9). % True % Some older Prologs may display "Yes" and "No" instead of True and % False. @@ -50,7 +50,7 @@ magicNumber(42). % starting with a capital letter is a variable in Prolog. ?- magicNumber(Presto). % Presto = 7 ; - % Presto = 9 ; + % Presto = 9 ; % Presto = 42. % Prolog makes magicNumber true by assigning one of the valid numbers to @@ -66,26 +66,33 @@ magicNumber(42). % follows: % If both sides are bound (ie, defined), check equality. % If one side is free (ie, undefined), assign to match the other side. -% If both sides are free, abort because this can't be resolved. +% If both sides are free, the assignment is remembered. With some luck, +% one of the two sides will eventually be bound, but this isn't +% necessary. +% % The = sign in Prolog represents unification, so: ?- 2 = 3. % False - equality test -?- X = 3. % X = 3 - assignment -?- X = 2, X = Y. % X = Y = 2 - two assignments +?- X = 3. % X = 3 - assignment +?- X = 2, X = Y. % X = Y = 2 - two assignments % Note Y is assigned to, even though it is % on the right hand side, because it is free ?- X = 3, X = 2. % False - % First acts as assignment and binds X=3 - % Second acts as equality because X is bound + % First acts as assignment and binds X=3 + % Second acts as equality because X is bound % Since 3 does not equal 2, gives False % Thus in Prolog variables are immutable ?- X = 3+2. % X = 3+2 - unification can't do arithmetic ?- X is 3+2. % X = 5 - "is" does arithmetic. -?- 5 = X+2. % This is why = can't do arithmetic - +?- 5 = X+2. % This is why = can't do arithmetic - % because Prolog can't solve equations ?- 5 is X+2. % Error. Unlike =, the right hand side of IS % must always be bound, thus guaranteeing % no attempt to solve an equation. +?- X = Y, X = 2, Z is Y + 3. % X = Y, Y = 2, Z = 5. + % X = Y are both free, so Prolog remembers + % it. Therefore assigning X will also + % assign Y. % Any unification, and thus any predicate in Prolog, can either: % Succeed (return True) without changing anything, @@ -101,11 +108,11 @@ magicNumber(42). % example, Prolog has a built in predicate plus which represents % arithmetic addition but can reverse simple additions. -?- plus(1, 2, 3). % True +?- plus(1, 2, 3). % True ?- plus(1, 2, X). % X = 3 because 1+2 = X. -?- plus(1, X, 3). % X = 2 because 1+X = 3. -?- plus(X, 2, 3). % X = 1 because X+1 = 3. -?- plus(X, 5, Y). % Error - although this could be solved, +?- plus(1, X, 3). % X = 2 because 1+X = 3. +?- plus(X, 2, 3). % X = 1 because X+2 = 3. +?- plus(X, 5, Y). % Error - although this could be solved, % the number of solutions is infinite, % which most predicates try to avoid. @@ -129,9 +136,9 @@ magicNumber(42). ?- print("Hello"). % "Hello" true. ?- X = 2, print(X). % 2 true. -?- X = 2, print(X), X = 3. % 2 false - print happens immediately when - % it is encountered, even though the overall - % compound goal fails (because 2 != 3, +?- X = 2, print(X), X = 3. % 2 false - print happens immediately when + % it is encountered, even though the overall + % compound goal fails (because 2 != 3, % see the example above). % By using Print we can see what actually happens when we give a @@ -156,7 +163,7 @@ magicNumber(42). % the interactive prompt by pressing ;, for example: ?- magicNumber(X), print(X), X > 8. % 7 9 X = 9 ; - % 42 X = 42. + % 42 X = 42. % As you saw above we can define our own simple predicates as facts. % More complex predicates are defined as rules, like this: @@ -168,7 +175,7 @@ nearby(X,Y) :- Y is X-1. % nearby(X,Y) is true if Y is X plus or minus 1. % However this predicate could be improved. Here's why: -?- nearby(2,3). % True ; False. +?- nearby(2,3). % True ; False. % Because we have three possible definitions, Prolog sees this as 3 % possibilities. X = Y fails, so Y is X+1 is then tried and succeeds, % giving the True answer. But Prolog still remembers there are more @@ -177,11 +184,11 @@ nearby(X,Y) :- Y is X-1. % the option of rejecting the True answer, which doesn't make a whole % lot of sense. -?- nearby(4, X). % X = 4 ; - % X = 5 ; - % X = 3. Great, this works -?- nearby(X, 4). % X = 4 ; - % error +?- nearby(4, X). % X = 4 ; + % X = 5 ; + % X = 3. Great, this works +?- nearby(X, 4). % X = 4 ; + % error % After rejecting X = 4 prolog backtracks and tries "Y is X+1" which is % "4 is X+1" after substitution of parameters. But as we know from above % "is" requires its argument to be fully instantiated and it is not, so @@ -195,10 +202,10 @@ nearbychk(X,Y) :- Y is X+1, !. nearbychk(X,Y) :- Y is X-1. % This solves the first problem: -?- nearbychk(2,3). % True. +?- nearbychk(2,3). % True. % But unfortunately it has consequences: -?- nearbychk(2,X). % X = 2. +?- nearbychk(2,X). % X = 2. % Because Prolog cannot backtrack past the cut after X = Y, it cannot % try the possibilities "Y is X+1" and "Y is X-1", so it only generates % one solution when there should be 3. @@ -230,14 +237,14 @@ nearby3(X,Y) :- nearby2(X,Y). % Here is the structured comment declaration for nearby3: -%% nearby3(+X:Int, +Y:Int) is semidet. -%% nearby3(+X:Int, -Y:Int) is multi. -%% nearby3(-X:Int, +Y:Int) is multi. +%! nearby3(+X:Int, +Y:Int) is semideterministic. +%! nearby3(+X:Int, -Y:Int) is multi. +%! nearby3(-X:Int, +Y:Int) is multi. % For each variable we list a type. The + or - before the variable name % indicates if the parameter is bound (+) or free (-). The word after % "is" describes the behaviour of the predicate: -% semidet - can succeed once or fail +% semideterministic - can succeed once or fail % ( Two specific numbers are either nearby or not ) % multi - can succeed multiple times but cannot fail % ( One number surely has at least 3 nearby numbers ) @@ -250,13 +257,13 @@ nearby3(X,Y) :- nearby2(X,Y). % An unusual feature of Prolog is its support for atoms. Atoms are % essentially members of an enumerated type that are created on demand % whenever an unquoted non variable value is used. For example: -character(batman). % Creates atom value batman -character(robin). % Creates atom value robin -character(joker). % Creates atom value joker -character(darthVader). % Creates atom value darthVader -?- batman = batman. % True - Once created value is reused -?- batman = batMan. % False - atoms are case sensitive -?- batman = darthVader. % False - atoms are distinct +character(batman). % Creates atom value batman +character(robin). % Creates atom value robin +character(joker). % Creates atom value joker +character(darthVader). % Creates atom value darthVader +?- batman = batman. % True - Once created value is reused +?- batman = batMan. % False - atoms are case sensitive +?- batman = darthVader. % False - atoms are distinct % Atoms are popular in examples but were created on the assumption that % Prolog would be used interactively by end users - they are less @@ -267,54 +274,55 @@ character(darthVader). % Creates atom value darthVader % Note that below, writeln is used instead of print because print is % intended for debugging. -%% countTo(+X:Int) is det. -%% countUpTo(+Value:Int, +Limit:Int) is det. +%! countTo(+X:Int) is deterministic. +%! countUpTo(+Value:Int, +Limit:Int) is deterministic. countTo(X) :- countUpTo(1,X). countUpTo(Value, Limit) :- Value = Limit, writeln(Value), !. countUpTo(Value, Limit) :- Value \= Limit, writeln(Value), - NextValue is Value+1, - countUpTo(NextValue, Limit). + NextValue is Value+1, + countUpTo(NextValue, Limit). -?- countTo(10). % Outputs 1 to 10 +?- countTo(10). % Outputs 1 to 10 % Note the use of multiple declarations in countUpTo to create an % IF test. If Value = Limit fails the second declaration is run. % There is also a more elegant syntax. -%% countUpTo2(+Value:Int, +Limit:Int) is det. +%! countUpTo2(+Value:Int, +Limit:Int) is deterministic. countUpTo2(Value, Limit) :- writeln(Value), - Value = Limit -> true ; ( - NextValue is Value+1, - countUpTo2(NextValue, Limit)). + Value = Limit -> true ; ( + NextValue is Value+1, + countUpTo2(NextValue, Limit)). -?- countUpTo2(1,10). % Outputs 1 to 10 +?- countUpTo2(1,10). % Outputs 1 to 10 % If a predicate returns multiple times it is often useful to loop % through all the values it returns. Older Prologs used a hideous syntax % called a "failure-driven loop" to do this, but newer ones use a higher % order function. -%% countTo2(+X:Int) is det. +%! countTo2(+X:Int) is deterministic. countTo2(X) :- forall(between(1,X,Y),writeln(Y)). -?- countTo2(10). % Outputs 1 to 10 +?- countTo2(10). % Outputs 1 to 10 % Lists are given in square brackets. Use memberchk to check membership. % A group is safe if it doesn't include Joker or does include Batman. -%% safe(Group:list(atom)) is det. + +%! safe(Group:list(atom)) is deterministic. safe(Group) :- memberchk(joker, Group) -> memberchk(batman, Group) ; true. -?- safe([robin]). % True -?- safe([joker]). % False -?- safe([joker, batman]). % True +?- safe([robin]). % True +?- safe([joker]). % False +?- safe([joker, batman]). % True % The member predicate works like memberchk if both arguments are bound, % but can accept free variables and thus can be used to loop through % lists. -?- member(X, [1,2,3]). % X = 1 ; X = 2 ; X = 3 . +?- member(X, [1,2,3]). % X = 1 ; X = 2 ; X = 3 . ?- forall(member(X,[1,2,3]), - (Y is X+1, writeln(Y))). % 2 3 4 + (Y is X+1, writeln(Y))). % 2 3 4 % The maplist function can be used to generate lists based on other % lists. Note that the output list is a free variable, causing an diff --git a/pt-br/amd-pt.html.markdown b/pt-br/amd-pt.html.markdown index 38c1f70f..40c7cd09 100644 --- a/pt-br/amd-pt.html.markdown +++ b/pt-br/amd-pt.html.markdown @@ -141,7 +141,7 @@ require(['jquery', 'coolLibFromBower', 'modules/algunsHelpers'], function($, coo coolLib.facaAlgoDoidoCom(helpers.transform($('#foo'))); }); ``` -Apps baseados em `require.js` geralmente terão u´m único ponto de acesso (`main.js`) que é passado à tag script do `require.js` como um data-attribute. Ele vai ser automaticamente carregado e executado com o carregamento da página: +Apps baseados em `require.js` geralmente terão um único ponto de acesso (`main.js`) que é passado à tag script do `require.js` como um data-attribute. Ele vai ser automaticamente carregado e executado com o carregamento da página: ```html <!DOCTYPE html> diff --git a/pt-br/asciidoc-pt.html.markdown b/pt-br/asciidoc-pt.html.markdown index 1dee31db..b12c0693 100644 --- a/pt-br/asciidoc-pt.html.markdown +++ b/pt-br/asciidoc-pt.html.markdown @@ -99,7 +99,7 @@ Para criar uma lista com marcadores use asteriscos. * baz ``` -Para criar uma lista númerada use pontos. +Para criar uma lista numerada use pontos. ``` . item 1 diff --git a/pt-br/asymptotic-notation-pt.html.markdown b/pt-br/asymptotic-notation-pt.html.markdown index 2e299d09..2f179f96 100644 --- a/pt-br/asymptotic-notation-pt.html.markdown +++ b/pt-br/asymptotic-notation-pt.html.markdown @@ -38,7 +38,7 @@ Na primeira seção desse documento, descrevemos como Notação Assintótica ide *f*, *n* como o tamanho da entrada e *f(n)* sendo o tempo de execução. Então, para dado algoritmo *f*, com entrada de tamanho *n*, você terá tempo de execução *f(n)*. Isto resulta em um gráfico onde a coordernada Y é o tempo de execução -, a coordernada X representa o tamanho da entrada e os pontos representao o tempo +, a coordernada X representa o tamanho da entrada e os pontos representam o tempo de execução para dado tamanho de entrada. Você pode representar a função, ou o algoritmo, com Notação Assintótica de várias @@ -88,7 +88,7 @@ Função Exponencial - a^n, onde *a* é uma constante Big-O, também escrita como O, é uma Notação Assintótica para o pior caso. Digamos *f(n)* seja o tempo de exeução de um algoritmo e *g(n)) um tempo de complexidade -arbritário que você quer relacionar com seu algoritmo. *f(n)* é O(g(n)), se, para +arbitrário que você quer relacionar com seu algoritmo. *f(n)* é O(g(n)), se, para quando constante real c (c > 0), *f(n)* <= *c g(n)* para todo tamanho de entrada n (n > 0). diff --git a/pt-br/awk-pt.html.markdown b/pt-br/awk-pt.html.markdown new file mode 100644 index 00000000..761f5294 --- /dev/null +++ b/pt-br/awk-pt.html.markdown @@ -0,0 +1,376 @@ +--- +language: awk +filename: learnawk-pt.awk +contributors: + - ["Marshall Mason", "http://github.com/marshallmason"] +translators: + - ["Paulo Henrique Rodrigues Pinheiro", "https://github.com/paulohrpinheiro"] +lang: pt-br + +--- + +AWK é uma ferramenta padrão em todos os sistemas UNIX compatíveis com POSIX. É +como um Perl despojado, perfeito para tarefas de processamento de texto e +outras tarefas de script. Possui uma sintaxe C-like, mas sem ponto e vírgula, +gerenciamento manual de memória, ou tipagem estática. Destaca-se no +processamento de texto. Você pode chamá-lo a partir de um shell-script, ou você +pode usá-lo como uma linguagem de script autônomo. + +Por que usar AWK ao invés de Perl? Principalmente porque AWK faz parte do UNIX. +Você pode sempre contar com ele, enquanto o futuro do Perl é indefinido. AWK é +também mais fácil de ler que Perl. Para scripts simples de processamento de +texto, particularmente aqueles que leem arquivos linha por linha e fatiam texto +por delimitadores, AWK é provavelmente a ferramenta certa para a tarefa. + +```awk +#!/usr/bin/awk -f + +# Comentários são assim + +# Programas AWK consistem de uma coleção de padrões e ações. O mais +# importante padrão é chamado BEGIN. Ações estão dentro de blocos +# entre chaves. + +BEGIN { + + # O bloco BEGIN será executado no começo do programa. É onde você coloca + # todo código que prepara a execução, antes que você processe qualquer + # arquivo de texto. Se você não tem arquivos de texto, então pense no + # BEGIN como o ponto principal de entrada. + + # Variáveis são globais. Simplesmente atribua valores ou as use, sem + # necessidade de declarar. + + # Operadores são como em C e similares + a = count + 1 + b = count - 1 + c = count * 1 + d = count / 1 # divisão inteira + e = count % 1 # módulo + f = count ^ 1 # exponenciação + + a += 1 + b -= 1 + c *= 1 + d /= 1 + e %= 1 + f ^= 1 + + # Incrementando e decrementando por um + a++ + b-- + + # Como um operador pré-fixado, retorna o valor incrementado + ++a + --b + + # Perceba, não há pontuação, como ponto-e-vírgula, ao final das declarações + + # Declarações de controle + if (count == 0) + print "Começando com count em 0" + else + print "Como é que é?" + + # Ou você pode usar o operador ternário + print (count == 0) ? "Começando com count em 0" : "Como é que é?" + + # Blocos multilinhas devem usar chaves + while (a < 10) { + print "Concatenação de texto é feita" " com uma série" " de" + " textos separados por espaço" + print a + + a++ + } + + for (i = 0; i < 10; i++) + print "Uma boa opção para um loop de uma linha" + + # Quanto a comparações, eis os padrões: + a < b # Menor que + a <= b # Menor ou igual a + a != b # Não igual + a == b # Igual + a > b # Maior que + a >= b # Maior ou igual a + + # Bem como operadores lógicos + a && b # E + a || b # OU (inclusivo) + + # Em adição, há o utilíssimo operador para expressões regulares + if ("foo" ~ "^fo+$") + print "Fooey!" + if ("boo" !~ "^fo+$") + print "Boo!" + + # Matrizes + arr[0] = "foo" + arr[1] = "bar" + # Infelizmente, não há outra forma para inicializar uma matriz. Apenas + # coloque cada valor em uma linha, como mostrado acima. + + # Você também pode ter matrizes associativas + assoc["foo"] = "bar" + assoc["bar"] = "baz" + + # E matrizes multidimensionais, com algumas limitações que não mencionarei + multidim[0,0] = "foo" + multidim[0,1] = "bar" + multidim[1,0] = "baz" + multidim[1,1] = "boo" + + # Você pode testar a pertinência de um elemento em uma matriz + if ("foo" in assoc) + print "Fooey!" + + # Você pode também usar o operador 'in' para percorrer as chaves de uma + # matriz associativa + for (key in assoc) + print assoc[key] + + # Os argumentos da linha de comando estão em uma matriz especial ARGV + for (argnum in ARGV) + print ARGV[argnum] + + # Você pode remover elementos de uma matriz + # Isso é muito útil para prevenir que o AWK assuma que os argumentos são + # arquivo para ele processar + delete ARGV[1] + + # A quantidade de argumentos passados está na variável ARGC + print ARGC + + # O AWK tem várias funções nativas. Elas estão separadas em três categorias. + # Demonstrarei cada uma delas logo mais abaixo. + + return_value = arithmetic_functions(a, b, c) + string_functions() + io_functions() +} + +# Eis como você deve definir uma função +function arithmetic_functions(a, b, c, d) { + + # Provavelmente a parte mais irritante do AWK é ele não possuir variáveis + # locais. Tudo é global. Para pequenos scripts, isso não é problema, e + # pode até mesmo ser considerado útil, mas para grandes scripts, isso pode + # ser um problema. + + # Mas há como contornar isso (um hack). Os argumentos de função são locais + # para a função e o AWK permite que você defina mais argumentos de função + # do que ele precise. Então, coloque a variável local na declaração de + # função, como eu fiz acima. Como uma convenção, adicione alguns espaços + # extras para distinguir entre parâmetros de função reais e variáveis + # locais. Neste exemplo, a, b e c são parâmetros reais, enquanto d é + # meramente uma variável local. + + # Agora, serão demonstradas as funções aritméticas + + # Muitas implementações AWK possuem algumas funções trigonométricas padrão + localvar = sin(a) + localvar = cos(a) + localvar = atan2(b, a) # arco-tangente de b / a + + # E conteúdo logarítmico + localvar = exp(a) + localvar = log(a) + + # Raiz quadrada + localvar = sqrt(a) + + # Descartando a parte não inteira de um número em ponto flutuante. + localvar = int(5.34) # localvar => 5 + + # Números aleatórios + srand() # Forneça uma semente como argumento. Por padrão, ele usa a hora atual + localvar = rand() # Número aleatório entre 0 e 1. + + # Aqui mostramos como retornar um valor + return localvar +} + +function string_functions( localvar, arr) { + + # Sendo o AWK uma linguagem para processamento de texto, ele possui + # várias funções para manipulação de texto, muitas das quais + # fortemente dependentes de expressões regulares. + + # Procurar e substituir, primeira instância (sub), ou todas (gsub) + # Ambas retornam o número de instâncias substituídas + localvar = "fooooobar" + sub("fo+", "Meet me at the ", localvar) # localvar => "Meet me at the bar" + gsub("e+", ".", localvar) # localvar => "m..t m. at th. bar" + + # Localiza um texto que casa com uma expressão regular + # index() faz a mesma coisa, mas não permite uma expressão regular + match(localvar, "t") # => 4, pois 't' é o quarto carácter + + # Separa por delimitador + split("foo-bar-baz", arr, "-") # a => ["foo", "bar", "baz"] + + # Outras coisas úteis + sprintf("%s %d %d %d", "Testing", 1, 2, 3) # => "Testing 1 2 3" + substr("foobar", 2, 3) # => "oob" + substr("foobar", 4) # => "bar" + length("foo") # => 3 + tolower("FOO") # => "foo" + toupper("foo") # => "FOO" +} + +function io_functions( localvar) { + + # Você já viu como imprimir + print "Hello world" + + # Também há o printf + printf("%s %d %d %d\n", "Testing", 1, 2, 3) + + # O AWK não disponibiliza manipuladores de arquivo. Ele irá automaticamente + # manipular um arquivo quando você fizer algo que precise disso. O texto + # que você usou para isso pode ser usado como um manipulador de arquivo, + # para propósitos de E/S. Isso faz ele parecer com um shell script: + + print "foobar" >"/tmp/foobar.txt" + + # Agora a string "/tmp/foobar.txt" é um manipulador de arquivos. Você pode + # fechá-lo: + close("/tmp/foobar.txt") + + # Aqui está como você pode executar alguma coisa no shell + system("echo foobar") # => prints foobar + + # Lê uma linha da entrada padrão e armazena em localvar + getline localvar + + # Lê uma linha de um pipe + "echo foobar" | getline localvar # localvar => "foobar" + close("echo foobar") + + # Lê uma linha de um arquivo e armazena em localvar + getline localvar <"/tmp/foobar.txt" + close("/tmp/foobar.txt") +} + +# Como dito no início, os programas AWK consistem de uma coleção de padrões +# e ações. Você já viu o padrão BEGIN, o mais importante. Outros padrões são +# usados apenas se você estiver processando linhas de arquivos ou a entrada +# padrão. + +# Quando você passa argumentos para o AWK, eles são tratados como nomes de +# arquivos para processar. Todos serão processados, em ordem. Pense nisso como +# um implícito para loop, iterando sobre as linhas nesses arquivos. Esses +# padrões e ações são como instruções de mudança dentro do loop. + +/^fo+bar$/ { + + # Esta ação será executada para cada linha que corresponda à expressão + # regular, / ^ fo + bar $ /, e será ignorada para qualquer linha que não + # corresponda. Vamos apenas imprimir a linha: + + print + + # Opa, sem argumento! Isso ocorre pois print tem um argumento padrão: $0. + # $0 é o nome da linha atual que está sendo processada. Essa variável é + # criada automaticamente para você. + + # Você provavelmente pode adivinhar que existem outras variáveis $. Toda + # linha é implicitamente dividida antes de cada ação ser chamada, como + # o shell faz. E, como o shell, cada campo pode ser acessado com um sinal + # de cifrão + + # Isso irá imprimir o segundo e quarto campos da linha + print $2, $4 + + # O AWK automaticamente define muitas outras variáveis para ajudar você + # a inspecionar processar cada linha. A mais importante delas é NF. + + # Imprime o número de campos da linha atual + print NF + + # Imprime o último campo da linha atual + print $NF +} + +# Todo padrão é na verdade um teste verdadeiro/falso. A expressão regular no +# último padrão também é um teste verdadeiro/falso, mas parte dele estava +# escondido. Se você não informar um texto para testar, AWK assumirá $0, +# a linha que está atualmente sendo processada. Assim, a versão completa +# é a seguinte: + +$0 ~ /^fo+bar$/ { + print "Equivalente ao último padrão" +} + +a > 0 { + # Isso será executado uma vez para cada linha, quando a for positivo +} + +# Você entendeu. Processar arquivos de texto, ler uma linha de cada vez, e +# fazer algo com ela, particularmente dividir com base em um delimitador, é +# tão comum no UNIX que AWK é uma linguagem de script que faz tudo por você, +# sem você precisa perguntar. Tudo o que você precisa fazer é escrever os +# padrões e ações com base no que você espera da entrada, e o que você quer +# fazer com isso. + +# Aqui está um exemplo rápido de um script simples, o tipo de coisa que o AWK +# é perfeito para fazer. Ele irá ler um nome da entrada padrão e depois +imprimirá a média de idade de todos com esse primeiro nome. Digamos que você +forneça como argumento o nome de um arquivo com esses dados: + +# Bob Jones 32 +# Jane Doe 22 +# Steve Stevens 83 +# Bob Smith 29 +# Bob Barker 72 +# +# Eis o script: + +BEGIN { + + # Primeiro, pergunte o nome do usuário + print "Para qual nome você quer calcular a média de idade?" + + # Pega uma linha da entrada padrão, não dos arquivos indicados na + # linha de comando + getline name <"/dev/stdin" +} + +# Agora, processa cada linha em que o primeiro nome é o nome informado +$1 == name { + + # Dentro desse bloco, nós temos acesso a algumas variáveis uteis, que + # foram pré-carregadas para nós: + # $0 é a linha corrente completa + # $3 é o terceiro campo, que é o que nos interessa aqui + # NF é a quantidade de campos, que deve ser 3 + # NR é o número de registros (linhas) lidas até agora + # FILENAME é o nome do arquivo sendo processado + # FS é o delimitador em uso, que é " " aqui + # ...etc. Há muito mais, documentadas no manual. + + # Mantenha um registro do total e da quantidade de linhas encontradas + sum += $3 + nlines++ +} + +# Outro padrão especial é chamado END. Ele será executado após o processamento +# de todos os arquivos de texto. Ao contrário de BEGIN, ele só será executado +# se você tiver dado a ele dados para processar. Ele será executado depois de +# todos os arquivos terem sido lidos e processados de acordo com as regras e +# ações que você forneceu. O objetivo disso em geral é produzir algum tipo de +# relatório final, ou fazer algo com o agregado dos dados acumulados ao longo +# do script. + +END { + if (nlines) + print "A média da idade para " name " é " sum / nlines +} + +``` +Leituras adicionais (em inglês): + +* [Awk tutorial](http://www.grymoire.com/Unix/Awk.html) +* [Awk man page](https://linux.die.net/man/1/awk) +* [The GNU Awk User's Guide](https://www.gnu.org/software/gawk/manual/gawk.html) GNU AWK é encontrado na maioria dos sistemas GNU/Linux. diff --git a/pt-br/bash-pt.html.markdown b/pt-br/bash-pt.html.markdown index ae18435a..3a48d994 100644 --- a/pt-br/bash-pt.html.markdown +++ b/pt-br/bash-pt.html.markdown @@ -16,7 +16,7 @@ lang: pt-br Tutorial de shell em português -Bash é o nome do shell do Unix, que também é distribuido como shell do sistema +Bash é o nome do shell do Unix, que também é distribuído como shell do sistema operacional GNU e como shell padrão para Linux e Mac OS X. Praticamente todos os exemplos abaixo podem fazer parte de um shell script e pode ser executados diretamente no shell. diff --git a/pt-br/bf-pt.html.markdown b/pt-br/bf-pt.html.markdown index 52a5269e..53baa9a2 100644 --- a/pt-br/bf-pt.html.markdown +++ b/pt-br/bf-pt.html.markdown @@ -13,7 +13,9 @@ lang: pt-br Brainfuck (em letras minúsculas, exceto no início de frases) é uma linguagem de programação Turing-completa extremamente simples com apenas 8 comandos. -``` +Você pode experimentar brainfuck pelo seu browser com [brainfuck-visualizer](http://fatiherikli.github.io/brainfuck-visualizer/). + +```bf Qualquer caractere exceto "><+-.,[]" (sem contar as aspas) é ignorado. Brainfuck é representado por um vetor com 30 000 células inicializadas em zero diff --git a/pt-br/c++-pt.html.markdown b/pt-br/c++-pt.html.markdown index c1cfbbb1..42a29991 100644 --- a/pt-br/c++-pt.html.markdown +++ b/pt-br/c++-pt.html.markdown @@ -18,9 +18,9 @@ foi concebida para - suportar programação orientada a objetos - suportar programação genérica -Embora sua sintaxe pode ser mais difícil ou complexa do que as linguagens mais -recentes, C++ é amplamente utilizado porque compila para instruções nativas que -podem ser executadas diretamente pelo processador e oferece um controlo rígido sobre hardware (como C), enquanto oferece recursos de alto nível, como os +Embora sua sintaxe possa ser mais difícil ou complexa do que as linguagens mais +recentes, C++ é amplamente utilizada porque compila para instruções nativas que +podem ser executadas diretamente pelo processador e oferece um controle rígido sobre o hardware (como C), enquanto oferece recursos de alto nível, como os genéricos, exceções e classes. Esta combinação de velocidade e funcionalidade faz C++ uma das linguagens de programação mais utilizadas. @@ -40,10 +40,10 @@ faz C++ uma das linguagens de programação mais utilizadas. int main(int argc, char** argv) { - // Argumentos de linha de comando são passados em pelo argc e argv da mesma + // Argumentos de linha de comando são passados para argc e argv da mesma // forma que eles estão em C. // argc indica o número de argumentos, - // e argv é um array de strings, feito C (char*) representado os argumentos + // e argv é um array de strings, feito C (char*) representando os argumentos // O primeiro argumento é o nome pelo qual o programa foi chamado. // argc e argv pode ser omitido se você não se importa com argumentos, // dando a assinatura da função de int main() @@ -274,7 +274,7 @@ public: void setWeight(int dogsWeight); - // Funções que não modificam o estado do objecto devem ser marcadas como + // Funções que não modificam o estado do objeto devem ser marcadas como // const. Isso permite que você chamá-los se for dada uma referência const // para o objeto. Além disso, observe as funções devem ser explicitamente // declarados como _virtual_, a fim de ser substituídas em classes @@ -564,15 +564,15 @@ void doSomethingWithAFile(const std::string& filename) // Isto tem _grandes_ vantagens: // 1. Não importa o que aconteça, -// o recurso (neste caso, o identificador de ficheiro) irá ser limpo. +// o recurso (neste caso, o identificador de ficheiro) será limpo. // Depois de escrever o destruidor corretamente, // É _impossível_ esquecer de fechar e vazar o recurso // 2. Nota-se que o código é muito mais limpo. // As alças destructor fecham o arquivo por trás das cenas // sem que você precise se preocupar com isso. // 3. O código é seguro de exceção. -// Uma exceção pode ser jogado em qualquer lugar na função e a limpeza -// irá ainda ocorrer. +// Uma exceção pode ser lançada em qualquer lugar na função e a limpeza +// ainda irá ocorrer. // Todos códigos C++ usam RAII extensivamente para todos os recursos. // Outros exemplos incluem @@ -609,7 +609,6 @@ h=sum<double>(f,g); ``` Leitura Adicional: -Uma referência atualizada da linguagem pode ser encontrada em -<http://cppreference.com/w/cpp> - -Uma fonte adicional pode ser encontrada em <http://cplusplus.com> +* Uma referência atualizada da linguagem pode ser encontrada em [CPP Reference](http://cppreference.com/w/cpp). +* Uma fonte adicional pode ser encontrada em [CPlusPlus](http://cplusplus.com). +* Um tutorial cobrindo o básico da linguagem e configurando o ambiente de codificação está disponível em [TheChernoProject - C ++](https://www.youtube.com/playlist?list=PLlrATfBNZ98dudnM48yfGUldqGD0S4FFb). diff --git a/pt-br/c-pt.html.markdown b/pt-br/c-pt.html.markdown index 6e7aa8c2..e1c27958 100644 --- a/pt-br/c-pt.html.markdown +++ b/pt-br/c-pt.html.markdown @@ -182,7 +182,7 @@ int main() { int a, b, c; a = b = c = 0; - // Aritimética é óbvia + // Aritmética é óbvia i1 + i2; // => 3 i2 - i1; // => 1 i2 * i1; // => 2 @@ -191,7 +191,7 @@ int main() { f1 / f2; // => 0.5, mais ou menos epsilon // Números e cálculos de ponto flutuante não são exatos - // Modulo também existe + // Módulo também existe 11 % 3; // => 2 // Operadores de comparação provavelmente são familiares, @@ -538,7 +538,7 @@ int area(retan r) return r.largura * r.altura; } -// Se você tiver structus grande, você pode passá-las "por ponteiro" +// Se você tiver structs grandes, você pode passá-las "por ponteiro" // para evitar cópia de toda a struct: int area(const retan *r) { @@ -638,16 +638,17 @@ typedef void (*minha_função_type)(char *); ## Leitura adicional É recomendado ter uma cópia de [K&R, aka "The C Programming Language"](https://en.wikipedia.org/wiki/The_C_Programming_Language). -Este é *o* livro sobre C, escrito pelos criadores da linguage. Mas cuidado - ele é antigo e contém alguns erros (bem, -ideias que não são consideradas boas hoje) ou práticas mudadas. +Este é *o* livro sobre C, escrito pelos criadores da linguagem. Mas cuidado - ele é antigo e contém alguns erros (bem, +ideias que não são mais consideradas boas) ou práticas ultrapassadas. Outra boa referência é [Learn C the hard way](http://c.learncodethehardway.org/book/). Se você tem uma pergunta, leia [compl.lang.c Frequently Asked Questions](http://c-faq.com). É importante usar espaços e indentação adequadamente e ser consistente com seu estilo de código em geral. -Código legível é melhor que código 'esperto' e rápido. Para adotar um estilo de código bom e são, veja +Código legível é melhor que código 'esperto' e rápido. Para adotar um estilo de código bom e sensato, veja [Linux kernel coding style](https://www.kernel.org/doc/Documentation/CodingStyle). Além disso, Google é teu amigo. + [1] http://stackoverflow.com/questions/119123/why-isnt-sizeof-for-a-struct-equal-to-the-sum-of-sizeof-of-each-member diff --git a/pt-br/cmake-pt.html.markdown b/pt-br/cmake-pt.html.markdown new file mode 100644 index 00000000..bc3e7050 --- /dev/null +++ b/pt-br/cmake-pt.html.markdown @@ -0,0 +1,178 @@ +--- +language: cmake +contributors: + - ["Bruno Alano", "https://github.com/brunoalano"] +filename: CMake +translators: + - ["Lucas Pugliesi", "https://github.com/fplucas"] +lang: pt-br +--- + +CMake é um programa de compilação open-source e multiplataforma. Essa ferramenta +permitirá testar, compilar e criar pacotes a partir do seu código fonte. + +O problema que o CMake tenta resolver são os problemas de configurar os Makefiles +e Autoconfigure (diferente dos interpretadores make que tem comandos diferentes) +e sua facilidade de uso envolvendo bibliotecas terceiras. + +CMake é um sistema open-source extensível que gerencia o processo de build em um +sistema operacional e um método independente de compilador. Diferente de sistemas +multiplataformas, CMake é designado a usar em conjunto ao ambiente de compilação +nativo. Seus simples arquivos de configuração localizados em seus diretórios +(chamados arquivos CMakeLists.txt) que são usados para gerar padrões de arquivos +de compilação (ex: makefiles no Unix e projetos em Windows MSVC) que são usados +de maneira simples. + +```cmake +# No CMake, isso é um comentário + +# Para rodar nosso código, iremos utilizar esses comandos: +# - mkdir build && cd build +# - cmake .. +# - make +# +# Com esses comandos, iremos seguir as melhores práticas para compilar em um +# subdiretório e na segunda linha pediremos ao CMake para gerar um novo Makefile +# independente de sistema operacional. E finalmente, rodar o comando make. + +#------------------------------------------------------------------------------ +# Básico +#------------------------------------------------------------------------------ +# +# O arquivo CMake deve ser chamado de "CMakeLists.txt". + +# Configura a versão mínima requerida do CMake para gerar o Makefile +cmake_minimum_required (VERSION 2.8) + +# Exibe FATAL_ERROR se a versão for menor que 2.8 +cmake_minimum_required (VERSION 2.8 FATAL_ERROR) + +# Configuramos o nome do nosso projeto. Mas antes disso, iremos alterar alguns +# diretórios em nome da convenção gerada pelo CMake. Podemos enviar a LANG do +# código como segundo parâmetro +project (learncmake C) + +# Configure o diretório do código do projeto (somente convenção) +set( LEARN_CMAKE_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR} ) +set( LEARN_CMAKE_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR} ) + +# Isso é muito útil para configurar a versão do nosso código no sistema de compilação +# usando um estilo `semver` +set (LEARN_CMAKE_VERSION_MAJOR 1) +set (LEARN_CMAKE_VERSION_MINOR 0) +set (LEARN_CMAKE_VERSION_PATCH 0) + +# Envie as variáveis (número da versão) para o cabeçalho de código-fonte +configure_file ( + "${PROJECT_SOURCE_DIR}/TutorialConfig.h.in" + "${PROJECT_BINARY_DIR}/TutorialConfig.h" +) + +# Inclua Diretórios +# No GCC, isso irá invocar o comando "-I" +include_directories( include ) + +# Onde as bibliotecas adicionais estão instaladas? Nota: permite incluir o path +# aqui, na sequência as checagens irão resolver o resto +set( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/CMake/modules/" ) + +# Condições +if ( CONDICAO ) + # reposta! + + # Informação incidental + message(STATUS "Minha mensagem") + + # Aviso CMake, continua processando + message(WARNING "Minha mensagem") + + # Aviso (dev) CMake, continua processando + message(AUTHOR_WARNING "Minha mensagem") + + # Erro CMake, continua processando, mas pula a geração + message(SEND_ERROR "Minha mensagem") + + # Erro CMake, para o processamento e a geração + message(FATAL_ERROR "Minha mensagem") +endif() + +if( CONDICAO ) + +elseif( CONDICAO ) + +else( CONDICAO ) + +endif( CONDICAO ) + +# Loops +foreach(loop_var arg1 arg2 ...) + COMANDO1(ARGS ...) + COMANDO2(ARGS ...) + ... +endforeach(loop_var) + +foreach(loop_var RANGE total) +foreach(loop_var RANGE start stop [step]) + +foreach(loop_var IN [LISTS [list1 [...]]] + [ITEMS [item1 [...]]]) + +while(condicao) + COMANDO1(ARGS ...) + COMANDO2(ARGS ...) + ... +endwhile(condicao) + + +# Operações Lógicas +if(FALSE AND (FALSE OR TRUE)) + message("Não exiba!") +endif() + +# Configure um cache normal, ou uma variável de ambiente com o dado valor. +# Se a opção PARENT_SCOPE for informada em uma variável que será setada no escopo +# acima do escopo corrente. +# `set(<variavel> <valor>... [PARENT_SCOPE])` + +# Como refencia variáveis dentro de aspas ou não, argumentos com strings vazias +# não serão setados +${nome_da_variavel} + +# Listas +# Configure a lista de arquivos código-fonte +set( LEARN_CMAKE_SOURCES + src/main.c + src/imagem.c + src/pather.c +) + +# Chama o compilador +# +# ${PROJECT_NAME} referencia ao Learn_CMake +add_executable( ${PROJECT_NAME} ${LEARN_CMAKE_SOURCES} ) + +# Linka as bibliotecas +target_link_libraries( ${PROJECT_NAME} ${LIBS} m ) + +# Onde as bibliotecas adicionais serão instaladas? Nota: nos permite incluir o path +# aqui, em seguida os testes irão resolver o restante +set( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/CMake/modules/" ) + +# Condição do compilador (gcc ; g++) +if ( "${CMAKE_C_COMPILER_ID}" STREQUAL "GNU" ) + message( STATUS "Setting the flags for ${CMAKE_C_COMPILER_ID} compiler" ) + add_definitions( --std=c99 ) +endif() + +# Checa o Sistema Operacional +if( UNIX ) + set( LEARN_CMAKE_DEFINITIONS + "${LEARN_CMAKE_DEFINITIONS} -Wall -Wextra -Werror -Wno-deprecated-declarations -Wno-unused-parameter -Wno-comment" ) +endif() +``` + +### Mais Recursos + ++ [cmake tutorial](https://cmake.org/cmake-tutorial/) ++ [cmake documentation](https://cmake.org/documentation/) ++ [mastering cmake](http://amzn.com/1930934319/) diff --git a/pt-br/common-lisp-pt.html.markdown b/pt-br/common-lisp-pt.html.markdown index 03a7c15c..c22cfd8e 100644 --- a/pt-br/common-lisp-pt.html.markdown +++ b/pt-br/common-lisp-pt.html.markdown @@ -19,7 +19,7 @@ Outro livro recente e popular é o [Land of Lisp](http://landoflisp.com/). -```common_lisp +```lisp ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;; 0. Sintaxe diff --git a/pt-br/csharp-pt.html.markdown b/pt-br/csharp-pt.html.markdown index 547f4817..be14a1c8 100644 --- a/pt-br/csharp-pt.html.markdown +++ b/pt-br/csharp-pt.html.markdown @@ -6,23 +6,23 @@ contributors: lang: pt-br --- -C# é uma linguagem elegante e altamente tipado orientada a objetos que permite aos desenvolvedores criarem uma variedade de aplicações seguras e robustas que são executadas no .NET Framework. +C# é uma linguagem elegante, altamente tipada e orientada a objetos que permite aos desenvolvedores criar uma variedade de aplicações seguras e robustas que são executadas no .NET Framework. -[Read more here.](http://msdn.microsoft.com/pt-br/library/vstudio/z1zx9t92.aspx) +[Leia mais aqui.](http://msdn.microsoft.com/pt-br/library/vstudio/z1zx9t92.aspx) ```c# -// Comentário de linha única começa com // +// Comentários de linha única começam com // /* -Múltipas linhas é desta forma +Comentários de múltiplas linhas são desta forma */ /// <summary> -/// Esta é uma documentação comentário XML que pode ser usado para gerar externo -/// documentação ou fornecer ajuda de contexto dentro de um IDE +/// Este é um comentário de documentação XML que pode ser usado para gerar documentação +/// externa ou para fornecer ajuda de contexto dentro de uma IDE /// </summary> //public void MethodOrClassOrOtherWithParsableHelp() {} -// Especificar qual namespace seu código irá usar -// Os namespaces a seguir são padrões do .NET Framework Class Library +// Especifica os namespaces que o código irá usar +// Os namespaces a seguir são padrões da biblioteca de classes do .NET Framework using System; using System.Collections.Generic; using System.Dynamic; @@ -33,11 +33,11 @@ using System.IO; // Mas este aqui não é : using System.Data.Entity; -// Para que consiga utiliza-lo, você precisa adicionar novas referências +// Para que consiga utilizá-lo, você precisa adicionar novas referências // Isso pode ser feito com o gerenciador de pacotes NuGet : `Install-Package EntityFramework` -// Namespaces são escopos definidos para organizar o códgo em "pacotes" or "módulos" -// Usando este código a partir de outra arquivo de origem: using Learning.CSharp; +// Namespaces são escopos definidos para organizar o código em "pacotes" ou "módulos" +// Usando este código a partir de outro arquivo de origem: using Learning.CSharp; namespace Learning.CSharp { // Cada .cs deve conter uma classe com o mesmo nome do arquivo @@ -762,7 +762,7 @@ on a new line! ""Wow!"", the masses cried"; } } - //Method to display the attribute values of this Object. + //Método para exibir os valores dos atributos deste objeto. public virtual string Info() { return "Gear: " + Gear + @@ -784,13 +784,13 @@ on a new line! ""Wow!"", the masses cried"; } // end class Bicycle - // PennyFarthing is a subclass of Bicycle + // PennyFarthing é uma subclasse de Bicycle class PennyFarthing : Bicycle { - // (Penny Farthings are those bicycles with the big front wheel. - // They have no gears.) + // (Penny Farthings são aquelas bicicletas com uma grande roda frontal. + // Elas não tem correias.) - // calling parent constructor + // chamando construtor pai public PennyFarthing(int startCadence, int startSpeed) : base(startCadence, startSpeed, 0, "PennyFarthing", true, BikeBrand.Electra) { @@ -823,10 +823,10 @@ on a new line! ""Wow!"", the masses cried"; } } - // Interfaces only contain signatures of the members, without the implementation. + // Interfaces contêm apenas as assinaturas dos membros, sem a implementação. interface IJumpable { - void Jump(int meters); // all interface members are implicitly public + void Jump(int meters); // todos os membros da interface são implicitamente públicos } interface IBreakable @@ -834,7 +834,7 @@ on a new line! ""Wow!"", the masses cried"; bool Broken { get; } // interfaces can contain properties as well as methods & events } - // Class can inherit only one other class, but can implement any amount of interfaces + // Classes podem herdar apenas de uma outra classe, mas podem implementar qualquer quantidade de interfaces. class MountainBike : Bicycle, IJumpable, IBreakable { int damage = 0; diff --git a/pt-br/css-pt.html.markdown b/pt-br/css-pt.html.markdown index b1fbd961..c73669d0 100644 --- a/pt-br/css-pt.html.markdown +++ b/pt-br/css-pt.html.markdown @@ -9,6 +9,8 @@ contributors: - ["Deepanshu Utkarsh", "https://github.com/duci9y"] translators: - ["Gabriel Gomes", "https://github.com/gabrielgomesferraz"] + - ["Gabriele Luz", "https://github.com/gabrieleluz"] + lang: pt-br --- @@ -25,7 +27,7 @@ O foco principal deste artigo é sobre a sintaxe e algumas dicas gerais. ```css /* Comentários aparecem dentro do slash-asterisk, tal como esta linha! - não há "comentários de uma linha"; este é o único estilo de comentário * / + Não há "comentários de uma linha"; este é o único estilo de comentário * / /* #################### ## SELETORES @@ -236,6 +238,45 @@ A precedência de estilo é a seguinte. Lembre-se, a precedência é para cada * `B` é o próximo. * `D` é a última. +## Media Queries +Media queries são recursos do CSS3 que permitem especificar quando determinadas regras de CSS devem ser aplicadas; é possível aplicar regras diferentes quando a página é impressa, quando a tela possui determinadas dimensões ou densidade de pixels e quando é lida por um leitor de tela. Media queries não adicionam especificidade ao seletor. + +```css +/* Uma regra que será aplicada a todos os dispositivos */ +h1 { + font-size: 2em; + color: white; + background-color: black; +} + +/* Altera a cor do h1 para utilizar menos tinta durante a impressão */ +@media print { + h1 { + color: black; + background-color: white; + } +} + +/* Altera o tamanho da fonte quando exibida numa tela com pelo menos 480px de largura */ +@media screen and (min-width: 480px) { + h1 { + font-size: 3em; + font-weight: normal; + } +} +``` +Media queries podem incluir os seguintes atributos: `width`, `height`, `device-width`, `device-height`, `orientation`, `aspect-ratio`, `device-aspect-ratio`, `color`, `color-index`, `monochrome`, `resolution`, `scan`, `grid`. A maioria desses atributos pode ser prefixada com `min-` ou `max-`. + +O atributo `resolution` não é suportado em dispositivos mais antigos. Em vez disso, use `device-pixel-ratio`. + +Muitos smartphones e tablets tentarão renderizar a página como se estivesse num desktop a menos que você utilize a meta-tag `viewport`. + +```html +<head> + <meta name="viewport" content="width=device-width; initial-scale=1.0"> +</head> +``` + ## Compatibilidade A maior parte dos recursos do CSS 2 (e muitos em CSS 3) estão disponíveis em todos os navegadores e dispositivos. Mas é sempre boa prática para verificar antes de usar um novo recurso. diff --git a/pt-br/cypher-pt.html.markdown b/pt-br/cypher-pt.html.markdown new file mode 100644 index 00000000..7cfd8dcd --- /dev/null +++ b/pt-br/cypher-pt.html.markdown @@ -0,0 +1,250 @@ +--- +language: cypher +filename: LearnCypher.cql +contributors: + - ["Théo Gauchoux", "https://github.com/TheoGauchoux"] + +lang: pt-br +--- + +O Cypher é a linguagem de consulta do Neo4j para manipular gráficos facilmente. Ela reutiliza a sintaxe do SQL e a mistura com o tipo de ascii-art para representar gráficos. Este tutorial pressupõe que você já conheça conceitos de gráficos como nós e relacionamentos. + +[Leia mais aqui.](https://neo4j.com/developer/cypher-query-language/) + + +Nós +--- + +**Representa um registro em um gráfico.** + +`()` +É um *nó* vazio, para indicar que existe um *nó*, mas não é relevante para a consulta. + +`(n)` +É um *nó* referido pela variável **n**, reutilizável na consulta. Começa com minúsculas e usa o camelCase. + +`(p:Person)` +Você pode adicionar um *label* ao seu nó, aqui **Person**. É como um tipo / uma classe / uma categoria. Começa com maiúsculas e usa o camelCase. + +`(p:Person:Manager)` +Um nó pode ter muitos *labels*. + +`(p:Person {name : 'Théo Gauchoux', age : 22})` +Um nó pode ter algumas *propriedades*, aqui **name** e **age**. Começa com minúsculas e usa o camelCase. + +Os tipos permitidos nas propriedades: + + - Numeric + - Boolean + - String + - Lista de tipos primitivos anteriores + +*Aviso: não há propriedade datetime no Cypher! Você pode usar String com um padrão específico ou um Numeric a partir de uma data específica.* + +`p.name` +Você pode acessar uma propriedade com o estilo de ponto. + + +Relacionamentos (ou Arestas) +--- + +**Conecta dois nós** + +`[:KNOWS]` +É um *relacionamento* com o *label* **KNOWS**. É um *label* como um rótulo do nó. Começa com maiúsculas e usa UPPER_SNAKE_CASE. + +`[k:KNOWS]` +O mesmo *relacionamento*, referido pela variável **k**, reutilizável na consulta, mas não é necessário. + +`[k:KNOWS {since:2017}]` +O mesmo *relacionamento*, com *propriedades* (como *nó*), aqui **since**. + +`[k:KNOWS*..4]` +É uma informação estrutural para usar em um *path* (visto posteriormente). Aqui, **\*..4** diz, “Corresponda o padrão, com a relação **k** que é repetida de 1 a 4 vezes. + + +Paths +--- + +**A maneira de misturar nós e relacionamentos.** + +`(a:Person)-[:KNOWS]-(b:Person)` +Um path descrevendo que **a** e **b** se conhecem. + +`(a:Person)-[:MANAGES]->(b:Person)` +Um path pode ser direcionado. Este path descreve que **a** é o gerente de **b**. + +`(a:Person)-[:KNOWS]-(b:Person)-[:KNOWS]-(c:Person)` +Você pode encadear vários relacionamentos. Este path descreve o amigo de um amigo. + +`(a:Person)-[:MANAGES]->(b:Person)-[:MANAGES]->(c:Person)` +Uma encadeamento também pode ser direcionada. Este path descreve que **a** é o chefe de **b** e o grande chefe de **c**. + +Padrões frequentemente usados (do Neo4j doc) : + +``` +// Amigo de um amigo +(user)-[:KNOWS]-(friend)-[:KNOWS]-(foaf) + +// Path mais curto +path = shortestPath( (user)-[:KNOWS*..5]-(other) ) + +// Filtragem colaborativa +(user)-[:PURCHASED]->(product)<-[:PURCHASED]-()-[:PURCHASED]->(otherProduct) + +// Navegação de árvore +(root)<-[:PARENT*]-(leaf:Category)-[:ITEM]->(data:Product) + +``` + + +Crie consultas +--- + +Create a new node +``` +CREATE (a:Person {name:"Théo Gauchoux"}) +RETURN a +``` +*`RETURN` permite ter um resultado após a consulta. Pode ser múltiplo, como `RETURN a, b`.* + +Crie um novo relacionamento (com 2 novos nós) +``` +CREATE (a:Person)-[k:KNOWS]-(b:Person) +RETURN a,k,b +``` + +Consultas que casam +--- + +Casam todos os nós +``` +MATCH (n) +RETURN n +``` + +Casam nós por label +``` +MATCH (a:Person) +RETURN a +``` + +Casam nós por label e propriedade +``` +MATCH (a:Person {name:"Théo Gauchoux"}) +RETURN a +``` + +Casam nós de acordo com os relacionamentos (não direcionados) +``` +MATCH (a)-[:KNOWS]-(b) +RETURN a,b +``` + +Casam nós de acordo com os relacionamentos (direcionados) +``` +MATCH (a)-[:MANAGES]->(b) +RETURN a,b +``` + +Casam nós com um cláusula `WHERE` +``` +MATCH (p:Person {name:"Théo Gauchoux"})-[s:LIVES_IN]->(city:City) +WHERE s.since = 2015 +RETURN p,state +``` + +Você pode usa a cláusula `MATCH WHERE` com a cláusula `CREATE` +``` +MATCH (a), (b) +WHERE a.name = "Jacquie" AND b.name = "Michel" +CREATE (a)-[:KNOWS]-(b) +``` + + +Atualizar consultas +--- + +Atualizar uma propriedade específica de um nó +``` +MATCH (p:Person) +WHERE p.name = "Théo Gauchoux" +SET p.age = 23 +``` + +Substituir todas as propriedades de um nó +``` +MATCH (p:Person) +WHERE p.name = "Théo Gauchoux" +SET p = {name: "Michel", age: 23} +``` + +Adicionar nova propriedade a um nó +``` +MATCH (p:Person) +WHERE p.name = "Théo Gauchoux" +SET p + = {studies: "IT Engineering"} +``` + +Adicione um label a um nó +``` +MATCH (p:Person) +WHERE p.name = "Théo Gauchoux" +SET p:Internship +``` + + +Excluir consultas +--- + +Excluir um nó específico (os relacionamentos vinculados devem ser excluídos antes) +``` +MATCH (p:Person)-[relationship]-() +WHERE p.name = "Théo Gauchoux" +DELETE relationship, p +``` + +Remover uma propriedade em um nó específico +``` +MATCH (p:Person) +WHERE p.name = "Théo Gauchoux" +REMOVE p.age +``` +*Prestar atenção à palavra chave `REMOVE`, não é `DELETE` !* + +Remover um label de um nó específico +``` +MATCH (p:Person) +WHERE p.name = "Théo Gauchoux" +DELETE p:Person +``` + +Excluir o banco de dados inteiro +``` +MATCH (n) +OPTIONAL MATCH (n)-[r]-() +DELETE n, r +``` +*Sério, é o `rm -rf /` do Cypher !* + + +Outras cláusulas úteis +--- + +`PROFILE` +Antes de uma consulta, mostre o plano de execução dela. + +`COUNT(e)` +Contar entidades (nós ou relacionamentos) que casam com **e**. + +`LIMIT x` +Limite o resultado aos primeiros x resultados. + + +Dicas Especiais +--- + +- Há apenas comentários de uma linha no Cypher, com barras duplas : // Comentários +- Você pode executar um script Cypher armazenado em um arquivo **.cql** diretamente no Neo4j (é uma importação). No entanto, você não pode ter várias instruções neste arquivo (separadas por **;**). +- Use o shell Neo4j para escrever Cypher, é realmente incrível. +- O Cypher será a linguagem de consulta padrão para todos os bancos de dados de gráficos (conhecidos como **OpenCypher**). diff --git a/pt-br/dart-pt.html.markdown b/pt-br/dart-pt.html.markdown new file mode 100644 index 00000000..e9d72850 --- /dev/null +++ b/pt-br/dart-pt.html.markdown @@ -0,0 +1,509 @@ +--- +language: dart +filename: learndart-pt.dart +contributors: + - ["Joao Pedrosa", "https://github.com/jpedrosa/"] +translators: + - ["Junior Damacena", "https://github.com/jdamacena/"] +lang: pt-br +--- + +Dart é uma novata no reino das linguagens de programação. +Ela empresta muito de outras linguagens mais conhecidas, e tem a meta de não se diferenciar muito de seu irmão, JavaScript. Assim como JavaScript, Dart foi pensada para oferecer grande integração com o Browser. + +A característica mais controversa da Dart é a sua Tipagem Opcional, ou seja, não é obrigatório declarar tipos. + +```dart +import "dart:collection"; +import "dart:math" as DM; + +// Bem vindo ao Aprenda Dart em 15 minutos. http://www.dartlang.org/ +// Este é um tutorial executável. Você pode rodar esse tutorial com Dart ou no +// site Try Dart!, é só copiar e colar este código lá. http://try.dartlang.org/ + +// Declarações de funções e métodos são iguais. Declarações de funções +// podem ser aninhadas. A declaração é feita das seguintes formas +// nome() {} ou nome() => expressaoDeUmaLinhaSo; +// A declaração feita com a seta tem um return implícito para o resultado da +// expressão. +example1() { + example1nested1() { + example1nested2() => print("Example1 nested 1 nested 2"); + example1nested2(); + } + example1nested1(); +} + +// Funções anônimas são criadas sem um nome. +example2() { + example2nested1(fn) { + fn(); + } + example2nested1(() => print("Example2 nested 1")); +} + +// Quando uma função é declarada como parâmetro, a declaração pode incluir o número +// de parâmetros que a função recebe, isso é feito especificando o nome de cada um dos +// parâmetros que serão recebidos pela função. +example3() { + example3nested1(fn(informSomething)) { + fn("Example3 nested 1"); + } + example3planB(fn) { // Ou não declare o número de parâmetros. + fn("Example3 plan B"); + } + example3nested1((s) => print(s)); + example3planB((s) => print(s)); +} + +// Funções têm acesso à variáveis fora de seu escopo +var example4Something = "Example4 nested 1"; +example4() { + example4nested1(fn(informSomething)) { + fn(example4Something); + } + example4nested1((s) => print(s)); +} + +// Declaração de classe com um método chamado sayIt, que também tem acesso +// à variável externa, como se fosse uma função como se viu antes. +var example5method = "Example5 sayIt"; +class Example5Class { + sayIt() { + print(example5method); + } +} +example5() { + // Criar uma instância anônima de Example5Class e chamar o método sayIt + // nela. + new Example5Class().sayIt(); +} + +// A declaração de uma classe é feita da seguinte maneira: class name { [classBody] }. +// onde classBody pode incluir métodos e variáveis de instância, assim como +// métodos e variáveis de classe. +class Example6Class { + var example6InstanceVariable = "Example6 instance variable"; + sayIt() { + print(example6InstanceVariable); + } +} +example6() { + new Example6Class().sayIt(); +} + +// Métodos e variáveis de classe são declarados como "static". +class Example7Class { + static var example7ClassVariable = "Example7 class variable"; + static sayItFromClass() { + print(example7ClassVariable); + } + sayItFromInstance() { + print(example7ClassVariable); + } +} +example7() { + Example7Class.sayItFromClass(); + new Example7Class().sayItFromInstance(); +} + +// Literais são ótimos, mas há uma limitação para o que eles podem ser +// quando estão fora do corpo de uma função/método. Literais fora do escopo da classe +// ou fora da classe têm que ser constantes. Strings e números são constantes +// por padrão. Mas arrays e mapas não. Eles podem ser declarados como constantes +// usando o comando "const". +var example8A = const ["Example8 const array"], + example8M = const {"someKey": "Example8 const map"}; +example8() { + print(example8A[0]); + print(example8M["someKey"]); +} + +// Loops em Dart são criados com for () {} ou while () {}, +// um pouco mais moderno temos for (.. in ..) {}, ou funções de callbacks com muitas +// funcionalidades, começando com o forEach. +var example9A = const ["a", "b"]; +example9() { + for (var i = 0; i < example9A.length; i++) { + print("Example9 for loop '${example9A[i]}'"); + } + var i = 0; + while (i < example9A.length) { + print("Example9 while loop '${example9A[i]}'"); + i++; + } + for (var e in example9A) { + print("Example9 for-in loop '${e}'"); + } + example9A.forEach((e) => print("Example9 forEach loop '${e}'")); +} + +// Para percorrer os caracteres de uma string ou extrair uma substring. +var example10S = "ab"; +example10() { + for (var i = 0; i < example10S.length; i++) { + print("Example10 String character loop '${example10S[i]}'"); + } + for (var i = 0; i < example10S.length; i++) { + print("Example10 substring loop '${example10S.substring(i, i + 1)}'"); + } +} + +// Int e double são os dois formatos de número suportados. +example11() { + var i = 1 + 320, d = 3.2 + 0.01; + print("Example11 int ${i}"); + print("Example11 double ${d}"); +} + +// DateTime traz operações com data/hora. +example12() { + var now = new DateTime.now(); + print("Example12 now '${now}'"); + now = now.add(new Duration(days: 1)); + print("Example12 tomorrow '${now}'"); +} + +// Expressões regulares são suportadas. +example13() { + var s1 = "some string", s2 = "some", re = new RegExp("^s.+?g\$"); + match(s) { + if (re.hasMatch(s)) { + print("Example13 regexp matches '${s}'"); + } else { + print("Example13 regexp doesn't match '${s}'"); + } + } + match(s1); + match(s2); +} + +// Expressões booleanas precisam retornar ou true ou false, já que +// Dart não faz a conversão implicitamente. +example14() { + var v = true; + if (v) { + print("Example14 value is true"); + } + v = null; + try { + if (v) { + // Nunca seria executada + } else { + // Nunca seria executada + } + } catch (e) { + print("Example14 null value causes an exception: '${e}'"); + } +} + +// try/catch/finally e throw são usados para tratamento de exceções. +// throw aceita qualquer objeto como parâmetro; +example15() { + try { + try { + throw "Some unexpected error."; + } catch (e) { + print("Example15 an exception: '${e}'"); + throw e; // Re-throw + } + } catch (e) { + print("Example15 catch exception being re-thrown: '${e}'"); + } finally { + print("Example15 Still run finally"); + } +} + +// Para mais eficiência ao criar strings longas dinamicamente, use o +// StringBuffer. Ou você pode também concatenar um array de strings. +example16() { + var sb = new StringBuffer(), a = ["a", "b", "c", "d"], e; + for (e in a) { sb.write(e); } + print("Example16 dynamic string created with " + "StringBuffer '${sb.toString()}'"); + print("Example16 join string array '${a.join()}'"); +} + +// Strings podem ser concatenadas apenas colocando strings literais uma perto +// da outra, sem necessidade de nenhum outro operador. +example17() { + print("Example17 " + "concatenar " + "strings " + "é simples assim"); +} + +// Strings podem ser delimitadas por apóstrofos ou aspas e não há +// diferença entre os dois. Essa flexibilidade pode ser boa para +// evitar a necessidade de escapar conteúdos que contenham o delimitador da string. +// Por exemplo, aspas dos atributos HTMLse a string conter HTML. +example18() { + print('Example18 <a href="etc">' + "Don't can't I'm Etc" + '</a>'); +} + +// Strings com três apóstrofos ou aspas podem +// ter muitas linhas e incluem os delimitadores de linha (ou seja, os enter). +example19() { + print('''Example19 <a href="etc"> +Example19 Don't can't I'm Etc +Example19 </a>'''); +} + +// Strings têm a função de interpolação que é chamada com o caractere $. +// Com $ { [expression] }, o retorno da expressão é interpolado. +// $ seguido pelo nome de uma variável interpola o conteúdo dessa variável. +// $ pode ser escapedo assim \$. +example20() { + var s1 = "'\${s}'", s2 = "'\$s'"; + print("Example20 \$ interpolation ${s1} or $s2 works."); +} + +// A tipagem opcional permite que APIs usem anotações e também ajuda os +// IDEs na hora das refatorações, auto-complete e checagem de +// erros. Note que até agora não declaramos nenhum tipo e o programa está +// funcionando normalmente. De fato, os tipos são ignorados em tempo de execução. +// Os tipos podem até mesmo estarem errados e o programa ainda vai dar o +// benefício da dúvida e rodar, visto que os tipos não importam. +// Existe um parâmetro que checa erros de tipagem que é o +// checked mode, dizem que é útil enquanto se está desenvolvendo, +// mas também é mais lento devido às checagens extras e por isso +// é evitado em ambiente de produção. +class Example21 { + List<String> _names; + Example21() { + _names = ["a", "b"]; + } + List<String> get names => _names; + set names(List<String> list) { + _names = list; + } + int get length => _names.length; + void add(String name) { + _names.add(name); + } +} +void example21() { + Example21 o = new Example21(); + o.add("c"); + print("Example21 names '${o.names}' and length '${o.length}'"); + o.names = ["d", "e"]; + print("Example21 names '${o.names}' and length '${o.length}'"); +} + +// Herança em classes é feito assim: class name extends AnotherClassName {}. +class Example22A { + var _name = "Some Name!"; + get name => _name; +} +class Example22B extends Example22A {} +example22() { + var o = new Example22B(); + print("Example22 class inheritance '${o.name}'"); +} + +// Mistura de classes também é possível, e é feito assim: +// class name extends SomeClass with AnotherClassName {} +// É necessário extender uma classe para poder misturar com outra. +// No momento, classes misturadas não podem ter construtor. +// Mistura de classes é mais usado para compartilhar métodos com classes distantes, então +// a herança comum não fica no caminho do reuso de código. +// As misturas aparecem após o comando "with" na declaração da classe. +class Example23A {} +class Example23Utils { + addTwo(n1, n2) { + return n1 + n2; + } +} +class Example23B extends Example23A with Example23Utils { + addThree(n1, n2, n3) { + return addTwo(n1, n2) + n3; + } +} +example23() { + var o = new Example23B(), r1 = o.addThree(1, 2, 3), + r2 = o.addTwo(1, 2); + print("Example23 addThree(1, 2, 3) results in '${r1}'"); + print("Example23 addTwo(1, 2) results in '${r2}'"); +} + +// O método construtor da classe usa o mesmo nome da classe e +// é feito assim SomeClass() : super() {}, onde a parte ": super()" +// é opcional e é usada para passar parâmetros estáticos para o +// construtor da classe pai. +class Example24A { + var _value; + Example24A({value: "someValue"}) { + _value = value; + } + get value => _value; +} +class Example24B extends Example24A { + Example24B({value: "someOtherValue"}) : super(value: value); +} +example24() { + var o1 = new Example24B(), + o2 = new Example24B(value: "evenMore"); + print("Example24 calling super during constructor '${o1.value}'"); + print("Example24 calling super during constructor '${o2.value}'"); +} + +// Há um atalho para passar parâmetros para o construtor no caso de classes mais simples. +// Simplesmente use o prefixo this.nomeDoParametro e isso irá passar o parâmetro para uma +// instância de variável de mesmo nome. +class Example25 { + var value, anotherValue; + Example25({this.value, this.anotherValue}); +} +example25() { + var o = new Example25(value: "a", anotherValue: "b"); + print("Example25 shortcut for constructor '${o.value}' and " + "'${o.anotherValue}'"); +} + +// Parâmetros com nome estão disponíveis quando declarados entre {}. +// Quando os parâmetros têm nomes, eles podem ser passados em qualquer ordem. +// Parâmetros declarados entre [] são opcionais. +example26() { + var _name, _surname, _email; + setConfig1({name, surname}) { + _name = name; + _surname = surname; + } + setConfig2(name, [surname, email]) { + _name = name; + _surname = surname; + _email = email; + } + setConfig1(surname: "Doe", name: "John"); + print("Example26 name '${_name}', surname '${_surname}', " + "email '${_email}'"); + setConfig2("Mary", "Jane"); + print("Example26 name '${_name}', surname '${_surname}', " + "email '${_email}'"); +} + +// Variáveis declaradas com um final só podem receber valor uma vez. +// No caso de classes, variáveis final podem ter valor atribuido através +// de um parâmetro no construtor +class Example27 { + final color1, color2; + // Um pouco de flexibilidade ao criar variáveis final com a sintaxe + // que é a seguinte: + Example27({this.color1, color2}) : color2 = color2; +} +example27() { + final color = "orange", o = new Example27(color1: "lilac", color2: "white"); + print("Example27 color is '${color}'"); + print("Example27 color is '${o.color1}' and '${o.color2}'"); +} + +// para importar uma biblioteca, use import "libraryPath" ou se for uma biblioteca da linguagem, +// import "dart:libraryName". Também tem o gerenciador de pacotes "pub"que tem +// sua própria convenção de import "package:packageName". +// Veja o import "dart:collection"; no início do arquivo. Imports devem vir no início +// do arquivo. IterableBase vem de dart:collection. +class Example28 extends IterableBase { + var names; + Example28() { + names = ["a", "b"]; + } + get iterator => names.iterator; +} +example28() { + var o = new Example28(); + o.forEach((name) => print("Example28 '${name}'")); +} + +// Para controle de fluxo nós temos: +// * switch com comandos break obrigatórios +// * if-else if-else e se-ternário ..?..:.. +// * closures e funções anônimas +// * comandos break, continue e return +example29() { + var v = true ? 30 : 60; + switch (v) { + case 30: + print("Example29 switch statement"); + break; + } + if (v < 30) { + } else if (v > 30) { + } else { + print("Example29 if-else statement"); + } + callItForMe(fn()) { + return fn(); + } + rand() { + v = new DM.Random().nextInt(50); + return v; + } + while (true) { + print("Example29 callItForMe(rand) '${callItForMe(rand)}'"); + if (v != 30) { + break; + } else { + continue; + } + // Nunca chega aqui. + } +} + +// Você pode converter string para int, double para int, ou só pegar a parte inteira da divisão +// usando o comando ~/. Vamos jogar um jogo de adivinhação. +example30() { + var gn, tooHigh = false, + n, n2 = (2.0).toInt(), top = int.parse("123") ~/ n2, bottom = 0; + top = top ~/ 6; + gn = new DM.Random().nextInt(top + 1); // +1 porque o máximo do nextInt conta o número passado - 1 + print("Example30 Diga um número entre 0 e ${top}"); + guessNumber(i) { + if (n == gn) { + print("Example30 Você acertou! O número é ${gn}"); + } else { + tooHigh = n > gn; + print("Example30 O número ${n} é muito " + "${tooHigh ? 'alto' : 'baixo'}. Tente de novo"); + } + return n == gn; + } + n = (top - bottom) ~/ 2; + while (!guessNumber(n)) { + if (tooHigh) { + top = n - 1; + } else { + bottom = n + 1; + } + n = bottom + ((top - bottom) ~/ 2); + } +} + +// Programas em Dart só têm um ponto de entrada, que é a função main. +// Nada será executado antes da funcão main de um programa. +// Isso ajuda a carregar o programa mais rapidamente, até mesmo quando o +// carregamento é "Lazy". +// O programa deve começar com: +main() { + print("Aprenda Dart em 15 minutos!"); + [example1, example2, example3, example4, example5, example6, example7, + example8, example9, example10, example11, example12, example13, example14, + example15, example16, example17, example18, example19, example20, + example21, example22, example23, example24, example25, example26, + example27, example28, example29, example30 + ].forEach((ef) => ef()); +} + +``` + +## Continue lendo + +Dart tem um site bastante fácil de entender. Ele tem os docs da API, tutoriais, artigos e muito mais, incluindo uma +opção muito útil de testar o Dart online. +* [https://www.dartlang.org](https://www.dartlang.org) +* [https://try.dartlang.org](https://try.dartlang.org) + + + + diff --git a/pt-br/dynamic-programming-pt.html.markdown b/pt-br/dynamic-programming-pt.html.markdown index 8de9bee6..518660a3 100644 --- a/pt-br/dynamic-programming-pt.html.markdown +++ b/pt-br/dynamic-programming-pt.html.markdown @@ -22,16 +22,16 @@ Sempre se lembre!! ## Maneiras de Solucionar tais Problemas -1. Top-Down (De cima para baixo): Começe solucionando o problema quebrando-o em +1. Top-Down (De cima para baixo): Comece solucionando o problema quebrando-o em partes. Se você perceber que o problema já foi resolvido, então simplemente pegue a resposta salva. Se ainda não foi resolvido, solucione-o e salve a resposta. Isso é geralmente fácil de pensar e muito intuitivo. É geralmente referenciado como Memorização. 2. Bottom-Up (De baixo para cima): Analise o problema e veja a ordem em que os -subproblemas são resolvidos e começe a solucionar dos problemas mais triviais, +subproblemas são resolvidos e comece a solucionar dos problemas mais triviais, até o problema dado. Neste processo, é garantido que os subproblemas são -resolvidos antes de resoler o problema. Isto é referenciado como Programação Dinâmica. +resolvidos antes de resolver o problema. Isto é referenciado como Programação Dinâmica. ## Exemplo de Programação Dinâmica @@ -51,7 +51,7 @@ array antecedente e uma variável como maiorSequenciasAteAgora e seu índice ajudariam a poupar muito tempo. Um conceito similar poderia ser aplicado ao procurar o maior caminho em um grafo acíclico dirigido. ---------------------------------------------------------------------------- + ``` for i=0 to n-1 LS[i]=1 @@ -62,14 +62,12 @@ grafo acíclico dirigido. if (largest < LS[i]) ``` -### Alguns Problemas Famosos de Programação Dinâmica -``` -Floyd Warshall Algorithm - Tutorial and C Program source code:http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs---floyd-warshall-algorithm-with-c-program-source-code - -Integer Knapsack Problem - Tutorial and C Program source code: http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---the-integer-knapsack-problem +## Alguns Problemas Famosos de Programação Dinâmica -Longest Common Subsequence - Tutorial and C Program source code : http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---longest-common-subsequence -``` +- Floyd Warshall Algorithm - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs---floyd-warshall-algorithm-with-c-program-source-code]() +- Integer Knapsack Problem - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---the-integer-knapsack-problem]() +- Longest Common Subsequence - Tutorial and C Program source code : [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---longest-common-subsequence]() + ## Recursos Online (EN) diff --git a/pt-br/elm-pt.html.markdown b/pt-br/elm-pt.html.markdown index 78a4f1b7..d2469a93 100644 --- a/pt-br/elm-pt.html.markdown +++ b/pt-br/elm-pt.html.markdown @@ -76,8 +76,8 @@ List.head [] -- Nothing -- Acesse os elementos de um par com as funções first e second. -- (Este é um atalho; nós iremos para o "caminho real" em breve.) -fst ("elm", 42) -- "elm" -snd ("elm", 42) -- 42 +Tuple.first ("elm", 42) -- "elm" +Tuple.second ("elm", 42) -- 42 -- Uma tupla vazia ou "unidade" às vezes é utilizada como um placeholder. -- É o único valor de seu tipo, também chamado de "Unit". diff --git a/pt-br/factor-pt.html.markdown b/pt-br/factor-pt.html.markdown new file mode 100644 index 00000000..e3c8f4a9 --- /dev/null +++ b/pt-br/factor-pt.html.markdown @@ -0,0 +1,184 @@ +--- +language: factor +contributors: + - ["hyphz", "http://github.com/hyphz/"] +filename: learnfactor.factor + +lang: pt-br +--- + +Factor é uma linguagem moderna baseada em pilha, baseado em Forth, criada por Slava Pestov. + +Código neste arquivo pode ser digitado em Fator, mas não importado diretamente porque o cabeçalho de vocabulário e importação faria o início completamente confuso. + +```factor +! Este é um comentário + +! Como Forth, toda a programação é feita manipulando a pilha. +! A indicação de um valor literal o coloca na pilha. +5 2 3 56 76 23 65 ! Nenhuma saída, mas a pilha é impressa no modo interativo + +! Esses números são adicionados à pilha, da esquerda para a direita. +! .s imprime a pilha de forma não destrutiva. +.s ! 5 2 3 56 76 23 65 + +! A aritmética funciona manipulando dados na pilha. +5 4 + ! Sem saída + +! `.` mostra o resultado superior da pilha e o imprime. +. ! 9 + +! Mais exemplos de aritmética: +6 7 * . ! 42 +1360 23 - . ! 1337 +12 12 / . ! 1 +13 2 mod . ! 1 + +99 neg . ! -99 +-99 abs . ! 99 +52 23 max . ! 52 +52 23 min . ! 23 + +! Várias palavras são fornecidas para manipular a pilha, coletivamente conhecidas como palavras embaralhadas. + +3 dup - ! duplica o primeiro item (1st agora igual a 2nd): 3 - 3 +2 5 swap / ! troca o primeiro com o segundo elemento: 5 / 2 +4 0 drop 2 / ! remove o primeiro item (não imprima na tela): 4 / 2 +1 2 3 nip .s ! remove o segundo item (semelhante a drop): 1 3 +1 2 clear .s ! acaba com toda a pilha +1 2 3 4 over .s ! duplica o segundo item para o topo: 1 2 3 4 3 +1 2 3 4 2 pick .s ! duplica o terceiro item para o topo: 1 2 3 4 2 3 + +! Criando Palavras +! O `:` conjuntos de palavras do Factor no modo de compilação até que ela veja a palavra `;`. +: square ( n -- n ) dup * ; ! Sem saída +5 square . ! 25 + +! Podemos ver o que as palavra fazem também. +! \ suprime a avaliação de uma palavra e coloca seu identificador na pilha. +\ square see ! : square ( n -- n ) dup * ; + +! Após o nome da palavra para criar, a declaração entre parênteses dá o efeito da pilha. +! Podemos usar os nomes que quisermos dentro da declaração: +: weirdsquare ( camel -- llama ) dup * ; + +! Contanto que sua contagem corresponda ao efeito da pilha da palavra: +: doubledup ( a -- b ) dup dup ; ! Error: Stack effect declaration is wrong +: doubledup ( a -- a a a ) dup dup ; ! Ok +: weirddoubledup ( i -- am a fish ) dup dup ; ! Além disso Ok + +! Onde Factor difere do Forth é no uso de citações. +! Uma citação é um bloco de código que é colocado na pilha como um valor. +! [ inicia o modo de citação; ] termina. +[ 2 + ] ! A citação que adiciona 2 é deixada na pilha +4 swap call . ! 6 + +! E assim, palavras de ordem mais alta. TONS de palavras de ordem superior. +2 3 [ 2 + ] dip .s ! Retira valor do topo da pilha, execute citação, empurre de volta: 4 3 +3 4 [ + ] keep .s ! Copie o valor do topo da pilha, execute a citação, envie a cópia: 7 4 +1 [ 2 + ] [ 3 + ] bi .s ! Executar cada citação no valor do topo, empurrar os dois resultados: 3 4 +4 3 1 [ + ] [ + ] bi .s ! As citações em um bi podem extrair valores mais profundos da pilha: 4 5 ( 1+3 1+4 ) +1 2 [ 2 + ] bi@ .s ! Executar a citação no primeiro e segundo valores +2 [ + ] curry ! Injeta o valor fornecido no início da citação: [ 2 + ] é deixado na pilha + +! Condicionais +! Qualquer valor é verdadeiro, exceto o valor interno f. +! m valor interno não existe, mas seu uso não é essencial. +! Condicionais são palavras de maior ordem, como com os combinadores acima. + +5 [ "Five is true" . ] when ! Cinco é verdadeiro +0 [ "Zero is true" . ] when ! Zero é verdadeiro +f [ "F is true" . ] when ! Sem saída +f [ "F is false" . ] unless ! F é falso +2 [ "Two is true" . ] [ "Two is false" . ] if ! Two é verdadeiro + +! Por padrão, as condicionais consomem o valor em teste, mas variantes com asterisco +! deixe sozinho se é verdadeiro: + +5 [ . ] when* ! 5 +f [ . ] when* ! Nenhuma saída, pilha vazia, f é consumida porque é falsa + + +! Laços +! Você adivinhou .. estas são palavras de ordem mais elevada também. + +5 [ . ] each-integer ! 0 1 2 3 4 +4 3 2 1 0 5 [ + . ] each-integer ! 0 2 4 6 8 +5 [ "Hello" . ] times ! Hello Hello Hello Hello Hello + +! Here's a list: +{ 2 4 6 8 } ! Goes on the stack as one item + +! Aqui está uma lista: +{ 2 4 6 8 } [ 1 + . ] each ! Exibe 3 5 7 9 +{ 2 4 6 8 } [ 1 + ] map ! Sai { 3 5 7 9 } na pilha + +! Reduzir laços ou criar listas: +{ 1 2 3 4 5 } [ 2 mod 0 = ] filter ! Mantém apenas membros da lista para os quais a citação é verdadeira: { 2 4 } +{ 2 4 6 8 } 0 [ + ] reduce . ! Como "fold" em linguagens funcionais: exibe 20 (0+2+4+6+8) +{ 2 4 6 8 } 0 [ + ] accumulate . . ! Como reduzir, mas mantém os valores intermediários em uma lista: exibe { 0 2 6 12 } então 20 +1 5 [ 2 * dup ] replicate . ! Repete a citação 5 vezes e coleta os resultados em uma lista: { 2 4 8 16 32 } +1 [ dup 100 < ] [ 2 * dup ] produce ! Repete a segunda citação até que a primeira retorne como falsa e colete os resultados: { 2 4 8 16 32 64 128 } + +! Se tudo mais falhar, uma finalidade geral, enquanto repete: +1 [ dup 10 < ] [ "Hello" . 1 + ] while ! Exibe "Hello" 10 vezes + ! Sim, é difícil de ler + ! Isso é o que todos esses loops variantes são para + +! Variáveis +! Normalmente, espera-se que os programas Factor mantenham todos os dados na pilha. +! Usar variáveis nomeadas torna a refatoração mais difícil (e é chamada de Factor por um motivo) +! Variáveis globais, se você precisar: + +SYMBOL: name ! Cria o nome como uma palavra identificadora +"Bob" name set-global ! Sem saída +name get-global . ! "Bob" + +! Variáveis locais nomeadas são consideradas uma extensão, mas estão disponíveis +! Em uma citação .. +[| m n ! A citação captura os dois principais valores da pilha em m e n + | m n + ] ! Leia-os + +! Ou em uma palavra.. +:: lword ( -- ) ! Note os dois pontos duplos para invocar a extensão da variável lexica + 2 :> c ! Declara a variável imutável c para manter 2 + c . ; ! Imprima isso + +! Em uma palavra declarada dessa maneira, o lado de entrada da declaração de pilha +! torna-se significativo e fornece os valores das variáveis em que os valores da pilha são capturados +:: double ( a -- result ) a 2 * ; + +! Variáveis são declaradas mutáveis ao terminar seu nome com um ponto de exclamação +:: mword2 ( a! -- x y ) ! Capture o topo da pilha na variável mutável a + a ! Empurrar a + a 2 * a! ! Multiplique por 2 e armazene o resultado em a + a ; ! Empurre novo valor de a +5 mword2 ! Pilha: 5 10 + +! Listas e Sequências +! Vimos acima como empurrar uma lista para a pilha + +0 { 1 2 3 4 } nth ! Acessar um membro específico de uma lista: 1 +10 { 1 2 3 4 } nth ! Error: índice de sequência fora dos limites +1 { 1 2 3 4 } ?nth ! O mesmo que nth se o índice estiver dentro dos limites: 2 +10 { 1 2 3 4 } ?nth ! Nenhum erro se estiver fora dos limites: f + +{ "at" "the" "beginning" } "Append" prefix ! { "Append" "at" "the" "beginning" } +{ "Append" "at" "the" } "end" suffix ! { "Append" "at" "the" "end" } +"in" 1 { "Insert" "the" "middle" } insert-nth ! { "Insert" "in" "the" "middle" } +"Concat" "enate" append ! "Concatenate" - strings are sequences too +"Concatenate" "Reverse " prepend ! "Reverse Concatenate" +{ "Concatenate " "seq " "of " "seqs" } concat ! "Concatenate seq of seqs" +{ "Connect" "subseqs" "with" "separators" } " " join ! "Connect subseqs with separators" + +! E se você quiser obter meta, as citações são seqüências e podem ser desmontadas.. +0 [ 2 + ] nth ! 2 +1 [ 2 + ] nth ! + +[ 2 + ] \ - suffix ! Quotation [ 2 + - ] + + +``` + +##Pronto para mais? + +* [Documentação do Factor](http://docs.factorcode.org/content/article-help.home.html) diff --git a/pt-br/go-pt.html.markdown b/pt-br/go-pt.html.markdown index c7339831..31473ee1 100644 --- a/pt-br/go-pt.html.markdown +++ b/pt-br/go-pt.html.markdown @@ -16,7 +16,7 @@ A linguagem Go foi criada a partir da necessidade de ver trabalho feito. Não forma de resolver os problemas do mundo real. Tem conceitos familiares de linguagens imperativas com tipagem estática. É -rápida a compilar e rápida a executar, acrescentando mecanismos de concorrência +rápida para compilar e rápida para executar, acrescentando mecanismos de concorrência fáceis de entender para tirar partido dos CPUs multi-core de hoje em dia, e tem recursos para ajudar com a programação em larga escala. @@ -39,10 +39,10 @@ import ( ) // Definição de uma função. Main é especial. É o ponto de entrada para o -// programa executável. Goste-se ou não, a linguagem Go usa chavetas. +// programa executável. Goste-se ou não, a linguagem Go usa chaves. func main() { // A função Println envia uma linha para stdout. - // É necessário qualifica-la com o nome do pacote, fmt. + // É necessário qualificá-la com o nome do pacote, fmt. fmt.Println("Olá Mundo!") // Chama outra função dentro deste pacote. diff --git a/pt-br/html-pt.html.markdown b/pt-br/html-pt.html.markdown new file mode 100644 index 00000000..5a4bc3bc --- /dev/null +++ b/pt-br/html-pt.html.markdown @@ -0,0 +1,125 @@ +--- +language: html +filename: learnhtml.txt +contributors: + - ["Christophe THOMAS", "https://github.com/WinChris"] +translators: + - ["Robert Steed", "https://github.com/robochat"] +lang: pt-br +--- + +HTML é um acrônimo de HyperText Markup Language(Linguagem de Marcação de HiperTexto). +É uma linguagem que nos permite escrever páginas para a "world wide web". +É uma linguagem de marcação, nos permite escrever páginas na web usando código +para indicar como o texto e os dados serão ser exibidos. +De fato, arquivos HTML são simples arquivos de texto. +O que seria marcação? É um método de organização dos dados da página envolvidos +por abertura e fechamento de tags. +Essa marcação serve para dar significado ao texto que envolve. +Assim como outras linguagens, o HTML tem diversas versões. Aqui falaremos sobre o HTML5. + +**NOTA :** Você pode testar diferentes tags e elementos conforme progride os +tutoriais em sites como [codepen](http://codepen.io/pen/) podendo ver seus efeitos, +entendendo como funcionam e se familiarizando com a linguagem. +Esse artigo tem seu foco principal na sintaxe do HTML e algumas dicas úteis. + + +```html +<!-- Comentários são envolvidos conforme essa linha! --> + +<!-- #################### As Tags #################### --> + +<!-- Aqui está um exemplo de arquivo HTML que iremos analisar. --> + +<!doctype html> + <html> + <head> + <title>Meu Site</title> + </head> + <body> + <h1>Olá, mundo!</h1> + <a href = "http://codepen.io/anon/pen/xwjLbZ">Venha ver como isso aparece</a> + <p>Esse é um parágrafo.</p> + <p>Esse é um outro parágrafo.</p> + <ul> + <li>Esse é um item de uma lista não enumerada (bullet list)</li> + <li>Esse é um outro item</li> + <li>E esse é o último item da lista</li> + </ul> + </body> + </html> + +<!-- Um arquivo HTML sempre inicia indicando ao navegador que é uma página HTML. --> +<!doctype html> + +<!-- Após isso, inicia abrindo a tag <html>. --> +<html> + +<!-- Essa tag deverá ser fechada ao final do arquivo com </html>. --> +</html> + +<!-- Não deverá haver nada após o fechamento desta tag. --> + +<!-- Entre a abertura e o fechamento das tags <html></html>, nós encontramos: --> + +<!-- Um cabeçalho definido por <head> (deverá ser fechado com </head>). --> +<!-- O cabeçalho contém uma descrição e algumas informações adicionais que não serão exibidas; chamam-se metadados. --> + +<head> + <title>Meu Site</title><!-- Essa tag <title> indica ao navegador o título a ser exibido na barra de títulos e no nome da aba. --> +</head> + +<!-- Após a seção <head>, nós encontramos a tag - <body> --> +<!-- Até esse ponto, nada descrito irá aparecer na janela do browser. --> +<!-- Nós deveremos preencher o body(corpo) com o conteúdo a ser exibido. --> + +<body> + <h1>Olá, mundo!</h1> <!-- A tag h1 cria um título. --> + <!-- Há também subtítulos do <h1>, o mais importante, aos mais precisos (h6). --> + <a href = "http://codepen.io/anon/pen/xwjLbZ">Venha ver o que isso exibe</a> <!-- Um hiperlink ao endereço preenchido no atributo href="" --> + <p>Esse é um parágrafo.</p> <!-- A tag <p> permite incluir um texto na página. --> + <p>Esse é um outro parágrafo.</p> + <ul> <!-- A tag <ul> cria uma lista de marcação. --> + <!-- Para criar uma lista ordenada, devemos usar <ol>, exibindo 1. para o primeiro elemento, 2. para o segundo, etc. --> + <li>Esse é um item de uma lista não-enumerada.</li> + <li>Esse é um outro item</li> + <li>E esse é o último item da lista</li> + </ul> +</body> + +<!-- E é isso, criar um arquivo HTML pode ser bem simples. --> + +<!-- Também é possível adicionar alguns outros tipos de tags HTML. --> + +<!-- Para inserir uma imagem. --> +<img src="http://i.imgur.com/XWG0O.gif"/> <!-- O caminho da imagem deve ser indicado usando o atributo src="" --> +<!-- O caminho da imagem pode ser uma URL ou até mesmo o caminho do arquivo no seu computador. --> + +<!-- Também é possível criar uma tabela. --> + +<table> <!-- Iniciamos a tabela com a tag <table>. --> + <tr> <!-- <tr> nos permite criar uma linha. --> + <th>Primeiro cabeçalho</th> <!-- <th> nos permite criar o título de uma coluna. --> + <th>Segundo cabeçalho</th> + </tr> + <tr> + <td>Primeira linha, primeira coluna</td> <!-- <td> nos permite criar uma célula da tabela. --> + <td>Primeira linha, segunda coluna</td> + </tr> + <tr> + <td>Segunda linha, primeira coluna</td> + <td>Segunda linha, segunda coluna</td> + </tr> +</table> + +``` + +## Uso + +HTML é escrito em arquivos com a extensão `.html` ou `.htm`. Seu mime type é `text/html`. + +## Para aprender mais + +* [wikipedia](https://en.wikipedia.org/wiki/HTML) +* [HTML tutorial](https://developer.mozilla.org/en-US/docs/Web/HTML) +* [W3School](http://www.w3schools.com/html/html_intro.asp) diff --git a/pt-br/java-pt.html.markdown b/pt-br/java-pt.html.markdown index 82989502..1b9d7fc6 100644 --- a/pt-br/java-pt.html.markdown +++ b/pt-br/java-pt.html.markdown @@ -42,7 +42,7 @@ public class LearnJava { " Double: " + 3.14 + " Boolean: " + true); - // Para imprimir sem inserir uma nova lina, use o System.out.print + // Para imprimir sem inserir uma nova linha, use o System.out.print System.out.print("Olá "); System.out.print("Mundo"); diff --git a/pt-br/javascript-pt.html.markdown b/pt-br/javascript-pt.html.markdown index 7b6729ef..ed4a6ff3 100644 --- a/pt-br/javascript-pt.html.markdown +++ b/pt-br/javascript-pt.html.markdown @@ -25,7 +25,7 @@ Feedback são muito apreciados! Você me encontrar em ```js // Comentários são como em C. Comentários de uma linha começam com duas barras, -/* e comentários de múltplas linhas começam com barra-asterisco +/* e comentários de múltiplas linhas começam com barra-asterisco e fecham com asterisco-barra */ // comandos podem ser terminados com ; diff --git a/pt-br/json-pt.html.markdown b/pt-br/json-pt.html.markdown index fd822c03..62d9ccad 100644 --- a/pt-br/json-pt.html.markdown +++ b/pt-br/json-pt.html.markdown @@ -16,7 +16,7 @@ Como JSON é um formato de intercâmbio de dados, este será, muito provavelment JSON na sua forma mais pura não tem comentários, mas a maioria dos analisadores aceitarão comentários no estilo C (//, /\* \*/). No entanto estes devem ser evitados para otimizar a compatibilidade. -Um valor JSON pode ser um numero, uma string, um array, um objeto, um booleano (true, false) ou null. +Um valor JSON pode ser um número, uma string, um array, um objeto, um booleano (true, false) ou null. Os browsers suportados são: Firefox 3.5+, Internet Explorer 8.0+, Chrome 1.0+, Opera 10.0+, e Safari 4.0+. diff --git a/pt-br/latex-pt.html.markdown b/pt-br/latex-pt.html.markdown new file mode 100644 index 00000000..103af28e --- /dev/null +++ b/pt-br/latex-pt.html.markdown @@ -0,0 +1,291 @@ +--- +language: latex +contributors: + - ["Chaitanya Krishna Ande", "http://icymist.github.io"] + - ["Colton Kohnke", "http://github.com/voltnor"] + - ["Sricharan Chiruvolu", "http://sricharan.xyz"] + - ["Ramanan Balakrishnan", "https://github.com/ramananbalakrishnan"] + - ["Svetlana Golubeva", "https://attillax.github.io/"] +translators: + - ["Paulo Henrique Rodrigues Pinheiro", "https://github.com/paulohrpinheiro"] +lang: pt-br +filename: learn-latex-pt.tex +--- + +```tex +% Todas as linhas de comentários começam com % +% Não existem comentários multilinhas + +$ LaTeX não é um programa processador de textos "Visual" como +% MS Word ou OpenOffice Writer + +$ Todo comando LaTeX começa com uma barra invertida (\) + +% Documentos LaTeX começam com a definição do tipo que será % compilado +% Os tipos de documento podem ser livro, relatório, apresentação, etc. +% As opções para um documento aparecem entre [] chaves. Nesse caso +% está especificado que queremos o tamanho da fonte em 12pt. +\documentclass[12pt]{article} + +% Em seguida definimos os pacotes que o documento usa. +% Se você quiser incluir gráficos, texto colorido, ou código fonte de outra +% linguagem em outro arquivo em seu documento, você precisa ampliar as +% capacidades do LaTeX. Isso é feito adicionando-se pacotes. +% Serão incluídos os pacotes float e caption para imagens e hyperref +% para links. +\usepackage{caption} +\usepackage{float} +\usepackage{hyperref} + +% Para poder usar caracteres acentuados, use o seguinte pacote: +\usepackage[utf8]{inputenc} + +% Podemos definir algumas outras propriedades do documento também! +\author{Chaitanya Krishna Ande, Colton Kohnke, Sricharan Chiruvolu \& \\ +Svetlana Golubeva} +\date{\today} +\title{Aprenda \LaTeX \hspace{1pt} em Y Minutos!} + +% Agora estamos prontos para começar o documento +% Tudo antes dessa linha é chamado "preâmbulo". +\begin{document} +% Se informarmos os campos author (autores), date (data), "title" (título), +% LaTeX poderá cria uma página inicial para nós. +\maketitle +% Se tivermos seções, poderemos criar uma tabela de conteúdo. Para isso, +% o documento deve ser compilado duas vezes, para que tudo apareça na ordem +% correta. +% É uma boa prática separar a tabela de conteúdo do corpo do documento. Para +% isso usa-se o comando \newpage +\newpage +\tableofcontents + +\newpage + +% Muitos artigos de pesquisa possuem um resumo, e pode-se isar comandos +% predefinidos para isso. +% Isso deve aparecer em sua ordem lógica, portanto, após o topo, +% mas antes das seções principais do corpo. +% Esse comando está disponível para os documentos do tipo artigo (article) +% e relatório (report). +\begin{abstract} + Documentação do \LaTeX \hspace{1pt} escrita em \LaTeX! Nada original! +\end{abstract} + +% Comandos para seções são intuitivos. +% Todos os títulos de seção são adicionados automaticamente à tabela de conteúdo. +\section{Introdução} +Olá, meu nome é Colton e juntos estamos explorando o mundo do \LaTeX! + +\section{Outra seção} +Esse é o texto para outra seção. Penso que precisamos de uma subseção. + +\subsection{Isso é uma subseção} % Subseções também são intuitivas. +Penso que precisamos de mais uma + +\subsubsection{Pythagoras} +Muito melhor agora. +\label{subsec:pythagoras} + +% Ao usar o asterisco nós impedimos a numeração automática. +% Isso funciona para outros comandos \LaTeX também. +\section*{Essa é uma seção não numerada} +Afinal nem todas as seções precisam ser numeradas! + +\section{Algumas notas sobre texto} +%\section{Espaçamento % É necessário mais informação sobre intervalos de espaço. +\LaTeX \hspace{1pt} geralmente é muito bom sobre colocar texto onde ele deve +ser posto. Se +uma linha \\ deve \\ ser \\ quebrada \\ adicione \textbackslash\textbackslash +\hspace{1pt} ao código de seu documento. \\ + +\section{Listas} +Listas são uma das coisas mais fáceis de criar no \LaTeX! Preciso fazer compras +amanhã, então façamos uma lista de compras. +\begin{enumerate} % Isso cria o bloco "enumerate". + % \item faz com que o enumerate incremente + \item Salada. + \item 27 melancias. + \item Uma lebre. + % pode-se também sobrescrever o número do item usando [] + \item[quantas?] Pistolas de água médias. + + Não é um item da lista, mas faz parte do bloco enumerate. + + \end{enumerate} % Todos os blocos devem ter um final (end{}). + +\section{Matemática} + +Um dos usos iniciais para \LaTeX \hspace{1pt} foi a produção de artigos +acadêmicos e técnicos. Usualmente nos campos da matemática e ciência. Assim, é +necessários que consigamos incluir alguns símbolos especiais em nosso texto! \\ + +A matemática tem muitos símbolos, além dos quais se pode encontrar no teclado; +símbolos para relações e conjuntos, setas, operadores, e letras gregas, apenas +para mencionar alguns.\\ + +Conjuntos e relações são essenciais em muitos textos de pesquisa em matemática. +Aqui está como você pode indicar como todo x que pertence +a X, $\forall$ x $\in$ X. \\ +% Perceba que é necessário adicionar os sinais $ antes e depois dos símbolos. +% Isso é porque quando escrevendo, estamos em modo texto. +% Mas os símbolos de matemática só existem no modo matemática. +% Podemos entrar no modo matemática a partir do modo texto com os símbolos $. +% O oposto também pode ocorrer. Variáveis podem ser renderizadas no modo +% matemática. +% Também podemos entrar no modo matemática com \[\] + +\[a^2 + b^2 = c^2 \] + +Minha letra grega favorita é $\xi$. Eu também gosto da $\beta$, $\gamma$ e $\sigma$. +Eu ainda não encontrei uma letra grega que o \LaTeX \hspace{1pt} não tenha!\\ + +Operadores são parte essencial de um documento sobre matemática: +funções trigonométricas ($\sin$, $\cos$, $\tan$), +logaritmo e exponencial ($\log$, $\exp$), +limites ($\lim$), etc. +possuem comandos pré-definidos em LaTex. +Vamos escrever uma equação para ver como se faz: +$\cos(2\theta) = \cos^{2}(\theta) - \sin^{2}(\theta)$ \\ + +Frações (numerador/denominador) podem ser escritas dessa forma: + +% 10 / 7 +$$ ^{10}/_{7} $$ + +% Frações relativamente complexas podem ser escritas como +% \frac{numerator}{denominator} +$$ \frac{n!}{k!(n - k)!} $$ \\ + +Também podemos escrever equações em um ``bloco de equação''. + +% Apresenta matemática com o 'bloco' equação +\begin{equation} % entra no modo matemática + c^2 = a^2 + b^2. + \label{eq:pythagoras} % para referência + \end{equation} % toda declaração \begin precisa de uma declaração end + +Podemos então referenciar nossa nova equação! +A equação~\ref{eq:pythagoras} é também conhecida como Teorema de Pitágoras que é +também assunto da Seção~\ref{subsec:pythagoras}. Muitas coisas podem ser +rotuladas: figuras, equações, seções, etc. + +Somatórios e Integrais são escritas com os comandos sum e int: + +% Alguns compiladores LaTeX irão reclamar se existirem linhas em branco +% em um bloco de equação. +\begin{equation} + \sum_{i=0}^{5} f_{i} +\end{equation} +\begin{equation} + \int_{0}^{\infty} \mathrm{e}^{-x} \mathrm{d}x +\end{equation} + +\section{Figuras} + +Insiramos uma Figura. O local para colocar a figura pode ser difícil +de determinar. Eu tenho sempre que verificar as opções toda vez. + +\begin{figure}[H] % H aqui é uma opção para o local da figura. + \centering % centra a figura na página + % Inclui uma figura com escala de 0.8 do tamanho da página. + %\includegraphics[width=0.8\linewidth]{right-triangle.png} + % Comentado para propósitos de compilação. Por favor, use sua imaginação. + \caption{Triângulo retângulo com lados $a$, $b$, $c$} + \label{fig:right-triangle} +\end{figure} + +\subsection{Tabelas} +Também podemos incluir tabelas da mesma forma que figuras. + +\begin{table}[H] + \caption{Título para a Tabela.} + % os argumentos {} abaixo descrevem como cada linha da tabela é desenhada. + % Aqui também, Preciso ver isso. Toda. E. Cada. Vez. + \begin{tabular}{c|cc} + Número & Sobrenome & Primeiro Nome \\ % Colunas são separadas por & + \hline % uma linha horizontal + 1 & Biggus & Dickus \\ + 2 & Monty & Python + \end{tabular} +\end{table} + +\section{Fazendo o \LaTeX \hspace{1pt} não compilar algo (o código fonte)} +Digamos que precisamos incluir algum código dentro do nosso +documento \LaTeX \hspace{1pt}, para isso precisamos com o \LaTeX \hspace{1pt} +não tente interpretar esse texto e que apenas inclua ele no documento. Fazemos +isso com o bloco verbatim. + +% Existem outros pacotes (por exemplo, minty, lstlisting, etc.) +% mas verbatim é o básico +\begin{verbatim} + print("Hello World!") + a%b; % olha só! Podemos usar os sinais % no bloco verbatim. + random = 4; #decided by fair random dice roll +\end{verbatim} + +\section{Compilando} + +Imagino que agora você esteja pensando como compilar esse fantástico documento +e visualizar a gloriosa glória que é um pdf gerado por \LaTeX \hspace{1pt} pdf. +(sim, esse documento é compilável). \\ + +Finalizando o documento usando \LaTeX \hspace{1pt} consiste nos seguintes passos: + \begin{enumerate} + \item Escrever o documento em texto puro (o ``código fonte''). + \item Compilar o código fonte para gerar um pdf. + Os passos para compilar se parecem (em Linux) com: \\ + \begin{verbatim} + > pdflatex learn-latex.tex + \end{verbatim} + \end{enumerate} + +Existem editores de \LaTeX \hspace{1pt} que combinam os passos 1 e 2 no mesmo +sistema de software. Assim, você pode ver o passo 1, mas não o passo 2 por +completo. Passo 2 estará acontecendo escondido\footnote{Por exemplo, quando usar +referências (como Equação~\ref{eq:pythagoras}), pode ser necessário executar o +passo 2 várias vezes, para gerar arquivos *.aux intermediários.}. +% É assim que você adiciona notas de rodapé em seus documentos! + +Você escreve toda a informação de formatação em texto puro, no passo 1. O +momento da compilação no passo 2 é responsável por produzir o documento no +formato que você definiu no passo 1. + +\section{Links} +Nós podemos inserir links em nosso documento. Para isso nós necessitamos incluir +o pacote hyperref no preâmbulo com o comando: +\begin{verbatim} + \usepackage{hyperref} +\end{verbatim} + +Existem dois tipos principais de links: URL visíveis \\ +\url{https://learnxinyminutes.com/docs/latex/}, ou +\href{https://learnxinyminutes.com/docs/latex/}{um texto alternativo} +% Você não pode adicionar espaços extras ou símbolos especiais no texto +% alternativo, pois isso causará problemas na compilação. + +Esse pacote também produz uma lista de thumbnails no documento pdf gerado e +ativa os links na tabela de conteúdo. + +\section{End} + +Por enquanto é isso! + +% Frequentemente você precisa de uma seção de referências em seu documento. +% A forma mais fácil de configurá-la é usando uma seção de bibliografia +\begin{thebibliography}{1} + % como em outras listas, o comando \bibitem pode ser usado para itens da lista + % cada entrada pode ser citada diretamente no corpo do texto + \bibitem{latexwiki} The amazing \LaTeX \hspace{1pt} wikibook: {\em +https://en.wikibooks.org/wiki/LaTeX} + \bibitem{latextutorial} An actual tutorial: {\em http://www.latex-tutorial.com} +\end{thebibliography} + +% end the document +\end{document} +``` + +## Mais sobre LaTeX + +* The amazing LaTeX wikibook: [https://en.wikibooks.org/wiki/LaTeX](https://en.wikibooks.org/wiki/LaTeX) +* An actual tutorial: [http://www.latex-tutorial.com/](http://www.latex-tutorial.com/) diff --git a/pt-br/less-pt.html.markdown b/pt-br/less-pt.html.markdown new file mode 100644 index 00000000..679a2ed2 --- /dev/null +++ b/pt-br/less-pt.html.markdown @@ -0,0 +1,390 @@ +--- +language: less +filename: learnless.less +contributors: + - ["Saravanan Ganesh", "http://srrvnn.me"] + +lang: pt-br +--- + +Less é um pré-processador de CSS, que adiciona recursos como variáveis, aninhamento, mixins e muito mais. +Less (e outros pré-processadores, como o [Sass](http://sass-lang.com/)) ajudam os desenvolvedores a escreverem código que pode ser mantido e DRY (não se repita). + +```css + + +//Comentários de linha única são removidos quando Less é compilado para CSS. + +/*Comentários de várias linhas são preservados.*/ + + + +/* Variáveis +==============================*/ + + +/* Você pode armazenar um valor de CSS (como uma cor) em uma variável. + Use o símbolo '@' para criar uma variável. */ + +@primary-color: #a3a4ff; +@secondary-color: #51527f; +@body-font: 'Roboto', sans-serif; + +/* Você pode usar as variáveis em toda a sua folha de estilo. + Agora, se você quiser alterar uma cor, só precisa fazer a alteração uma vez. */ + +body { + background-color: @primary-color; + color: @secondary-color; + font-family: @body-font; +} + +/* Isso compilará para: */ + +body { + background-color: #a3a4ff; + color: #51527F; + font-family: 'Roboto', sans-serif; +} + + +/* Isso é muito mais sustentável do que ter que mudar a cor + cada vez que aparece em toda a sua folha de estilo. */ + + + +/* Mixins +==============================*/ + + +/* Se você achar que está escrevendo o mesmo código para mais de um + elemento, você pode querer reutilizá-lo facilmente. */ + +.center { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; +} + +/* Você pode usar o mixin simplesmente adicionando o seletor como um estilo. */ + +div { + .center; + background-color: @primary-color; +} + +/* Que compilaria para: */ + +.center { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; +} +div { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; + background-color: #a3a4ff; +} + +/* Você pode omitir o código mixin de ser compilado adicionando parênteses + depois do seletor. */ + +.center() { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; +} + +div { + .center; + background-color: @primary-color; +} + +/* Que compilaria para: */ +div { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; + background-color: #a3a4ff; +} + + + +/* Aninhamento +==============================*/ + + +/* Less permite aninhar seletores nos seletores. */ + +ul { + list-style-type: none; + margin-top: 2em; + + li { + background-color: #f00; + } +} + +/* '&' será substituído pelo seletor pai. */ +/* Você também pode aninhar pseudo-classes. */ +/* Tenha em mente que o aninhamento excessivo tornará seu código menos sustentável. + As melhores práticas recomendam não ultrapassar 3 níveis de profundidade ao aninhar. + Por exemplo: */ + +ul { + list-style-type: none; + margin-top: 2em; + + li { + background-color: red; + + &:hover { + background-color: blue; + } + + a { + color: white; + } + } +} + +/* Compila para: */ + +ul { + list-style-type: none; + margin-top: 2em; +} + +ul li { + background-color: red; +} + +ul li:hover { + background-color: blue; +} + +ul li a { + color: white; +} + + + +/* Functions +==============================*/ + + +/* Less fornece funções que podem ser usadas para realizar uma variedade de + tarefas. Considere o seguinte: */ + +/* Funções podem ser invocadas usando seu nome e passando os + argumentos requeridos. */ + +body { + width: round(10.25px); +} + +.header { + background-color: lighten(#000, 0.5); +} + +.footer { + background-color: fadeout(#000, 0.25) +} + +/* Compila para: */ + +body { + width: 10px; +} + +.header { + background-color: #010101; +} + +.footer { + background-color: rgba(0, 0, 0, 0.75); +} + +/* Você também pode definir suas próprias funções. Funções são muito semelhantes às + mixins. Ao tentar escolher entre uma função ou a um mixin, lembre-se + que mixins são melhores para gerar CSS, enquanto as funções são melhores para + lógica que pode ser usada em todo o seu código Less. Os exemplos na + seção 'Operadores Matemáticos' são candidatos ideais para se tornarem funções reutilizáveis. */ + +/* Esta função calcula a média de dois números: */ + +.average(@x, @y) { + @average-result: ((@x + @y) / 2); +} + +div { + .average(16px, 50px); // "chama" o mixin + padding: @average-result; // use seu valor de "retorno" +} + +/* Compila para: */ + +div { + padding: 33px; +} + + + +/* Estender (herança) +==============================*/ + + +/* Estender é uma maneira de compartilhar as propriedades de um seletor com outro. */ + +.display { + height: 50px; +} + +.display-success { + &:extend(.display); + border-color: #22df56; +} + +/* Compila para: */ + +.display, +.display-success { + height: 50px; +} +.display-success { + border-color: #22df56; +} + +/* Estender uma instrução CSS é preferível para criar um mixin + por causa da maneira como agrupa as classes que compartilham + o mesmo estilo base. Se isso foi feito com um mixin, as propriedades + seriam duplicadas para cada declaração que + chamou o mixin. Embora isso não afete o seu fluxo de trabalho, + adicione o inchaço desnecessário aos arquivos criados pelo compilador Less. */ + + + +/* Parciais e Importações +==============================*/ + + +/* Less permite criar arquivos parciais. Isso pode ajudar a manter o seu + código Less modularizado. Arquivos parciais convencionalmente começam com um '_', + por exemplo. _reset.less. e são importados para um arquivo less principal que recebe + o css compilado. */ + +/* Considere o seguinte CSS que vamos colocar em um arquivo chamado _reset.less */ + +html, +body, +ul, +ol { + margin: 0; + padding: 0; +} + +/* Less disponibiliza @import que podem ser usadas para importar parciais em um arquivo. + Isso difere da declaração tradicional CSS @import que faz + outra solicitação HTTP para buscar o arquivo importado. Less leva o + arquivo importado e combina com o código compilado. */ + +@import 'reset'; + +body { + font-size: 16px; + font-family: Helvetica, Arial, Sans-serif; +} + +/* Compila para: */ + +html, body, ul, ol { + margin: 0; + padding: 0; +} + +body { + font-size: 16px; + font-family: Helvetica, Arial, Sans-serif; +} + + + +/* Operações Matemáticas +==============================*/ + + +/* Less fornece os seguintes operadores: +, -, *, / e %. Estes podem + ser úteis para calcular valores diretamente nos seus arquivos Less + para usar valores que você já calculou manualmente. Abaixo está um exemplo + de como configurar um design simples de duas colunas. */ + +@content-area: 960px; +@main-content: 600px; +@sidebar-content: 300px; + +@main-size: @main-content / @content-area * 100%; +@sidebar-size: @sidebar-content / @content-area * 100%; +@gutter: 100% - (@main-size + @sidebar-size); + +body { + width: 100%; +} + +.main-content { + width: @main-size; +} + +.sidebar { + width: @sidebar-size; +} + +.gutter { + width: @gutter; +} + +/* Compila para: */ + +body { + width: 100%; +} + +.main-content { + width: 62.5%; +} + +.sidebar { + width: 31.25%; +} + +.gutter { + width: 6.25%; +} + + +``` + +## Pratique Less + +Se você quiser praticar com Less no seu navegador, confira: * [Codepen](http://codepen.io/) * [LESS2CSS](http://lesscss.org/less-preview/) + +## Compatibilidade + +Less pode ser usado em qualquer projeto, desde que você tenha um programa para compilá-lo em CSS. Você deseja verificar +se o CSS que você está usando é compatível com seus navegadores de destino. + +[QuirksMode CSS](http://www.quirksmode.org/css/) e [CanIUse](http://caniuse.com) são ótimos recursos para verificar a compatibilidade. + +## Leitura adicional +* [Documentação Oficial](http://lesscss.org/features/) +* [Less CSS - Guia do iniciante](http://www.hongkiat.com/blog/less-basic/) diff --git a/pt-br/make-pt.html.markdown b/pt-br/make-pt.html.markdown new file mode 100644 index 00000000..8e7603cc --- /dev/null +++ b/pt-br/make-pt.html.markdown @@ -0,0 +1,242 @@ +---
+language: make
+contributors:
+ - ["Robert Steed", "https://github.com/robochat"]
+ - ["Stephan Fuhrmann", "https://github.com/sfuhrm"]
+filename: Makefile
+
+lang: pt-br
+---
+
+Um Makefile define um gráfico de regras para criar um alvo (ou alvos). Sua finalidade é fazer o mínimo de trabalho necessário para atualizar um alvo para a versão mais recente da fonte. Famosamente escrito ao longo de um fim de semana por Stuart Feldman em 1976, ainda é amplamente usada (particularmente no Unix e no Linux) apesar de muitos concorrentes e críticas.
+
+Existem muitas variedades de make na existência, no entanto, este artigo pressupõe que estamos usando o GNU make, que é o padrão no Linux.
+
+```make
+
+# Comentários podem ser escritos assim.
+
+# O arquivo deve ser nomeado Makefile e então pode ser executado como `make <alvo>`.
+# Caso contrário, nós usamos `make -f "nome-do-arquivo" <alvo>`.
+
+# Aviso - use somente TABS para identar em Makefiles, nunca espaços!
+
+#-----------------------------------------------------------------------
+# Noções básicas
+#-----------------------------------------------------------------------
+
+# Regras são do formato
+# alvo: <pré-requisito>
+# onde os pré-requisitos são opcionais.
+
+# Uma regra - esta regra só será executada se o arquivo0.txt não existir.
+arquivo0.txt:
+ echo "foo" > arquivo0.txt
+ # Mesmo os comentários nestas seções da 'receita' são passados para o shell.
+ # Experimentar `make arquivo0.txt` or simplyou simplesmente `make` - primeira regra é o padrão.
+
+# Esta regra só será executada se arquivo0.txt for mais recente que arquivo1.txt.
+arquivo1.txt: arquivo0.txt
+ cat arquivo0.txt > arquivo1.txt
+ # se as mesmas regras de citação do shell.
+ @cat arquivo0.txt >> arquivo1.txt
+ # @ pára o comando de ser ecoado para stdout.
+ -@echo 'hello'
+ # - significa que make continuará em caso de erro.
+ # Experimentar `make arquivo1.txt` na linha de comando.
+
+# Uma regra pode ter vários alvos e vários pré-requisitos
+arquivo2.txt arquivo3.txt: arquivo0.txt arquivo1.txt
+ touch arquivo2.txt
+ touch arquivo3.txt
+
+# Make vai reclamar sobre várias receitas para a mesma regra. Esvaziar
+# receitas não contam e podem ser usadas para adicionar novas dependências.
+
+#-----------------------------------------------------------------------
+# Alvos falsos
+#-----------------------------------------------------------------------
+
+# Um alvo falso. Qualquer alvo que não seja um arquivo.
+# Ele nunca será atualizado, portanto, o make sempre tentará executá-lo.
+all: maker process
+
+# Podemos declarar as coisas fora de ordem.
+maker:
+ touch ex0.txt ex1.txt
+
+# Pode evitar quebrar regras falsas quando um arquivo real tem o mesmo nome
+.PHONY: all maker process
+# Este é um alvo especial. Existem vários outros.
+
+# Uma regra com dependência de um alvo falso sempre será executada
+ex0.txt ex1.txt: maker
+
+# Alvos falsos comuns são: todos fazem instalação limpa ...
+
+#-----------------------------------------------------------------------
+# Variáveis Automáticas e Curingas
+#-----------------------------------------------------------------------
+
+process: Arquivo*.txt # Usando um curinga para corresponder nomes de arquivos
+ @echo $^ # $^ é uma variável que contém a lista de pré-requisitos
+ @echo $@ # imprime o nome do alvo
+ #(fpara várias regras alvo, $@ é o que causou a execução da regra)
+ @echo $< # o primeiro pré-requisito listado
+ @echo $? # somente as dependências que estão desatualizadas
+ @echo $+ # todas as dependências, incluindo duplicadas (ao contrário do normal)
+ #@echo $| # todos os pré-requisitos 'somente pedidos'
+
+# Mesmo se dividirmos as definições de dependência de regra, $^ vai encontrá-los
+process: ex1.txt arquivo0.txt
+# ex1.txt será encontrado, mas arquivo0.txt será desduplicado.
+
+#-----------------------------------------------------------------------
+# Padrões
+#-----------------------------------------------------------------------
+
+# Pode ensinar make a converter certos arquivos em outros arquivos.
+
+%.png: %.svg
+ inkscape --export-png $^
+
+# As regras padrões só farão qualquer coisa se decidirem criar o alvo.
+
+# Os caminhos de diretório são normalmente ignorados quando as regras de
+# padrões são correspondentes. Mas make tentará usar a regra mais
+# apropriada disponível.
+small/%.png: %.svg
+ inkscape --export-png --export-dpi 30 $^
+
+# make utilizará a última versão para uma regra de padrão que encontrar.
+%.png: %.svg
+ @echo esta regra é escolhida
+
+# No entanto, o make usará a primeira regra padrão que pode se tornar o alvo
+%.png: %.ps
+ @echo esta regra não é escolhida se *.svg and *.ps estão ambos presentes
+
+# make já tem algumas regras padrões embutidas. Por exemplo, ele sabe
+# como transformar arquivos *.c em arquivos *.o.
+
+# Makefiles antigos podem usar regras de sufixo em vez de regras padrões
+.png.ps:
+ @echo essa regra é semelhante a uma regra de padrão.
+
+# make sobre a regra de sufixo
+.SUFFIXES: .png
+
+#-----------------------------------------------------------------------
+# Variáveis
+#-----------------------------------------------------------------------
+# aka. macros
+
+# As variáveis são basicamente todos os tipos de string
+
+name = Ted
+name2="Sarah"
+
+echo:
+ @echo $(name)
+ @echo ${name2}
+ @echo $name # Isso não funcionará, tratado como $ (n)ame.
+ @echo $(name3) # Variáveis desconhecidas são tratadas como strings vazias.
+
+# Existem 4 lugares para definir variáveis.
+# Em ordem de prioridade, do maior para o menor:
+# 1: argumentos de linha de comando
+# 2: Makefile
+# 3: variáveis de ambiente do shell - faça importações automaticamente.
+# 4: make tem algumas variáveis predefinidas
+
+name4 ?= Jean
+# Somente defina a variável se a variável de ambiente ainda não estiver definida.
+
+override name5 = David
+# Pára os argumentos da linha de comando de alterar essa variável.
+
+name4 +=grey
+# Anexar valores à variável (inclui um espaço).
+
+# Valores variáveis específicos de padrões (extensão GNU).
+echo: name2 = Sara # Verdadeiro dentro da regra de correspondência
+ # e também dentro de suas recursivas dependências
+ # (exceto que ele pode quebrar quando seu gráfico ficar muito complicado!)
+
+# Algumas variáveis definidas automaticamente pelo make
+echo_inbuilt:
+ echo $(CC)
+ echo ${CXX}
+ echo $(FC)
+ echo ${CFLAGS}
+ echo $(CPPFLAGS)
+ echo ${CXXFLAGS}
+ echo $(LDFLAGS)
+ echo ${LDLIBS}
+
+#-----------------------------------------------------------------------
+# Variáveis 2
+#-----------------------------------------------------------------------
+
+# O primeiro tipo de variáveis é avaliado a cada vez que elas são usadas.
+# TIsso pode ser caro, então existe um segundo tipo de variável que é
+# avaliado apenas uma vez. (Esta é uma extensão do GNU make)
+
+var := hello
+var2 ::= $(var) hello
+#:= e ::= são equivalentes.
+
+# Essas variáveis são avaliadas procedimentalmente (na ordem em que
+# aparecem), quebrando assim o resto da línguagem!
+
+# Isso não funciona
+var3 ::= $(var4) and good luck
+var4 ::= good night
+
+#-----------------------------------------------------------------------
+# Funções
+#-----------------------------------------------------------------------
+
+# make tem muitas funções disponíveis.
+
+sourcefiles = $(wildcard *.c */*.c)
+objectfiles = $(patsubst %.c,%.o,$(sourcefiles))
+
+# O formato é $(func arg0,arg1,arg2...)
+
+# Alguns exemplos
+ls: * src/*
+ @echo $(filter %.txt, $^)
+ @echo $(notdir $^)
+ @echo $(join $(dir $^),$(notdir $^))
+
+#-----------------------------------------------------------------------
+# Diretivas
+#-----------------------------------------------------------------------
+
+# Inclua outros makefiles, úteis para código específico da plataforma
+include foo.mk
+
+sport = tennis
+# Compilação condicional
+report:
+ifeq ($(sport),tennis)
+ @echo 'game, set, match'
+else
+ @echo "They think it's all over; it is now"
+endif
+
+# Há também ifneq, ifdef, ifndef
+
+foo = true
+
+ifdef $(foo)
+bar = 'hello'
+endif
+```
+
+### More Resources
+
++ [documentação gnu make](https://www.gnu.org/software/make/manual/)
++ [tutorial de carpintaria de software](http://swcarpentry.github.io/make-novice/)
++ aprenda C da maneira mais difícil [ex2](http://c.learncodethehardway.org/book/ex2.html) [ex28](http://c.learncodethehardway.org/book/ex28.html)
diff --git a/pt-br/markdown-pt.html.markdown b/pt-br/markdown-pt.html.markdown index f22093f9..c2aa515d 100644 --- a/pt-br/markdown-pt.html.markdown +++ b/pt-br/markdown-pt.html.markdown @@ -14,7 +14,7 @@ escrever sintaxe que converte facilmente em HTML (hoje, suporta outros formatos Dê-me feedback tanto quanto você quiser! / Sinta-se livre para a garfar (fork) e puxar o projeto (pull request) -```markdown +```md <!-- Markdown é um superconjunto do HTML, de modo que qualquer arvquivo HTML é um arquivo Markdown válido, isso significa que nós podemos usar elementos HTML em Markdown, como o elemento de comentário, e eles não serão afetados pelo analisador diff --git a/pt-br/matlab-pt.html.markdown b/pt-br/matlab-pt.html.markdown index eb660d4c..5ed6b7ba 100644 --- a/pt-br/matlab-pt.html.markdown +++ b/pt-br/matlab-pt.html.markdown @@ -206,8 +206,7 @@ size(A) % Resposta = 3 3 A(1, :) =[] % Remove a primeira linha da matriz A(:, 1) =[] % Remove a primeira coluna da matriz -transpose(A) % Transposta a matriz, que é o mesmo de: -A one +transpose(A) % Transposta a matriz, que é o mesmo de: A.' ctranspose(A) % Transposta a matriz % (a transposta, seguida pelo conjugado complexo de cada elemento) diff --git a/pt-br/perl-pt.html.markdown b/pt-br/perl-pt.html.markdown index cc07a2ec..217861f9 100644 --- a/pt-br/perl-pt.html.markdown +++ b/pt-br/perl-pt.html.markdown @@ -21,7 +21,7 @@ Perl 5 roda em mais de 100 plataformas, de portáteis a mainframes e é adequada # Variáveis iniciam com um sigilo, que é um símbolo que mostra o tipo. # Um nome de variável válido começa com uma letra ou sublinhado, -# seguido por qualquer número de letras, números ou sublinhados. +# seguido por qualquer quantidade de letras, números ou sublinhados. ### Perl has three main variable types: $scalar, @array, e %hash. @@ -52,10 +52,10 @@ my %fruta_cor = ( banana => "amarelo", ); -# Scalars, arrays and hashes são documentados mais profundamentes em perldata. +# Scalars, arrays and hashes são documentados mais profundamente em perldata. # (perldoc perldata). -# Mais tipos de dados complexos podem ser construídas utilizando referências, +# Mais tipos de dados complexos podem ser construídos utilizando referências, # o que permite que você crie listas e hashes dentro de listas e hashes. #### Condicionais e construtores de iteração diff --git a/pt-br/pyqt-pt.html.markdown b/pt-br/pyqt-pt.html.markdown index 10d55784..40fe82d5 100644 --- a/pt-br/pyqt-pt.html.markdown +++ b/pt-br/pyqt-pt.html.markdown @@ -10,7 +10,7 @@ lang: pt-br --- **Qt** é amplamente conhecido como um framework para desenvolvimento de -software multi-plataforma que pode rodar em vários outras plataformas de +software multi-plataforma que pode rodar em várias outras plataformas de softwares e hardwares com pouca ou nenhuma alteração no código, enquanto mantém o poder e a velocidade de uma aplicação nativa. Embora o **Qt** tenha sido originalmente escrito em *C++*. diff --git a/pt-br/rust-pt.html.markdown b/pt-br/rust-pt.html.markdown index 8134d3c5..b2bab214 100644 --- a/pt-br/rust-pt.html.markdown +++ b/pt-br/rust-pt.html.markdown @@ -11,7 +11,7 @@ Rust é uma linguagem de programação desenvolvida pelo Mozilla Research. Rust combina controle de baixo nível sobre o desempenho com facilidades de alto nível e garantias de segurança. -Ele atinge esse objetico sem necessitar de um coletor de lixo ou um processo +Ele atinge esse objetivo sem necessitar de um coletor de lixo ou um processo *runtime*, permitindo que se use bibliotecas Rust em substituição a bibliotecas em C. @@ -27,7 +27,7 @@ noite. Rust adotou um modelo de versões *train-based* com novas versões regularmente liberadas a cada seis semanas. A versão 1.1 beta de Rust foi disponibilizada ao mesmo tempo que a versão 1.0. -Apesar de Rust ser uma linguagem mais e baixo nível, Rust tem alguns conceitos +Apesar de Rust ser uma linguagem mais de baixo nível, Rust tem alguns conceitos funcionais geralmente encontradas em linguagens de alto nível. Isso faz Rust não apenas rápido, mas também fácil e eficiente para programar. @@ -68,7 +68,7 @@ fn main() { // Em geral, o compilador Rust consegue inferir qual o tipo de uma // variável, então você não tem que escrever uma anotação explícita de tipo. // Ao longo desse tutorial, os tipos serão explicitamente anotados em - // muitos lugares, mas apenas com propóstico demonstrativo. A inferência de + // muitos lugares, mas apenas com propósito demonstrativo. A inferência de // tipos pode gerenciar isso na maioria das vezes. let implicit_x = 1; let implicit_f = 1.3; diff --git a/pt-br/solidity-pt.html.markdown b/pt-br/solidity-pt.html.markdown index 37d15bf2..d4555fa7 100644 --- a/pt-br/solidity-pt.html.markdown +++ b/pt-br/solidity-pt.html.markdown @@ -1,6 +1,6 @@ --- language: Solidity -filename: learnSolidity.sol +filename: learnSolidity-br.sol contributors: - ["Nemil Dalal", "https://www.nemil.com"] - ["Joseph Chow", ""] diff --git a/pt-br/vim-pt.html.markdown b/pt-br/vim-pt.html.markdown index 51eddb48..d7617bbe 100644 --- a/pt-br/vim-pt.html.markdown +++ b/pt-br/vim-pt.html.markdown @@ -13,7 +13,7 @@ filename: LearnVim-pt.txt [Vim](http://www.vim.org) (Vi IMproved - Vi Melhorado) é um clone do editor vi para Unix. Ele é um editor de texto projetado para ter velocidade e produtividade, e está presente -na maioria dos systemas UNIX. O editor tem um grande número de atalhos de teclado +na maioria dos sistemas UNIX. O editor tem um grande número de atalhos de teclado para agilizar a navegação para pontos específicos no arquivo, além de edição rápida. ## Navegação do Vim: o básico @@ -25,7 +25,7 @@ para agilizar a navegação para pontos específicos no arquivo, além de ediç :wq # Salva o arquivo e fecha o vim :q! # Fecha o vim e descarta as alterações no arquivo # ! *força* :q a executar, fechando o vim sem salvar antes - :x # Salvar o arquivo e fechao vim (atalho para :wq) + :x # Salva o arquivo e fecha o vim (atalho para :wq) u # Desfazer CTRL+R # Refazer @@ -62,7 +62,7 @@ para agilizar a navegação para pontos específicos no arquivo, além de ediç # Movendo por palavras - w # Move o cursor uma palavra a diante + w # Move o cursor uma palavra adiante b # Move o cursor uma palavra atrás e # Move o cursor ao fim da palavra atual diff --git a/pt-br/visualbasic-pt.html.markdown b/pt-br/visualbasic-pt.html.markdown index 76cca567..2a7205cd 100644 --- a/pt-br/visualbasic-pt.html.markdown +++ b/pt-br/visualbasic-pt.html.markdown @@ -8,16 +8,16 @@ lang: pt-br filename: learnvisualbasic-pt.vb --- -```vb +``` Module Module1 module Module1 Sub Main () ' Uma visão geral de console de aplicativos do Visual Basic antes de - ' mergulharmos mais profundamente na linguagem + ' mergulharmos mais profundamente na linguagem. ' Aspas simples começam comentários. - ' Para Navegar este tutorial dentro do compilador do Visual Basic, + ' Para navegar neste tutorial dentro do compilador do Visual Basic, ' eu criei um sistema de navegação. ' Este sistema de navegação vai ser explicado conforme avançarmos no ' tutorial, e você vai entender o que isso significa. @@ -93,16 +93,16 @@ module Module1 Private Sub HelloWorldInput () Console.Title = " Olá Mundo YourName | Saiba X em Y Minutes" ' Variáveis - 'Os dados inseridos por um usuário precisa ser armazenada . + 'Os dados inseridos por um usuário precisam ser armazenados. ' As variáveis também começar com um Dim e terminar com um Como VariableType . - ' Neste tutorial, nós queremos saber o que o seu nome, e faça o programa + ' Neste tutorial, nós queremos saber qual é o seu nome, e faça o programa ' Responder ao que é dito. Nome de usuário Dim As String " Nós usamos string como string é uma variável de texto baseado . Console.WriteLine (" Olá, Qual é o seu nome? ") ' Peça ao usuário seu nome. - username = Console.ReadLine () ' armazena o nome usuários. - Console.WriteLine (" Olá " + nome do usuário) " A saída é Olá ' Seu nome ' + username = Console.ReadLine () ' armazena o nome do usuário. + Console.WriteLine (" Olá " + username) ' A saída é "Olá < seu nome >". Console.ReadLine () ' Outsputs acima. ' O código acima irá lhe fazer uma pergunta seguiu imprimindo sua resposta. " Outras variáveis incluem Integer e usamos inteiro para números inteiros. diff --git a/pt-br/whip-pt.html.markdown b/pt-br/whip-pt.html.markdown new file mode 100644 index 00000000..989bae05 --- /dev/null +++ b/pt-br/whip-pt.html.markdown @@ -0,0 +1,247 @@ +--- +language: whip +contributors: + - ["Tenor Biel", "http://github.com/L8D"] + - ["Saurabh Sandav", "http://github.com/SaurabhSandav"] +author: Tenor Biel +author_url: http://github.com/L8D +translators: + - ["Paulo Henrique Rodrigues Pinheiro", "https://github.com/paulohrpinheiro"] +lang: pt-br +filename: whip-pt.lisp +--- + +Whip é um dialeto de Lisp feito para construir scripts e trabalhar com +conceitos mais simples. +Ele também copia muitas funções e sintaxe de Haskell (uma linguagem não correlata) + +Esse documento foi escrito pelo próprio autor da linguagem. Então é isso. + +```scheme +; Comentário são como em Lisp. Pontos-e-vírgulas... + +; A maioria das declarações de primeiro nível estão dentro de "listas" +; que nada mais são que coisas entre parêntesis separadas por espaços em branco +nao_é_uma_lista +(uma lista) + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +; 1. Números, texto e operadores + +; Whip tem um tipo numérico (que é um double de 64 bits IEE 754, do JavaScript) +3 ; => 3 +1.5 ; => 1.5 + +; Funções são chamadas se elas são o primeiro elemento em uma lista +(funcao_chamada argumentos) + +; A maioria das operações são feitas com funções +; Todas as funções aritméticas básicas são bem diretas +(+ 1 1) ; => 2 +(- 2 1) ; => 1 +(* 1 2) ; => 2 +(/ 2 1) ; => 2 +; até mesmo o módulo +(% 9 4) ; => 1 +; Divisão não inteira ao estilo JavaScript. +(/ 5 2) ; => 2.5 + +; Aninhamento de listas funciona como esperado. +(* 2 (+ 1 3)) ; => 8 + +; Há um tipo boleano. +true +false + +; Textos são criados com ". +"Hello, world" + +; Caracteres são criados com '. +'a' + +; Para negação usa-se a função 'not'. +(not true) ; => false +(not false) ; => true + +; Mas a maioria das funções não-haskell tem atalhos +; o não atalho é um '!'. +(! (! true)) ; => true + +; Igualdade é `equal` ou `=`. +(= 1 1) ; => true +(equal 2 1) ; => false + +; Por exemplo, inigualdade pode ser verificada combinando as funções +;`not` e `equal`. +(! (= 2 1)) ; => true + +; Mais comparações +(< 1 10) ; => true +(> 1 10) ; => false +; e suas contra partes para texto. +(lesser 1 10) ; => true +(greater 1 10) ; => false + +; Texto pode ser concatenado com +. +(+ "Hello " "world!") ; => "Hello world!" + +; Você pode usar as características comparativas do JavaScript. +(< 'a' 'b') ; => true +; ... e coerção de tipos +(= '5' 5) + +; As funções `at` ou `@` acessarão caracteres de um texto, começando em 0. +(at 0 'a') ; => 'a' +(@ 3 "foobar") ; => 'b' + +; Também existem as variáveis `null` e `undefined`. +null ; usada para indicar a ausência de algum valor +undefined ; usada para indicar que um valor não foi informado + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +; 2. Variáveis, matrizes e dicionários + +; Variáveis são declaradas com as funções `def` ou `let`. +; Variáveis que não tiveram valor atribuído serão `undefined`. +(def some_var 5) +; `def` deixará a variável no contexto global. +; `let` deixará a variável no contexto local, e tem uma sintaxe estranha. +(let ((a_var 5)) (+ a_var 5)) ; => 10 +(+ a_var 5) ; = undefined + 5 => undefined + +; Matrizes são listas de valores de qualquer tipo. +; Elas basicamente são listas sem funções no início +(1 2 3) ; => [1, 2, 3] (sintaxe JavaScript) + +; Dicionários em Whip são o equivalente a 'object' em JavaScript ou +; 'dict' em python ou 'hash' em Ruby: eles s]ão uma coleção desordenada +de pares chave-valor. +{"key1" "value1" "key2" 2 3 3} + +; Chaves podem ser apenas identificadores, números ou texto. +(def my_dict {my_key "my_value" "my other key" 4}) +; Mas em Whip, dicionários são parceados como: valor, espaço, valor; +; com mais espaço entre cada. Então isso significa que +{"key" "value" +"another key" +1234 +} +é avaliado da mesma forma que +{"key" "value" "another key" 1234} + +; Dicionários podem ser acessados usando a função `at` +; (como em texto e listas) +(@ "my other key" my_dict) ; => 4 + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +; 3. Lógica e controle de fluxo + +; A função `if` é muito simples, ainda que muito diferente do que em muitas +linguagens imperativas. +(if true "returned if first arg is true" "returned if first arg is false") +; => "returned if first arg is true" + +; E por conta do legado operador ternário +; `?` é o atalho não utilizado para `if`. +(? false true false) ; => false + +; `both` é uma declaração lógica `and`, e `either` é o `or` lógico. +(both true true) ; => true +(both true false) ; => false +(either true false) ; => true +(either false false) ; => false +; E seus atalhos são +; & => both +; ^ => either +(& true true) ; => true +(^ false true) ; => true + +;;;;;;;;; +; Lambdas + +; Lambdas em Whip são declaradas com as funções `lambda` ou `->`. +; E funções são na verdade lambdas com nomes. +(def my_function (-> (x y) (+ (+ x y) 10))) +; | | | | +; | | | valor retornado (com escopo contento argumentos) +; | | argumentos +; | declaração de funções lambda +; | +; nome do lambda a ser declarado + +(my_function 10 10) ; = (+ (+ 10 10) 10) => 30 + +; Obviamente, todos os lambdas por definição são anônimos e +; tecnicamente sempre usados anonimamente. Redundância. +((lambda (x) x) 10) ; => 10 + +;;;;;;;;;;;;;;;; +; Comprehensions + +; `range` or `..` geram uma lista dos números para +; cada número entre seus dois argumentos. +(range 1 5) ; => (1 2 3 4 5) +(.. 0 2) ; => (0 1 2) + +; `map` aplica seu primeiro argumento (que deve ser um lambda/função) +; a cada item dos argumentos seguintes (que precisa ser uma lista) +(map (-> (x) (+ x 1)) (1 2 3)) ; => (2 3 4) + +; Reduce +(reduce + (.. 1 5)) +; equivalente a +((+ (+ (+ 1 2) 3) 4) 5) + +; Nota: map e reduce não possuem atalhos + +; `slice` ou `\` é similar ao .slice() do JavaScript +; mas veja que ele pega uma lista como primeiro argumento, não o último. +(slice (.. 1 5) 2) ; => (3 4 5) +(\ (.. 0 100) -5) ; => (96 97 98 99 100) + +; `append` ou `<<` são auto explicativos +(append 4 (1 2 3)) ; => (1 2 3 4) +(<< "bar" ("foo")) ; => ("foo" "bar") + +; Length é auto explicativo. +(length (1 2 3)) ; => 3 +(_ "foobar") ; => 6 + +;;;;;;;;;;;;;;; +; Delicadezas Haskell + +; Primeiro item de uma lista +(head (1 2 3)) ; => 1 +; Pega do segundo ao último elemento de uma lista +(tail (1 2 3)) ; => (2 3) +; Último item de uma lista +(last (1 2 3)) ; => 3 +; Contrário de `tail` +(init (1 2 3)) ; => (1 2) +; Pega do primeiro até o elemento especificado da lista +(take 1 (1 2 3 4)) ; (1 2) +; Contrário de `take` +(drop 1 (1 2 3 4)) ; (3 4) +; Menos valor em uma lista +(min (1 2 3 4)) ; 1 +; Maior valor em uma lista +(max (1 2 3 4)) ; 4 +; Verifica se o valor está em uma lista ou objeto +(elem 1 (1 2 3)) ; true +(elem "foo" {"foo" "bar"}) ; true +(elem "bar" {"foo" "bar"}) ; false +; Inverte a ordem de uma lista +(reverse (1 2 3 4)) ; => (4 3 2 1) +; Verifica se o valor é par ou ímpar +(even 1) ; => false +(odd 1) ; => true +; Separa um texto cortando por espaço em branco +(words "foobar nachos cheese") ; => ("foobar" "nachos" "cheese") +; Junta lista de textos +(unwords ("foo" "bar")) ; => "foobar" +; Sucessor e predecessor +(pred 21) ; => 20 +(succ 20) ; => 21 +``` + +Para mais informação, verifique o [repositório](http://github.com/L8D/whip) diff --git a/purescript.html.markdown b/purescript.html.markdown index df0cb66e..6b74ac64 100644 --- a/purescript.html.markdown +++ b/purescript.html.markdown @@ -71,7 +71,8 @@ world""" -- "Hello\nworld" -- -- 2. Arrays are Javascript arrays, but must be homogeneous -[1,1,2,3,5,8] :: Array Number -- [1,1,2,3,5,8] +[1,1,2,3,5,8] :: Array Int -- [1,1,2,3,5,8] +[1.2,2.0,3.14] :: Array Number -- [1.2,2.0,3.14] [true, true, false] :: Array Boolean -- [true,true,false] -- [1,2, true, "false"] won't work -- `Cannot unify Prim.Int with Prim.Boolean` diff --git a/python.html.markdown b/python.html.markdown index 946cbc0c..df1ca6f2 100644 --- a/python.html.markdown +++ b/python.html.markdown @@ -7,6 +7,7 @@ contributors: - ["evuez", "http://github.com/evuez"] - ["asyne", "https://github.com/justblah"] - ["habi", "http://github.com/habi"] + - ["Rommel Martinez", "https://ebzzry.io"] filename: learnpython.py --- @@ -363,6 +364,12 @@ filled_set | other_set # => {1, 2, 3, 4, 5, 6} # Check for existence in a set with in 2 in filled_set # => True 10 in filled_set # => False +10 not in filled_set # => True + +# Check data type of variable +type(li) # => list +type(filled_dict) # => dict +type(5) # => int #################################################### @@ -502,9 +509,9 @@ all_the_args(1, 2, a=3, b=4) prints: # Use * to expand positional args and use ** to expand keyword args. args = (1, 2, 3, 4) kwargs = {"a": 3, "b": 4} -all_the_args(*args) # equivalent to foo(1, 2, 3, 4) -all_the_args(**kwargs) # equivalent to foo(a=3, b=4) -all_the_args(*args, **kwargs) # equivalent to foo(1, 2, 3, 4, a=3, b=4) +all_the_args(*args) # equivalent to all_the_args(1, 2, 3, 4) +all_the_args(**kwargs) # equivalent to all_the_args(a=3, b=4) +all_the_args(*args, **kwargs) # equivalent to all_the_args(1, 2, 3, 4, a=3, b=4) # you can pass args and kwargs along to other functions that take args/kwargs diff --git a/python3.html.markdown b/python3.html.markdown index 5aa61b65..c7fbf342 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -6,6 +6,8 @@ contributors: - ["Andre Polykanine", "https://github.com/Oire"] - ["Zachary Ferguson", "http://github.com/zfergus2"] - ["evuez", "http://github.com/evuez"] + - ["Rommel Martinez", "https://ebzzry.io"] + - ["Roberto Fernandez Diaz", "https://github.com/robertofd1995"] filename: learnpython3.py --- @@ -137,6 +139,12 @@ len("This is a string") # => 16 # still use the old style of formatting: "%s can be %s the %s way" % ("Strings", "interpolated", "old") # => "Strings can be interpolated the old way" +# You can also format using f-strings or formatted string literals (in Python 3.6+) +name = "Reiko" +f"She said her name is {name}." # => "She said her name is Reiko" +# You can basically put any Python statement inside the braces and it will be output in the string. +f"{name} is {len(name)} characters long." + # None is an object None # => None @@ -209,9 +217,9 @@ li[4] # Raises an IndexError # The start index is included, the end index is not # (It's a closed/open range for you mathy types.) li[1:3] # => [2, 4] -# Omit the end +# Omit the beginning and return the list li[2:] # => [4, 3] -# Omit the beginning +# Omit the end and return the list li[:3] # => [1, 2, 4] # Select every second entry li[::2] # =>[1, 4] @@ -273,7 +281,8 @@ a, b, c = (1, 2, 3) # a is now 1, b is now 2 and c is now 3 # You can also do extended unpacking a, *b, c = (1, 2, 3, 4) # a is now 1, b is now [2, 3] and c is now 4 # Tuples are created by default if you leave out the parentheses -d, e, f = 4, 5, 6 +d, e, f = 4, 5, 6 # tuple 4, 5, 6 is unpacked into variables d, e and f +# respectively such that d = 4, e = 5 and f = 6 # Now look how easy it is to swap two values e, d = d, e # d is now 5 and e is now 4 @@ -347,6 +356,8 @@ valid_set = {(1,), 1} # Add one more item to the set filled_set = some_set filled_set.add(5) # filled_set is now {1, 2, 3, 4, 5} +# Sets do not have duplicate elements +filled_set.add(5) # it remains as before {1, 2, 3, 4, 5} # Do set intersection with & other_set = {3, 4, 5, 6} @@ -546,9 +557,9 @@ all_the_args(1, 2, a=3, b=4) prints: # Use * to expand tuples and use ** to expand kwargs. args = (1, 2, 3, 4) kwargs = {"a": 3, "b": 4} -all_the_args(*args) # equivalent to foo(1, 2, 3, 4) -all_the_args(**kwargs) # equivalent to foo(a=3, b=4) -all_the_args(*args, **kwargs) # equivalent to foo(1, 2, 3, 4, a=3, b=4) +all_the_args(*args) # equivalent to all_the_args(1, 2, 3, 4) +all_the_args(**kwargs) # equivalent to all_the_args(a=3, b=4) +all_the_args(*args, **kwargs) # equivalent to all_the_args(1, 2, 3, 4, a=3, b=4) # Returning multiple values (with tuple assignments) def swap(x, y): @@ -669,7 +680,7 @@ class Human: # An instance method. All methods take "self" as the first argument def say(self, msg): - print ("{name}: {message}".format(name=self.name, message=msg)) + print("{name}: {message}".format(name=self.name, message=msg)) # Another instance method def sing(self): @@ -740,10 +751,105 @@ if __name__ == '__main__': #################################################### -## 6.1 Multiple Inheritance +## 6.1 Inheritance +#################################################### + +# Inheritance allows new child classes to be defined that inherit methods and +# variables from their parent class. + +# Using the Human class defined above as the base or parent class, we can +# define a child class, Superhero, which inherits the class variables like +# "species", "name", and "age", as well as methods, like "sing" and "grunt" +# from the Human class, but can also have its own unique properties. + +# To take advantage of modularization by file you could place the classes above in their own files, +# say, human.py + +# To import functions from other files use the following format +# from "filename-without-extension" import "function-or-class" + +from human import Human + + +# Specify the parent class(es) as parameters to the class definition +class Superhero(Human): + + # If the child class should inherit all of the parent's definitions without + # any modifications, you can just use the "pass" keyword (and nothing else) + # but in this case it is commented out to allow for a unique child class: + # pass + + # Child classes can override their parents' attributes + species = 'Superhuman' + + # Children automatically inherit their parent class's constructor including + # its arguments, but can also define additional arguments or definitions + # and override its methods such as the class constructor. + # This constructor inherits the "name" argument from the "Human" class and + # adds the "superpower" and "movie" arguments: + def __init__(self, name, movie=False, + superpowers=["super strength", "bulletproofing"]): + + # add additional class attributes: + self.fictional = True + self.movie = movie + self.superpowers = superpowers + + # The "super" function lets you access the parent class's methods + # that are overridden by the child, in this case, the __init__ method. + # This calls the parent class constructor: + super().__init__(name) + + # override the sing method + def sing(self): + return 'Dun, dun, DUN!' + + # add an additional instance method + def boast(self): + for power in self.superpowers: + print("I wield the power of {pow}!".format(pow=power)) + + +if __name__ == '__main__': + sup = Superhero(name="Tick") + + # Instance type checks + if isinstance(sup, Human): + print('I am human') + if type(sup) is Superhero: + print('I am a superhero') + + # Get the Method Resolution search Order used by both getattr() and super() + # This attribute is dynamic and can be updated + print(Superhero.__mro__) # => (<class '__main__.Superhero'>, + # => <class 'human.Human'>, <class 'object'>) + + # Calls parent method but uses its own class attribute + print(sup.get_species()) # => Superhuman + + # Calls overridden method + print(sup.sing()) # => Dun, dun, DUN! + + # Calls method from Human + sup.say('Spoon') # => Tick: Spoon + + # Call method that exists only in Superhero + sup.boast() # => I wield the power of super strength! + # => I wield the power of bulletproofing! + + # Inherited class attribute + sup.age = 31 + print(sup.age) # => 31 + + # Attribute that only exists within Superhero + print('Am I Oscar eligible? ' + str(sup.movie)) + +#################################################### +## 6.2 Multiple Inheritance #################################################### # Another class definition +# bat.py class Bat: species = 'Baty' @@ -765,31 +871,25 @@ if __name__ == '__main__': print(b.say('hello')) print(b.fly) -# To take advantage of modularization by file you could place the classes above in their own files, -# say, human.py and bat.py - -# To import functions from other files use the following format -# from "filename-without-extension" import "function-or-class" +# And yet another class definition that inherits from Superhero and Bat # superhero.py -from human import Human +from superhero import Superhero from bat import Bat -# Batman inherits from both Human and Bat -class Batman(Human, Bat): - - # Batman has its own value for the species class attribute - species = 'Superhero' +# Define Batman as a child that inherits from both Superhero and Bat +class Batman(Superhero, Bat): def __init__(self, *args, **kwargs): # Typically to inherit attributes you have to call super: - #super(Batman, self).__init__(*args, **kwargs) + # super(Batman, self).__init__(*args, **kwargs) # However we are dealing with multiple inheritance here, and super() # only works with the next base class in the MRO list. # So instead we explicitly call __init__ for all ancestors. # The use of *args and **kwargs allows for a clean way to pass arguments, # with each parent "peeling a layer of the onion". - Human.__init__(self, 'anonymous', *args, **kwargs) + Superhero.__init__(self, 'anonymous', movie=True, + superpowers=['Wealthy'], *args, **kwargs) Bat.__init__(self, *args, can_fly=False, **kwargs) # override the value for the name attribute self.name = 'Sad Affleck' @@ -801,22 +901,17 @@ class Batman(Human, Bat): if __name__ == '__main__': sup = Batman() - # Instance type checks - if isinstance(sup, Human): - print('I am human') - if isinstance(sup, Bat): - print('I am bat') - if type(sup) is Batman: - print('I am Batman') - # Get the Method Resolution search Order used by both getattr() and super(). # This attribute is dynamic and can be updated - print(Batman.__mro__) # => (<class '__main__.Batman'>, <class 'human.Human'>, <class 'bat.Bat'>, <class 'object'>) + print(Batman.__mro__) # => (<class '__main__.Batman'>, + # => <class 'superhero.Superhero'>, + # => <class 'human.Human'>, + # => <class 'bat.Bat'>, <class 'object'>) # Calls parent method but uses its own class attribute - print(sup.get_species()) # => Superhero + print(sup.get_species()) # => Superhuman - # Calls overloaded method + # Calls overridden method print(sup.sing()) # => nan nan nan nan nan batman! # Calls method from Human, because inheritance order matters @@ -827,10 +922,10 @@ if __name__ == '__main__': # Inherited class attribute sup.age = 100 - print(sup.age) + print(sup.age) # => 100 # Inherited attribute from 2nd ancestor whose default value was overridden. - print('Can I fly? ' + str(sup.fly)) + print('Can I fly? ' + str(sup.fly)) # => Can I fly? False diff --git a/pythonstatcomp.html.markdown b/pythonstatcomp.html.markdown index 79bbcd8d..4cff3535 100644 --- a/pythonstatcomp.html.markdown +++ b/pythonstatcomp.html.markdown @@ -13,10 +13,11 @@ This is a tutorial on how to do some typical statistical programming tasks using # 0. Getting set up ==== -""" Get set up with IPython and pip install the following: numpy, scipy, pandas, +""" To get started, pip install the following: jupyter, numpy, scipy, pandas, matplotlib, seaborn, requests. - Make sure to do this tutorial in the IPython notebook so that you get - the inline plots and easy documentation lookup. + Make sure to do this tutorial in a Jupyter notebook so that you get + the inline plots and easy documentation lookup. The shell command to open + one is simply `jupyter notebook`, then click New -> Python. """ # 1. Data acquisition ==== @@ -37,18 +38,16 @@ r.text # raw page source print(r.text) # prettily formatted # save the page source in a file: os.getcwd() # check what's the working directory -f = open("learnxinyminutes.html", "wb") -f.write(r.text.encode("UTF-8")) -f.close() +with open("learnxinyminutes.html", "wb") as f: + f.write(r.text.encode("UTF-8")) # downloading a csv fp = "https://raw.githubusercontent.com/adambard/learnxinyminutes-docs/master/" fn = "pets.csv" r = requests.get(fp + fn) print(r.text) -f = open(fn, "wb") -f.write(r.text.encode("UTF-8")) -f.close() +with open(fn, "wb") as f: + f.write(r.text.encode("UTF-8")) """ for more on the requests module, including APIs, see http://docs.python-requests.org/en/latest/user/quickstart/ @@ -70,8 +69,8 @@ pets # 1 vesuvius 6 23 fish # 2 rex 5 34 dog -""" R users: note that Python, like most normal programming languages, starts - indexing from 0. R is the unusual one for starting from 1. +""" R users: note that Python, like most C-influenced programming languages, starts + indexing from 0. R starts indexing at 1 due to Fortran influence. """ # two different ways to print out a column @@ -147,7 +146,7 @@ ggplot(aes(x="age",y="weight"), data=pets) + geom_point() + labs(title="pets") """ # load some data on Holy Roman Emperors -url = "https://raw.githubusercontent.com/e99n09/R-notes/master/data/hre.csv" +url = "https://raw.githubusercontent.com/adambard/learnxinyminutes-docs/master/hre.csv" r = requests.get(url) fp = "hre.csv" with open(fp, "wb") as f: @@ -157,26 +156,19 @@ hre = pd.read_csv(fp) hre.head() """ - Ix Dynasty Name Birth Death Election 1 -0 NaN Carolingian Charles I 2 April 742 28 January 814 NaN -1 NaN Carolingian Louis I 778 20 June 840 NaN -2 NaN Carolingian Lothair I 795 29 September 855 NaN -3 NaN Carolingian Louis II 825 12 August 875 NaN -4 NaN Carolingian Charles II 13 June 823 6 October 877 NaN - - Election 2 Coronation 1 Coronation 2 Ceased to be Emperor -0 NaN 25 December 800 NaN 28 January 814 -1 NaN 11 September 813 5 October 816 20 June 840 -2 NaN 5 April 823 NaN 29 September 855 -3 NaN Easter 850 18 May 872 12 August 875 -4 NaN 29 December 875 NaN 6 October 877 - - Descent from whom 1 Descent how 1 Descent from whom 2 Descent how 2 -0 NaN NaN NaN NaN -1 Charles I son NaN NaN -2 Louis I son NaN NaN -3 Lothair I son NaN NaN -4 Louis I son NaN NaN + Ix Dynasty Name Birth Death +0 NaN Carolingian Charles I 2 April 742 28 January 814 +1 NaN Carolingian Louis I 778 20 June 840 +2 NaN Carolingian Lothair I 795 29 September 855 +3 NaN Carolingian Louis II 825 12 August 875 +4 NaN Carolingian Charles II 13 June 823 6 October 877 + + Coronation 1 Coronation 2 Ceased to be Emperor +0 25 December 800 NaN 28 January 814 +1 11 September 813 5 October 816 20 June 840 +2 5 April 823 NaN 29 September 855 +3 Easter 850 18 May 872 12 August 875 +4 29 December 875 NaN 6 October 877 """ # clean the Birth and Death columns @@ -194,6 +186,8 @@ rx = re.compile(r'\d+$') # match trailing digits - http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.html """ +from functools import reduce + def extractYear(v): return(pd.Series(reduce(lambda x, y: x + y, map(rx.findall, v), [])).astype(int)) @@ -204,7 +198,7 @@ hre["DeathY"] = extractYear(hre.Death) hre["EstAge"] = hre.DeathY.astype(int) - hre.BirthY.astype(int) # simple scatterplot, no trend line, color represents dynasty -sns.lmplot("BirthY", "EstAge", data=hre, hue="Dynasty", fit_reg=False); +sns.lmplot("BirthY", "EstAge", data=hre, hue="Dynasty", fit_reg=False) # use scipy to run a linear regression from scipy import stats @@ -221,7 +215,7 @@ rval**2 # 0.020363950027333586 pval # 0.34971812581498452 # use seaborn to make a scatterplot and plot the linear regression trend line -sns.lmplot("BirthY", "EstAge", data=hre); +sns.lmplot("BirthY", "EstAge", data=hre) """ For more information on seaborn, see - http://web.stanford.edu/~mwaskom/software/seaborn/ diff --git a/red.html.markdown b/red.html.markdown index 3575032f..73baf462 100644 --- a/red.html.markdown +++ b/red.html.markdown @@ -103,7 +103,8 @@ type? my-integer integer! ; A variable can be initialized using another variable that gets initialized -; at the same time. +; at the same time. Initialize here refers to both declaring a variable and +; assigning a value to it. i2: 1 + i1: 1 ; Arithmetic is straightforward diff --git a/ro-ro/elixir-ro.html.markdown b/ro-ro/elixir-ro.html.markdown new file mode 100644 index 00000000..10fec3c5 --- /dev/null +++ b/ro-ro/elixir-ro.html.markdown @@ -0,0 +1,459 @@ +--- +language: elixir +contributors: + - ["Joao Marques", "http://github.com/mrshankly"] + - ["Dzianis Dashkevich", "https://github.com/dskecse"] + - ["Ryan Plant", "https://github.com/ryanplant-au"] + - ["Ev Bogdanov", "https://github.com/evbogdanov"] +translators: + - ["Vitalie Lazu", "https://github.com/vitaliel"] +lang: ro-ro +filename: learnelixir-ro.ex +--- + +Elixir este un limbaj funcțional modern construit pe baza mașinii virtuale Erlang. +E total compatibil cu Erlang, dar are o sintaxă mai prietenoasă și propune mai multe +posibilități. + +```elixir + +# Comentariile de o linie încep cu simbolul diez. + +# Pentru comentarii pe mai multe linii nu există sintaxă separată, +# de aceea folosiți mai multe linii cu comentarii. + +# Pentru a folosi shell-ul elixir utilizați comanda `iex`. +# Compilați modulele cu comanda `elixirc`. + +# Ambele comenzi vor lucra în terminal, dacă ați instalat Elixir corect. + +## --------------------------- +## -- Tipuri de bază +## --------------------------- + +# Numere +3 # număr întreg +0x1F # număr întreg +3.0 # număr cu virgulă mobilă + +# Atomii, sunt constante nenumerice. Ei încep cu `:`. +:salut # atom + +# Tuplele sunt păstrate în memorie consecutiv. +{1,2,3} # tuple + +# Putem accesa elementul tuplelui folosind funcția `elem`: +elem({1, 2, 3}, 0) #=> 1 + +# Listele sunt implementate ca liste înlănțuite. +[1,2,3] # listă + +# Fiecare listă ne vidă are cap (primul element al listei) +# și coadă (restul elementelor). +# Putem accesa capul și coada listei cum urmează: +[cap | coadă] = [1,2,3] +cap #=> 1 +coadă #=> [2, 3] + +# În Elixir, ca și în Erlang, simbolul `=` denotă potrivirea șabloanelor și +# nu atribuire. +# +# Aceasta înseamnă că expresia din stînga (șablonul) se potrivește cu +# expresia din dreaptă. +# +# În modul acesta exemplul de mai sus lucrează accesînd capul și coada unei liste. + +# Potrivirea șablonului va da eroare cînd expresiile din stînga și dreapta nu se +# potrivesc, în exemplu acesta tuplele au lungime diferită. +{a, b, c} = {1, 2} #=> ** (MatchError) + +# Există și date binare +<<1,2,3>> + +# Sunt două tipuri de șiruri de caractere +"salut" # șir de caractere Elixir +'salut' # listă de caractere Erlang + +# Șir de caractere pe mai multe linii +""" +Sunt un șir de caractere +pe mai multe linii. +""" +#=> "Sunt un șir de caractere\npe mai multe linii..\n" + +# Șirurile de caractere sunt codificate în UTF-8: +"Bună dimineața" #=> "Bună dimineața" + +# Șirurile de caractere sunt date binare, listele de caractere doar liste. +<<?a, ?b, ?c>> #=> "abc" +[?a, ?b, ?c] #=> 'abc' + +# `?a` în Elixir întoarce codul ASCII pentru litera `a` +?a #=> 97 + +# Pentru a concatena listele folosiți `++`, pentru date binare - `<>` +[1,2,3] ++ [4,5] #=> [1,2,3,4,5] +'Salut ' ++ 'lume' #=> 'Salut lume' + +<<1,2,3>> <> <<4,5>> #=> <<1,2,3,4,5>> +"Salut " <> "lume" #=> "Salut lume" + +# Diapazoanele sunt reprezentate ca `început..sfîrșit` (inclusiv) +1..10 #=> 1..10 +început..sfîrșit = 1..10 # Putem folosi potrivirea șabloanelor cu diapazoane de asemenea +[început, sfîrșit] #=> [1, 10] + +# Dicţionarele stochează chei şi o valoare pentru fiecare cheie +genuri = %{"Ion" => "bărbat", "Maria" => "femeie"} +genuri["Ion"] #=> "bărbat" + +# Dicționare cu chei de tip atom au sintaxă specială +genuri = %{ion: "bărbat", maria: "femeie"} +genuri.ion #=> "bărbat" + +## --------------------------- +## -- Operatori +## --------------------------- + +# Operații matematice +1 + 1 #=> 2 +10 - 5 #=> 5 +5 * 2 #=> 10 +10 / 2 #=> 5.0 + +# În Elixir operatorul `/` întotdeauna întoarce un număr cu virgulă mobilă. + +# Folosiți `div` pentru împărțirea numerelor întregi +div(10, 2) #=> 5 + +# Pentru a obține restul de la împărțire utilizați `rem` +rem(10, 3) #=> 1 + +# Există și operatori booleni: `or`, `and` and `not`. +# Acești operatori așteaptă ca primul argument o expresie booleană. +true and true #=> true +false or true #=> true +1 and true #=> ** (BadBooleanError) + +# Elixir de asemenea oferă `||`, `&&` și `!` care acceptă argumente de orice tip. +# Toate valorile în afară de `false` și `nil` se vor evalua ca `true`. +1 || true #=> 1 +false && 1 #=> false +nil && 20 #=> nil +!true #=> false + +# Operatori de comparație: `==`, `!=`, `===`, `!==`, `<=`, `>=`, `<` și `>` +1 == 1 #=> true +1 != 1 #=> false +1 < 2 #=> true + +# `===` și `!==` au strictețe mai mare cînd comparăm numere întregi și reale: +1 == 1.0 #=> true +1 === 1.0 #=> false + +# Putem compara de asemenea și date de diferite tipuri: +1 < :salut #=> true + +# La compararea diferitor tipuri folosiți următoare prioritate: +# număr < atom < referință < funcție < port < proces < tuple < listă < șir de caractere + +# Cităm pe Joe Armstrong în acest caz: "Ordinea actuală nu e importantă, +dar că ordinea totală este bine definită este important." + +## --------------------------- +## -- Ordinea execuției +## --------------------------- + +# expresia `if` +if false do + "Aceasta nu veți vedea niciodată" +else + "Aceasta veți vedea" +end + +# expresia opusă `unless` +unless true do + "Aceasta nu veți vedea niciodată" +else + "Aceasta veți vedea" +end + +# Țineți minte potrivirea șabloanelor? Multe structuri în Elixir se bazează pe ea. + +# `case` ne permite să comparăm o valoare cu multe șabloane: +case {:unu, :doi} do + {:patru, :cinci} -> + "Aceasta nu se potrivește" + {:unu, x} -> + "Aceasta se potrivește și atribuie lui `x` `:doi` în acest bloc" + _ -> + "Aceasta se va potrivi cu orice valoare" +end + +# Simbolul `_` se numește variabila anonimă. +# Folosiți-l pentru valori ce nu vă interesează. +# De exemplu, dacă doar capul listei ne intereseaza: +[cap | _] = [1,2,3] +cap #=> 1 + +# Pentru o citire mai bună putem scri: +[cap | _coadă] = [:a, :b, :c] +cap #=> :a + +# `cond` ne permite să verificăm multe condiții de odată. +# Folosiți `cond` în schimbul la multe expresii `if`. +cond do + 1 + 1 == 3 -> + "Aceasta nu veți vedea niciodată" + 2 * 5 == 12 -> + "Pe mine la fel" + 1 + 2 == 3 -> + "Aceasta veți vedea" +end + +# Este obușnuit de setat ultima condiție cu `true`, care se va potrivi întotdeauna. +cond do + 1 + 1 == 3 -> + "Aceasta nu veți vedea niciodată" + 2 * 5 == 12 -> + "Pe mine la fel" + true -> + "Aceasta veți vedea (este else în esență)" +end + +# Blocul `try/catch` se foloște pentru prelucrarea excepțiilor. +# Elixir suportă blocul `after` care se execută în orice caz. +try do + throw(:salut) +catch + mesaj -> "Am primit #{mesaj}." +after + IO.puts("Sunt în blocul after.") +end +#=> Sunt în blocul after. +# "Am primit salut" + +## --------------------------- +## -- Module și Funcții +## --------------------------- + +# Funcții anonime (atenție la punct la apelarea funcției) +square = fn(x) -> x * x end +square.(5) #=> 25 + +# Ele de asemenea aceptă multe clauze și expresii de gardă. +# Expresiile de gardă vă permit să acordați potrivirea șabloanelor, +# ele sunt indicate după cuvîntul cheie `when`: +f = fn + x, y when x > 0 -> x + y + x, y -> x * y +end + +f.(1, 3) #=> 4 +f.(-1, 3) #=> -3 + +# Elixir de asemenea oferă multe funcții incorporate. +# Ele sunt accesibile în scopul curent. +is_number(10) #=> true +is_list("salut") #=> false +elem({1,2,3}, 0) #=> 1 + +# Puteți grupa cîteva funcții într-un modul. În interiorul modulului folosiți `def` +# pentru a defini funcțiile necesare. +defmodule Math do + def sum(a, b) do + a + b + end + + def square(x) do + x * x + end +end + +Math.sum(1, 2) #=> 3 +Math.square(3) #=> 9 + +# Pentru a compila modulul nostru simplu Math îl salvăm ca `math.ex` și utilizăm `elixirc`. +# în terminal: elixirc math.ex + +# În interiorul modulului putem defini funcții cu `def` și funcții private cu `defp`. +defmodule PrivateMath do + # O funcție definită cu `def` este accesibilă pentru apelare din alte module, + def sum(a, b) do + do_sum(a, b) + end + + # O funcție privată poate fi apelată doar local. + defp do_sum(a, b) do + a + b + end +end + +PrivateMath.sum(1, 2) #=> 3 +PrivateMath.do_sum(1, 2) #=> ** (UndefinedFunctionError) + +# Declarația funcției de asemenea suportă expresii de gardă și multe clauze: +defmodule Geometry do + def area({:rectangle, w, h}) do + w * h + end + + def area({:circle, r}) when is_number(r) do + 3.14 * r * r + end +end + +Geometry.area({:rectangle, 2, 3}) #=> 6 +Geometry.area({:circle, 3}) #=> 28.25999999999999801048 +Geometry.area({:circle, "not_a_number"}) #=> ** (FunctionClauseError) + +# Din cauza variabilelor imutabile, un rol important îl ocupă funcțiile recursive +defmodule Recursion do + def sum_list([head | tail], acc) do + sum_list(tail, acc + head) + end + + def sum_list([], acc) do + acc + end +end + +Recursion.sum_list([1,2,3], 0) #=> 6 + +# Modulele în Elixir suportă atribute, există atribute incorporate și +# puteți adăuga altele. +defmodule MyMod do + @moduledoc """ + Este un atribut incorporat + """ + + @my_data 100 # Acesta e atributul nostru + IO.inspect(@my_data) #=> 100 +end + +# Operatorul |> permite transferarea rezultatului unei expresii din stînga +# ca primul argument al unei funcții din dreapta. +Range.new(1,10) +|> Enum.map(fn x -> x * x end) +|> Enum.filter(fn x -> rem(x, 2) == 0 end) +#=> [4, 16, 36, 64, 100] + +## --------------------------- +## -- Structuri și Excepții +## --------------------------- + +# Structurile sunt extensii a dicționarelor ce au valori implicite, +# verificări în timpul compilării și polimorfism +defmodule Person do + defstruct name: nil, age: 0, height: 0 +end + +joe_info = %Person{ name: "Joe", age: 30, height: 180 } +#=> %Person{age: 30, height: 180, name: "Joe"} + +# Acesarea cîmpului din structură +joe_info.name #=> "Joe" + +# Actualizarea valorii cîmpului +older_joe_info = %{ joe_info | age: 31 } +#=> %Person{age: 31, height: 180, name: "Joe"} + +# Blocul `try` cu cuvîntul cheie `rescue` e folosit pentru a prinde excepții +try do + raise "o eroare" +rescue + RuntimeError -> "a fost prinsă o eroare runtime" + _error -> "aici vor fi prinse toate erorile" +end +#=> "a fost prinsă o eroare runtime" + +# Toate excepțiile au un mesaj +try do + raise "o eroare" +rescue + x in [RuntimeError] -> + x.message +end +#=> "o eroare" + +## --------------------------- +## -- Concurența +## --------------------------- + +# Concurența în Elixir se bazează pe modelul actor. Pentru a scrie programe +# concurente avem nevoie de trei lucruri: +# 1. Crearea proceselor +# 2. Trimiterea mesajelor +# 3. Primirea mesajelor + +# Un nou proces se crează folosind funcția `spawn`, care primește o funcție +# ca argument. +f = fn -> 2 * 2 end #=> #Function<erl_eval.20.80484245> +spawn(f) #=> #PID<0.40.0> + +# `spawn` întoarce identificatorul procesului pid, îl puteți folosi pentru +# a trimite mesaje procesului. Mesajele se transmit folosind operatorul `send`. +# Pentru primirea mesajelor se folosește mecanismul `receive`: + +# Blocul `receive do` este folosit pentru așteptarea mesajelor și prelucrarea lor +# cînd au fost primite. Blocul `receive do` va procesa doar un singur mesaj primit. +# Pentru a procesa mai multe mesaje, funcția cu blocul `receive do` trebuie +# recursiv să se auto apeleze. + +defmodule Geometry do + def area_loop do + receive do + {:rectangle, w, h} -> + IO.puts("Aria = #{w * h}") + area_loop() + {:circle, r} -> + IO.puts("Aria = #{3.14 * r * r}") + area_loop() + end + end +end + +# Compilați modulul și creați un proces +pid = spawn(fn -> Geometry.area_loop() end) #=> #PID<0.40.0> +# Un alt mod +pid = spawn(Geometry, :area_loop, []) + +# Trimiteți un mesaj către `pid` care se va potrivi cu un șablon din blocul `receive` +send pid, {:rectangle, 2, 3} +#=> Aria = 6 +# {:rectangle,2,3} + +send pid, {:circle, 2} +#=> Aria = 12.56000000000000049738 +# {:circle,2} + +# Interpretatorul este de asemenea un proces, puteți folosi `self` +# pentru a primi identificatorul de proces: +self() #=> #PID<0.27.0> + +## --------------------------- +## -- Agenții +## --------------------------- + +# Un agent este un proces care urmărește careva valori ce se schimbă. + +# Creați un agent cu `Agent.start_link`, transmițînd o funcție. +# Stare inițială a agentului va fi rezultatul funcției. +{ok, my_agent} = Agent.start_link(fn -> ["roșu", "verde"] end) + +# `Agent.get` primește numele agentului și o `fn` care primește starea curentă +# Orice va întoarce `fn` este ceea ce veți primi înapoi: +Agent.get(my_agent, fn colors -> colors end) #=> ["roșu", "verde"] + +# Actualizați starea agentului în acelaș mod: +Agent.update(my_agent, fn colors -> ["albastru" | colors] end) +``` + +## Link-uri utile + +* [Primii pași](http://elixir-lang.org/getting-started/introduction.html) de pe [situl Elixir](http://elixir-lang.org) +* [Documentația oficială Elixir](http://elixir-lang.org/docs/master/) +* [Un mic conspect pe Elixir](http://media.pragprog.com/titles/elixir/ElixirCheat.pdf) +* [Cartea "Programming Elixir"](https://pragprog.com/book/elixir/programming-elixir) de Dave Thomas +* [Cartea "Learn You Some Erlang for Great Good!"](http://learnyousomeerlang.com/) de Fred Hebert +* [Cartea "Programming Erlang: Software for a Concurrent World"](https://pragprog.com/book/jaerlang2/programming-erlang) de Joe Armstrong diff --git a/rst.html.markdown b/rst.html.markdown index 65f848ed..01595fe4 100644 --- a/rst.html.markdown +++ b/rst.html.markdown @@ -47,10 +47,7 @@ Title are underlined with equals signs too Subtitles with dashes --------------------- -And sub-subtitles with tildes -~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -You can put text in *italic* or in **bold**, you can "mark" text as code with double backquote ``: ``print()``. +You can put text in *italic* or in **bold**, you can "mark" text as code with double backquote ``print()``. Lists are as simple as in Markdown: @@ -73,7 +70,7 @@ France Paris Japan Tokyo =========== ======== -More complex tabless can be done easily (merged columns and/or rows) but I suggest you to read the complete doc for this :) +More complex tables can be done easily (merged columns and/or rows) but I suggest you to read the complete doc for this :) There are multiple ways to make links: diff --git a/ru-ru/c++-ru.html.markdown b/ru-ru/c++-ru.html.markdown index b9704fc3..35994749 100644 --- a/ru-ru/c++-ru.html.markdown +++ b/ru-ru/c++-ru.html.markdown @@ -886,7 +886,6 @@ v.swap(vector<Foo>()); ``` ## Дальнейшее чтение: -Наиболее полное и обновленное руководство по С++ можно найти на -<http://cppreference.com/w/cpp> - -Дополнительные ресурсы могут быть найдены на <http://cplusplus.com> +* Наиболее полное и обновленное руководство по С++ можно найти на [CPP Reference](http://cppreference.com/w/cpp). +* Дополнительные ресурсы могут быть найдены на [CPlusPlus](http://cplusplus.com). +* Учебник, посвященный основам языка и настройке среды кодирования, доступен в [TheChernoProject - C ++](https://www.youtube.com/playlist?list=PLlrATfBNZ98dudnM48yfGUldqGD0S4FFb). diff --git a/ru-ru/clojure-ru.html.markdown b/ru-ru/clojure-ru.html.markdown index 356d1cc0..19233d23 100644 --- a/ru-ru/clojure-ru.html.markdown +++ b/ru-ru/clojure-ru.html.markdown @@ -8,9 +8,9 @@ translators: lang: ru-ru --- -Clojure, это представитель семейства Lisp-подобных языков, разработанный +Clojure — это представитель семейства Lisp-подобных языков, разработанный для Java Virtual Machine. Язык идейно гораздо ближе к чистому -[функциональному программированию](https://ru.wikipedia.org/wiki/%D0%A4%D1%83%D0%BD%D0%BA%D1%86%D0%B8%D0%BE%D0%BD%D0%B0%D0%BB%D1%8C%D0%BD%D0%BE%D0%B5_%D0%BF%D1%80%D0%BE%D0%B3%D1%80%D0%B0%D0%BC%D0%BC%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5) чем его прародитель Common Lisp, но в то же время обладает набором инструментов для работы с состоянием, +[функциональному программированию](https://ru.wikipedia.org/wiki/%D0%A4%D1%83%D0%BD%D0%BA%D1%86%D0%B8%D0%BE%D0%BD%D0%B0%D0%BB%D1%8C%D0%BD%D0%BE%D0%B5_%D0%BF%D1%80%D0%BE%D0%B3%D1%80%D0%B0%D0%BC%D0%BC%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5), чем его прародитель Common Lisp, но в то же время обладает набором инструментов для работы с состоянием, таких как [STM](https://ru.wikipedia.org/wiki/Software_transactional_memory). Благодаря такому сочетанию технологий в одном языке, разработка программ, @@ -23,9 +23,9 @@ Clojure, это представитель семейства Lisp-подобн ```clojure ; Комментарии начинаются символом ";". -; Код на языке Clojure записывается в виде "форм", +; Код на языке Clojure записывается в виде «форм», ; которые представляют собой обычные списки элементов, разделенных пробелами, -; заключённые в круглые скобки +; заключённые в круглые скобки. ; ; Clojure Reader (инструмент языка, отвечающий за чтение исходного кода), ; анализируя форму, предполагает, что первым элементом формы (т.е. списка) @@ -76,32 +76,32 @@ Clojure, это представитель семейства Lisp-подобн '(+ 1 2) ; => (+ 1 2) ; ("'", это краткая запись формы (quote (+ 1 2)) -; "Квотированный" список можно вычислить, передав его функции eval +; «Квотированный» список можно вычислить, передав его функции eval (eval '(+ 1 2)) ; => 3 ; Коллекции и Последовательности ;;;;;;;;;;;;;;;;;;; -; Списки (Lists) в clojure структурно представляют собой "связанные списки", +; Списки (Lists) в clojure структурно представляют собой «связанные списки», ; тогда как Векторы (Vectors), устроены как массивы. ; Векторы и Списки тоже являются классами Java! (class [1 2 3]); => clojure.lang.PersistentVector (class '(1 2 3)); => clojure.lang.PersistentList -; Список может быть записан, как (1 2 3), но в этом случае +; Список может быть записан как (1 2 3), но в этом случае ; он будет воспринят reader`ом, как вызов функции. ; Есть два способа этого избежать: ; '(1 2 3) - квотирование, ; (list 1 2 3) - явное конструирование списка с помощью функции list. -; "Коллекции", это некие наборы данных +; «Коллекции» — это некие наборы данных. ; И списки, и векторы являются коллекциями: (coll? '(1 2 3)) ; => true (coll? [1 2 3]) ; => true -; "Последовательности" (seqs), это абстракция над наборами данных, +; «Последовательности» (seqs) — это абстракция над наборами данных, ; элементы которых "упакованы" последовательно. -; Списки - последовательности, а вектора - нет. +; Списки — последовательности, а векторы — нет. (seq? '(1 2 3)) ; => true (seq? [1 2 3]) ; => false @@ -119,7 +119,7 @@ Clojure, это представитель семейства Lisp-подобн ; Функция conj добавляет элемент в коллекцию ; максимально эффективным для неё способом. -; Для списков эффективно добавление в начло, а для векторов - в конец. +; Для списков эффективно добавление в начло, а для векторов — в конец. (conj [1 2 3] 4) ; => [1 2 3 4] (conj '(1 2 3) 4) ; => (4 1 2 3) @@ -130,7 +130,7 @@ Clojure, это представитель семейства Lisp-подобн (map inc [1 2 3]) ; => (2 3 4) (filter even? [1 2 3]) ; => (2) -; reduce поможет "свернуть" коллекцию +; reduce поможет «свернуть» коллекцию (reduce + [1 2 3 4]) ; = (+ (+ (+ 1 2) 3) 4) ; => 10 @@ -144,12 +144,12 @@ Clojure, это представитель семейства Lisp-подобн ;;;;;;;;;;;;;;;;;;;;; ; Функция создается специальной формой fn. -; "Тело" функции может состоять из нескольких форм, +; «Тело» функции может состоять из нескольких форм, ; но результатом вызова функции всегда будет результат вычисления ; последней из них. (fn [] "Hello World") ; => fn -; (Вызов функции требует "оборачивания" fn-формы в форму вызова) +; (Вызов функции требует «оборачивания» fn-формы в форму вызова) ((fn [] "Hello World")) ; => "Hello World" ; Назначить значению имя можно специальной формой def @@ -160,7 +160,7 @@ x ; => 1 (def hello-world (fn [] "Hello World")) (hello-world) ; => "Hello World" -; Поскольку именование функций - очень частая операция, +; Поскольку именование функций — очень частая операция, ; clojure позволяет, сделать это проще: (defn hello-world [] "Hello World") @@ -211,7 +211,7 @@ x ; => 1 ; Отображения могут использовать в качестве ключей любые хэшируемые значения, ; однако предпочтительными являются ключи, -; являющиеся "ключевыми словами" (keywords) +; являющиеся «ключевыми словами» (keywords) (class :a) ; => clojure.lang.Keyword (def stringmap {"a" 1, "b" 2, "c" 3}) @@ -263,7 +263,7 @@ keymap ; => {:a 1, :b 2, :c 3} - оригинал не был затронут ; Исключаются - посредством disj (disj #{1 2 3} 1) ; => #{2 3} -; Вызов множества, как функции, позволяет проверить +; Вызов множества как функции позволяет проверить ; принадлежность элемента этому множеству: (#{1 2 3} 1) ; => 1 (#{1 2 3} 4) ; => nil @@ -274,8 +274,8 @@ keymap ; => {:a 1, :b 2, :c 3} - оригинал не был затронут ; Полезные формы ;;;;;;;;;;;;;;;;; -; Конструкции ветвления в clojure, это обычные макросы -; и подобны их собратьям в других языках: +; Конструкции ветвления в clojure — это обычные макросы, +; они подобны своим собратьям в других языках: (if false "a" "b") ; => "b" (if false "a") ; => nil @@ -285,7 +285,7 @@ keymap ; => {:a 1, :b 2, :c 3} - оригинал не был затронут (let [a 1 b 2] (> a b)) ; => false -; Несколько форм можно объединить в одну форму посредством do +; Несколько форм можно объединить в одну форму посредством do. ; Значением do-формы будет значение последней формы из списка вложенных в неё: (do (print "Hello") @@ -298,7 +298,7 @@ keymap ; => {:a 1, :b 2, :c 3} - оригинал не был затронут (str "Hello " name)) (print-and-say-hello "Jeff") ;=> "Hello Jeff" (prints "Saying hello to Jeff") -; Ещё один пример - let: +; Ещё один пример — let: (let [name "Urkel"] (print "Saying hello to " name) (str "Hello " name)) ; => "Hello Urkel" (prints "Saying hello to Urkel") @@ -306,7 +306,7 @@ keymap ; => {:a 1, :b 2, :c 3} - оригинал не был затронут ; Модули ;;;;;;;;; -; Форма "use" позволяет добавить в текущее пространство имен +; Форма use позволяет добавить в текущее пространство имен ; все имена (вместе со значениями) из указанного модуля: (use 'clojure.set) @@ -392,7 +392,7 @@ keymap ; => {:a 1, :b 2, :c 3} - оригинал не был затронут my-atom ;=> Atom<#...> (Возвращает объект типа Atom) @my-atom ; => {:a 1 :b 2} -; Пример реализации счётчика на атоме +; Пример реализации счётчика на атоме: (def counter (atom 0)) (defn inc-counter [] (swap! counter inc)) @@ -414,13 +414,13 @@ my-atom ;=> Atom<#...> (Возвращает объект типа Atom) Это руководство не претендует на полноту, но мы смеем надеяться, способно вызвать интерес к дальнейшему изучению языка. -Clojure.org - сайт содержит большое количество статей по языку: +Сайт Clojure.org содержит большое количество статей по языку: [http://clojure.org/](http://clojure.org/) -Clojuredocs.org - сайт документации языка с примерами использования функций: +Clojuredocs.org — сайт документации языка с примерами использования функций: [http://clojuredocs.org/quickref/Clojure%20Core](http://clojuredocs.org/quickref/Clojure%20Core) -4Clojure - отличный способ закрепить навыки программирования на clojure, решая задачи вместе с коллегами со всего мира: +4Clojure — отличный способ закрепить навыки программирования на clojure, решая задачи вместе с коллегами со всего мира: [http://www.4clojure.com/](http://www.4clojure.com/) Clojure-doc.org (да, именно) неплохой перечень статей для начинающих: diff --git a/ru-ru/common-lisp-ru.html.markdown b/ru-ru/common-lisp-ru.html.markdown new file mode 100644 index 00000000..d5f9bf0e --- /dev/null +++ b/ru-ru/common-lisp-ru.html.markdown @@ -0,0 +1,704 @@ +--- + +language: "Common Lisp" +filename: commonlisp.lisp +contributors: + - ["Paul Nathan", "https://github.com/pnathan"] + - ["Rommel Martinez", "https://ebzzry.io"] +translators: + - ["Michael Filonenko", "https://github.com/filonenko-mikhail"] +lang: ru-ru +--- + +Common Lisp - мультипарадигменный язык программирования общего назначения, подходящий для широкого +спектра задач. +Его частенько называют программируемым языком программирования. + +Идеальная отправная точка - книга [Common Lisp на практике (перевод)](http://lisper.ru/pcl/). +Ещё одна популярная книга [Land of Lisp](http://landoflisp.com/). +И одна из последних книг [Common Lisp Recipes](http://weitz.de/cl-recipes/) вобрала в себя лучшие +архитектурные решения на основе опыта коммерческой работки автора. + + + +```common-lisp + +;;;----------------------------------------------------------------------------- +;;; 0. Синтаксис +;;;----------------------------------------------------------------------------- + +;;; Основные формы + +;;; Существует два фундамента CL: АТОМ и S-выражение. +;;; Как правило, сгруппированные S-выражения называют `формами`. + +10 ; атом; вычисляется в самого себя +:thing ; другой атом; вычисляется в символ :thing +t ; ещё один атом, обозначает `истину` (true) +(+ 1 2 3 4) ; s-выражение +'(4 :foo t) ; ещё одно s-выражение + +;;; Комментарии + +;;; Однострочные комментарии начинаются точкой с запятой. Четыре знака подряд +;;; используют для комментария всего файла, три для раздела, два для текущего +;;; определения; один для текущей строки. Например: + +;;;; life.lisp + +;;; То-сё - пятое-десятое. Оптимизировано для максимального бадабума и ччччч. +;;; Требуется для функции PoschitatBenzinIsRossiiVBelarus + +(defun meaning (life) + "Возвращает смысл Жизни" + (let ((meh "abc")) + ;; Вызывает бадабум + (loop :for x :across meh + :collect x))) ; сохранить значения в x, и потом вернуть + +;;; А вот целый блок комментария можно использовать как угодно. +;;; Для него используются #| и |# + +#| Целый блок комментария, который размазан + на несколько строк + #| + которые могут быть вложенными! + |# +|# + +;;; Чем пользоваться + +;;; Существует несколько реализаций: и коммерческих, и открытых. +;;; Все они максимально соответствуют стандарту языка. +;;; SBCL, например, добротен. А за дополнительными библиотеками +;;; нужно ходить в Quicklisp + +;;; Обычно разработка ведется в текстовом редакторе с запущенным в цикле +;;; интерпретатором (в CL это Read Eval Print Loop). Этот цикл (REPL) +;;; позволяет интерактивно выполнять части программы вживую сразу наблюдая +;;; результат. + +;;;----------------------------------------------------------------------------- +;;; 1. Базовые типы и операторы +;;;----------------------------------------------------------------------------- + +;;; Символы + +'foo ; => FOO Символы автоматически приводятся к верхнему регистру. + +;;; INTERN создаёт символ из строки. + +(intern "AAAA") ; => AAAA +(intern "aaa") ; => |aaa| + +;;; Числа + +9999999999999999999999 ; целые +#b111 ; двоичные => 7 +#o111 ; восьмеричные => 73 +#x111 ; шестнадцатиричные => 273 +3.14159s0 ; с плавающей точкой +3.14159d0 ; с плавающей точкой с двойной точностью +1/2 ; рациональные) +#C(1 2) ; комплексные + +;;; Вызов функции пишется как s-выражение (f x y z ....), где f это функция, +;;; x, y, z, ... аругменты. + +(+ 1 2) ; => 3 + +;;; Если вы хотите просто представить код как данные, воспользуйтесь формой QUOTE +;;; Она не вычисляет аргументы, а возвращает их как есть. +;;; Она даёт начало метапрограммированию + +(quote (+ 1 2)) ; => (+ 1 2) +(quote a) ; => A + +;;; QUOTE можно сокращенно записать знаком ' + +'(+ 1 2) ; => (+ 1 2) +'a ; => A + +;;; Арифметические операции + +(+ 1 1) ; => 2 +(- 8 1) ; => 7 +(* 10 2) ; => 20 +(expt 2 3) ; => 8 +(mod 5 2) ; => 1 +(/ 35 5) ; => 7 +(/ 1 3) ; => 1/3 +(+ #C(1 2) #C(6 -4)) ; => #C(7 -2) + +;;; Булевые + +t ; истина; любое не-NIL значение `истинно` +nil ; ложь; а ещё пустой список () тоже `ложь` +(not nil) ; => T +(and 0 t) ; => T +(or 0 nil) ; => 0 + +;;; Строковые символы + +#\A ; => #\A +#\λ ; => #\GREEK_SMALL_LETTER_LAMDA +#\u03BB ; => #\GREEK_SMALL_LETTER_LAMDA + +;;; Строки это фиксированные массивы символов + +"Hello, world!" +"Тимур \"Каштан\" Бадтрудинов" ; экранировать двойную кавычку обратным слешом + +;;; Строки можно соединять + +(concatenate 'string "ПРивет, " "мир!") ; => "ПРивет, мир!" + +;;; Можно пройтись по строке как по массиву символов + +(elt "Apple" 0) ; => #\A + +;;; Для форматированного вывода используется FORMAT. Он умеет выводить, как просто значения, +;;; так и производить циклы и учитывать условия. Первый агрумент указывает куда отправить +;;; результат. Если NIL, FORMAT вернет результат как строку, если T результат отправиться +;;; консоль вывода а форма вернет NIL. + +(format nil "~A, ~A!" "Привет" "мир") ; => "Привет, мир!" +(format t "~A, ~A!" "Привет" "мир") ; => NIL + + +;;;----------------------------------------------------------------------------- +;;; 2. Переменные +;;;----------------------------------------------------------------------------- + +;;; С помощью DEFVAR и DEFPARAMETER вы можете создать глобальную (динамческой видимости) +;;; переменную. +;;; Имя переменной может состоять из любых символов кроме: ()",'`;#|\ + +;;; Разница между DEFVAR и DEFPARAMETER в том, что повторное выполнение DEFVAR +;;; переменную не поменяет. А вот DEFPARAMETER меняет переменную при каждом вызове. + +;;; Обычно глобальные (динамически видимые) переменные содержат звездочки в имени. + +(defparameter *some-var* 5) +*some-var* ; => 5 + +;;; Можете использовать unicode. +(defparameter *КУКУ* nil) + +;;; Доступ к необъявленной переменной - это непредсказуемое поведение. Не делайте так. + +;;; С помощью LET можете сделать локальное связывание. +;;; В следующем куске кода, `я` связывается с "танцую с тобой" только +;;; внутри формы (let ...). LET всегда возвращает значение последней формы. + +(let ((я "танцую с тобой")) я) ; => "танцую с тобой" + + +;;;-----------------------------------------------------------------------------; +;;; 3. Структуры и коллекции +;;;-----------------------------------------------------------------------------; + + +;;; Структуры + +(defstruct dog name breed age) +(defparameter *rover* + (make-dog :name "rover" + :breed "collie" + :age 5)) +*rover* ; => #S(DOG :NAME "rover" :BREED "collie" :AGE 5) +(dog-p *rover*) ; => T +(dog-name *rover*) ; => "rover" + +;;; DEFSTRUCT автоматически создала DOG-P, MAKE-DOG, и DOG-NAME + + +;;; Пары (cons-ячейки) + +;;; CONS создаёт пары. CAR и CDR возвращают начало и конец CONS-пары. + +(cons 'SUBJECT 'VERB) ; => '(SUBJECT . VERB) +(car (cons 'SUBJECT 'VERB)) ; => SUBJECT +(cdr (cons 'SUBJECT 'VERB)) ; => VERB + + +;;; Списки + +;;; Списки это связанные CONS-пары, в конце самой последней из которых стоит NIL +;;; (или '() ). + +(cons 1 (cons 2 (cons 3 nil))) ; => '(1 2 3) + +;;; Списки с произвольным количеством элементов удобно создавать с помощью LIST + +(list 1 2 3) ; => '(1 2 3) + +;;; Если первый аргумент для CONS это атом и второй аргумент список, CONS +;;; возвращает новую CONS-пару, которая представляет собой список + +(cons 4 '(1 2 3)) ; => '(4 1 2 3) + +;;; Чтобы объединить списки, используйте APPEND + +(append '(1 2) '(3 4)) ; => '(1 2 3 4) + +;;; Или CONCATENATE + +(concatenate 'list '(1 2) '(3 4)) ; => '(1 2 3 4) + +;;; Списки это самый используемый элемент языка. Поэтому с ними можно делать +;;; многие вещи. Вот несколько примеров: + +(mapcar #'1+ '(1 2 3)) ; => '(2 3 4) +(mapcar #'+ '(1 2 3) '(10 20 30)) ; => '(11 22 33) +(remove-if-not #'evenp '(1 2 3 4)) ; => '(2 4) +(every #'evenp '(1 2 3 4)) ; => NIL +(some #'oddp '(1 2 3 4)) ; => T +(butlast '(subject verb object)) ; => (SUBJECT VERB) + + +;;; Вектора + +;;; Вектора заданные прямо в коде - это массивы с фиксированной длинной. + +#(1 2 3) ; => #(1 2 3) + +;;; Для соединения векторов используйте CONCATENATE + +(concatenate 'vector #(1 2 3) #(4 5 6)) ; => #(1 2 3 4 5 6) + + +;;; Массивы + +;;; И вектора и строки это подмножества массивов. + +;;; Двухмерные массивы + +(make-array (list 2 2)) ; => #2A((0 0) (0 0)) +(make-array '(2 2)) ; => #2A((0 0) (0 0)) +(make-array (list 2 2 2)) ; => #3A(((0 0) (0 0)) ((0 0) (0 0))) + +;;; Внимание: значение по-умолчанию элемента массива зависит от реализации. +;;; Лучше явно указывайте: + +(make-array '(2) :initial-element 'unset) ; => #(UNSET UNSET) + +;;; Для доступа к элементу в позиции 1, 1, 1: + +(aref (make-array (list 2 2 2)) 1 1 1) ; => 0 + + +;;; Вектора с изменяемой длиной + +;;; Вектора с изменяемой длиной при выводе на консоль выглядят также, +;;; как и вектора, с константной длиной + +(defparameter *adjvec* (make-array '(3) :initial-contents '(1 2 3) + :adjustable t :fill-pointer t)) +*adjvec* ; => #(1 2 3) + +;;; Добавление новых элементов + +(vector-push-extend 4 *adjvec*) ; => 3 +*adjvec* ; => #(1 2 3 4) + + +;;; Множества, это просто списки: + +(set-difference '(1 2 3 4) '(4 5 6 7)) ; => (3 2 1) +(intersection '(1 2 3 4) '(4 5 6 7)) ; => 4 +(union '(1 2 3 4) '(4 5 6 7)) ; => (3 2 1 4 5 6 7) +(adjoin 4 '(1 2 3 4)) ; => (1 2 3 4) + +;;; Несмотря на все, для действительно больших объемов данных, вам нужно что-то +;;; лучше, чем просто связанные списки + +;;; Словари представлены хеш таблицами. + +;;; Создание хеш таблицы: + +(defparameter *m* (make-hash-table)) + +;;; Установка пары ключ-значение + +(setf (gethash 'a *m*) 1) + +;;; Возврат значения по ключу + +(gethash 'a *m*) ; => 1, T + +;;; CL выражения умеют возвращать сразу несколько значений. + +(values 1 2) ; => 1, 2 + +;;; которые могут быть распределены по переменным с помощью MULTIPLE-VALUE-BIND + +(multiple-value-bind (x y) + (values 1 2) + (list y x)) + +; => '(2 1) + +;;; GETHASH как раз та функция, которая возвращает несколько значений. Первое +;;; значение - это значение по ключу в хеш таблицу. Если ключ не был найден, +;;; возвращает NIL. + +;;; Второе возвращаемое значение, указывает был ли ключ в хеш таблице. Если ключа +;;; не было, то возвращает NIL. Таким образом можно проверить, это значение +;;; NIL, или ключа просто не было. + +;;; Вот возврат значений, в случае когда ключа в хеш таблице не было: + +(gethash 'd *m*) ;=> NIL, NIL + +;;; Можете задать значение по умолчанию. + +(gethash 'd *m* :not-found) ; => :NOT-FOUND + +;;; Давайте обработаем возврат несколько значений. + +(multiple-value-bind (a b) + (gethash 'd *m*) + (list a b)) +; => (NIL NIL) + +(multiple-value-bind (a b) + (gethash 'a *m*) + (list a b)) +; => (1 T) + + +;;;----------------------------------------------------------------------------- +;;; 3. Функции +;;;----------------------------------------------------------------------------- + +;;; Для создания анонимных функций используйте LAMBDA. Функций всегда возвращают +;;; значение последнего своего выражения. Как выглядит функция при выводе в консоль +;;; зависит от реализации. + +(lambda () "Привет Мир") ; => #<FUNCTION (LAMBDA ()) {1004E7818B}> + +;;; Для вызова анонимной функции пользуйтесь FUNCALL + +(funcall (lambda () "Привет Мир")) ; => "Привет мир" +(funcall #'+ 1 2 3) ; => 6 + +;;; FUNCALL сработает и тогда, когда анонимная функция стоит в начале +;;; неэкранированного списка + +((lambda () "Привет Мир")) ; => "Привет Мир" +((lambda (val) val) "Привет Мир") ; => "Привет Мир" + +;;; FUNCALL используется, когда аргументы заранее известны. +;;; В противном случае используйте APPLY + +(apply #'+ '(1 2 3)) ; => 6 +(apply (lambda () "Привет Мир") nil) ; => "Привет Мир" + +;;; Для обычной функции с именем используйте DEFUN + +(defun hello-world () "Привет Мир") +(hello-world) ; => "Привет Мир" + +;;; Выше видно пустой список (), это место для определения аргументов + +(defun hello (name) (format nil "Hello, ~A" name)) +(hello "Григорий") ; => "Привет, Григорий" + +;;; Можно указать необязательные аргументы. По умолчанию они будут NIL + +(defun hello (name &optional from) + (if from + (format t "Приветствие для ~A от ~A" name from) + (format t "Привет, ~A" name))) + +(hello "Георгия" "Василия") ; => Приветствие для Георгия от Василия + +;;; Можно явно задать значения по умолчанию + +(defun hello (name &optional (from "Мира")) + (format nil "Приветствие для ~A от ~A" name from)) + +(hello "Жоры") ; => Приветствие для Жоры от Мира +(hello "Жоры" "альпаки") ; => Приветствие для Жоры от альпаки + +;;; Можно также задать именованные параметры + +(defun generalized-greeter (name &key (from "Мира") (honorific "Господин")) + (format t "Здравствуйте, ~A ~A, от ~A" honorific name from)) + +(generalized-greeter "Григорий") +; => Здравствуйте, Господин Григорий, от Мира + +(generalized-greeter "Григорий" :from "альпаки" :honorific "гражданин") +; => Здравствуйте, Гражданин Григорий, от альпаки + + +;;;----------------------------------------------------------------------------- +;;; 4. Равенство или эквивалентность +;;;----------------------------------------------------------------------------- + +;;; У CL сложная система эквивалентности. Взглянем одним глазом. + +;;; Для чисел используйте `=' +(= 3 3.0) ; => T +(= 2 1) ; => NIL + +;;; Для идентичености объектов используйте EQL +(eql 3 3) ; => T +(eql 3 3.0) ; => NIL +(eql (list 3) (list 3)) ; => NIL + +;;; Для списков, строк, и битовых векторов - EQUAL +(equal (list 'a 'b) (list 'a 'b)) ; => T +(equal (list 'a 'b) (list 'b 'a)) ; => NIL + + +;;;----------------------------------------------------------------------------- +;;; 5. Циклы и ветвления +;;;----------------------------------------------------------------------------- + +;;; Ветвления + +(if t ; проверямое значение + "случилась истина" ; если, оно было истинно + "случилась ложь") ; иначе, когда оно было ложно +; => "случилась истина" + +;;; В форме ветвления if, все не-NIL значения это `истина` + +(member 'Groucho '(Harpo Groucho Zeppo)) ; => '(GROUCHO ZEPPO) +(if (member 'Groucho '(Harpo Groucho Zeppo)) + 'yep + 'nope) +; => 'YEP + +;;; COND это цепочка проверок для нахождения искомого +(cond ((> 2 2) (error "мимо!")) + ((< 2 2) (error "опять мимо!")) + (t 'ok)) ; => 'OK + +;;; TYPECASE выбирает ветку исходя из типа выражения +(typecase 1 + (string :string) + (integer :int)) +; => :int + + +;;; Циклы + +;;; С рекурсией + +(defun fact (n) + (if (< n 2) + 1 + (* n (fact(- n 1))))) + +(fact 5) ; => 120 + +;;; И без + +(defun fact (n) + (loop :for result = 1 :then (* result i) + :for i :from 2 :to n + :finally (return result))) + +(fact 5) ; => 120 + +(loop :for x :across "abc" :collect x) +; => (#\a #\b #\c #\d) + +(dolist (i '(1 2 3 4)) + (format t "~A" i)) +; => 1234 + + +;;;----------------------------------------------------------------------------- +;;; 6. Установка значений в переменные (и не только) +;;;----------------------------------------------------------------------------- + +;;; Для присвоения переменной нового значения используйте SETF. Это уже было +;;; при работе с хеш таблицами. + +(let ((variable 10)) + (setf variable 2)) +; => 2 + +;;; Для функционального подхода в программировании, старайтесь избегать измений +;;; в переменных. + +;;;----------------------------------------------------------------------------- +;;; 7. Классы и объекты +;;;----------------------------------------------------------------------------- + +;;; Никаких больше животных в примерах. Берем устройства приводимые в движение +;;; мускульной силой человека. + +(defclass human-powered-conveyance () + ((velocity + :accessor velocity + :initarg :velocity) + (average-efficiency + :accessor average-efficiency + :initarg :average-efficiency)) + (:documentation "Устройство движимое человеческой силой")) + +;;; Аргументы DEFCLASS: +;;; 1. Имя класса +;;; 2. Список родительских классов +;;; 3. Список полей +;;; 4. Необязательная метаинформация + +;;; Если родительские классы не заданы, используется "стандартный" класс +;;; Это можно *изменить*, но хорошенько подумайте прежде. Если все-таки +;;; решились вам поможет "Art of the Metaobject Protocol" + +(defclass bicycle (human-powered-conveyance) + ((wheel-size + :accessor wheel-size + :initarg :wheel-size + :documentation "Diameter of the wheel.") + (height + :accessor height + :initarg :height))) + +(defclass recumbent (bicycle) + ((chain-type + :accessor chain-type + :initarg :chain-type))) + +(defclass unicycle (human-powered-conveyance) nil) + +(defclass canoe (human-powered-conveyance) + ((number-of-rowers + :accessor number-of-rowers + :initarg :number-of-rowers))) + +;;; Если вызвать DESCRIBE для HUMAN-POWERED-CONVEYANCE то получите следующее: + +(describe 'human-powered-conveyance) + +; COMMON-LISP-USER::HUMAN-POWERED-CONVEYANCE +; [symbol] +; +; HUMAN-POWERED-CONVEYANCE names the standard-class #<STANDARD-CLASS +; HUMAN-POWERED-CONVEYANCE>: +; Documentation: +; A human powered conveyance +; Direct superclasses: STANDARD-OBJECT +; Direct subclasses: UNICYCLE, BICYCLE, CANOE +; Not yet finalized. +; Direct slots: +; VELOCITY +; Readers: VELOCITY +; Writers: (SETF VELOCITY) +; AVERAGE-EFFICIENCY +; Readers: AVERAGE-EFFICIENCY +; Writers: (SETF AVERAGE-EFFICIENCY) + +;;; CL задизайнен как интерактивная система. В рантайме доступна информация о +;;; типе объектов. + +;;; Давайте посчитаем расстояние, которое пройдет велосипед за один оборот колеса +;;; по формуле C = d * pi + +(defmethod circumference ((object bicycle)) + (* pi (wheel-size object))) + +;;; PI - это константа в CL + +;;; Предположим мы нашли, что критерий эффективности логарифмически связан +;;; с гребцами каноэ. Тогда вычисление можем сделать сразу при инициализации. + +;;; Инициализируем объект после его создания: + +(defmethod initialize-instance :after ((object canoe) &rest args) + (setf (average-efficiency object) (log (1+ (number-of-rowers object))))) + + +;;; Давайте проверим что получилось с этой самой эффективностью... + +(average-efficiency (make-instance 'canoe :number-of-rowers 15)) +; => 2.7725887 + + +;;;----------------------------------------------------------------------------- +;;; 8. Макросы +;;;----------------------------------------------------------------------------- + +;;; Макросы позволяют расширить синаксис языка. В CL нет например цикла WHILE, +;;; но его проще простого реализовать на макросах. Если мы отбросим наши +;;; ассемблерные (или алгольные) инстинкты, мы взлетим на крыльях: + +(defmacro while (condition &body body) + "Пока `условие` истинно, выполняется `тело`. +`Условие` проверяется перед каждым выполнением `тела`" + (let ((block-name (gensym)) (done (gensym))) + `(tagbody + ,block-name + (unless ,condition + (go ,done)) + (progn + ,@body) + (go ,block-name) + ,done))) + +;;; Взглянем на более высокоуровневую версию этого макроса: + +(defmacro while (condition &body body) + "Пока `условие` истинно, выполняется `тело`. +`Условие` проверяется перед каждым выполнением `тела`" + `(loop while ,condition + do + (progn + ,@body))) + +;;; В современных комиляторах LOOP так же эффективен как и приведенный +;;; выше код. Поэтому используйте его, его проще читать. + +;;; В макросах используются символы ```, `,` и `@`. ``` - это оператор +;;; квазиквотирования - это значит что форма исполнятся не будет, а вернется +;;; как данные. Оператаор `,` позволяет исполнить форму внутри +;;; квазиквотирования. Оператор `@` исполняет форму внутри квазиквотирования +;;; но полученный список вклеивает по месту. + +;;; GENSYM создаёт уникальный символ, который гарантировано больше нигде в +;;; системе не используется. Так надо потому, что макросы разворачиваются +;;; во время компиляции и переменные объявленные в макросе могут совпасть +;;; по имени с переменными в обычном коде. + +;;; Дальнйешую информацию о макросах ищите в книгах Practical Common Lisp +;;; и On Lisp +``` + +## Для чтения + +На русском +- [Practical Common Lisp](http://www.gigamonkeys.com/book/) + +На английском +- [Practical Common Lisp](http://www.gigamonkeys.com/book/) +- [Common Lisp: A Gentle Introduction to Symbolic Computation](https://www.cs.cmu.edu/~dst/LispBook/book.pdf) + + +## Дополнительная информация + +На русском + +- [Lisper.ru](http://lisper.ru/) + +На английском + +- [CLiki](http://www.cliki.net/) +- [common-lisp.net](https://common-lisp.net/) +- [Awesome Common Lisp](https://github.com/CodyReichert/awesome-cl) +- [Lisp Lang](http://lisp-lang.org/) + + +## Благодарности в английской версии + +Спасибо людям из Scheme за отличную статью, взятую за основу для +Common Lisp. + + +- [Paul Khuong](https://github.com/pkhuong) за хорошую вычитку. diff --git a/ru-ru/crystal-ru.html.markdown b/ru-ru/crystal-ru.html.markdown new file mode 100644 index 00000000..87d12f23 --- /dev/null +++ b/ru-ru/crystal-ru.html.markdown @@ -0,0 +1,584 @@ +--- +language: crystal +filename: learncrystal-ru.cr +contributors: + - ["Vitalii Elenhaupt", "http://veelenga.com"] + - ["Arnaud Fernandés", "https://github.com/TechMagister/"] +translators: + - ["Den Patin", "https://github.com/denpatin"] +lang: ru-ru +--- + +```crystal +# — так начинается комментарий + + +# Всё является объектом +nil.class #=> Nil +100.class #=> Int32 +true.class #=> Bool + +# Возвращают false только nil, false и пустые указатели +!nil #=> true : Bool +!false #=> true : Bool +!0 #=> false : Bool + + +# Целые числа + +1.class #=> Int32 + +# Четыре типа целых чисел со знаком +1_i8.class #=> Int8 +1_i16.class #=> Int16 +1_i32.class #=> Int32 +1_i64.class #=> Int64 + +# Четыре типа целых чисел без знака +1_u8.class #=> UInt8 +1_u16.class #=> UInt16 +1_u32.class #=> UInt32 +1_u64.class #=> UInt64 + +2147483648.class #=> Int64 +9223372036854775808.class #=> UInt64 + +# Двоичные числа +0b1101 #=> 13 : Int32 + +# Восьмеричные числа +0o123 #=> 83 : Int32 + +# Шестнадцатеричные числа +0xFE012D #=> 16646445 : Int32 +0xfe012d #=> 16646445 : Int32 + +# Числа с плавающей точкой + +1.0.class #=> Float64 + +# Два типа чисел с плавающей запятой +1.0_f32.class #=> Float32 +1_f32.class #=> Float32 + +1e10.class #=> Float64 +1.5e10.class #=> Float64 +1.5e-7.class #=> Float64 + + +# Символьные литералы + +'a'.class #=> Char + +# Восьмеричный код символа +'\101' #=> 'A' : Char + +# Код символа Unicode +'\u0041' #=> 'A' : Char + + +# Строки + +"s".class #=> String + +# Строки неизменяемы +s = "hello, " #=> "hello, " : String +s.object_id #=> 134667712 : UInt64 +s += "Crystal" #=> "hello, Crystal" : String +s.object_id #=> 142528472 : UInt64 + +# Поддерживается интерполяция строк +"sum = #{1 + 2}" #=> "sum = 3" : String + +# Поддерживается многострочность +"This is + multiline string" + +# Строка с двойными кавычками +%(hello "world") #=> "hello \"world\"" + + +# Символы — константы без значения, определяемые только именем. Часто +# используются вместо часто используемых строк для лучшей производительности. +# На внутреннем уровне они представлены как Int32. + +:symbol.class #=> Symbol + +sentence = :question? # :"question?" : Symbol + +sentence == :question? #=> true : Bool +sentence == :exclamation! #=> false : Bool +sentence == "question?" #=> false : Bool + + +# Массивы + +[1, 2, 3].class #=> Array(Int32) +[1, "hello", 'x'].class #=> Array(Int32 | String | Char) + +# При объявлении пустого массива необходимо указать тип его элементов +[] # Syntax error: for empty arrays use '[] of ElementType' +[] of Int32 #=> [] : Array(Int32) +Array(Int32).new #=> [] : Array(Int32) + +# Элементы внутри массива имеют свои индексы +array = [1, 2, 3, 4, 5] #=> [1, 2, 3, 4, 5] : Array(Int32) +array[0] #=> 1 : Int32 +array[10] # raises IndexError +array[-6] # raises IndexError +array[10]? #=> nil : (Int32 | Nil) +array[-6]? #=> nil : (Int32 | Nil) + +# Можно получать элементы по индексу с конца +array[-1] #=> 5 + +# С начала и с указанием размера итогового массива +array[2, 3] #=> [3, 4, 5] + +# Или посредством указания диапазона +array[1..3] #=> [2, 3, 4] + +# Добавление в массив +array << 6 #=> [1, 2, 3, 4, 5, 6] + +# Удаление элемента из конца массива +array.pop #=> 6 +array #=> [1, 2, 3, 4, 5] + +# Удаление элемента из начала массива +array.shift #=> 1 +array #=> [2, 3, 4, 5] + +# Проверка на наличие элемента в массиве +array.includes? 3 #=> true + +# Синтаксический сахар для массива строк и символов +%w(one two three) #=> ["one", "two", "three"] : Array(String) +%i(one two three) #=> [:one, :two, :three] : Array(Symbol) + +# Массивоподобный синтаксис используется и для других типов, только если для +# них определены методы .new и #<< +set = Set{1, 2, 3} #=> [1, 2, 3] +set.class #=> Set(Int32) + +# Вышеприведенное эквивалентно следующему +set = Set(typeof(1, 2, 3)).new +set << 1 +set << 2 +set << 3 + + +# Хэши + +{1 => 2, 3 => 4}.class #=> Hash(Int32, Int32) +{1 => 2, 'a' => 3}.class #=> Hash(Int32 | Char, Int32) + +# При объявлении пустого хэша необходимо указать типы ключа и значения +{} # Syntax error +{} of Int32 => Int32 # {} +Hash(Int32, Int32).new # {} + +# Значения в хэше легко найти по ключу +hash = {"color" => "green", "number" => 5} +hash["color"] #=> "green" +hash["no_such_key"] #=> Missing hash key: "no_such_key" (KeyError) +hash["no_such_key"]? #=> nil + +# Проверка наличия ключа в хэше +hash.has_key? "color" #=> true + +# Синтаксический сахар для символьных и строковых ключей +{key1: 'a', key2: 'b'} # {:key1 => 'a', :key2 => 'b'} +{"key1": 'a', "key2": 'b'} # {"key1" => 'a', "key2" => 'b'} + +# Хэшеподобный синтаксис используется и для других типов, только если для них +# определены методы .new и #[]= +class MyType + def []=(key, value) + puts "do stuff" + end +end + +MyType{"foo" => "bar"} + +# Вышеприведенное эквивалентно следующему +tmp = MyType.new +tmp["foo"] = "bar" +tmp + + +# Диапазоны + +1..10 #=> Range(Int32, Int32) +Range.new(1, 10).class #=> Range(Int32, Int32) + +# Включающий и исключающий диапазоны +(3..5).to_a #=> [3, 4, 5] +(3...5).to_a #=> [3, 4] + +# Проверка на вхождение в диапазон +(1..8).includes? 2 #=> true + + +# Кортежи +# Неизменяемые последовательности фиксированного размера, содержащие, +# как правило, элементы разных типов + +{1, "hello", 'x'}.class #=> Tuple(Int32, String, Char) + +# Доступ к элементам осуществляется по индексу +tuple = {:key1, :key2} +tuple[1] #=> :key2 +tuple[2] #=> syntax error : Index out of bound + +# Элементы кортежей можно попарно присвоить переменным +a, b, c = {:a, 'b', "c"} +a #=> :a +b #=> 'b' +c #=> "c" + + +# Процедуры +# Указатели на функцию с необязательным содержимым (замыкание). +# Обычно создаётся с помощью специального литерала -> + +proc = ->(x : Int32) { x.to_s } +proc.class # Proc(Int32, String) +# Или посредством метода .new +Proc(Int32, String).new { |x| x.to_s } + +# Вызываются посредством метода .call +proc.call 10 #=> "10" + + +# Управляющие операторы + +if true + "if statement" +elsif false + "else-if, optional" +else + "else, also optional" +end + +puts "if as a suffix" if true + +# if как часть выражения +a = if 2 > 1 + 3 + else + 4 + end + +a #=> 3 + +# Тернарный if +a = 1 > 2 ? 3 : 4 #=> 4 + +# Оператор выбора +cmd = "move" + +action = case cmd + when "create" + "Creating..." + when "copy" + "Copying..." + when "move" + "Moving..." + when "delete" + "Deleting..." +end + +action #=> "Moving..." + + +# Циклы + +index = 0 +while index <= 3 + puts "Index: #{index}" + index += 1 +end +# Index: 0 +# Index: 1 +# Index: 2 +# Index: 3 + +index = 0 +until index > 3 + puts "Index: #{index}" + index += 1 +end +# Index: 0 +# Index: 1 +# Index: 2 +# Index: 3 + +# Но лучше использовать each +(1..3).each do |index| + puts "Index: #{index}" +end +# Index: 1 +# Index: 2 +# Index: 3 + +# Тип переменной зависит от типа выражения +if a < 3 + a = "hello" +else + a = true +end +typeof a #=> (Bool | String) + +if a && b + # здесь гарантируется, что и a, и b — не nil +end + +if a.is_a? String + a.class #=> String +end + + +# Методы + +def double(x) + x * 2 +end + +# Методы (а также любые блоки) всегда возвращают значение последнего выражения +double(2) #=> 4 + +# Скобки можно опускать, если вызов метода не вносит двусмысленности +double 3 #=> 6 + +double double 3 #=> 12 + +def sum(x, y) + x + y +end + +# Параметры методов перечисляются через запятую +sum 3, 4 #=> 7 + +sum sum(3, 4), 5 #=> 12 + + +# yield + +# У всех методов есть неявный необязательный параметр блока, который можно +# вызвать ключевым словом yield + +def surround + puts '{' + yield + puts '}' +end + +surround { puts "hello world" } + +# { +# hello world +# } + +# Методу можно передать блок +# & — ссылка на переданный блок +def guests(&block) + block.call "some_argument" +end + +# Методу можно передать список параметров, доступ к ним будет как к массиву +# Для этого используется оператор * +def guests(*array) + array.each { |guest| puts guest } +end + +# Если метод возвращает массив, можно попарно присвоить значение каждого из его +# элементов переменным +def foods + ["pancake", "sandwich", "quesadilla"] +end +breakfast, lunch, dinner = foods +breakfast #=> "pancake" +dinner #=> "quesadilla" + +# По соглашению название методов, возвращающих булево значение, должно +# оканчиваться вопросительным знаком +5.even? # false +5.odd? # true + +# Если название метода оканчивается восклицательным знаком, по соглашению это +# означает, что метод делает что-то необратимое, например изменяет получателя. +# Некоторые методы имеют две версии: "опасную" версию с !, которая что-то +# меняет, и "безопасную", которая просто возвращает новое значение +company_name = "Dunder Mifflin" +company_name.gsub "Dunder", "Donald" #=> "Donald Mifflin" +company_name #=> "Dunder Mifflin" +company_name.gsub! "Dunder", "Donald" +company_name #=> "Donald Mifflin" + + +# Классы +# Определяются с помощью ключевого слова class + +class Human + + # Переменная класса является общей для всех экземпляров этого класса + @@species = "H. sapiens" + + # Объявление типа переменной name экземпляра класса + @name : String + + # Базовый конструктор + # Значением первого параметра инициализируем переменную @name. + # То же делаем и со вторым параметром — переменная @age. В случае, если мы + # не передаём второй параметр, для инициализации @age будет взято значение + # по умолчанию (в данном случае — 0) + def initialize(@name, @age = 0) + end + + # Базовый метод установки значения переменной + def name=(name) + @name = name + end + + # Базовый метод получения значения переменной + def name + @name + end + + # Синтаксический сахар одновременно для двух методов выше + property :name + + # А также по отдельности + getter :name + setter :name + + # Метод класса определяется ключевым словом self, чтобы его можно было + # различить с методом экземпляра класса. Такой метод можно вызвать только + # на уровне класса, а не экземпляра. + def self.say(msg) + puts msg + end + + def species + @@species + end +end + + +# Создание экземпляра класса +jim = Human.new("Jim Halpert") + +dwight = Human.new("Dwight K. Schrute") + +# Вызов методов экземпляра класса +jim.species #=> "H. sapiens" +jim.name #=> "Jim Halpert" +jim.name = "Jim Halpert II" #=> "Jim Halpert II" +jim.name #=> "Jim Halpert II" +dwight.species #=> "H. sapiens" +dwight.name #=> "Dwight K. Schrute" + +# Вызов метода класса +Human.say("Hi") #=> выведет "Hi" и вернёт nil + +# Переменные экземпляра класса (@) видно только в пределах экземпляра +class TestClass + @var = "I'm an instance var" +end + +# Переменные класса (@) видны как в экземплярах класса, так и в самом классе +class TestClass + @@var = "I'm a class var" +end + +# Переменные с большой буквы — это константы +Var = "I'm a constant" +Var = "can't be updated" # Error: already initialized constant Var + +# Примеры + +# Базовый класс +class Human + @@foo = 0 + + def self.foo + @@foo + end + + def self.foo=(value) + @@foo = value + end +end + +# Класс-потомок +class Worker < Human +end + +Human.foo #=> 0 +Worker.foo #=> 0 + +Human.foo = 2 #=> 2 +Worker.foo #=> 0 + +Worker.foo = 3 #=> 3 +Human.foo #=> 2 +Worker.foo #=> 3 + +module ModuleExample + def foo + "foo" + end +end + +# Подключение модуля в класс добавляет его методы в экземпляр класса +# Расширение модуля добавляет его методы в сам класс + +class Person + include ModuleExample +end + +class Book + extend ModuleExample +end + +Person.foo # => undefined method 'foo' for Person:Class +Person.new.foo # => 'foo' +Book.foo # => 'foo' +Book.new.foo # => undefined method 'foo' for Book + + +# Обработка исключений + +# Создание пользовательского типа исключения +class MyException < Exception +end + +# Ещё одного +class MyAnotherException < Exception; end + +ex = begin + raise MyException.new +rescue ex1 : IndexError + "ex1" +rescue ex2 : MyException | MyAnotherException + "ex2" +rescue ex3 : Exception + "ex3" +rescue ex4 # без указания конкретного типа исключения будут "отлавливаться" все + "ex4" +end + +ex #=> "ex2" + +``` + +## Дополнительная информация + +### На русском + +- [Официальная документация](http://ru.crystal-lang.org/docs/) + +### На английском + +- [Official Documentation](http://crystal-lang.org/) diff --git a/ru-ru/jquery-ru.html.markdown b/ru-ru/jquery-ru.html.markdown new file mode 100644 index 00000000..471b4e24 --- /dev/null +++ b/ru-ru/jquery-ru.html.markdown @@ -0,0 +1,127 @@ +--- +category: tool +tool: jquery +contributors: + - ["Sawyer Charles", "https://github.com/xssc"] +translators: + - ["Ev Bogdanov", "https://github.com/evbogdanov"] +lang: ru-ru +filename: jquery-ru.js +--- + +jQuery — это библиотека JavaScript, которая помогает "делать больше, писать меньше". Она выполняет множество типичных JavaScript-задач, упрощая написание кода. jQuery используется крупными компаниями и разработчиками со всего мира. Она упрощает и ускоряет работу с AJAX, с событиями, с DOM и со многим другим. + +Поскольку jQuery является библиотекой JavaScript, вам следует начать с [изучения JavaScript](https://learnxinyminutes.com/docs/ru-ru/javascript-ru/). + +```js + + +/////////////////////////////////// +// 1. Селекторы + +// Для получения элемента в jQuery используются селекторы +var page = $(window); // Получить страницу целиком + +// В качестве селектора может выступать CSS-селектор +var paragraph = $('p'); // Получить все <p> элементы +var table1 = $('#table1'); // Получить элемент с идентификатором 'table1' +var squares = $('.square'); // Получить все элементы с классом 'square' +var square_p = $('p.square') // Получить <p> элементы с классом 'square' + + +/////////////////////////////////// +// 2. События и эффекты +// jQuery прекрасно справляется с обработкой событий +// Часто используемое событие — это событие документа 'ready' +// Вы можете использовать метод 'ready', который сработает, как только документ полностью загрузится +$(document).ready(function(){ + // Код не выполнится до тех пор, пока документ не будет загружен +}); +// Обработку события можно вынести в отдельную функцию +function onAction() { + // Код выполнится, когда произойдёт событие +} +$('#btn').click(onAction); // Обработчик события сработает при клике + +// Другие распространённые события: +$('#btn').dblclick(onAction); // Двойной клик +$('#btn').hover(onAction); // Наведение курсора +$('#btn').focus(onAction); // Фокус +$('#btn').blur(onAction); // Потеря фокуса +$('#btn').submit(onAction); // Отправка формы +$('#btn').select(onAction); // Когда выбрали элемент +$('#btn').keydown(onAction); // Когда нажали клавишу +$('#btn').keyup(onAction); // Когда отпустили клавишу +$('#btn').keypress(onAction); // Когда нажали символьную клавишу (нажатие привело к появлению символа) +$('#btn').mousemove(onAction); // Когда переместили курсор мыши +$('#btn').mouseenter(onAction); // Когда навели курсор на элемент +$('#btn').mouseleave(onAction); // Когда сдвинули курсор с элемента + + +// Вы можете не только обрабатывать события, но и вызывать их +$('#btn').dblclick(); // Вызвать двойной клик на элементе + +// Для одного селектора возможно назначить несколько обработчиков событий +$('#btn').on( + {dblclick: myFunction1} // Обработать двойной клик + {blur: myFunction1} // Обработать исчезновение фокуса +); + +// Вы можете перемещать и прятать элементы с помощью методов-эффектов +$('.table').hide(); // Спрятать элемент(ы) + +// Обратите внимание: вызов функции в этих методах всё равно спрячет сам элемент +$('.table').hide(function(){ + // Сначала спрятать элемент, затем вызвать функцию +}); + +// Вы можете хранить селекторы в переменных +var tables = $('.table'); + +// Некоторые основные методы для манипуляций с документом: +tables.hide(); // Спрятать элемент(ы) +tables.show(); // Показать элемент(ы) +tables.toggle(); // Спрятать/показать +tables.fadeOut(); // Плавное исчезновение +tables.fadeIn(); // Плавное появление +tables.fadeToggle(); // Плавное исчезновение или появление +tables.fadeTo(0.5); // Изменение прозрачности +tables.slideUp(); // Свернуть элемент +tables.slideDown(); // Развернуть элемент +tables.slideToggle(); // Свернуть или развернуть + +// Все эти методы принимают скорость (в миллисекундах) и функцию обратного вызова +tables.hide(1000, myFunction); // Анимация длится 1 секунду, затем вызов функции + +// В методе 'fadeTo' вторым параметром обязательно идёт прозрачность +tables.fadeTo(2000, 0.1, myFunction); // Прозрачность меняется в течение 2 секунд до 0.1, затем вызывается функция + +// Метод 'animate' позволяет делать более продвинутую анимацию +tables.animate({"margin-top": "+=50", height: "100px"}, 500, myFunction); + + +/////////////////////////////////// +// 3. Манипуляции + +// Манипуляции похожи на эффекты, но позволяют добиться большего +$('div').addClass('taming-slim-20'); // Добавить класс 'taming-slim-20' ко всем <div> элементам + +// Часто встречающиеся методы манипуляций +$('p').append('Hello world'); // Добавить в конец элемента +$('p').attr('class'); // Получить атрибут +$('p').attr('class', 'content'); // Установить атрибут +$('p').hasClass('taming-slim-20'); // Проверить наличие класса +$('p').height(); // Получить или установить высоту элемента + + +// Во многих методах вам доступна информация ТОЛЬКО о первом элементе из выбранных +$('p').height(); // Вы получите высоту только для первого <p> элемента + +// Метод 'each' позволяет это исправить и пройтись по всем выбранным вами элементам +var heights = []; +$('p').each(function() { + heights.push($(this).height()); // Добавить высоту всех <p> элементов в массив +}); + + +``` diff --git a/ru-ru/kotlin-ru.html.markdown b/ru-ru/kotlin-ru.html.markdown index 21940e41..58dab4cd 100644 --- a/ru-ru/kotlin-ru.html.markdown +++ b/ru-ru/kotlin-ru.html.markdown @@ -8,7 +8,7 @@ translators: - ["Vadim Toptunov", "https://github.com/VadimToptunov"] --- -Kotlin - статистически типизированный язык для JVM, Android и браузера. Язык полностью cjdvtcnbv c Java. +Kotlin - статистически типизированный язык для JVM, Android и браузера. Язык полностью совместим c Java. [Более детальная информация здесь.](https://kotlinlang.org/) ```kotlin diff --git a/ru-ru/markdown-ru.html.markdown b/ru-ru/markdown-ru.html.markdown index ff7a0cc3..579a9a20 100644 --- a/ru-ru/markdown-ru.html.markdown +++ b/ru-ru/markdown-ru.html.markdown @@ -36,13 +36,14 @@ lang: ru-ru Markdown является надмножеством HTML, поэтому любой HTML-файл является корректным документом Markdown. - ```markdown + ```md <!-- Это позволяет использовать напрямую любые элементы HTML-разметки, такие, например, как этот комментарий. Встроенные в документ HTML-элементы не затрагиваются парсером Markdown и попадают в итоговый HTML без изменений. Однако следует понимать, что эта же особенность не позволяет использовать разметку Markdown внутри HTML-элементов --> +``` ## Заголовки @@ -50,7 +51,7 @@ HTML-элементы от <h1> до <h6> размечаются очень пр текст, который должен стать заголовком, предваряется соответствующим количеством символов "#": -```markdown +```md # Это заголовок h1 ## Это заголовок h2 ### Это заголовок h3 @@ -60,7 +61,7 @@ HTML-элементы от <h1> до <h6> размечаются очень пр ``` Markdown позволяет размечать заголовки <h1> и <h2> ещё одним способом: -```markdown +```md Это заголовок h1 ================ @@ -72,7 +73,7 @@ Markdown позволяет размечать заголовки <h1> и <h2> Текст легко сделать полужирным и/или курсивным: -```markdown +```md *Этот текст будет выведен курсивом.* _Так же, как этот._ @@ -87,7 +88,7 @@ __И этот тоже.__ В Github Flavored Markdown, стандарте, который используется в Github, текст также можно сделать зачёркнутым: -```markdown +```md ~~Зачёркнутый текст.~~ ``` @@ -96,7 +97,7 @@ __И этот тоже.__ Абзацами являются любые строки, следующие друг за другом. Разделяются же абзацы одной или несколькими пустыми строками: -```markdown +```md Это абзац. Я печатаю в абзаце, разве это не прикольно? А тут уже абзац №2. @@ -108,7 +109,7 @@ __И этот тоже.__ Для вставки принудительных переносов можно завершить абзац двумя дополнительными пробелами: -```markdown +```md Эта строка завершается двумя пробелами (выделите, чтобы увидеть!). Над этой строкой есть <br />! @@ -116,7 +117,7 @@ __И этот тоже.__ Цитаты размечаются с помощью символа «>»: -```markdown +```md > Это цитата. В цитатах можно > принудительно переносить строки, вставляя «>» в начало каждой следующей строки. А можно просто оставлять их достаточно длинными, и такие длинные строки будут перенесены автоматически. > Разницы между этими двумя подходами к переносу строк нет, коль скоро @@ -133,7 +134,7 @@ __И этот тоже.__ одного из символов «*», «+» или «-»: (символ должен быть одним и тем же для всех элементов) -```markdown +```md * Список, * Размеченный * Звёздочками @@ -154,7 +155,7 @@ __И этот тоже.__ В нумерованных списках каждая строка начинается с числа и точки вслед за ним: -```markdown +```md 1. Первый элемент 2. Второй элемент 3. Третий элемент @@ -164,7 +165,7 @@ __И этот тоже.__ любое число в начале каждого элемента, и парсер пронумерует элементы сам! Правда, злоупотреблять этим не стоит :) -```markdown +```md 1. Первый элемент 1. Второй элемент 1. Третий элемент @@ -173,7 +174,7 @@ __И этот тоже.__ Списки могут быть вложенными: -```markdown +```md 1. Введение 2. Начало работы 3. Примеры использования @@ -184,7 +185,7 @@ __И этот тоже.__ Можно даже делать списки задач. Блок ниже создаёт HTML-флажки. -```markdown +```md Для отметки флажка используйте «x» - [ ] Первая задача - [ ] Вторая задача @@ -197,7 +198,7 @@ __И этот тоже.__ Фрагменты исходного кода (обычно отмечаемые тегом `<code>`) выделяются просто: каждая строка блока должна иметь отступ в четыре пробела либо в один символ табуляции. -```markdown +```md Это код, причём многострочный ``` @@ -205,7 +206,7 @@ __И этот тоже.__ Вы также можете делать дополнительные отступы, добавляя символы табуляции или по четыре пробела: -```markdown +```md my_array.each do |item| puts item end @@ -215,7 +216,7 @@ __И этот тоже.__ не выделяя код в блок. Для этого фрагменты кода нужно обрамлять символами «`»: -```markdown +```md Ваня даже не знал, что делает функция `go_to()`! ``` @@ -237,7 +238,7 @@ end Разделители (`<hr>`) добавляются вставкой строки из трёх и более (одинаковых) символов «*» или «-», с пробелами или без них: -```markdown +```md *** --- - - - @@ -251,18 +252,18 @@ end текст ссылки, заключив его в квадратные скобки, и сразу после — URL-адрес, заключенный в круглые -```markdown +```md [Ссылка!](http://test.com/) ``` Также для ссылки можно указать всплывающую подсказку (`title`), используя кавычки внутри круглых скобок: -```markdown +```md [Ссылка!](http://test.com/ "Ссылка на Test.com") ``` Относительные пути тоже возможны: -```markdown +```md [Перейти к музыке](/music/). ``` @@ -290,7 +291,7 @@ Markdown также позволяет размечать ссылку в вид Разметка изображений очень похожа на разметку ссылок. Нужно всего лишь добавить перед ссылкой восклицательный знак! -```markdown +```md  ``` Изображения тоже могут быть оформлены, как сноски. @@ -301,20 +302,20 @@ Markdown также позволяет размечать ссылку в вид ## Разное ### Автоссылки -```markdown +```md Ссылка вида <http://testwebsite.com/> эквивалентна [http://testwebsite.com/](http://testwebsite.com/) ``` ### Автоссылки для адресов электронной почты -```markdown +```md <foo@bar.com> ``` ### Экранирование символов -```markdown +```md Я хочу напечатать *текст, заключённый в звёздочки*, но я не хочу, чтобы он был курсивным. Тогда я делаю так: \*Текст, заключённый в звёздочки\* @@ -324,7 +325,7 @@ Markdown также позволяет размечать ссылку в вид В Github Flavored Markdown для представления клавиш на клавиатуре вы можете использовать тег `<kbd>`. -```markdown +```md Ваш компьютер завис? Попробуйте нажать <kbd>Ctrl</kbd>+<kbd>Alt</kbd>+<kbd>Del</kbd> ``` @@ -334,7 +335,7 @@ Markdown также позволяет размечать ссылку в вид да и синтаксис имеют не слишком удобный. Но если очень нужно, размечайте таблицы так: -```markdown +```md | Столбец 1 | Столбец 2 | Столбец 3 | | :----------- | :----------: | -----------: | | Выравнивание | Выравнивание | Выравнивание | @@ -342,7 +343,7 @@ Markdown также позволяет размечать ссылку в вид ``` Или более компактно -```markdown +```md Столбец 1|Столбец 2|Столбец 3 :--|:-:|--: Выглядит|это|страшновато... diff --git a/ru-ru/php-ru.html.markdown b/ru-ru/php-ru.html.markdown index 014ff5d0..af77a9ca 100644 --- a/ru-ru/php-ru.html.markdown +++ b/ru-ru/php-ru.html.markdown @@ -61,6 +61,8 @@ $int4 = 0x0F; // => 15 (ведущие символы 0x означают шес // Двоичная запись integer доступна начиная с PHP 5.4.0. $int5 = 0b11111111; // 255 (0b в начале означает двоичное число) +// Удаление переменной +unset($int1); // Дробные числа $float = 1.234; diff --git a/ru-ru/python3-ru.html.markdown b/ru-ru/python3-ru.html.markdown index 2b6b59a7..bf80fed2 100644 --- a/ru-ru/python3-ru.html.markdown +++ b/ru-ru/python3-ru.html.markdown @@ -106,6 +106,9 @@ False or True #=> True # И строки тоже могут складываться! Хотя лучше не злоупотребляйте этим. "Привет " + "мир!" #=> "Привет мир!" +# Строки можно умножать. +"aa" * 4 #=> "aaaaaaaa" + # Со строкой можно работать, как со списком символов "Это строка"[0] #=> 'Э' diff --git a/ru-ru/rust-ru.html.markdown b/ru-ru/rust-ru.html.markdown new file mode 100644 index 00000000..7bd2809a --- /dev/null +++ b/ru-ru/rust-ru.html.markdown @@ -0,0 +1,316 @@ +--- +language: rust + +filename: learnrust-ru.rs +contributors: + - ["P1start", "http://p1start.github.io/"] +translators: + - ["Anatolii Kosorukov", "https://github.com/java1cprog"] +lang: ru-ru + +--- + +Rust сочетает в себе низкоуровневый контроль над производительностью с удобством высокого уровня и предоставляет гарантии +безопасности. +Он достигает этих целей, не требуя сборщика мусора или времени выполнения, что позволяет использовать библиотеки Rust как замену +для C-библиотек. + +Первый выпуск Rust, 0.1, произошел в январе 2012 года, и в течение 3 лет развитие продвигалось настолько быстро, что до +недавнего времени использование стабильных выпусков было затруднено, и вместо этого общий совет заключался в том, чтобы +использовать последние сборки. + +15 мая 2015 года был выпущен Rust 1.0 с полной гарантией обратной совместимости. Усовершенствования времени компиляции и +других аспектов компилятора в настоящее время доступны в ночных сборках. Rust приняла модель выпуска на поезде с регулярными выпусками каждые шесть недель. Rust 1.1 beta был доступен одновременно с выпуском Rust 1.0. + +Хотя Rust является языком относительно низкого уровня, Rust имеет некоторые функциональные концепции, которые обычно +встречаются на языках более высокого уровня. Это делает Rust не только быстрым, но и простым и эффективным для ввода кода. + + +```rust +// Это однострочный комментарии +// + +/// Так выглядит комментарий для документации +/// # Examples +/// +/// +/// let seven = 7 +/// + +/////////////// +// 1. Основы // +/////////////// + +// Функции +// `i32` это целочисленный знаковый тип 32-bit +#[allow(dead_code)] +fn add2(x: i32, y: i32) -> i32 { + // метод возвращает сумму x и y + x + y +} + +// Главная функция программы +#[allow(unused_variables)] +#[allow(unused_assignments)] +#[allow(dead_code)] +fn main() { + // Числа // + + // неизменяемая переменная + let x: i32 = 1; + + // Суффиксы целое/дробное + let y: i32 = 13i32; + let f: f64 = 1.3f64; + + // Автоматическое выявление типа данных + // В большинстве случаев компилятор Rust может вычислить + // тип переменной, поэтому + // вам не нужно писать явные аннотации типа. + + let implicit_x = 1; + let implicit_f = 1.3; + + // Арифметика + let sum = x + y + 13; + + // Изменяемая переменная + let mut mutable = 1; + mutable = 4; + mutable += 2; + + // Строки // + + // Строковые литералы + let x: &str = "hello world!"; + + // Печать на консоль + println!("{} {}", f, x); // 1.3 hello world + + // `String` – изменяемя строка + let s: String = "hello world".to_string(); + + // Строковый срез - неизменяемый вид в строки + // Это в основном неизменяемая пара указателей на строку - + // Это указатель на начало и конец строкового буфера + + let s_slice: &str = &s; + + println!("{} {}", s, s_slice); // hello world hello world + + // Vectors/arrays // + + // фиксированный массив + let four_ints: [i32; 4] = [1, 2, 3, 4]; + + // динамический массив + let mut vector: Vec<i32> = vec![1, 2, 3, 4]; + vector.push(5); + + // Срез - неизменяемое представление значений вектора + let slice: &[i32] = &vector; + + // Используйте шаблон `{:?}`для печати отладочной информации структур с данными + println!("{:?} {:?}", vector, slice); // [1, 2, 3, 4, 5] [1, 2, 3, 4, 5] + + // Кортежи // + + // Кортеж - это фиксированный набор. + // В нём могут находиться значения разных типов данных. + let x: (i32, &str, f64) = (1, "hello", 3.4); + + // Инициализация группы переменных `let` + let (a, b, c) = x; + println!("{} {} {}", a, b, c); // 1 hello 3.4 + + // Доступ по индексу + println!("{}", x.1); // hello + + ////////////// + // 2. Типы // + ////////////// + + // Struct + struct Point { + x: i32, + y: i32, + } + + let origin: Point = Point { x: 0, y: 0 }; + + // Структуры могут быть с безымянными полями ‘tuple struct’ + struct Point2(i32, i32); + + let origin2 = Point2(0, 0); + + // Перечисление + enum Direction { + Left, + Right, + Up, + Down, + } + + let up = Direction::Up; + + // Перечисление с полями + enum OptionalI32 { + AnI32(i32), + Nothing, + } + + let two: OptionalI32 = OptionalI32::AnI32(2); + let nothing = OptionalI32::Nothing; + + // Обобщенные типы данных // + + struct Foo<T> { bar: T } + + // Частоиспользуемое перечисление стандартной библиотеки `Option` + enum Optional<T> { + SomeVal(T), + NoVal, + } + + // Методы // + + impl<T> Foo<T> { + fn get_bar(self) -> T { + self.bar + } + } + + let a_foo = Foo { bar: 1 }; + println!("{}", a_foo.get_bar()); // 1 + + // Типаж + + trait Frobnicate<T> { + fn frobnicate(self) -> Option<T>; + } + + impl<T> Frobnicate<T> for Foo<T> { + fn frobnicate(self) -> Option<T> { + Some(self.bar) + } + } + + let another_foo = Foo { bar: 1 }; + println!("{:?}", another_foo.frobnicate()); // Some(1) + + ///////////////////////// + // 3. Поиск по шаблону // + ///////////////////////// + + let foo = OptionalI32::AnI32(1); + match foo { + OptionalI32::AnI32(n) => println!("it’s an i32: {}", n), + OptionalI32::Nothing => println!("it’s nothing!"), + } + + // Более сложный пример + struct FooBar { x: i32, y: OptionalI32 } + let bar = FooBar { x: 15, y: OptionalI32::AnI32(32) }; + + match bar { + FooBar { x: 0, y: OptionalI32::AnI32(0) } => + println!("The numbers are zero!"), + FooBar { x: n, y: OptionalI32::AnI32(m) } if n == m => + println!("The numbers are the same"), + FooBar { x: n, y: OptionalI32::AnI32(m) } => + println!("Different numbers: {} {}", n, m), + FooBar { x: _, y: OptionalI32::Nothing } => + println!("The second number is Nothing!"), + } + + ///////////////////// + // 4. Управление ходом выполнения программы // + ///////////////////// + + // `for` loops/iteration + let array = [1, 2, 3]; + for i in array.iter() { + println!("{}", i); + } + + // Отрезки + for i in 0u32..10 { + print!("{} ", i); + } + println!(""); + // prints `0 1 2 3 4 5 6 7 8 9 ` + + // `if` + if 1 == 1 { + println!("Maths is working!"); + } else { + println!("Oh no..."); + } + + // `if` as expression + let value = if true { + "good" + } else { + "bad" + }; + + // `while` loop + while 1 == 1 { + println!("The universe is operating normally."); + break; + } + + // Infinite loop + loop { + println!("Hello!"); + break; + } + + ///////////////////////////////// + // 5. Защита памяти и указатели // + ///////////////////////////////// + + // Владеющий указатель – такой указатель может быть только один + // Это значит, что при вызоде из блока переменная автоматически становится недействительной. + let mut mine: Box<i32> = Box::new(3); + *mine = 5; // dereference + // Здесь, `now_its_mine` получает во владение `mine`. Т.е. `mine` была перемещена. + let mut now_its_mine = mine; + *now_its_mine += 2; + + println!("{}", now_its_mine); // 7 + // println!("{}", mine); + + // Ссылки - это неизменяемые указатели + // Если ссылка получает значения, то говорят, что она заимствует это значение. + // Такое значение не может быть изменено или перемещено. + let mut var = 4; + var = 3; + let ref_var: &i32 = &var; + + println!("{}", var); + println!("{}", *ref_var); + // var = 5; // не скомпилируется + // *ref_var = 6; // и это + + // Изменяемые ссылки + // + let mut var2 = 4; + let ref_var2: &mut i32 = &mut var2; + *ref_var2 += 2; // '*' используется для изменения значения + + println!("{}", *ref_var2); // 6 , // var2 would not compile. + // ref_var2 имеет тип &mut i32, т.е. он содержит ссылку на i32, а не значение. + // var2 = 2; // не скомпилируется, т.к. эта переменная уже была заимствована ранее +} + +``` + +## Более подробная информация о языке + +Уже есть хорошие книги для изучающих Rust. Основным источником остаётся +[The Rust Programming Language](http://doc.rust-lang.org/book/index.html) + +Для компиляции программ при изучении языка весьма удобно использовать +[Rust playpen](http://play.rust-lang.org). +Множество ресурсов на разных языках можно найти в [этом проекте](https://github.com/ctjhoa/rust-learning). diff --git a/ruby-ecosystem.html.markdown b/ruby-ecosystem.html.markdown index 50eedcd0..3c80075b 100644 --- a/ruby-ecosystem.html.markdown +++ b/ruby-ecosystem.html.markdown @@ -10,6 +10,16 @@ contributors: People using Ruby generally have a way to install different Ruby versions, manage their packages (or gems), and manage their gem dependencies. +## Ruby Versions + +Ruby was created by Yukihiro "Matz" Matsumoto, who remains somewhat of a +[BDFL](https://en.wikipedia.org/wiki/Benevolent_Dictator_for_Life), although +that is changing recently. As a result, the reference implementation of Ruby is +called MRI (Matz' Reference Implementation), and when you hear a Ruby version, +it is referring to the release version of MRI. + +New major versions of Ruby are traditionally released on Christmas Day. The current major version (25 December 2017) is 2.5. The most popular stable versions are 2.4.4 and 2.3.7 (both released 28 March 2018). + ## Ruby Managers Some platforms have Ruby pre-installed or available as a package. Most rubyists @@ -29,28 +39,6 @@ The following are the popular Ruby environment managers: * [chruby](https://github.com/postmodern/chruby) - Only switches between rubies. Similar in spirit to rbenv. Unopinionated about how rubies are installed. -## Ruby Versions - -Ruby was created by Yukihiro "Matz" Matsumoto, who remains somewhat of a -[BDFL](https://en.wikipedia.org/wiki/Benevolent_Dictator_for_Life), although -that is changing recently. As a result, the reference implementation of Ruby is -called MRI (Matz' Reference Implementation), and when you hear a Ruby version, -it is referring to the release version of MRI. - -The three major version of Ruby in use are: - -* 2.0.0 - Released in February 2013. Most major libraries and frameworks support - 2.0.0. -* 1.9.3 - Released in October 2011. This is the version most rubyists use - currently. Also [retired](https://www.ruby-lang.org/en/news/2015/02/23/support-for-ruby-1-9-3-has-ended/) -* 1.8.7 - Ruby 1.8.7 has been - [retired](http://www.ruby-lang.org/en/news/2013/06/30/we-retire-1-8-7/). - -The change between 1.8.7 to 1.9.x is a much larger change than 1.9.3 to 2.0.0. -For instance, the 1.9 series introduced encodings and a bytecode VM. There -are projects still on 1.8.7, but they are becoming a small minority, as most of -the community has moved to at least 1.9.2 or 1.9.3. - ## Ruby Implementations The Ruby ecosystem enjoys many different implementations of Ruby, each with diff --git a/ruby.html.markdown b/ruby.html.markdown index e0a6bb6e..2595d1d5 100644 --- a/ruby.html.markdown +++ b/ruby.html.markdown @@ -15,32 +15,30 @@ contributors: - ["Gabriel Halley", "https://github.com/ghalley"] - ["Persa Zula", "http://persazula.com"] - ["Jake Faris", "https://github.com/farisj"] + - ["Corey Ward", "https://github.com/coreyward"] + - ["Jannik Siebert", "https://github.com/janniks"] + - ["Keith Miyake", "https://github.com/kaymmm"] --- ```ruby # This is a comment -=begin -This is a multiline comment -No-one uses them -You shouldn't either -=end +# In Ruby, (almost) everything is an object. +# This includes numbers... +3.class #=> Integer -# First and foremost: Everything is an object. - -# Numbers are objects - -3.class #=> Fixnum - -3.to_s #=> "3" +# ...and strings... +"Hello".class #=> String +# ...and even methods! +"Hello".method(:class).class #=> Method # Some basic arithmetic 1 + 1 #=> 2 8 - 1 #=> 7 10 * 2 #=> 20 35 / 5 #=> 7 -2**5 #=> 32 +2 ** 5 #=> 32 5 % 3 #=> 2 # Bitwise operators @@ -52,6 +50,7 @@ You shouldn't either # for calling a method on an object 1.+(3) #=> 4 10.* 5 #=> 50 +100.methods.include?(:/) #=> true # Special values are objects nil # equivalent to null in other languages @@ -70,11 +69,12 @@ false.class #=> FalseClass 1 != 1 #=> false 2 != 1 #=> true -# apart from false itself, nil is the only other 'falsey' value +# Apart from false itself, nil is the only other 'falsey' value -!nil #=> true -!false #=> true -!0 #=> false +!!nil #=> false +!!false #=> false +!!0 #=> true +!!"" #=> true # More comparisons 1 < 10 #=> true @@ -82,15 +82,15 @@ false.class #=> FalseClass 2 <= 2 #=> true 2 >= 2 #=> true -# Combined comparison operator -1 <=> 10 #=> -1 -10 <=> 1 #=> 1 -1 <=> 1 #=> 0 +# Combined comparison operator (returns `1` when the first argument is greater, +# `-1` when the second argument is greater, and `0` otherwise) +1 <=> 10 #=> -1 (1 < 10) +10 <=> 1 #=> 1 (10 > 1) +1 <=> 1 #=> 0 (1 == 1) # Logical operators true && false #=> false true || false #=> true -!true #=> false # There are alternate versions of the logical operators with much lower # precedence. These are meant to be used as flow-control constructs to chain @@ -101,61 +101,54 @@ do_something() and do_something_else() # `log_error` only called if `do_something` fails. do_something() or log_error() - -# Strings are objects - -'I am a string'.class #=> String -"I am a string too".class #=> String +# String interpolation placeholder = 'use string interpolation' "I can #{placeholder} when using double quoted strings" #=> "I can use string interpolation when using double quoted strings" -# Prefer single quoted strings to double quoted ones where possible -# Double quoted strings perform additional inner calculations - -# Combine strings, but not with numbers +# You can combine strings using `+`, but not with other types 'hello ' + 'world' #=> "hello world" 'hello ' + 3 #=> TypeError: can't convert Fixnum into String 'hello ' + 3.to_s #=> "hello 3" +"hello #{3}" #=> "hello 3" -# Combine strings and operators +# ...or combine strings and operators 'hello ' * 3 #=> "hello hello hello " -# Append to string +# ...or append to string 'hello' << ' world' #=> "hello world" -# print to the output with a newline at the end +# You can print to the output with a newline at the end puts "I'm printing!" #=> I'm printing! #=> nil -# print to the output without a newline +# ...or print to the output without a newline print "I'm printing!" -#=> I'm printing! => nil +#=> "I'm printing!" => nil # Variables x = 25 #=> 25 x #=> 25 -# Note that assignment returns the value assigned -# This means you can do multiple assignment: +# Note that assignment returns the value assigned. +# This means you can do multiple assignment. x = y = 10 #=> 10 x #=> 10 y #=> 10 -# By convention, use snake_case for variable names +# By convention, use snake_case for variable names. snake_case = true # Use descriptive variable names path_to_project_root = '/good/name/' -path = '/bad/name/' +m = '/bad/name/' -# Symbols (are objects) # Symbols are immutable, reusable constants represented internally by an # integer value. They're often used instead of strings to efficiently convey -# specific, meaningful values +# specific, meaningful values. :pending.class #=> Symbol @@ -167,77 +160,85 @@ status == 'pending' #=> false status == :approved #=> false +# Strings can be converted into symbols and vice versa. +status.to_s #=> "pending" +"argon".to_sym #=> :argon + # Arrays -# This is an array +# This is an array. array = [1, 2, 3, 4, 5] #=> [1, 2, 3, 4, 5] -# Arrays can contain different types of items - +# Arrays can contain different types of items. [1, 'hello', false] #=> [1, "hello", false] -# Arrays can be indexed -# From the front +# Arrays can be indexed. +# From the front... array[0] #=> 1 array.first #=> 1 array[12] #=> nil -# Like arithmetic, [var] access -# is just syntactic sugar -# for calling a method [] on an object -array.[] 0 #=> 1 -array.[] 12 #=> nil - -# From the end +# ...or from the back... array[-1] #=> 5 array.last #=> 5 -# With a start index and length +# ...or with a start index and length... array[2, 3] #=> [3, 4, 5] -# Reverse an Array -a=[1,2,3] -a.reverse! #=> [3,2,1] - -# Or with a range +# ...or with a range... array[1..3] #=> [2, 3, 4] -# Add to an array like this +# You can reverse an Array. +# Return a new array with reversed values +[1,2,3].reverse #=> [3,2,1] +# Reverse an array in place to update variable with reversed values +a = [1,2,3] +a.reverse! #=> a==[3,2,1] because of the bang ('!') call to reverse + +# Like arithmetic, [var] access is just syntactic sugar +# for calling a method '[]' on an object. +array.[] 0 #=> 1 +array.[] 12 #=> nil + +# You can add to an array... array << 6 #=> [1, 2, 3, 4, 5, 6] # Or like this array.push(6) #=> [1, 2, 3, 4, 5, 6] -# Check if an item exists in an array +# ...and check if an item exists in an array array.include?(1) #=> true # Hashes are Ruby's primary dictionary with key/value pairs. -# Hashes are denoted with curly braces: +# Hashes are denoted with curly braces. hash = { 'color' => 'green', 'number' => 5 } hash.keys #=> ['color', 'number'] -# Hashes can be quickly looked up by key: -hash['color'] #=> 'green' +# Hashes can be quickly looked up by key. +hash['color'] #=> "green" hash['number'] #=> 5 -# Asking a hash for a key that doesn't exist returns nil: +# Asking a hash for a key that doesn't exist returns nil. hash['nothing here'] #=> nil -# Since Ruby 1.9, there's a special syntax when using symbols as keys: +# When using symbols for keys in a hash, you can use an alternate syntax. -new_hash = { defcon: 3, action: true } +hash = { :defcon => 3, :action => true } +hash.keys #=> [:defcon, :action] -new_hash.keys #=> [:defcon, :action] +hash = { defcon: 3, action: true } +hash.keys #=> [:defcon, :action] # Check existence of keys and values in hash -new_hash.key?(:defcon) #=> true -new_hash.value?(3) #=> true +hash.key?(:defcon) #=> true +hash.value?(3) #=> true -# Tip: Both Arrays and Hashes are Enumerable -# They share a lot of useful methods such as each, map, count, and more +# Tip: Both Arrays and Hashes are Enumerable! +# They share a lot of useful methods such as each, map, count, and more. # Control structures +# Conditionals if true 'if statement' elsif false @@ -246,35 +247,26 @@ else 'else, also optional' end +# Loops +# In Ruby, traditional `for` loops aren't very common. Instead, these +# basic loops are implemented using enumerable, which hinges on `each`. +(1..5).each do |counter| + puts "iteration #{counter}" +end + +# Which is roughly equivalent to the following, which is unusual to see in Ruby. for counter in 1..5 puts "iteration #{counter}" end -#=> iteration 1 -#=> iteration 2 -#=> iteration 3 -#=> iteration 4 -#=> iteration 5 -# HOWEVER, No-one uses for loops. -# Instead you should use the "each" method and pass it a block. -# A block is a bunch of code that you can pass to a method like "each". -# It is analogous to lambdas, anonymous functions or closures in other -# programming languages. +# The `do |variable| ... end` construct above is called a 'block'. Blocks are similar +# to lambdas, anonymous functions or closures in other programming languages. They can +# be passed around as objects, called, or attached as methods. # -# The "each" method of a range runs the block once for each element of the range. +# The 'each' method of a range runs the block once for each element of the range. # The block is passed a counter as a parameter. -# Calling the "each" method with a block looks like this: -(1..5).each do |counter| - puts "iteration #{counter}" -end -#=> iteration 1 -#=> iteration 2 -#=> iteration 3 -#=> iteration 4 -#=> iteration 5 - -# You can also surround blocks in curly brackets: +# You can also surround blocks in curly brackets. (1..5).each { |counter| puts "iteration #{counter}" } # The contents of data structures can also be iterated using each. @@ -285,8 +277,8 @@ hash.each do |key, value| puts "#{key} is #{value}" end -# If you still need an index you can use "each_with_index" and define an index -# variable +# If you still need an index you can use 'each_with_index' and define an index +# variable. array.each_with_index do |element, index| puts "#{element} is number #{index} in the array" end @@ -302,9 +294,9 @@ end #=> iteration 4 #=> iteration 5 -# There are a bunch of other helpful looping functions in Ruby, -# for example "map", "reduce", "inject", the list goes on. Map, -# for instance, takes the array it's looping over, does something +# There are a bunch of other helpful looping functions in Ruby. +# For example: 'map', 'reduce', 'inject', the list goes on. +# Map, for instance, takes the array it's looping over, does something # to it as defined in your block, and returns an entirely new array. array = [1,2,3,4,5] doubled = array.map do |element| @@ -315,6 +307,7 @@ puts doubled puts array #=> [1,2,3,4,5] +# Case construct grade = 'B' case grade @@ -333,7 +326,7 @@ else end #=> "Better luck next time" -# cases can also use ranges +# Cases can also use ranges grade = 82 case grade when 90..100 @@ -345,9 +338,9 @@ else end #=> "OK job" -# exception handling: +# Exception handling begin - # code here that might raise an exception + # Code here that might raise an exception raise NoMemoryError, 'You ran out of memory.' rescue NoMemoryError => exception_variable puts 'NoMemoryError was raised', exception_variable @@ -365,10 +358,10 @@ def double(x) x * 2 end -# Methods (and all blocks) implicitly return the value of the last statement +# Methods (and blocks) implicitly return the value of the last statement. double(2) #=> 4 -# Parentheses are optional where the result is unambiguous +# Parentheses are optional where the interpretation is unambiguous. double 3 #=> 6 double double 3 #=> 12 @@ -377,15 +370,14 @@ def sum(x, y) x + y end -# Method arguments are separated by a comma +# Method arguments are separated by a comma. sum 3, 4 #=> 7 sum sum(3, 4), 5 #=> 12 # yield -# All methods have an implicit, optional block parameter -# it can be called with the 'yield' keyword - +# All methods have an implicit, optional block parameter. +# It can be called with the 'yield' keyword. def surround puts '{' yield @@ -394,46 +386,78 @@ end surround { puts 'hello world' } -# { -# hello world -# } +#=> { +#=> hello world +#=> } - -# You can pass a block to a method -# "&" marks a reference to a passed block +# Blocks can be converted into a 'proc' object, which wraps the block +# and allows it to be passed to another method, bound to a different scope, +# or manipulated otherwise. This is most common in method parameter lists, +# where you frequently see a trailing '&block' parameter that will accept +# the block, if one is given, and convert it to a 'Proc'. The naming here is +# convention; it would work just as well with '&pineapple'. def guests(&block) - block.call 'some_argument' + block.class #=> Proc + block.call(4) end -# You can pass a list of arguments, which will be converted into an array -# That's what splat operator ("*") is for +# The 'call' method on the Proc is similar to calling 'yield' when a block is +# present. The arguments passed to 'call' will be forwarded to the block as arugments. + +guests { |n| "You have #{n} guests." } +# => "You have 4 guests." + +# You can pass a list of arguments, which will be converted into an array. +# That's what splat operator ("*") is for. def guests(*array) array.each { |guest| puts guest } end -# If a method returns an array, you can use destructuring assignment -def foods - ['pancake', 'sandwich', 'quesadilla'] +# Destructuring + +# Ruby will automatically destructure arrays on assignment to multiple variables. +a, b, c = [1, 2, 3] +a #=> 1 +b #=> 2 +c #=> 3 + +# In some cases, you will want to use the splat operator: `*` to prompt destructuring +# of an array into a list. +ranked_competitors = ["John", "Sally", "Dingus", "Moe", "Marcy"] + +def best(first, second, third) + puts "Winners are #{first}, #{second}, and #{third}." +end + +best *ranked_competitors.first(3) #=> Winners are John, Sally, and Dingus. + +# The splat operator can also be used in parameters. +def best(first, second, third, *others) + puts "Winners are #{first}, #{second}, and #{third}." + puts "There were #{others.count} other participants." end -breakfast, lunch, dinner = foods -breakfast #=> 'pancake' -dinner #=> 'quesadilla' -# By convention, all methods that return booleans end with a question mark -5.even? # false -5.odd? # true +best *ranked_competitors +#=> Winners are John, Sally, and Dingus. +#=> There were 2 other participants. -# And if a method ends with an exclamation mark, it does something destructive +# By convention, all methods that return booleans end with a question mark. +5.even? #=> false +5.odd? #=> true + +# By convention, if a method name ends with an exclamation mark, it does something destructive # like mutate the receiver. Many methods have a ! version to make a change, and -# a non-! version to just return a new changed version +# a non-! version to just return a new changed version. company_name = "Dunder Mifflin" company_name.upcase #=> "DUNDER MIFFLIN" company_name #=> "Dunder Mifflin" -company_name.upcase! # we're mutating company_name this time! +# We're mutating company_name this time. +company_name.upcase! #=> "DUNDER MIFFLIN" company_name #=> "DUNDER MIFFLIN" +# Classes -# Define a class with the class keyword +# You can define a class with the 'class' keyword. class Human # A class variable. It is shared by all instances of this class. @@ -441,7 +465,7 @@ class Human # Basic initializer def initialize(name, age = 0) - # Assign the argument to the "name" instance variable for the instance + # Assign the argument to the 'name' instance variable for the instance. @name = name # If no age given, we will fall back to the default in the arguments list. @age = age @@ -457,10 +481,10 @@ class Human @name end - # The above functionality can be encapsulated using the attr_accessor method as follows + # The above functionality can be encapsulated using the attr_accessor method as follows. attr_accessor :name - # Getter/setter methods can also be created individually like this + # Getter/setter methods can also be created individually like this. attr_reader :name attr_writer :name @@ -475,13 +499,11 @@ class Human end end - -# Instantiate a class +# Instantiating of a class jim = Human.new('Jim Halpert') - dwight = Human.new('Dwight K. Schrute') -# Let's call a couple of methods +# You can call the methods of the generated object. jim.species #=> "H. sapiens" jim.name #=> "Jim Halpert" jim.name = "Jim Halpert II" #=> "Jim Halpert II" @@ -489,30 +511,30 @@ jim.name #=> "Jim Halpert II" dwight.species #=> "H. sapiens" dwight.name #=> "Dwight K. Schrute" -# Call the class method +# Calling of a class method Human.say('Hi') #=> "Hi" # Variable's scopes are defined by the way we name them. -# Variables that start with $ have global scope +# Variables that start with $ have global scope. $var = "I'm a global var" defined? $var #=> "global-variable" -# Variables that start with @ have instance scope +# Variables that start with @ have instance scope. @var = "I'm an instance var" defined? @var #=> "instance-variable" -# Variables that start with @@ have class scope +# Variables that start with @@ have class scope. @@var = "I'm a class var" defined? @@var #=> "class variable" -# Variables that start with a capital letter are constants +# Variables that start with a capital letter are constants. Var = "I'm a constant" defined? Var #=> "constant" -# Class is also an object in ruby. So class can have instance variables. -# Class variable is shared among the class and all of its descendants. +# Class is also an object in ruby. So a class can have instance variables. +# A class variable is shared among the class and all of its descendants. -# base class +# Base class class Human @@foo = 0 @@ -525,18 +547,17 @@ class Human end end -# derived class +# Derived class class Worker < Human end -Human.foo # 0 -Worker.foo # 0 +Human.foo #=> 0 +Worker.foo #=> 0 -Human.foo = 2 # 2 -Worker.foo # 2 - -# Class instance variable is not shared by the class's descendants. +Human.foo = 2 +Worker.foo #=> 2 +# A class instance variable is not shared by the class's descendants. class Human @bar = 0 @@ -552,8 +573,8 @@ end class Doctor < Human end -Human.bar # 0 -Doctor.bar # nil +Human.bar #=> 0 +Doctor.bar #=> nil module ModuleExample def foo @@ -561,9 +582,8 @@ module ModuleExample end end -# Including modules binds their methods to the class instances -# Extending modules binds their methods to the class itself - +# Including modules binds their methods to the class instances. +# Extending modules binds their methods to the class itself. class Person include ModuleExample end @@ -572,13 +592,12 @@ class Book extend ModuleExample end -Person.foo # => NoMethodError: undefined method `foo' for Person:Class -Person.new.foo # => 'foo' -Book.foo # => 'foo' -Book.new.foo # => NoMethodError: undefined method `foo' +Person.foo #=> NoMethodError: undefined method `foo' for Person:Class +Person.new.foo #=> "foo" +Book.foo #=> "foo" +Book.new.foo #=> NoMethodError: undefined method `foo' # Callbacks are executed when including and extending a module - module ConcernExample def self.included(base) base.extend(ClassMethods) @@ -602,10 +621,10 @@ class Something include ConcernExample end -Something.bar # => 'bar' -Something.qux # => NoMethodError: undefined method `qux' -Something.new.bar # => NoMethodError: undefined method `bar' -Something.new.qux # => 'qux' +Something.bar #=> "bar" +Something.qux #=> NoMethodError: undefined method `qux' +Something.new.bar #=> NoMethodError: undefined method `bar' +Something.new.qux #=> "qux" ``` ## Additional resources diff --git a/rust.html.markdown b/rust.html.markdown index 6b75fa87..71bc16b5 100644 --- a/rust.html.markdown +++ b/rust.html.markdown @@ -41,6 +41,7 @@ Rust not only fast, but also easy and efficient to code in. // 1. Basics // /////////////// +#[allow(dead_code)] // Functions // `i32` is the type for 32-bit signed integers fn add2(x: i32, y: i32) -> i32 { @@ -48,6 +49,9 @@ fn add2(x: i32, y: i32) -> i32 { x + y } +#[allow(unused_variables)] +#[allow(unused_assignments)] +#[allow(dead_code)] // Main function fn main() { // Numbers // @@ -256,11 +260,16 @@ fn main() { // `while` loop while 1 == 1 { println!("The universe is operating normally."); + // break statement gets out of the while loop. + // It avoids useless iterations. + break } // Infinite loop loop { println!("Hello!"); + // break statement gets out of the loop + break } ///////////////////////////////// diff --git a/scala.html.markdown b/scala.html.markdown index 78053b40..28424684 100644 --- a/scala.html.markdown +++ b/scala.html.markdown @@ -276,6 +276,8 @@ r foreach println // NB: Scala is quite lenient when it comes to dots and brackets - study the // rules separately. This helps write DSLs and APIs that read like English +// Why doesn't `println` need any parameters here? +// Stay tuned for first-class functions in the Functional Programming section below! (5 to 1 by -1) foreach (println) // A while loop @@ -299,7 +301,7 @@ do { // Recursion is the idiomatic way of repeating an action in Scala (as in most // other functional languages). // Recursive functions need an explicit return type, the compiler can't infer it. -// Here it's Unit. +// Here it's Unit, which is analagous to a `void` return type in Java def showNumbersInRange(a: Int, b: Int): Unit = { print(a) if (a < b) @@ -412,8 +414,8 @@ class Dog(br: String) { private def sleep(hours: Int) = println(s"I'm sleeping for $hours hours") - // Abstract methods are simply methods with no body. If we uncomment the next - // line, class Dog would need to be declared abstract + // Abstract methods are simply methods with no body. If we uncomment the + // def line below, class Dog would need to be declared abstract like so: // abstract class Dog(...) { ... } // def chaseAfter(what: String): String } @@ -455,7 +457,7 @@ george.phoneNumber // => "1234" Person("George", "1234") == Person("Kate", "1236") // => false // Easy way to copy -// otherGeorge == Person("george", "9876") +// otherGeorge == Person("George", "9876") val otherGeorge = george.copy(phoneNumber = "9876") // And many others. Case classes also get pattern matching for free, see below. @@ -523,7 +525,9 @@ def matchPerson(person: Person): String = person match { case Person(name, number) => "We matched someone : " + name + ", phone : " + number } -val email = "(.*)@(.*)".r // Define a regex for the next example. +// Regular expressions are also built in. +// Create a regex with the `r` method on a string: +val email = "(.*)@(.*)".r // Pattern matching might look familiar to the switch statements in the C family // of languages, but this is much more powerful. In Scala, you can match much @@ -589,6 +593,8 @@ List("Dom", "Bob", "Natalia") foreach println // Combinators +// Using `s` from above: +// val s = Set(1, 3, 7) s.map(sq) @@ -608,8 +614,8 @@ List( ).filter(_.age > 25) // List(Person("Bob", 30)) -// Scala a foreach method defined on certain collections that takes a type -// returning Unit (a void method) +// Certain collections (such as List) in Scala have a `foreach` method, +// which takes as an argument a type returning Unit - that is, a void method val aListOfNumbers = List(1, 2, 3, 4, 10, 20, 100) aListOfNumbers foreach (x => println(x)) aListOfNumbers foreach println @@ -710,7 +716,7 @@ import scala.collection.immutable.{Map => _, Set => _, _} // Java classes can also be imported. Scala syntax can be used import java.swing.{JFrame, JWindow} -// Your programs entry point is defined in an scala file using an object, with a +// Your programs entry point is defined in a scala file using an object, with a // single method, main: object Application { def main(args: Array[String]): Unit = { diff --git a/sk-sk/bash.html.markdown b/sk-sk/bash-sk.html.markdown index e9d1490c..e9d1490c 100644 --- a/sk-sk/bash.html.markdown +++ b/sk-sk/bash-sk.html.markdown diff --git a/sk-sk/coffeescript.html.markdown b/sk-sk/coffeescript-sk.html.markdown index 30bbceec..30bbceec 100644 --- a/sk-sk/coffeescript.html.markdown +++ b/sk-sk/coffeescript-sk.html.markdown diff --git a/sk-sk/elixir.html.markdown b/sk-sk/elixir-sk.html.markdown index 2401f92e..2401f92e 100644 --- a/sk-sk/elixir.html.markdown +++ b/sk-sk/elixir-sk.html.markdown diff --git a/sk-sk/git.html.markdown b/sk-sk/git-sk.html.markdown index 21741406..21741406 100644 --- a/sk-sk/git.html.markdown +++ b/sk-sk/git-sk.html.markdown diff --git a/sk-sk/json.html.markdown b/sk-sk/json-sk.html.markdown index 2b1fbb58..2b1fbb58 100644 --- a/sk-sk/json.html.markdown +++ b/sk-sk/json-sk.html.markdown diff --git a/sk-sk/latex.html.markdown.tex b/sk-sk/latex-sk.html.markdown.tex index 5e2f9c7f..5e2f9c7f 100644 --- a/sk-sk/latex.html.markdown.tex +++ b/sk-sk/latex-sk.html.markdown.tex diff --git a/sk-sk/ruby.html.markdown b/sk-sk/ruby-sk.html.markdown index 799865b0..799865b0 100644 --- a/sk-sk/ruby.html.markdown +++ b/sk-sk/ruby-sk.html.markdown diff --git a/smalltalk.html.markdown b/smalltalk.html.markdown index a253df55..87135cf4 100644 --- a/smalltalk.html.markdown +++ b/smalltalk.html.markdown @@ -1,46 +1,96 @@ --- -language: smalltalk +language: Smalltalk filename: smalltalk.st contributors: - ["Jigyasa Grover", "https://github.com/jig08"] + - ["tim Rowledge", "tim@rowledge.org"] --- -- Smalltalk is an object-oriented, dynamically typed, reflective programming language. +- Smalltalk is a fully object-oriented, dynamically typed, reflective programming language with no 'non-object' types. - Smalltalk was created as the language to underpin the "new world" of computing exemplified by "human–computer symbiosis." - It was designed and created in part for educational use, more so for constructionist learning, at the Learning Research Group (LRG) of Xerox PARC by Alan Kay, Dan Ingalls, Adele Goldberg, Ted Kaehler, Scott Wallace, and others during the 1970s. Feedback highly appreciated! Reach me at [@jigyasa_grover](https://twitter.com/jigyasa_grover) or send me an e-mail at `grover.jigyasa1@gmail.com`. - -##Allowable characters: +## The Basics +### Everything is an object +Yes, everything. Integers are instances of one of the numeric classes. Classes are instances of the class Metaclass and are just as manipulable as any other object. All classes are part of a single class tree; no disjoint class trees. Stack frames are objects and can be manipulated, which is how the debugger works. There are no pointers into memory locations that you can dereference and mess with. + +### Functions are not called; messages are sent to objects +Work is done by sending messages to objects, which decide how to respond to that message and run a method as a result, which eventually returns some object to the original message sending code. +The system knows the class of the object receiving a message and looks up the message in that class's list of methods. If it is not found, the lookup continues in the super class until either it is found or the root of the classes is reached and there is still no relevant method. +If a suitable method is found the code is run, and the same process keeps on going with all the methods sent by that method and so on forever. +If no suitable method is found an exception is raised, which typically results in a user interface notifier to tell the user that the message was not understood. It is entirely possible to catch the exception and do something to fix the problem, which might range from 'ignore it' to 'load some new packages for this class and try again'. +A method (more strictly an instance of the class CompiledMethod) is a chunk of Smalltalk code that has been compiled into bytecodes. Executing methods start at the beginning and return to the sender when a return is encountered (we use ^ to signify 'return the follwing object') or the end of the code is reached, in which case the current object running the code is returned. + +### Simple syntax +Smalltalk has a simple syntax with very few rules. +The most basic operation is to send a message to an object +`anObject aMessage` + +There are three sorts of messages +- unary - a single string that may be several words conjoined in what we call camelcase form, with no arguments. For example 'size', 'reverseBytes', 'convertToLargerFormatPixels' +- binary - a small set of symbols of the sort often used for arithmetic operations in most languages, requiring a single argument. For example '+', '//', '@'. We do not use traditional arithmetic precedence, something to keep an eye on. +- keyword - the general form where multiple arguments can be passed. As with the unary form we use camelcase to join words together but arguments are inserted in the midst of the message with colons used to separate them lexically. For example 'setTemperature:', 'at:put:', 'drawFrom:to:lineWidth:fillColor:' + +#### An example +`result := myObject doSomethingWith: thatObject` +We are sending the message 'doSomethingWith:' to myObject. This happens to be a message that has a single argument but that's not important yet. +'myObject' is a 'MyExampleClass' instance so the system looks at the list of messages understood by MyExampleClass +- beClever +- doWierdThing: +- doSomethingWith + +In searching we see what initially looks like a match - but no, it lacks the final colon. So we find the super class of MyExampleClass - BigExampleClass. Which has a list of known messages of its own +- beClever +- doSomethingWith: +- buildCastleInAir +- annoyUserByDoing: + +We find a proper exact match and start to execute the code +``` +doSomethingWith: argumentObject +"A comment about what this code is meant to do and any known limitations, problems, where it might be further documented etc" +self size > 4 ifTrue: [^argumentObject sizeRelatingTo: self]. +``` + +Everything here except the `^` involves sending more messages. Event the `ifTrue:` that you might think is a language control structure is just Smalltalk code. +We start by sending `size` to `self`. `self` is the object currently running the code - so in this case it is the myObject we started with. `size` is a very common message that we might anticipate tells us something about how big an object is; you could look it up with the Smalltalk tools very simply. The result we get is then sent the message `>` with the plain old integer 4 (which is an object too; no strange primitive types to pollute the system here) and nobody should be surprised the `>` is a comparison that answers true or false. That boolean (which is actually a Boolean object in Smalltalk) is sent the message `ifTrue:` with the block of code between the `[]` as its argument; obvioulsy a true boolean might be expected to run that block of code and a false to ignore it. +If the block is run then we do some more message sending to the argument object and noting the `^` we return the answer back to our starting point and it gets assigned to `result`. If the block is ignored we seem to run out of code and so `self` is returned and assigned to `result`. + +## Smalltalk quick reference cheat-sheet +Taken from [Smalltalk Cheatsheet](http://www.angelfire.com/tx4/cus/notes/smalltalk.html) + +#### Allowable characters: - a-z - A-Z - 0-9 - .+/\*~<>@%|&? - blank, tab, cr, ff, lf -##Variables: -- variables must be declared before use -- shared vars must begin with uppercase -- local vars must begin with lowercase -- reserved names: `nil`, `true`, `false`, `self`, `super`, and `Smalltalk` +#### Variables: +- variable names must be declared before use but are untyped +- shared vars (globals, class vars) conventionally begin with uppercase (except the reserved names shown below) +- local vars (instance vars, temporaries, method & block arguments) conventionally begin with lowercase +- reserved names: `nil`, `true`, `false`, `self`, `super`, and `thisContext` -##Variable scope: -- Global: defined in Dictionary Smalltalk and accessible by all objects in system - Special: (reserved) `Smalltalk`, `super`, `self`, `true`, `false`, & `nil` +#### Variable scope: +- Global: defined in a Dictionary named 'Smalltalk' and accessible by all objects in system +- Special: (reserved) `Smalltalk`, `super`, `self`, `true`, `false`, & `nil` - Method Temporary: local to a method - Block Temporary: local to a block -- Pool: variables in a Dictionary object -- Method Parameters: automatic local vars created as a result of message call with params -- Block Parameters: automatic local vars created as a result of value: message call -- Class: shared with all instances of one class & its subclasses -- Class Instance: unique to each instance of a class -- Instance Variables: unique to each instance +- Pool: variables in a Dictionary object, possibly shared with classes not directly related by inheritance +- Method Parameters: automatic method temp vars that name the incoming parameters. Cannot be assigned to +- Block Parameters: automatic block temp vars that name the incoming parameters. Cannot be assigned to +- Class: shared with all instances of a class & its subclasses +- Class Instance: unique to each instance of a class. Too commonly confused with class variables +- Instance Variables: unique to each instance of a class -`"Comments are enclosed in quotes"` +`"Comments are enclosed in quotes and may be arbitrary length"` -`"Period (.) is the statement separator"` +`"Period (.) is the statement separator. Not required on last line of a method"` -## Transcript: +#### Transcript: ``` Transcript clear. "clear to transcript window" Transcript show: 'Hello World'. "output string in transcript window" @@ -54,7 +104,7 @@ Transcript cr. "carriage return / l Transcript endEntry. "flush the output buffer" ``` -##Assignment: +#### Assignment: ``` | x y | x _ 4. "assignment (Squeak) <-" @@ -73,7 +123,7 @@ y := x deepCopy. "copy object and ins y := x veryDeepCopy. "complete tree copy using a dictionary" ``` -##Constants: +#### Constants: ``` | b | b := true. "true constant" @@ -91,10 +141,9 @@ x := $ . "character constant x := #aSymbol. "symbol constants" x := #(3 2 1). "array constants" x := #('abc' 2 $a). "mixing of types allowed" - ``` -## Booleans: +#### Booleans: ``` | b x y | x := 1. y := 2. @@ -130,10 +179,9 @@ b := x isFloat. "test if object is f b := x isNumber. "test if object is number" b := $A isUppercase. "test if upper case character" b := $A isLowercase. "test if lower case character" - ``` -## Arithmetic expressions: +#### Arithmetic expressions: ``` | x | x := 6 + 3. "addition" @@ -188,10 +236,9 @@ x := Float infinity. "infinity" x := Float nan. "not-a-number" x := Random new next; yourself. x next. "random number stream (0.0 to 1.0)" x := 100 atRandom. "quick random number" - ``` -##Bitwise Manipulation: +#### Bitwise Manipulation: ``` | b x | x := 16rFF bitAnd: 16r0F. "and bits" @@ -205,10 +252,9 @@ x := 16r80 highbit. "position of highest b := 16rFF allMask: 16r0F. "test if all bits set in mask set in receiver" b := 16rFF anyMask: 16r0F. "test if any bits set in mask set in receiver" b := 16rFF noMask: 16r0F. "test if all bits set in mask clear in receiver" - ``` -## Conversion: +#### Conversion: ``` | x | x := 3.99 asInteger. "convert number to integer (truncates in Squeak)" @@ -221,10 +267,9 @@ x := 3.99 storeString. "convert object to s x := 15 radix: 16. "convert to string in given base" x := 15 printStringBase: 16. x := 15 storeStringBase: 16. - ``` -## Blocks: +#### Blocks: - blocks are objects and may be assigned to a variable - value is last expression evaluated unless explicit return - blocks may be nested @@ -242,10 +287,11 @@ Transcript show: (x value: 'First' value: 'Second'); cr. "use block with argu "x := [ | z | z := 1.]. *** localvars not available in squeak blocks" ``` -## Method calls: +#### Method calls: - unary methods are messages with no arguments - binary methods -- keyword methods are messages with selectors including colons standard categories/protocols: - initialize-release (methods called for new instance) +- keyword methods are messages with selectors including colons standard categories/protocols: +- initialize-release (methods called for new instance) - accessing (get/set methods) - testing (boolean tests - is) - comparing (boolean tests with parameter @@ -254,6 +300,7 @@ Transcript show: (x value: 'First' value: 'Second'); cr. "use block with argu - updating (receive notification of changes) - private (methods private to class) - instance-creation (class methods for creating instance) + ``` | x | x := 2 sqrt. "unary message" @@ -268,7 +315,7 @@ Transcript "Cascading - send mu x := 3 + 2; * 100. "result=300. Sends message to same receiver (3)" ``` -##Conditional Statements: +#### Conditional Statements: ``` | x | x > 10 ifTrue: [Transcript show: 'ifTrue'; cr]. "if then" @@ -300,7 +347,7 @@ switch at: $C put: [Transcript show: 'Case C'; cr]. result := (switch at: $B) value. ``` -## Iteration statements: +#### Iteration statements: ``` | x y | x := 4. y := 1. @@ -312,7 +359,7 @@ x timesRepeat: [y := y * 2]. "times repeat loop ( #(5 4 3) do: [:a | x := x + a]. "iterate over array elements" ``` -## Character: +#### Character: ``` | x y | x := $A. "character assignment" @@ -330,10 +377,9 @@ y := x asciiValue. "convert to numeric y := x asString. "convert to string" b := $A <= $B. "comparison" y := $A max: $B. - ``` -## Symbol: +#### Symbol: ``` | b x y | x := #Hello. "symbol assignment" @@ -355,7 +401,7 @@ y := x asBag. "convert symbol to b y := x asSet. "convert symbol to set collection" ``` -## String: +#### String: ``` | b x y | x := 'This is a string'. "string assignment" @@ -385,7 +431,9 @@ y := x asSet. "convert string to s y := x shuffled. "randomly shuffle string" ``` -## Array: Fixed length collection +#### Array: +Fixed length collection + - ByteArray: Array limited to byte elements (0-255) - WordArray: Array limited to word elements (0-2^32) @@ -428,7 +476,9 @@ y := x asBag. "convert to bag coll y := x asSet. "convert to set collection" ``` -##OrderedCollection: acts like an expandable array +#### OrderedCollection: +acts like an expandable array + ``` | b x y sum max | x := OrderedCollection with: 4 with: 3 with: 2 with: 1. "create collection with up to 4 elements" @@ -471,7 +521,9 @@ y := x asBag. "convert to bag coll y := x asSet. "convert to set collection" ``` -## SortedCollection: like OrderedCollection except order of elements determined by sorting criteria +#### SortedCollection: +like OrderedCollection except order of elements determined by sorting criteria + ``` | b x y sum max | x := SortedCollection with: 4 with: 3 with: 2 with: 1. "create collection with up to 4 elements" @@ -513,7 +565,9 @@ y := x asBag. "convert to bag coll y := x asSet. "convert to set collection" ``` -## Bag: like OrderedCollection except elements are in no particular order +#### Bag: +like OrderedCollection except elements are in no particular order + ``` | b x y sum max | x := Bag with: 4 with: 3 with: 2 with: 1. "create collection with up to 4 elements" @@ -544,8 +598,12 @@ y := x asBag. "convert to bag coll y := x asSet. "convert to set collection" ``` -## Set: like Bag except duplicates not allowed -## IdentitySet: uses identity test (== rather than =) +#### Set: +like Bag except duplicates not allowed + +#### IdentitySet: +uses identity test (== rather than =) + ``` | b x y sum max | x := Set with: 4 with: 3 with: 2 with: 1. "create collection with up to 4 elements" @@ -575,7 +633,7 @@ y := x asBag. "convert to bag coll y := x asSet. "convert to set collection" ``` -## Interval: +#### Interval: ``` | b x y sum max | x := Interval from: 5 to: 10. "create interval object" @@ -604,7 +662,7 @@ y := x asBag. "convert to bag coll y := x asSet. "convert to set collection" ``` -##Associations: +#### Associations: ``` | x y | x := #myVar->'hello'. @@ -612,8 +670,10 @@ y := x key. y := x value. ``` -## Dictionary: -## IdentityDictionary: uses identity test (== rather than =) +#### Dictionary: +#### IdentityDictionary: +uses identity test (== rather than =) + ``` | b x y | x := Dictionary new. "allocate collection" @@ -677,7 +737,7 @@ Smalltalk removeKey: #CMRGlobal ifAbsent: []. "remove entry from S Smalltalk removeKey: #CMRDictionary ifAbsent: []. "remove user dictionary from Smalltalk dictionary" ``` -## Internal Stream: +#### Internal Stream: ``` | b x ios | ios := ReadStream on: 'Hello read stream'. @@ -707,7 +767,7 @@ x := ios contents. b := ios atEnd. ``` -## FileStream: +#### FileStream: ``` | b x ios | ios := FileStream newFileNamed: 'ios.txt'. @@ -728,7 +788,7 @@ b := ios atEnd. ios close. ``` -## Date: +#### Date: ``` | x y | x := Date today. "create date for today" @@ -762,7 +822,7 @@ y := x printFormat: #(2 1 3 $/ 1 1). "print formatted dat b := (x <= Date today). "comparison" ``` -## Time: +#### Time: ``` | x y | x := Time now. "create time from current time" @@ -782,7 +842,7 @@ x := Time millisecondsToRun: [ "timing facility" b := (x <= Time now). "comparison" ``` -## Point: +#### Point: ``` | x y | x := 200@100. "obtain a new point" @@ -807,12 +867,12 @@ x := 200@100 min: 50@200. "min x and y" x := 20@5 dotProduct: 10@2. "sum of product (x1*x2 + y1*y2)" ``` -## Rectangle: +#### Rectangle: ``` Rectangle fromUser. ``` -## Pen: +#### Pen: ``` | myPen | Display restoreAfter: [ @@ -839,7 +899,7 @@ Display height. "get display height" ]. ``` -## Dynamic Message Calling/Compiling: +#### Dynamic Message Calling/Compiling: ``` | receiver message result argument keyword1 keyword2 argument1 argument2 | "unary message" @@ -875,7 +935,7 @@ result := (Message sentTo: receiver. ``` -## Class/Meta-class: +#### Class/Meta-class: ``` | b x | x := String name. "class name" @@ -908,7 +968,7 @@ b := String isWords. "true if index insta Object withAllSubclasses size. "get total number of class entries" ``` -## Debugging: +#### Debugging: ``` | a b x | x yourself. "returns receiver" @@ -931,7 +991,7 @@ a := 'A1'. b := 'B2'. a become: b. "switch two objects" Transcript show: a, b; cr. ``` -## Misc +#### Misc ``` | x | "Smalltalk condenseChanges." "compress the change file" @@ -939,19 +999,25 @@ x := FillInTheBlank request: 'Prompt Me'. "prompt user for inp Utilities openCommandKeyHelp ``` - - - ## Ready For More? -### Free Online +### Online Smalltalk systems +Most Smalltalks are either free as in OSS or have a free downloadable version with some payment required for commercial usage. +* [Squeak](https://www.squeak.org) +* [Pharo](http://pharo.org) +* [Smalltalk/X](https://www.exept.de/en/smalltalk-x.html) +* [Gemstone](http://gemtalksystems.com/) +* [VA Smalltalk](http://www.instantiations.com/products/vasmalltalk/) +* [VisualWorks Smalltalk](http://www.cincomsmalltalk.com/) -* [GNU Smalltalk User's Guide](https://www.gnu.org/software/smalltalk/manual/html_node/Tutorial.html) -* [smalltalk dot org](http://www.smalltalk.org/) -* [Computer Programming using GNU Smalltalk](http://www.canol.info/books/computer_programming_using_gnu_smalltalk/) +### Online Smalltalk books and articles +* [Smalltalk Programming Resources](http://www.whoishostingthis.com/resources/smalltalk/) * [Smalltalk Cheatsheet](http://www.angelfire.com/tx4/cus/notes/smalltalk.html) * [Smalltalk-72 Manual](http://www.bitsavers.org/pdf/xerox/parc/techReports/Smalltalk-72_Instruction_Manual_Mar76.pdf) +* [GNU Smalltalk User's Guide](https://www.gnu.org/software/smalltalk/manual/html_node/Tutorial.html) + +#### Historical doc * [BYTE: A Special issue on Smalltalk](https://archive.org/details/byte-magazine-1981-08) +* [Smalltalk-72 Manual](http://www.bitsavers.org/pdf/xerox/parc/techReports/Smalltalk-72_Instruction_Manual_Mar76.pdf) * [Smalltalk, Objects, and Design](https://books.google.co.in/books?id=W8_Une9cbbgC&printsec=frontcover&dq=smalltalk&hl=en&sa=X&ved=0CCIQ6AEwAWoVChMIw63Vo6CpyAIV0HGOCh3S2Alf#v=onepage&q=smalltalk&f=false) * [Smalltalk: An Introduction to Application Development Using VisualWorks](https://books.google.co.in/books?id=zalQAAAAMAAJ&q=smalltalk&dq=smalltalk&hl=en&sa=X&ved=0CCgQ6AEwAmoVChMIw63Vo6CpyAIV0HGOCh3S2Alf/) -* [Smalltalk Programming Resources](http://www.whoishostingthis.com/resources/smalltalk/) diff --git a/solidity.html.markdown b/solidity.html.markdown index c1f910fd..acf750f7 100644 --- a/solidity.html.markdown +++ b/solidity.html.markdown @@ -4,6 +4,7 @@ filename: learnSolidity.sol contributors: - ["Nemil Dalal", "https://www.nemil.com"] - ["Joseph Chow", ""] + - ["Bhoomtawath Plinsut", "https://github.com/varshard"] --- Solidity lets you program on [Ethereum](https://www.ethereum.org/), a @@ -37,8 +38,8 @@ features are typically marked, and subject to change. Pull requests welcome. // simple_bank.sol (note .sol extension) /* **** START EXAMPLE **** */ -// Declare the source file compiler version. -pragma solidity ^0.4.2; +// Declare the source file compiler version +pragma solidity ^0.4.19; // Start with Natspec comment (the three slashes) // used for documentation - and as descriptive data for UI elements/actions @@ -65,7 +66,7 @@ contract SimpleBank { // CapWords event LogDepositMade(address accountAddress, uint amount); // Constructor, can receive one or many variables here; only one allowed - function SimpleBank() { + function SimpleBank() public { // msg provides details about the message that's sent to the contract // msg.sender is contract caller (address of contract creator) owner = msg.sender; @@ -73,7 +74,11 @@ contract SimpleBank { // CapWords /// @notice Deposit ether into bank /// @return The balance of the user after the deposit is made - function deposit() public returns (uint) { + function deposit() public payable returns (uint) { + // Use 'require' to test user inputs, 'assert' for internal invariants + // Here we are making sure that there isn't an overflow issue + require((balances[msg.sender] + msg.value) >= balances[msg.sender]); + balances[msg.sender] += msg.value; // no "this." or "self." required with state variable // all values set to data type's initial value by default @@ -88,38 +93,28 @@ contract SimpleBank { // CapWords /// @param withdrawAmount amount you want to withdraw /// @return The balance remaining for the user function withdraw(uint withdrawAmount) public returns (uint remainingBal) { - if(balances[msg.sender] >= withdrawAmount) { - // Note the way we deduct the balance right away, before sending - due to - // the risk of a recursive call that allows the caller to request an amount greater - // than their balance - balances[msg.sender] -= withdrawAmount; - - if (!msg.sender.send(withdrawAmount)) { - // increment back only on fail, as may be sending to contract that - // has overridden 'send' on the receipt end - balances[msg.sender] += withdrawAmount; - } - } + require(withdrawAmount <= balances[msg.sender]); + + // Note the way we deduct the balance right away, before sending + // Every .transfer/.send from this contract can call an external function + // This may allow the caller to request an amount greater + // than their balance using a recursive call + // Aim to commit state before calling external functions, including .transfer/.send + balances[msg.sender] -= withdrawAmount; + + // this automatically throws on a failure, which means the updated balance is reverted + msg.sender.transfer(withdrawAmount); return balances[msg.sender]; } /// @notice Get balance /// @return The balance of the user - // 'constant' prevents function from editing state variables; + // 'view' (ex: constant) prevents function from editing state variables; // allows function to run locally/off blockchain - function balance() constant returns (uint) { + function balance() view public returns (uint) { return balances[msg.sender]; } - - // Fallback function - Called if other functions don't match call or - // sent ether without data - // Typically, called when invalid data is sent - // Added so ether sent to this contract is reverted if the contract fails - // otherwise, the sender's money is transferred to contract - function () { - throw; // throw reverts state to before call - } } // ** END EXAMPLE ** @@ -137,6 +132,11 @@ int256 constant a = 8; // same effect as line above, here the 256 is explicit uint constant VERSION_ID = 0x123A1; // A hex constant // with 'constant', compiler replaces each occurrence with actual value +// All state variables (those outside a function) +// are by default 'internal' and accessible inside contract +// and in all contracts that inherit ONLY +// Need to explicitly set to 'public' to allow external contracts to access +int256 public a = 8; // For int and uint, can explicitly set space in steps of 8 up to 256 // e.g., int8, int16, int24 @@ -145,6 +145,12 @@ int64 c; uint248 e; // Be careful that you don't overflow, and protect against attacks that do +// For example, for an addition, you'd do: +uint256 c = a + b; +assert(c >= a); // assert tests for internal invariants; require is used for user inputs +// For more examples of common arithmetic issues, see Zeppelin's SafeMath library +// https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/contracts/math/SafeMath.sol + // No random functions built in, use other contracts for randomness @@ -165,14 +171,14 @@ address public owner; // a getter is automatically created, but NOT a setter // All addresses can be sent ether -owner.send(SOME_BALANCE); // returns false on failure -if (owner.send) {} // REMEMBER: wrap in 'if', as contract addresses have +owner.transfer(SOME_BALANCE); // fails and reverts on failure + +// Can also do a lower level .send call, which returns a false if it failed +if (owner.send) {} // REMEMBER: wrap send in 'if', as contract addresses have // functions executed on send and these can fail // Also, make sure to deduct balances BEFORE attempting a send, as there is a risk of a recursive // call that can drain the contract -// can override send by defining your own - // Can check balance owner.balance; // the balance of the owner (user or contract) @@ -213,7 +219,7 @@ uint x = 5; // Destructuring/Tuples -(x, y) = (2, 7); // assign/swap multiple value +(x, y) = (2, 7); // assign/swap multiple values // 2. DATA STRUCTURES @@ -250,7 +256,7 @@ delete balances; // sets all elements to 0 // mapping, without knowing source keys - can build data structure // on top to do this -// Structs and enums +// Structs struct Bank { address owner; uint balance; @@ -273,7 +279,7 @@ state = State.Created; // enums can be explicitly converted to ints uint createdState = uint(State.Created); // 0 -// Data locations: Memory vs. storage vs. stack - all complex types (arrays, +// Data locations: Memory vs. storage vs. calldata - all complex types (arrays, // structs) have a data location // 'memory' does not persist, 'storage' does // Default is 'storage' for local and state variables; 'memory' for func params @@ -292,13 +298,13 @@ uint createdState = uint(State.Created); // 0 // 4. Global Variables of note // ** this ** this; // address of contract -// often used at end of contract life to send remaining balance to party +// often used at end of contract life to transfer remaining balance to party this.balance; this.someFunction(); // calls func externally via call, not via internal jump // ** msg - Current message received by the contract ** ** msg.sender; // address of sender -msg.value; // amount of ether provided to this contract in wei +msg.value; // amount of ether provided to this contract in wei, the function should be marked "payable" msg.data; // bytes, complete call data msg.gas; // remaining gas @@ -308,6 +314,8 @@ tx.gasprice; // gas price of the transaction // ** block - Information about current block ** now; // current time (approximately), alias for block.timestamp (uses Unix time) +// Note that this can be manipulated by miners, so use carefully + block.number; // current block number block.difficulty; // current block difficulty block.blockhash(1); // returns bytes32, only works for most recent 256 blocks @@ -334,23 +342,33 @@ function increment(uint x, uint y) returns (uint x, uint y) { // Call previous functon uint (a,b) = increment(1,1); -// 'constant' indicates that function does not/cannot change persistent vars -// Constant function execute locally, not on blockchain -uint y; +// 'view' (alias for 'constant') +// indicates that function does not/cannot change persistent vars +// View function execute locally, not on blockchain +// Noted: constant keyword will soon be deprecated. +uint y = 1; -function increment(uint x) constant returns (uint x) { +function increment(uint x) view returns (uint x) { x += 1; y += 1; // this line would fail - // y is a state variable, and can't be changed in a constant function + // y is a state variable, and can't be changed in a view function } +// 'pure' is more strict than 'view' or 'constant', and does not +// even allow reading of state vars +// The exact rules are more complicated, so see more about +// view/pure: +// http://solidity.readthedocs.io/en/develop/contracts.html#view-functions + // 'Function Visibility specifiers' -// These can be placed where 'constant' is, including: -// public - visible externally and internally (default) -// external +// These can be placed where 'view' is, including: +// public - visible externally and internally (default for function) +// external - only visible externally (including a call made with this.) // private - only visible in the current contract // internal - only visible in current contract, and those deriving from it +// Generally, a good idea to mark each function explicitly + // Functions hoisted - and can assign a function to a variable function a() { var z = b; @@ -361,8 +379,15 @@ function b() { } +// All functions that receive ether must be marked 'payable' +function depositEther() public payable { + balances[msg.sender] += msg.value; +} + // Prefer loops to recursion (max call stack depth is 1024) +// Also, don't setup loops that you haven't bounded, +// as this can hit the gas limit // B. Events // Events are notify external parties; easy to search and @@ -376,10 +401,11 @@ function b() { event LogSent(address indexed from, address indexed to, uint amount); // note capital first letter // Call -Sent(from, to, amount); +LogSent(from, to, amount); -// For an external party (a contract or external entity), to watch: -Coin.Sent().watch({}, '', function(error, result) { +// For an external party (a contract or external entity), to watch using +// the Web3 Javascript library: +Coin.LogSent().watch({}, '', function(error, result) { if (!error) { console.log("Coin transfer: " + result.args.amount + " coins were sent from " + result.args.from + @@ -398,10 +424,10 @@ Coin.Sent().watch({}, '', function(error, result) { // '_' (underscore) often included as last line in body, and indicates // function being called should be placed there -modifier onlyAfter(uint _time) { if (now <= _time) throw; _ } -modifier onlyOwner { if (msg.sender == owner) _ } +modifier onlyAfter(uint _time) { require (now >= _time); _; } +modifier onlyOwner { require(msg.sender == owner) _; } // commonly used with state machines -modifier onlyIfState (State currState) { if (currState != State.A) _ } +modifier onlyIfStateA (State currState) { require(currState == State.A) _; } // Append right after function declaration function changeOwner(newOwner) @@ -415,12 +441,10 @@ onlyIfState(State.A) // underscore can be included before end of body, // but explicitly returning will skip, so use carefully modifier checkValue(uint amount) { - _ + _; if (msg.value > amount) { uint amountToRefund = amount - msg.value; - if (!msg.sender.send(amountToRefund)) { - throw; - } + msg.sender.transfer(amountToRefund); } } @@ -437,22 +461,21 @@ modifier checkValue(uint amount) { // amount of gas for a block of code - and will fail if that is exceeded // For example: for(uint x = 0; x < refundAddressList.length; x++) { - if (!refundAddressList[x].send(SOME_AMOUNT)) { - throw; - } + refundAddressList[x].transfer(SOME_AMOUNT); } // Two errors above: -// 1. A failure on send stops the loop from completing, tying up money +// 1. A failure on transfer stops the loop from completing, tying up money // 2. This loop could be arbitrarily long (based on the amount of users who need refunds), and // therefore may always fail as it exceeds the max gas for a block // Instead, you should let people withdraw individually from their subaccount, and mark withdrawn +// e.g., favor pull payments over push payments // 7. OBJECTS/CONTRACTS // A. Calling external contract -contract infoFeed { +contract InfoFeed { function info() returns (uint ret) { return 42; } } @@ -502,23 +525,10 @@ function someAbstractFunction(uint x); import "filename"; import "github.com/ethereum/dapp-bin/library/iterable_mapping.sol"; -// Importing under active development -// Cannot currently be done at command line - // 8. OTHER KEYWORDS -// A. Throwing -// Throwing -throw; // reverts unused money to sender, state is reverted -// Can't currently catch - -// Common design pattern is: -if (!addr.send(123)) { - throw; -} - -// B. Selfdestruct +// A. Selfdestruct // selfdestruct current contract, sending funds to address (often creator) selfdestruct(SOME_ADDRESS); @@ -543,7 +553,7 @@ function remove() { // that is private needs to be obfuscated (e.g., hashed w/secret) // Steps: 1. Commit to something, 2. Reveal commitment -sha3("some_bid_amount", "some secret"); // commit +keccak256("some_bid_amount", "some secret"); // commit // call contract's reveal function in the future // showing bid plus secret that hashes to SHA3 @@ -617,6 +627,7 @@ contract SomeOracle { // ** START EXAMPLE ** // CrowdFunder.sol +pragma solidity ^0.4.19; /// @title CrowdFunder /// @author nemild @@ -650,22 +661,20 @@ contract CrowdFunder { event LogWinnerPaid(address winnerAddress); modifier inState(State _state) { - if (state != _state) throw; - _ + require(state == _state); + _; } modifier isCreator() { - if (msg.sender != creator) throw; - _ + require(msg.sender == creator); + _; } - // Wait 6 months after final contract state before allowing contract destruction + // Wait 24 weeks after final contract state before allowing contract destruction modifier atEndOfLifecycle() { - if(!((state == State.ExpiredRefund || state == State.Successful) && - completeAt + 6 months < now)) { - throw; - } - _ + require(((state == State.ExpiredRefund || state == State.Successful) && + completeAt + 24 weeks < now)); + _; } function CrowdFunder( @@ -673,6 +682,7 @@ contract CrowdFunder { string _campaignUrl, address _fundRecipient, uint _minimumToRaise) + public { creator = msg.sender; fundRecipient = _fundRecipient; @@ -683,7 +693,9 @@ contract CrowdFunder { function contribute() public + payable inState(State.Fundraising) + returns(uint256 id) { contributions.push( Contribution({ @@ -699,7 +711,9 @@ contract CrowdFunder { return contributions.length - 1; // return id } - function checkIfFundingCompleteOrExpired() { + function checkIfFundingCompleteOrExpired() + public + { if (totalRaised > minimumToRaise) { state = State.Successful; payOut(); @@ -715,31 +729,23 @@ contract CrowdFunder { public inState(State.Successful) { - if(!fundRecipient.send(this.balance)) { - throw; - } - - + fundRecipient.transfer(this.balance); LogWinnerPaid(fundRecipient); } - function getRefund(id) - public + function getRefund(uint256 id) inState(State.ExpiredRefund) + public + returns(bool) { - if (contributions.length <= id || id < 0 || contributions[id].amount == 0 ) { - throw; - } + require(contributions.length > id && id >= 0 && contributions[id].amount != 0 ); - uint amountToRefund = contributions[id].amount; + uint256 amountToRefund = contributions[id].amount; contributions[id].amount = 0; - if(!contributions[id].contributor.send(amountToSend)) { - contributions[id].amount = amountToSend; - return false; - } + contributions[id].contributor.transfer(amountToRefund); - return true; + return true; } function removeContract() @@ -750,8 +756,6 @@ contract CrowdFunder { selfdestruct(msg.sender); // creator gets all money that hasn't be claimed } - - function () { throw; } } // ** END EXAMPLE ** @@ -798,6 +802,7 @@ someContractAddress.callcode('function_name'); // 13. STYLE NOTES // Based on Python's PEP8 style guide +// Full Style guide: http://solidity.readthedocs.io/en/develop/style-guide.html // Quick summary: // 4 spaces for indentation @@ -825,11 +830,15 @@ someContractAddress.callcode('function_name'); ## Additional resources - [Solidity Docs](https://solidity.readthedocs.org/en/latest/) -- [Solidity Style Guide](https://ethereum.github.io/solidity//docs/style-guide/): Ethereum's style guide is heavily derived from Python's [pep8](https://www.python.org/dev/peps/pep-0008/) style guide. -- [Browser-based Solidity Editor](http://chriseth.github.io/browser-solidity/) +- [Smart Contract Best Practices](https://github.com/ConsenSys/smart-contract-best-practices) +- [EthFiddle - The JsFiddle for Solidity](https://ethfiddle.com/) +- [Browser-based Solidity Editor](https://remix.ethereum.org/) - [Gitter Solidity Chat room](https://gitter.im/ethereum/solidity) - [Modular design strategies for Ethereum Contracts](https://docs.erisindustries.com/tutorials/solidity/) +## Important libraries +- [Zeppelin](https://github.com/OpenZeppelin/zeppelin-solidity/): Libraries that provide common contract patterns (crowdfuding, safemath, etc) + ## Sample contracts - [Dapp Bin](https://github.com/ethereum/dapp-bin) - [Solidity Baby Step Contracts](https://github.com/fivedogit/solidity-baby-steps/tree/master/contracts) @@ -841,13 +850,11 @@ someContractAddress.callcode('function_name'); - [Smart Contract Security](https://blog.ethereum.org/2016/06/10/smart-contract-security/) - [Hacking Distributed Blog](http://hackingdistributed.com/) -## Information purposefully excluded -- Libraries - ## Style -- Python's [PEP8](https://www.python.org/dev/peps/pep-0008/) is used as the baseline style guide, including its general philosophy +- [Solidity Style Guide](http://solidity.readthedocs.io/en/latest/style-guide.html): Ethereum's style guide is heavily derived from Python's [PEP 8](https://www.python.org/dev/peps/pep-0008/) style guide. ## Editors +- [Emacs Solidity Mode](https://github.com/ethereum/emacs-solidity) - [Vim Solidity](https://github.com/tomlion/vim-solidity) - Editor Snippets ([Ultisnips format](https://gist.github.com/nemild/98343ce6b16b747788bc)) diff --git a/standard-ml.html.markdown b/standard-ml.html.markdown index 5db15b5c..b34f1c08 100644 --- a/standard-ml.html.markdown +++ b/standard-ml.html.markdown @@ -6,6 +6,7 @@ contributors: - ["David Pedersen", "http://lonelyproton.com/"] - ["James Baker", "http://www.jbaker.io/"] - ["Leo Zovic", "http://langnostic.inaimathi.ca/"] + - ["Chris Wilson", "http://sencjw.com/"] --- Standard ML is a functional programming language with type inference and some @@ -266,6 +267,16 @@ fun second_elem (x::y::xs) = y fun evenly_positioned_elems (odd::even::xs) = even::evenly_positioned_elems xs | evenly_positioned_elems [odd] = [] (* Base case: throw away *) | evenly_positioned_elems [] = [] (* Base case *) + +(* The case expression can also be used to pattern match and return a value *) +datatype temp = + C of real + | F of real + +fun temp_to_f t = + case t of + C x => x * (9.0 / 5.0) + 32.0 + | F x => x (* When matching on records, you must use their slot names, and you must bind every slot in a record. The order of the slots doesn't matter though. *) diff --git a/sv-se/haskell-sv.html.markdown b/sv-se/haskell-sv.html.markdown new file mode 100644 index 00000000..da2d6ab0 --- /dev/null +++ b/sv-se/haskell-sv.html.markdown @@ -0,0 +1,461 @@ +--- +language: Haskell +filename: learnhaskell-sv.hs +contributors: + - ["Adit Bhargava", "http://adit.io"] +translators: + - ["Edward Tjörnhammar", "http://edwtjo.me"] +lang: sv-se +--- + +Haskell skapades för att vara ett praktiskt, rent, funktionellt +programmeringsspråk. Det är känt för sin använding av monader och dess +härledande typsystem men anledningen till att jag ständigt återbesöker språket +är på grund av dess elegans. Haskell gör programmering till ett rent nöje. + +```haskell +-- Radkommenterar börjar med två bindestreck. +{- Flerradskommentarer innesluts av vänster/höger måsvinge bindestreck +block på detta vis. +-} + +---------------------------------------------------- +-- 1. Fördefinierade datatyper och operatorer +---------------------------------------------------- + +-- Du har siffror +3 -- 3 + +-- Matte fungerar som förväntat +1 + 1 -- 2 +8 - 1 -- 7 +10 * 2 -- 20 +35 / 5 -- 7.0 + +-- Division är normalt inte heltalsdivision +35 / 4 -- 8.75 + +-- Heltalsdivision, här infix div +35 `div` 4 -- 8 + +-- Boolar (Sant och Falskt) är fördefinierade +True +False + +-- Samt dess operationer +not True -- False +not False -- True +1 == 1 -- True +1 /= 1 -- False +1 < 10 -- True + +-- I ovanstående exempel är `not` en funktion vilken bara tar ett argument. +-- Haskell behöver inte paranteser för sina funktionsanrop... alla argument +-- ges mellanslagsseparerade direkt efter funktionen. Det övergripande mönstret +-- är: +-- func arg1 arg2 arg3... +-- Se sektionen om funktioner för information om hur du skriver dina egna. + +-- Strängar och bokstäver +"Detta är en sträng" +'a' -- bokstav +'Du kan inte använda enkelfnutt för strängar.' -- fel! + +-- Strängar kan konkateneras +"Hej " ++ "världen!" -- "Hej världen!" + +-- En sträng är en lista av bokstäver +['H', 'e', 'j', 's', 'a', 'n'] -- "Hejsan" +"Detta är en sträng" !! 0 -- 'D' + + +---------------------------------------------------- +-- 2. Listor och Tupler +---------------------------------------------------- + +-- Varje element i en lista måste ha samma typ. +-- Dessa listor är ekvivalenta: +[1, 2, 3, 4, 5] +[1..5] + +-- Intervall är mångsidiga. +['A'..'F'] -- "ABCDEF" + +-- Man kan stega intervall. +[0,2..10] -- [0, 2, 4, 6, 8, 10] +[5..1] -- [] (Haskell förutsätter normalt inkrement) +[5,4..1] -- [5, 4, 3, 2, 1] + +-- Indexering in i en lista +[1..10] !! 3 -- 4 (nollindexerat) + +-- Man kan ha oändliga listor i Haskell! +[1..] -- listan över alla naturliga tal + +-- Oändliga listor fungerar enbart för att Haskell har "lat evaluering". +-- Det betyder att Haskell bara evaluerar de uttryck den måste. Du kan alltså +-- fråga efter det 1000:e elementet i en oändlig lista och Haskell kommer då ge +-- dig det: + +[1..] !! 999 -- 1000 + +-- Nu har Haskell evaluerat element 1 till 1000 i denna lista... men resten +-- av medlemmarna i denna oändliga lista existerar inte ännu! Haskell kommer +-- faktiskt inte utvärdera element den inte måste. + +-- Sammanslagning av två listor +[1..5] ++ [6..10] + +-- Lägg till 0 vid listhuvudet +0:[1..5] -- [0, 1, 2, 3, 4, 5] + +-- fler listoperationer som huvud, svans, initiella samt sista +head [1..5] -- 1 +tail [1..5] -- [2, 3, 4, 5] +init [1..5] -- [1, 2, 3, 4] +last [1..5] -- 5 + +-- listomfattningar +[x*2 | x <- [1..5]] -- [2, 4, 6, 8, 10] + +-- med bivilkor +[x*2 | x <- [1..5], x*2 > 4] -- [6, 8, 10] + +-- Varje element i en tupel kan ha olika typ men en tupel kan bara ha en +-- fixerad, eller statisk, längd. +-- En tupel: +("haskell", 1) + +-- För att komma åt element i ett par, alltså en 2-tupel, finns +-- de fördefinierade funktionerna: +fst ("haskell", 1) -- "haskell" +snd ("haskell", 1) -- 1 + +---------------------------------------------------- +-- 3. Funktioner +---------------------------------------------------- +-- En enkel funktion med två parametrar +add a b = a + b + +-- Notera även att om du använder ghci (Haskellinterpretatorn) kommer du behöva +-- använda `let` namnbindning för att synliggöra din funktionsdeklaration, +-- alltså +let add a b = a + b + +-- För att använda funktionen +add 1 2 -- 3 + +-- Man kan även göra funktionsanropet infix, alltså mellan parametersättningen, +-- med hjälp av bakåtfnuttar: +1 `add` 2 -- 3 + +-- Du kan även definiera funktioner vars funktionsnamn avsaknar bokstäver! +-- Med hjälp av parenteser kan du därmed definiera operatorer (normalt infix)! +-- Följande är en operator för heltalsdivision, vilken förlitar sig på div: +(//) a b = a `div` b +35 // 4 -- 8 + +-- Funktionsvakter: ett enkelt sätt att grena ut dina funktioner +fib x + | x < 2 = 1 + | otherwise = fib (x - 1) + fib (x - 2) + +-- Mönstermatchning fungerar på liknande vis. Här ger vi tre olika +-- parametermatchningar för vårat fib-resulat. Haskell kommer automatiskt följa +-- första bästa träff, uppifrån ned, vars vänstra sida om likhetstecknet matchar +-- anroparens parametervärde. +fib 1 = 1 +fib 2 = 2 +fib x = fib (x - 1) + fib (x - 2) + +-- Mönstermatchning på tupler: +foo (x, y) = (x + 1, y + 2) + +-- Mönstermatchning på listor. Här är `x` det första elementet i listan och `xs` +-- är resten av listan. Nu kan vi skriva våran egen map-funktion +minMap func [] = [] +minMap func (x:xs) = func x:(minMap func xs) + +-- Anonyma funktioner, eller lambdauttryck, skapas med hjälp av omvänt +-- snedstreck, följt av parametrarna +minMap (\x -> x + 2) [1..5] -- [3, 4, 5, 6, 7] + +-- Användning av fold (även kallad `inject`, `reduce`, osv.) tillsammans med en +-- anonym funktion. `fold1` är en vänstervikande funktion och använder första +-- värdet i listan som det initiella värdet för ackumulatorn. +foldl1 (\acc x -> acc + x) [1..5] -- 15 + +---------------------------------------------------- +-- 4. Mer funktioner +---------------------------------------------------- + +-- Partiell applikation: +-- Om du inte anropar funktionen med alla sina argument +-- blir den partiellt applicerad. Det betyder att du erhåller en funktion där en +-- delmängd av parametrarna blivit värdesatta men några är fortfarande fria. +add a b = a + b +foo = add 10 -- foo är nu en funktion som tar ett nummer och lägger till 10 till + -- det +foo 5 -- 15 + +-- Ett annat sätt att skriva samma sak +foo = (10+) +foo 5 -- 15 + +-- Funktionskomposition: +-- Operatorn `.` kedjar ihop funktioner +-- Till exempel, nedan är `foo` en funktion som tar ett värde, den adderar 10 +-- till det, multiplicerar det resultatet med 4 och sen ersätts med det värdet. +foo = (4*) . (10+) + +-- 4*(10+5) = 60 +foo 5 -- 60 + +-- Precedensordning: +-- Haskell har en operator `$`. Denna operator applicerar en funktion till en +-- given parameter med dess precedens. I kontrast mot vanlig +-- funktionsapplikation, vilket har den högsta utvärderingsprioriteten 10 och +-- associerar till vänster, har denna prioritetsordning 0 och är +-- högerassociativ. Denna låga prioritet medför att parameteruttrycket till +-- höger om operatorn får det reducerat innan det appliceras till sin vänster. + +-- före +even (fib 7) -- falskt + +-- ekvivalent +even $ fib 7 -- falskt + +-- med funktionskomposition +even . fib $ 7 -- falskt + + +---------------------------------------------------- +-- 5. Typsignaturer +---------------------------------------------------- + +-- Haskell har ett väldigt starkt typsystem, alla giltiga uttryck har en typ. + +-- Några grundläggande typer: +5 :: Integer +"hello" :: String +True :: Bool + +-- Funktioner har också typer, +-- `not` tar en bool och returnerar en bool: +-- not :: Bool -> Bool + +-- Här är ett exempel på en funktionssignatur vilken beskriver en funktion som +-- reducerar två heltal till ett: +-- add :: Integer -> Integer -> Integer + +-- Trots att Haskell härleder typen på icke typsatta uttryck är det bra form att +-- explicit ange dessa för ens deklarerade funktioner: +double :: Integer -> Integer +double x = x * 2 + +---------------------------------------------------- +-- 6. Kontrollflöde och Ifsatser +---------------------------------------------------- + +-- if-sats +haskell = if 1 == 1 then "awesome" else "awful" -- haskell = "awesome" + +-- if-statser kan spridas över rader men indentering har betydelse +haskell = if 1 == 1 + then "awesome" + else "awful" + +-- case uttryck: följande är ett exempel på kommandoradsparsning +case args of + "help" -> printHelp + "start" -> startProgram + _ -> putStrLn "bad args" + +-- Haskell har inte loopar istället används recursion. +-- map applicerar en funktion över varje element i en lista + +map (*2) [1..5] -- [2, 4, 6, 8, 10] + +-- man kan deklarera en for funktion genom att använda map +for array func = map func array + +-- och därefter använda den tillsammans med en anonym funktion för att +-- efterlikna en loop +for [0..5] $ \i -> show i + +-- men vi kunde även ha skrivit på följande vis: +for [0..5] show + +-- Du kan använda foldl eller foldr för att reducera en lista +-- foldl <fn> <initial value> <list> +foldl (\x y -> 2*x + y) 4 [1,2,3] -- 43 + +-- Vilket är samma sak som +(2 * (2 * (2 * 4 + 1) + 2) + 3) + +-- foldl viker från vänster, foldr från höger +foldr (\x y -> 2*x + y) 4 [1,2,3] -- 16 + +-- Vilket alltså är samma sak som +(2 * 1 + (2 * 2 + (2 * 3 + 4))) + +---------------------------------------------------- +-- 7. Datatyper +---------------------------------------------------- + +-- Såhär definierar du din egen datatyp i Haskell +data Color = Red | Blue | Green + +-- När du gjort det kan du använda den i funktionssignaturer och uttryck +say :: Color -> String +say Red = "Du är Rö!" +say Blue = "Du är Blå!" +say Green = "Du är Grön!" + +-- Dina datatyper kan även ta parametrar +data Maybe a = Nothing | Just a + +-- Följande uttryck är alla specialiseringar av typen Maybe +Just "hello" -- har typen `Maybe String` +Just 1 -- har typen `Maybe Int` +Nothing -- har typen `Maybe a` för alla `a` + +---------------------------------------------------- +-- 8. Haskell IO +---------------------------------------------------- + +-- Även om IO inte kan förstås fullt ut utan att först förklara monader är det +-- inte svårt att lära sig tillräckligt för att komma igång + +-- När ett Haskellprogram körs är det topnivåns main som körs. Main måste +-- returnerna ett värde av typen `IO a`, för någon typ `a`. Till exempel: + +main :: IO () +main = putStrLn $ "Hej, himmelen! " ++ (say Blue) +-- putStrLn har typen type String -> IO () + +-- Det är enkelt att göra IO om du kan implementera ditt program som en funktion +-- från String till String. Funktionen +-- interact :: (String -> String) -> IO () +-- tar denna funktion och matar den med strängdata från stdin och skriver ut +-- resultatet som en sträng på stdout + +countLines :: String -> String +countLines = show . length . lines + +main' = interact countLines + +-- Du kan tänka på värden av typen `IO ()` som att representera +-- händelsesekvenser du vill att din dator skall utföra, likt imperativa språk. +-- För att kedja ihop händelsesekvenser använder man ett syntaktiskt socker +-- kallat do-notation. Som exempel: + +sägHej :: IO () +sägHej = do + putStrLn "Vad heter du?" + namn <- getLine -- denna raden läser en rad från stdin och vi binder den till + -- funktionsnamnet `namn` + putStrLn $ "Hejsan, " ++ namn + +-- Övning: Skriv din egen version av interageringsfunktionen `interact` som bara +-- läser en rad från stdin, vanliga `interact` läser till EOF. + +-- Koden i sägHej kommer dock aldrig exekveras. Den enda handlingen som blir det +-- är som bekant utvärderingen av `main`. +-- För att köra `sägHej` kommentera ut definition av `main` ovan och +-- avkommentera nedanstående version: +-- main = sayHello + +-- Låt oss bättre förstå hur funktionen `getLine` vi just använde fungerar. Dess +-- typsignatur är: +-- getLine :: IO String +-- Du kan tänka på typen `IO a` som att representeras av ett datorprogram vilken +-- kommer generera ett värde av typen `a` när det exekveras (utöver allt annat +-- det kan tänkas göra). Vi kan därtill binda detta värde till ett namn för +-- återanvändning genom att använda `<-`. Vi kan även skapa våran egen handling +-- av typen `IO String`: + +handling :: IO String +handling = do + putStrLn "Detta är en rad, tihi" + input1 <- getLine + input2 <- getLine + -- Typen av hela `do` blocket är vad som står på sista raden. Här är även + -- `return` inte ett nyckelord i språket utan en funktion med en typsignatur + return (input1 ++ "\n" ++ input2) -- return :: String -> IO String + +-- Vi kan använda `return` på samma sätt som vi använde `getLine`: + +main'' = do + putStrLn "Jag kommer eka två rader!" + result <- handling + putStrLn result + putStrLn "Tack och hej leverpastej!" + +-- Typen `IO` är ett exempel på en monad. Sättet Haskell utnyttjar monader på är +-- anledningen till hur språket kan bibehålla sin renhet. En funktion vilken +-- interagerar med omvärlden (alltså gör IO) blir markerad med `IO` i sin +-- typsignatur. Detta låter oss enkelt upptäcka vilka funktioner som är "rena" +-- (inte interagerar med omvärlden eller är tillståndsoberoende) and vilka +-- funktioner som inte är det. + +-- Detta är ett mäktigt särdrag eftersom det är enkelt att köra rena funktioner +-- sammanlöpande; Samtidig programmering är enkel att göra i Haskell. + +---------------------------------------------------- +-- 9. Haskell REPL (kodtolk) +---------------------------------------------------- + +-- Efter installation av GHC kan vi starta tolken genom att skriva `ghci`. +-- Nu kan du mata in Haskellkod direkt i den. Nya värden måste introduceras med +-- `let` bindning: + +let foo = 5 + +-- Du kan även se typen av namnbindningen med `:t` + +> :t foo +foo :: Integer + +-- Operatorer, som `+`, `:` och `$` är funktioner. Deras typ kan inspekteras +-- genom att skriva operatorn mellan parenteser: + +> :t (:) +(:) :: a -> [a] -> [a] + +-- Du kan få ytterliggare information om något namn genom att använda `:i` + +> :i (+) +class Num a where + (+) :: a -> a -> a + ... + -- Defined in ‘GHC.Num’ +infixl 6 + + +-- Du kan även köra alla handlingar av typen `IO ()` direkt i tolken + +> sägHej +Vad är ditt namn? +Kompis! +Hello, Kompis! + +``` + +Det finns mycket mer att upptäcka med Haskell, inklusive typklasser och monader. +Vilka är de stora idéerna som gör Haskell till det roliga programmeringsspråket +det är. Jag lämar dig med ett sista exempel; En implementation av quicksort: + +```haskell +qsort [] = [] +qsort (p:xs) = qsort mindre ++ [p] ++ qsort större + where mindre = filter (< p) xs + större = filter (>= p) xs +``` + +Det finns två populära sätt att installera Haskell på: Den traditionella [Cabal sättet](http://www.haskell.org/platform/), eller det nyare [Stack sättet](https://www.stackage.org/install). + +Du kan finna vänligare och/eller djupare introduktioner till Haskell på engelska +från: +[Learn you a Haskell](http://learnyouahaskell.com/), +[Happy Learn Haskell Tutorial](http://www.happylearnhaskelltutorial.com/) eller +[Real World Haskell](http://book.realworldhaskell.org/). diff --git a/sv-se/nix-sv.html.markdown b/sv-se/nix-sv.html.markdown new file mode 100644 index 00000000..15d9456b --- /dev/null +++ b/sv-se/nix-sv.html.markdown @@ -0,0 +1,368 @@ +--- +language: nix +filename: learn-sv.nix +contributors: + - ["Chris Martin", "http://chris-martin.org/"] +translators: + - ["Edward Tjörnhammar", "http://edwtjo.me"] +lang: sv-se +--- + +Nix är ett enkelt funktionelt språk utvecklat för +[Nix pakethanteraren](https://nixos.org/nix/) och +[NixOS](https://nixos.org/) linuxdistributionen. + +Du kan utvärdera Nix uttryck genom att använda +[nix-instantiate](https://nixos.org/nix/manual/#sec-nix-instantiate) +eller [`nix-repl`](https://github.com/edolstra/nix-repl). + +``` +with builtins; [ + + # Kommentarer + #========================================= + + # Inlinekommentarer ser ut såhär. + + /* Flerradskommentarer ser ut + såhär. */ + + + # Booleaner + #========================================= + + (true && false) # Och + #=> false + + (true || false) # Eller + #=> true + + (if 3 < 4 then "a" else "b") # Villkorlig + #=> "a" + + + # Heltal + #========================================= + + # Heltal är den enda numeriska typen. + + 1 0 42 (-3) # Några heltal + + (4 + 6 + 12 - 2) # Addition + #=> 20 + + (7 / 2) # Division + #=> 3 + + + # Strängar + #========================================= + + "Stränglitteraler omgärdas av raka citationstecken." + + " + Stränglitteraler kan sträcka sig + över flera rader. + " + + '' + Detta kallas för en indenterad strängliteral, omgärdad av dubbla apostrofer + Den plockar intelligent bort ledande blanktecken. + '' + + '' + a + b + '' + #=> "a\n b" + + ("ab" + "cd") # Strängkonkatenering + #=> "abcd" + + # Antikvotering låter dig bädda in språkvärden i strängar. + ("Din hemkatalog är ${getEnv "HOME"}") + #=> "Din hemkatalog är /home/alice" + + + # Sökvägar + #========================================= + + # Nix har en primitiv, inbyggd, typ för sökvägar. + /tmp/tutorials/learn.nix + + # Relativa sökvägar förenas med sökvägen till dess definerande fils sökväg + # vid tolkningstillfället för att skapa dess absoluta sökväg. + + tutorials/learn.nix + #=> /the-base-path/tutorials/learn.nix + + # En sökväg måste innehålla åtminstonde ett snedstreck, så en relativ sökväg + # till en fil i samma katalog måste ges ett "./" prefix + + ./learn.nix + #=> /the-base-path/learn.nix + + # Divisionsoperatorn / måste omges av blanksteg om man vill att det skall + # tolkas som heltalsdivision + + 7/2 # Detta är en sökväg + (7 / 2) # Detta är heltalsdivision + + + # Importer + #========================================= + + # En nix fil innehåller ett enstaka topnivåuttryck utan fria variabler. + # Ett importuttryck evalueras till värdet på filen som den importerar. + (import /tmp/foo.nix) + + # Importer kan också specificeras med hjälp av strängar. + (import "/tmp/foo.nix") + + # Importsökvägar måste vara absoluta. Sökvägslitteraler härleds vid + # tolkningstillfället så följande är ok. + (import ./foo.nix) + + # Men detta är inte något som sker med strängar. + (import "./foo.nix") + #=> error: string ‘foo.nix’ doesn't represent an absolute path + + + # Let + #========================================= + + # `let` block tillåter oss att binda värden till namn. + (let x = "a"; in + x + x + x) + #=> "aaa" + + # Bindingar kan referera till varandra och deras ordning sinsemellan spelar + # ingen roll. + (let y = x + "b"; + x = "a"; in + y + "c") + #=> "abc" + + # Innre bindningar skuggar utanpåliggande bindingar. + (let a = 1; in + let a = 2; in + a) + #=> 2 + + + # Funktioner + #========================================= + + (n: n + 1) # En lambdafunktion som lägger till 1 + + ((n: n + 1) 5) # Samma funktion applicerad på 5 + #=> 6 + + # Det finns ingen syntax för direkt namngivna funktioner, istället binder man + # dessa med `let` block som andra värden. + (let succ = (n: n + 1); in succ 5) + #=> 6 + + # En funktion är en lambda med en parameter. Flera parameterar kan ges med + # hjälp av currying. + ((x: y: x + "-" + y) "a" "b") + #=> "a-b" + + # Vi kan också ha namngivna funktionsparametrar, vilket vi kommer komma till + # senare, efter att vi introducerat attributset. + + # Listor + #========================================= + + # Listor noteras med hakparenteser. + + (length [1 2 3 "x"]) + #=> 4 + + ([1 2 3] ++ [4 5]) + #=> [1 2 3 4 5] + + (concatLists [[1 2] [3 4] [5]]) + #=> [1 2 3 4 5] + + (head [1 2 3]) + #=> 1 + (tail [1 2 3]) + #=> [2 3] + + (elemAt ["a" "b" "c" "d"] 2) + #=> "c" + + (elem 2 [1 2 3]) + #=> true + (elem 5 [1 2 3]) + #=> false + + (filter (n: n < 3) [1 2 3 4]) + #=> [ 1 2 ] + + + # Mängder + #========================================= + + # Ett attributset är en oordnad mappning av strängnycklar och värden. + { foo = [1 2]; bar = "x"; } + + # Punktoperatorn . väljer ett värde från attributset:et + { a = 1; b = 2; }.a + #=> 1 + + # Frågeoperatorn ? testar om en nyckel är närvarande i ett attributset + ({ a = 1; b = 2; } ? a) + #=> true + ({ a = 1; b = 2; } ? c) + #=> false + + # Snedstrecksoperatorn // slår ihop två attributset:ar. + ({ a = 1; } // { b = 2; }) + #=> { a = 1; b = 2; } + + # Värden på höger skriver över värden till vänster. + ({ a = 1; b = 2; } // { a = 3; c = 4; }) + #=> { a = 3; b = 2; c = 4; } + + # Recursionsnyckelordet rec noterar ett rekursivt attributset (en fixpunkt) + # i vilket attributen kan referera till varandra. + (let a = 1; in { a = 2; b = a; }.b) + #=> 1 + (let a = 1; in rec { a = 2; b = a; }.b) + #=> 2 + + # Nästlade attributset:ar kan definieras bit för bit. + { + a.b = 1; + a.c.d = 2; + a.c.e = 3; + }.a.c + #=> { d = 2; e = 3; } + + # Ett attributsets barn kan inte tilldelas på detta vis om attributsetet + # självt blivit direkt tilldelat. + { + a = { b = 1; }; + a.c = 2; + } + #=> error: attribute ‘a’ already defined + + + # Bindningsintroduktion, `with` + #========================================= + + # Det attributset vilket återfinns i ett `with` uttryck kommer få sina + # värdebindningar introducerade i efterkommande uttryck. + (with { a = 1; b = 2; }; + a + b) + # => 3 + + # Innre bindningar skuggar yttre bindningar. + (with { a = 1; b = 2; }; + (with { a = 5; }; + a + b)) + #=> 7 + + # Första raden av detta exempel börjar med "with builtins;" eftersom builtins + # är ett attributset innehållande alla inbyggda hjälpfunktioner såsom + # (length, head, tail, filter, etc.). Detta sparar oss från att hela tiden + # referera in i det attributset:et , alltså du kan använda bara "length" + # istället för "builtins.length". + + + # Attributsetmönster + #========================================= + + # Attributset är användbara när vi skall skicka med flera värden till en + # funktion. + (args: args.x + "-" + args.y) { x = "a"; y = "b"; } + #=> "a-b" + + # Man kan använda attributsetmönster för ökad tydlighet. + ({x, y}: x + "-" + y) { x = "a"; y = "b"; } + #=> "a-b" + + # Attributmönster misslyckas dock om det medskickade attributmönstret + # innehåller extra nycklar. + ({x, y}: x + "-" + y) { x = "a"; y = "b"; z = "c"; } + #=> error: anonymous function called with unexpected argument ‘z’ + + # Genom att lägga till ", ..." kan vi ignorera ytterliggare nycklar. + ({x, y, ...}: x + "-" + y) { x = "a"; y = "b"; z = "c"; } + #=> "a-b" + + + # Felmeddelanden + #========================================= + + # `throw` gör att programtolken gör abort med dess tillhörande felmeddelande + causes evaluation to abort with an error message. + (2 + (throw "foo")) + #=> error: foo + + # `tryEval` fångar kastade fel `throw`. + (tryEval 42) + #=> { success = true; value = 42; } + (tryEval (2 + (throw "foo"))) + #=> { success = false; value = false; } + + # `abort` fungerar som `throw`, men är kritiskt och kan inte fångas. + (tryEval (abort "foo")) + #=> error: evaluation aborted with the following error message: ‘foo’ + + # `assert` utvärderas till det givna värdet om dess predikat är sant. + # annars skickar den ett fångbart fel. + (assert 1 < 2; 42) + #=> 42 + (assert 1 > 2; 42) + #=> error: assertion failed at (string):1:1 + (tryEval (assert 1 > 2; 42)) + #=> { success = false; value = false; } + + + # Orenhet + #========================================= + + # Eftersom repeterbarhet för byggen är en kritisk egenskap för + # Nix-pakethanteraren betonas funktionell renhet i Nix-programmeringsspråket. + # Men med det sagt existerar det källor till orenhet + + # Man kan referera till miljövariabler. + (getEnv "HOME") + #=> "/home/alice" + + # `trace` funktionen används för att debugga. Den skriver ut första argumentet + # till stderr och reduceras samtidigt till det andra argumentet. + (trace 1 2) + #=> trace: 1 + #=> 2 + + # Man kan skriva filer till Nix-store, lagringsplatsen för alla Nix-uttryck. + # Även om detta är orent beteende är det hyfsat säkert eftersom filens + # lagringsplats är härledd från dess innehåll och beroenden. Man kan läsa + # filer från precis överallt. I nedanstående exempel skriver vi en fil till + # Nix-store och sedan läser tillbaka den. + + (let filename = toFile "foo.txt" "hello!"; in + [filename (builtins.readFile filename)]) + #=> [ "/nix/store/ayh05aay2anx135prqp0cy34h891247x-foo.txt" "hello!" ] + + # Vi kan också ladda ned filer till Nix-store. + (fetchurl "https://example.com/package-1.2.3.tgz") + #=> "/nix/store/2drvlh8r57f19s9il42zg89rdr33m2rm-package-1.2.3.tgz" + +] +``` + +### Vidare Läsning (eng) + +* [Nix Manual - Nix expression language] + (https://nixos.org/nix/manual/#ch-expression-language) + +* [James Fisher - Nix by example - Part 1: The Nix expression language] + (https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55) + +* [Susan Potter - Nix Cookbook - Nix By Example] + (http://funops.co/nix-cookbook/nix-by-example/) diff --git a/swift.html.markdown b/swift.html.markdown index 516debed..f834f373 100644 --- a/swift.html.markdown +++ b/swift.html.markdown @@ -13,9 +13,9 @@ filename: learnswift.swift Swift is a programming language for iOS and OS X development created by Apple. Designed to coexist with Objective-C and to be more resilient against erroneous code, Swift was introduced in 2014 at Apple's developer conference WWDC. It is built with the LLVM compiler included in Xcode 6+. -The official [Swift Programming Language](https://itunes.apple.com/us/book/swift-programming-language/id881256329) book from Apple is now available via iBooks. +The official _[Swift Programming Language](https://itunes.apple.com/us/book/swift-programming-language/id881256329)_ book from Apple is now available via iBooks. -See also Apple's [getting started guide](https://developer.apple.com/library/prerelease/ios/referencelibrary/GettingStarted/DevelopiOSAppsSwift/), which has a complete tutorial on Swift. +Another great reference is _About Swift_ on Swift's [website](https://docs.swift.org/swift-book/). ```swift // import a module diff --git a/tcl.html.markdown b/tcl.html.markdown index 40d9111a..3d23870b 100644 --- a/tcl.html.markdown +++ b/tcl.html.markdown @@ -5,7 +5,7 @@ contributors: filename: learntcl.tcl --- -Tcl was created by [John Ousterhout](https://wiki.tcl.tk/John%20Ousterout) as a +Tcl was created by [John Ousterhout](https://wiki.tcl-lang.org/page/John+Ousterhout) as a reusable scripting language for circuit design tools that he authored. In 1997 he was awarded the [ACM Software System Award](https://en.wikipedia.org/wiki/ACM_Software_System_Award) for Tcl. Tcl @@ -283,7 +283,7 @@ set c [expr {$a + $b}] # Since "expr" performs variable substitution on its own, brace the expression # to prevent Tcl from performing variable substitution first. See -# "http://wiki.tcl.tk/Brace%20your%20#%20expr-essions" for details. +# "https://wiki.tcl-lang.org/page/Brace+your+expr-essions" for details. # "expr" understands variable and script substitution: @@ -328,6 +328,7 @@ proc greet {greeting name} { # the third argument to "proc", is a string. The previous command # can be rewritten using no braces: proc greet greeting\ name return\ \"\$greeting,\ \$name!\" +# " @@ -580,8 +581,8 @@ a ## Reference -[Official Tcl Documentation](http://www.tcl.tk/man/tcl/) +[Official Tcl Documentation](https://www.tcl-lang.org) -[Tcl Wiki](http://wiki.tcl.tk) +[Tcl Wiki](https://wiki.tcl-lang.org) [Tcl Subreddit](http://www.reddit.com/r/Tcl) diff --git a/textile.html.markdown b/textile.html.markdown new file mode 100644 index 00000000..2b81674a --- /dev/null +++ b/textile.html.markdown @@ -0,0 +1,505 @@ +--- +language: textile +contributors: + - ["Keith Miyake", "https://github.com/kaymmm"] +filename: learn-textile.textile +--- + + +Textile is a lightweight markup language that uses a text formatting syntax to +convert plain text into structured HTML markup. The syntax is a shorthand +version of HTML that is designed to be easy to read and write. Textile is used +for writing articles, forum posts, readme documentation, and any other type of +written content published online. + +- [Comments](#comments) +- [Paragraphs](#paragraphs) +- [Headings](#headings) +- [Simple Text Styles](#simple-text-styles) +- [Lists](#lists) +- [Code blocks](#code-blocks) +- [Horizontal rule](#horizontal-rule) +- [Links](#links) +- [Images](#images) +- [Footnotes and Endnotes](#footnotes-and-endnotes) +- [Tables](#tables) +- [Character Conversions](#character-conversions) +- [CSS](#css) +- [Spans and Divs](#spans-and-divs) +- [Additional Info](#additional-info) + +## Comments + +``` +###. Comments begin with three (3) '#' signs followed by a full-stop period '.'. +Comments can span multiple lines until a blank line is reached. + +###.. +Multi-line comments (including blank lines) are indicated by three (3) '#' +signs followed by two (2) full-stop periods '..'. + +This line is also part of the above comment. + +The comment continues until the next block element is reached + +p. This line is not commented + +<!-- HTML comments are also… + +respected --> + +``` + +## Paragraphs + +``` +###. Paragraphs are a one or multiple adjacent lines of text separated by one or +multiple blank lines. They can also be indicated explicitly with a 'p. ' + +This is a paragraph. I'm typing in a paragraph isn't this fun? + +Now I'm in paragraph 2. +I'm still in paragraph 2 too! +Line breaks without blank spaces are equivalent to a <br /> in XHTML. + +p. I'm an explicitly defined paragraph + + Lines starting with a blank space are not wrapped in <p>..</p> tags. + +###. Paragraphs (and all block elements) can be aligned using shorthand: + +p<. Left aligned paragraph (default). + +p>. Right aligned paragraph. + +p=. Centered paragraph. + +p<>. Justified paragraph. + +h3>. Right aligned <h3> + + +###. Paragraphs can be indented using a parentheses for each em +Indentation utilizes padding-[left/right] css styles. + +p(. Left indent 1em. + +p((. Left indent 2em. + +p))). Right indent 3em. + +h2). This is equivalent to <h2 style="padding-right: 1em;">..</h2> + + +###. Block quotes use the tag 'bq.' + +bq. This is a block quote. + +bq.:http://someurl.com You can include a citation URL immediately after the '.' + +bq.. Multi-line blockquotes containing + +blank lines are indicated using two periods + +p. Multi-line blockquotes continue until a new block element is reached. + +bq. You can add a footer to a blockquote using html: +<footer>citation text</footer> + + +###. Preformatted text blocks: + +pre. This text is preformatted. <= those two spaces will carry through. + +pre.. This is a multi-line preformatted… + +…text block that includes blank lines + +p. End a multi-line preformatted text block with a new block element. + +``` + +## Headings + +You can create HTML elements `<h1>` through `<h6>` easily by prepending the +text you want to be in that element by 'h#.' where # is the level 1-6. +A blank line is required after headings. + + +``` +h1. This is an <h1> + +h2. This is an <h2> + +h3. This is an <h3> + +h4. This is an <h4> + +h5. This is an <h5> + +h6. This is an <h6> + +``` + + +## Simple text styles + +``` +###. Bold and strong text are indicated using asterisks: + +*This is strong text* +**This is bold text** +This is [*B*]old text within a word. + +*Strong* and **Bold** usually display the same in browsers +but they use different HTML markup, thus the distinction. + +###. Italics and emphasized text are indicated using underscores. + +_This is Emphasized text_ +__This is Italics text__ +This is It[_al_]ics within a word. + +_Emphasized_ and __Italics__ text typically display the same in browsers, +but again, they use different HTML markup and thus the distinction. + +###. Superscripts and Subscripts use carats and tildes: + +Superscripts are 2 ^nd^ to none, but subscripts are CO ~2~ L too. +Note the spaces around the superscripts and subscripts. + +To avoid the spaces, add square brackets around them: +2[^nd^] and CO[~2~]L + +###. Insertions and deletions are indicated using -/+ symbols: +This is -deleted- text and this is +inserted+ text. + +###. Citations are indicated using double '?': + +??This is a cool citation?? + +``` + +## Lists + +``` +###. Unordered lists can be made using asterisks '*' to indicate levels: + +* Item +** Sub-Item +* Another item +** Another sub-item +** Yet another sub-item +*** Three levels deep + +###. Ordered lists are done with a pound sign '#': + +# Item one +# Item two +## Item two-a +## Item two-b +# Item three +** Mixed unordered list within ordered list + +###. Ordered lists can start above 1 and can continue after another block: + +#5 Item 5 +# Item 6 + +additional paragraph + +#_ Item 7 continued from above +# Item 8 + +###. Definition lists are indicated with a dash and assignment: + +- First item := first item definition +- Second := second def. +- Multi-line := +Multi-line +definition =: +``` + +## Code blocks + +``` +Code blocks use the 'bc.' shorthand: + +bc. This is code + So is this + +This is outside of the code block + +bc.. This is a multi-line code block + +Blank lines are included in the multi-line code block + +p. End a multi-line code block with any block element + +p. Indicate @inline code@ using the '@' symbol. + +``` + +## Horizontal rule + +Horizontal rules (`<hr/>`) are easily added with two hyphens + +``` +-- +``` + +## Links + +``` +###. Link text is in quotes, followed by a colon and the URL: + +"Link text":http://linkurl.com/ plain text. + +"Titles go in parentheses at the end of the link text"(mytitle):http://url.com +###. produces <a href... title="mytitle">...</a> + +###. Use square brackets when the link text or URL might be ambiguous: +["Textile on Wikipedia":http://en.wikipedia.org/wiki/Textile_(markup_language)] + +###. Named links are useful if the same URL is referenced multiple times. +Multiple "references":txstyle to the "txstyle":txstyle website. + +[txstyle]https://txstyle.org/ + +``` + +## Images + +``` +###. Images can be included by surrounding its URL with exclamation marks (!) +Alt text is included in parenthesis after the URL, and they can be linked too: + +!http://imageurl.com! + +!http://imageurl.com(image alt-text)! + +!http://imageurl.com(alt-text)!:http://image-link-url.com + +``` + +## Footnotes and Endnotes + +``` +A footnote is indicated with the reference id in square brackets.[1] + +fn1. Footnote text with a "link":http://link.com. + +A footnote without a link.[2!] + +fn2. The corresponding unlinked footnote. + +A footnote with a backlink from the footnote back to the text.[3] + +fn3^. This footnote links back to the in-text citation. + + +Endnotes are automatically numbered[#first] and are indicated using square[#second] +brackets and a key value[#first]. They can also be unlinked[#unlinkednote!] + +###. Give the endnotes text: + +note#first. This is the first endnote text. + +note#second. This is the second text. + +note#unlinkednote. This one isn't linked from the text. + +### Use the notelist block to place the list of notes in the text: +This list will start with #1. Can also use alpha or Greeks. +notelist:1. ###. start at 1 (then 2, 3, 4...) +notelist:c. ###. start at c (then d, e, f...) +notelist:α. ###. start at α (then β, γ, δ...) + +###. The notelist syntax is as follows: + +notelist. Notes with backlinks to every citation made to them. +notelist+. Notes with backlinks to every citation made to them, + followed by the unreferenced notes. +notelist^. Notes with one backlink to the first citation made to each note. +notelist^+. Notes with one backlink to the first citation made to each note, + followed by unreferenced notes. +notelist!. Notes with no backlinks to the citations. +notelist!+. Notes with no backlinks to the citations, followed by + unreferenced notes. +``` + +## Tables + + +``` +###. Tables are simple to define using the pipe '|' symbol + +| A | simple | table | row | +| And | another | table | row | +| With an | | empty | cell | + +###. Headers are preceded by '|_.' +|_. First Header |_. Second Header | +| Content Cell | Content Cell | + +###. The <thead> tag is added when |^. above and |-. below the heading are used. + +|^. +|_. First Header |_. Second Header | +|-. +| Content Cell | Content Cell | +| Content Cell | Content Cell | + +###. The <tfoot> tag is added when |~. above and |-. below the footer are used. + +|~. +|\2=. A footer, centered & across two columns | +|-. +| Content Cell | Content Cell | +| Content Cell | Content Cell | + +###. Attributes are be applied either to individual cells, rows, or to +the entire table. Cell attributes are placed within each cell: + +|a|{color:red}. styled|cell| + +###. Row attributes are placed at the beginning of a row, +followed by a dot and a space: + +(rowclass). |a|classy|row| + +###. Table attributes are specified by placing the special 'table.' block +modifier immediately before the table: + +table(tableclass). +|a|classy|table| +|a|classy|table| + +###. Spanning rows and colums: +A backslash \ is used for a column span: + +|\2. spans two cols | +| col 1 | col 2 | + +###. A forward slash / is used for a row span: + +|/3. spans 3 rows | row a | +| row b | +| row c | + +###. Vertical alignments within a table cell: + +|^. top alignment| +|-. middle alignment| +|~. bottom alignment| + +###. Horizontal alignments within a table cell + +|:\1. |400| +|=. center alignment | +| no alignment | +|>. right alignment | + +``` +or, for the same results + +``` +Col 1 | Col2 | Col3 +:-- | :-: | --: +Ugh this is so ugly | make it | stop +``` + + +## Character Conversions + +### Registered, Trademark, Copyright Symbols + +``` +RegisteredTrademark(r), Trademark(tm), Copyright (c) +``` + +### Acronyms + +``` +###. Acronym definitions can be provided in parentheses: + +EPA(Environmental Protection Agency) and CDC(Center for Disease Control) +``` + +### Angle Brackets and Ampersand + +``` +### Angled brackets < and > and ampersands & are automatically escaped: +< => < +> => > +& => & +``` + +### Ellipses + +``` +p. Three consecutive periods are translated into ellipses...automatically +``` + +### Em and En dashes + +``` +###. En dashes (short) is a hyphen surrounded by spaces: + +This line uses an en dash to separate Oct - Nov 2018. + +###. Em dashes (long) are two hyphens with or without spaces: + +This is an em dash--used to separate clauses. +But we can also use it with spaces -- which is a less-used convention. +That last hyphen between 'less' and 'used' is not converted between words. +``` + +## Fractions and other Math Symbols + +``` +One quarter: (1/4) => ¼ +One half: (1/2) => ½ +Three quarters: (3/4) => ¾ +Degree: (o) => ° +Plus/minus: (+/-) => ± +``` +### Multiplication/Dimension + +``` +p. Numbers separated by the letter 'x' translate to the multiplication +or dimension symbol '×': +3 x 5 => 3 × 5 +``` + +### Quotes and Apostrophes + +``` +###. Straight quotes and apostrophes are automatically converted to +their curly equivalents: + +"these", 'these', and this'n are converted to their HTML entity equivalents. +Leave them straight using '==' around the text: =="straight quotes"==. +``` + +## CSS + +``` +p{color:blue}. CSS Styles are enclosed in curly braces '{}' +p(my-class). Classes are enclosed in parenthesis +p(#my-id). IDs are enclosed in parentheses and prefaced with a pound '#'. +``` + +## Spans and Divs + +``` +%spans% are enclosed in percent symbols +div. Divs are indicated by the 'div.' shorthand +``` +--- + +## For More Info + +* TxStyle Textile Documentation: [https://txstyle.org/](https://txstyle.org/) +* promptworks Textile Reference Manual: [https://www.promptworks.com/textile](https://www.promptworks.com/textile) +* Redmine Textile Formatting: [http://www.redmine.org/projects/redmine/wiki/RedmineTextFormattingTextile](http://www.redmine.org/projects/redmine/wiki/RedmineTextFormattingTextile) diff --git a/tmux.html.markdown b/tmux.html.markdown index 1214a5ba..b28a4f59 100644 --- a/tmux.html.markdown +++ b/tmux.html.markdown @@ -78,6 +78,7 @@ combinations called 'Prefix' keys. p # Change to the previous window { # Swap the current pane with the previous pane } # Swap the current pane with the next pane + ] # Enter Copy Mode to copy text or view history. s # Select a new session for the attached client interactively diff --git a/toml.html.markdown b/toml.html.markdown index 980563f9..814e57e7 100755 --- a/toml.html.markdown +++ b/toml.html.markdown @@ -12,7 +12,7 @@ It is an alternative to YAML and JSON. It aims to be more human friendly than JS Be warned, TOML's spec is still changing a lot. Until it's marked as 1.0, you should assume that it is unstable and act accordingly. This document follows TOML v0.4.0. -```toml +``` # Comments in TOML look like this. ################ @@ -102,9 +102,10 @@ boolMustBeLowercase = true # Datetime # ############ -date1 = 1979-05-27T07:32:00Z # follows the RFC 3339 spec -date2 = 1979-05-27T07:32:00 # without offset -date3 = 1979-05-27 # without offset nor time +date1 = 1979-05-27T07:32:00Z # UTC time, following RFC 3339/ISO 8601 spec +date2 = 1979-05-26T15:32:00+08:00 # with RFC 3339/ISO 8601 offset +date3 = 1979-05-27T07:32:00 # without offset +date4 = 1979-05-27 # without offset or time #################### # COLLECTION TYPES # diff --git a/tr-tr/c++-tr.html.markdown b/tr-tr/c++-tr.html.markdown new file mode 100644 index 00000000..9d65cf9c --- /dev/null +++ b/tr-tr/c++-tr.html.markdown @@ -0,0 +1,1076 @@ +--- +language: c++ +lang: tr-tr +filename: learncpp-tr.cpp +contributors: + - ["Steven Basart", "http://github.com/xksteven"] + - ["Matt Kline", "https://github.com/mrkline"] + - ["Geoff Liu", "http://geoffliu.me"] + - ["Connor Waters", "http://github.com/connorwaters"] + - ["Ankush Goyal", "http://github.com/ankushg07"] + - ["Jatin Dhankhar", "https://github.com/jatindhankhar"] + - ["Adem Budak", "https://github.com/p1v0t"] +--- + +C++ +[yaratıcısı Bjarne Stroustrup'a göre](http://channel9.msdn.com/Events/Lang-NEXT/Lang-NEXT-2014/Keynote), + +- "daha iyi bir C" yapmak +- veri soyutlamayı desteklemek +- nesneye yönelik programlamayı deskteklemek +- tipten bağımsız programlamayı desteklemek + +için tasarlanmış bir sistem programlama dilir. + +Sözdizimi daha yeni dillerden daha zor veya karmaşık olsa da işlemcinin doğrudan çalıştırabileceği +native komutlara derlenerek, donanım üzerinde (C gibi) sıkı bir kontrol sağlar, bunu yaparken +tipten bağımsızlık, exception'lar ve sınıflar gibi yüksek-seviyeli özellikleri destekler. +Bu hız ve kullanışlılık C++'ı en çok kullanılan dillerden biri yapar. + +```c++ +////////////////////// +// C ile karşılaştırma +////////////////////// + +// C++ _neredeyse_ C'nin bir üstkümesidir, değişken tanımı, basit tipleri +// ve fonksiyonları için temelde aynı sözdizimini paylaşır. + +// Aynı C gibi, programın başlangıç noktası bir integer döndüren +// main fonksiyonudur. +// Bu değer programın bitiş statüsünü belli eder. +// Daha fazla bilgi için bknz http://en.wikipedia.org/wiki/Exit_status . + +int main(int argc, char** argv) +{ + // Komut satırı argümanları C'de olduğu gibi argv ve argc ile geçilir + // argc, argüman sayısını belli eder, + // argv, argümanları belli eden, C-stili string'lerin (char*) dizisidir. + // İlk argüman çağrılan programın adıdır. + // Eğer argümanları umursamıyorsan, argv ve argc kullanılmayabilir + // int main() gibi + + // 0 çıkış durumu başarıyı belirtir. + return 0; +} + +// Bunlara rağmen C++ aşağıdaki noktalarda farklılaşır: + +// C++'ta, karakterler char türündendir +sizeof('c') == sizeof(char) == 1 + +// C'de, karakterler int türündendir +sizeof('c') == sizeof(int) + + +// C++ katı bir prototip kuralına sahiptir +void func(); // fonksiyon argüman kabul etmez + +// C'de +void func(); // fonksiyon herhangi bir sayıda argüman kabul edebilir + +// C++'da NULL yerine nullptr kullanılır +int* ip = nullptr; + +// C standard başlıkları başına "c" eklenip, sondaki .h +// kullanılmadan C++'ta kullanılabilir +#include <cstdio> + +int main() +{ + printf("Hello, world!\n"); + return 0; +} + +////////////////////////////////// +// Fonksiyonun fazladan yüklenmesi +////////////////////////////////// + +// C++ herbir fonksiyonun farklı parametereler +// aldığı fonksiyon fazladan yüklenmesini desktekler + +void print(char const* myString) +{ + printf("String %s\n", myString); +} + +void print(int myInt) +{ + printf("My int is %d", myInt); +} + +int main() +{ + print("Hello"); // void print(const char*) fonksiyonunu çağırır. + print(15); // void print(int) fonksiyonunu çağırır. +} + +//////////////////////////////// +// Default fonksiyon argümanları +//////////////////////////////// + +// Eğer çağırıcı tarafından fonksiyona argüman sağlanmamışsa, +// fonksiyona default argüman verebilirsin + +void doSomethingWithInts(int a = 1, int b = 4) +{ + // Burada int'lerle birşeyler yap +} + +int main() +{ + doSomethingWithInts(); // a = 1, b = 4 + doSomethingWithInts(20); // a = 20, b = 4 + doSomethingWithInts(20, 5); // a = 20, b = 5 +} + +// Default argümanlar, argüman listesinin sonunda yer almalı. + +void invalidDeclaration(int a = 1, int b) // Hata! +{ +} + + +///////////////////////// +// Namespace(İsim uzayı) +///////////////////////// + +// Namespace'ler değişken, fonksiyon ve diğer bildirimlerin +// kapsama alanını ayırır. +// Namespace'ler içiçe geçebilir. + +namespace First { + namespace Nested { + void foo() + { + printf("This is First::Nested::foo\n"); + } + } // Nested namespace'inin sonu +} // First namespace'inin sonu + +namespace Second { + void foo() + { + printf("This is Second::foo\n"); + } +} + +void foo() +{ + printf("This is global foo\n"); +} + +int main() +{ + // Second namespace'i içinideki tüm sembolleri mevcut kapsama alanına dahil eder. + // Dikkat edersen artık yalnızca foo() çağrısı çalışmayacaktır çünkü hangi + // namespace'ten çağrıldığı açık değildir. + using namespace Second; + + Second::foo(); // "This is Second::foo" yazdırıır + First::Nested::foo(); // "This is First::Nested::foo" yazdırır + ::foo(); // "This is global foo" yazdırır. +} + +/////////////// +// Input/Output +/////////////// + +// C++'ta input ve output stream'leri kullanır. +// cin, cout ve cerr,sırasıyla, stdin, stdout, ve stderr'i temsil eder. +// << araya ekleme ve >> aradan çıkarma operatörüdür. + +#include <iostream> // I/O stream'lerini dahil etmek için + +using namespace std; // Streamler std namespace'i içindedir(standard kütüphane) + +int main() +{ + int myInt; + + // stdout (veya terminal/screen)'ta çıktı verir + cout << "Enter your favorite number:\n"; + // Girdiyi alır + cin >> myInt; + + // cout ayrıca formatlanabilir + cout << "Your favorite number is " << myInt << "\n"; + // prints "Your favorite number is <myInt>" + + cerr << "Used for error messages"; +} + +////////////// +// String'ler +///////////// + +// String'ler C++'ta nesnedir ve pek çok üye fonksiyonu vardır +#include <string> + +using namespace std; // String'ler de std namespace'i içindedir. (standard kütüphane) + +string myString = "Hello"; +string myOtherString = " World"; + +// + eklemek için kullanıldır +cout << myString + myOtherString; // "Hello World" + +cout << myString + " You"; // "Hello You" + +// C++'ta stringler are mutable'dır (değişebilir). +myString.append(" Dog"); +cout << myString; // "Hello Dog" + + +/////////////////////// +// Reference (Referans) +/////////////////////// + +// C'deki pointer'lara ek olarak +// C++ _reference_'lara sahiptir. +// Bunlar bir kere atandınğında tekrardan atanamayan pointer'dır +// ve null olamaz. +// Değişkenin kendisiyle aynı sözdizimine sahiptir: +// Değerine ulaşmak için * ihtiyaç yoktur ve +// atama için & (address of) kullanılmaz. + +using namespace std; + +string foo = "I am foo"; +string bar = "I am bar"; + + +string& fooRef = foo; // Bu foo'nun reference'ını oluşturur. +fooRef += ". Hi!"; // foo'yu reference'ı üzerinden değiştirir. +cout << fooRef; // "I am foo. Hi!" yazdırır. + +// "fooRef"e yeniden atama yapmaz. Bu "foo = bar" denktir ve bu satırdan sonra +// foo == "I am bar" olur +cout << &fooRef << endl; // foo'un adresini yazdırır +fooRef = bar; +cout << &fooRef << endl; //Hala foo'nun adresini yazdırır +cout << fooRef; //"I am bar" yazdırır + +// fooRef'in adresi aynı kalır yani hala foo'nun adresidir. + +const string& barRef = bar; // bar'a const reference oluşturur +// C'de olduğu gibi, const değerler (pointer'lar ve reference'ler) değiştirilemez. +barRef += ". Hi!"; // Hata, const reference'ler değiştirilemez. + +// Kısa bir ekleme: reference'lere devam etmeden önce, geçici nesne konseptinden +// bahsetmeliyiz. Mesela aşadaki gibi bir kod var: +string tempObjectFun() { ... } +string retVal = tempObjectFun(); + +// Bu iki satırda aslında ne oluyor: +// - tempObjectFun fonksiyonundan bir string nesnesi dönüyor +// - dönmüş olan nesneyle yeni bir string oluşturuyor +// - dönmüş olan nesne yok ediliyor +// İşte bu dönen nesneye geçici nesne denir. Geçici nesneler fonksiyon nesne +// döndürdüğünde oluşturulur ve ifade işini bitirdiğinde yok edilir (Aslında, +// standard'ın söylediği şey bu ama derleyiciler bu davranışı değiştirmemize +// izin veriyor. Daha fazla detay için "return value optimization" diye +// aratabilirsin. Sonuç olarak aşağıdaki kodda: +foo(bar(tempObjectFun())) + +// foo ve bar'ın varolduğunu kabul ediyoruz, tempObjectFun'dan dönen nesne +// bar'a geçti ve foo çağrılmadan önce yokedildir. + +// Şimdi reference'lara dönelim. "ifadenin sonunda" kuralının bir istisnası +// eğer geçici nesne const reference'a geçildiyse oratya çıkar, bu durumda +// nesnenin ömrü mevcut kapsama alanına kadar uzar: + +void constReferenceTempObjectFun() { + // constRef geçici nesneyi alır ve bu durum fonksiyonun sonuna kadar geçerlidir. + const string& constRef = tempObjectFun(); + ... +} + +// C++11 ile gelen diğer bir reference geçici nesnelere özeldir. Bu türden birden +// bir tip tanımlayamazsın ama aşırı yüklenme sırasında bu tipler öncelik alır: +void someFun(string& s) { ... } // Regular reference +void someFun(string&& s) { ... } // Geçici nesneye reference + +string foo; +someFun(foo); // regular reference'ı çağırır +someFun(tempObjectFun()); // geçici reference'ı çağırır + +///////////////////// +// Enum +///////////////////// + +// Enum'lar sabit değerler yapmak için kullanılır ve çoğunlukla kodun daha okunaklı +// olması için kullanılır + +enum ECarTypes +{ + Sedan, + Hatchback, + SUV, + Wagon +}; + +ECarTypes GetPreferredCarType() +{ + return ECarTypes::Hatchback; +} + +// C++11 ile beraber bir tipi enum'a atamanın kolay bir yolu var, bu enum'un istenen +// tipe dönüştürmek için kullanışlı bir yöntem +enum ECarTypes : uint8_t +{ + Sedan, // 0 + Hatchback, // 1 + SUV = 254, // 254 + Hybrid // 255 +}; + +void WriteByteToFile(uint8_t InputValue) +{ + // Serialize the InputValue to a file +} + +void WritePreferredCarTypeToFile(ECarTypes InputCarType) +{ + // enum uint8_t tipine dönüştürüldü + WriteByteToFile(InputCarType); +} + +// Diğer yandan enum'ların yanlışlıkla integer tipini veya diğer enumlara dönüşmesini +// istemiyorsan enum class olarak tanımlayabilirsin +enum class ECarTypes : uint8_t +{ + Sedan, // 0 + Hatchback, // 1 + SUV = 254, // 254 + Hybrid // 255 +}; + +void WriteByteToFile(uint8_t InputValue) +{ + // Serialize the InputValue to a file +} + +void WritePreferredCarTypeToFile(ECarTypes InputCarType) +{ + // ECarTypes, uint8_t tipinde olmasına rağmen, "enum class" olarak + // tanımlandığından derlenmeyecektir! + WriteByteToFile(InputCarType); +} + +/////////////////////////////////////////// +// Sınıflar ve nesneye yönelik proglamalama +/////////////////////////////////////////// + +// Sınıflara(class) ilk örnek +#include <iostream> + +// Sınıfı tanımla. +// Sınıflar genelde header (.h veya .hpp) dosyalarında tanımlanır. +class Dog { + // Üye değişkenler ve fonksiyonlar default olarak private'dir. + std::string name; + int weight; + +// Aşağıda, "private:" veya "protected:" bulunana kadar +// bütün üyeler public'tir. +public: + + // Default constructor + Dog(); + + // Üye fonksiyon bildirimi (gerçeklenimi aşağıda) + // Dikkat ederseniz using namespace std; yerine + // std::string kullandık. + // Hiçbir zaman header dosyasında "using namespace std;" kullanma. + void setName(const std::string& dogsName); + + void setWeight(int dogsWeight); + + // Nesnenin durumunu değiştirmeyen fonksiyonlar const ile işaretlenmelidir + + // Türetilen sınıflarda fonksiyonu override edebilmek için başına + // _virtual_ eklenmelidir. + // Fonksiyonlar, performanslar ilgili nedenlerden ötürü default olarak virtual değildir + virtual void print() const; + + // Fonksiyonlar class içinde de tanımlanabilir. + // Bu şekille tanımlanan fonksiyonlar otomatik olarak inline olur. + void bark() const { std::cout << name << " barks!\n"; } + + // C++ constructor'ların yanında destructor'da sağlar. + // Bunlar nesne silindiğinde veya scope'un dışına çıktığında çağrılır. + // Bu RAII gibi güçlü paradigmaları etkin kılar. + // (aşağıda açıklandı) + // Eğer sınıf kendisinden türetiliyorsa, destructor virtual olmalıdır, + // eğer virtual değilse, türetilmiş sınıfın destructor'ı nesne, ana sınıf + // referans'ı veya pointer'ı üzerinden yok edildiğinde, çağrılmayacaktır. + virtual ~Dog(); + +}; // class tanımının sonuda noktalı virgül(;) olmalıdır. + +// Sınıfın üye fonksiyonları genelde .cpp dosyaları içinde gerçeklenir. +Dog::Dog() +{ + std::cout << "A dog has been constructed\n"; +} + +// Objects (such as strings) should be passed by reference +// Nesneler (string gibi) reference ile fonksiyonlara geçilmelidir +// Eğer nesneleri değiştirilecekse reference ile fonksiyonlara geçilmelidir, +// değiştirilmeyecekse const reference ile geçilmelidir. +void Dog::setName(const std::string& dogsName) +{ + name = dogsName; +} + +void Dog::setWeight(int dogsWeight) +{ + weight = dogsWeight; +} + +// Dikkat edersen "virtual" yalnızca bildirimde gerekli, tanımlamada değil. +void Dog::print() const +{ + std::cout << "Dog is " << name << " and weighs " << weight << "kg\n"; +} + +Dog::~Dog() +{ + std::cout << "Goodbye " << name << "\n"; +} + +int main() { + Dog myDog; // "A dog has been constructed" yazdırır + myDog.setName("Barkley"); + myDog.setWeight(10); + myDog.print(); // "Dog is Barkley and weighs 10 kg" yazdırır. + return 0; +} // "Goodbye Barkley" yazdırır. + +// Inheritance(Miras) + +// Bu sınıf, Dog sınıfında public ve protected olan herşeyi miras alır, +// private olanları da miras alır ama, public ve protected sınıflar aracılıyla +// yapılmıyorsa, doğrudan erişemez. +class OwnedDog : public Dog { + +public: + void setOwner(const std::string& dogsOwner); + + // print fonksiyonunun davranışını bütün OwnedDogs sınıfı için override eder + // (üstünden geçer, kendine uyarlar). + // bknz http://en.wikipedia.org/wiki/Polymorphism_(computer_science) + // override anahtar sözcüpü kullanılma da olur ama kullanılması aslında bir temel + // temel sınıf fonksiyonunun üzerinden geçtiğimizi gösterir. + void print() const override; + +private: + std::string owner; +}; + +// Bu arada takip eden .cpp dosyasında: + +void OwnedDog::setOwner(const std::string& dogsOwner) +{ + owner = dogsOwner; +} + +void OwnedDog::print() const +{ + Dog::print(); // Ana dog sınıfındaki print fonksiyonunu çağırır + std::cout << "Dog is owned by " << owner << "\n"; + // "Dog is <name> and weights <weight>" + // "Dog is owned by <owner>" + // yazdırır +} + +///////////////////////////////////////////////////// +// ilk değer atama ve Operatörün fazladan yüklenmesi +///////////////////////////////////////////////////// + +// C++ dilinde +, -, *, /, gibi operatörlerin davranışını fazladan yükleyebilirsiniz. +// Bu, operator her kullandınıldığında çağrılan bir fonksiyon tanımlamasıyla yapılır. + +#include <iostream> +using namespace std; + +class Point { +public: + // Üye değişkenkenlere default değer atanabilir. + double x = 0; + double y = 0; + + // Default constructor + Point() { }; + + Point (double a, double b) : + x(a), + y(b) + { /* İlk değer atama dışında birşey yapma */ } + + // + operatorünün fazladan yükle. + Point operator+(const Point& rhs) const; + + // += operatorünü fazladan yükle + Point& operator+=(const Point& rhs); + + // - ve -= operatorleri fazladan yüklemek de mantıklı olurdu + // ama kısa tutmak için burda değinmedik. +}; + +Point Point::operator+(const Point& rhs) const +{ + // yeni bir nokta oluştur ve bunu rhs ile topla + return Point(x + rhs.x, y + rhs.y); +} + +Point& Point::operator+=(const Point& rhs) +{ + x += rhs.x; + y += rhs.y; + return *this; +} + +int main () { + Point up (0,1); + Point right (1,0); + // Bu Point + operatorünü çağırır + Point result = up + right; + // "Result is upright (1,1)" yazdırır. + cout << "Result is upright (" << result.x << ',' << result.y << ")\n"; + return 0; +} + +//////////////////////// +// Şablonlar (Templates) +//////////////////////// + +// Şablonlar C++ dilinde tipten bağımsız programlama için kullanılır. + +// Zaten aşina olduğun tipten bağımsız programlamayla başladık. Bir tip parametresi +// alan fonksiyon veya sınıf tanımlamaık için: +template<class T> +class Box { +public: + // Bu sınıfta T, herhangi bir tip için kullanılabilir. + void insert(const T&) { ... } +}; + +// Derleme esnasında derleyici aslında, parametreleri yerine konmuş şekilde herbir şablonu üretir, +// bu yüzden sınıfın tam tanımı her çağrılma sırasında var olmak zorundadır. Bu nedenle şablon sınıflarını +// tamamen header dosyalarında görürsün. + +// Stack'ta şablon sınıfın bir örneğini oluşturmak için: +Box<int> intBox; + +// ve, anladığın gibi, kullanabilirsin: +intBox.insert(123); + +// Tabi, şablonları içiçe geçirebilirsin: +Box<Box<int> > boxOfBox; +boxOfBox.insert(intBox); + +// C++11'den önce iki '>' arasına boşluk koymak zorundaydık yoksa sağa kaydırma +// operatörü olarak algılanabilirdi. + +// Bazen şunu da görebilirsin +// template<typename T> +// 'class' ve 'typename' anahtar sözcükleri çoğunlukla +// birbirlerinin yerine kullanılabilir. Tam açıklama için, bknz. +// http://en.wikipedia.org/wiki/Typename +// (evet, bu anahtar sözcüğün kendi Wikipedia sayfası var). + +// Benzer şekilde, bir şablon fonksiyon: +template<class T> +void barkThreeTimes(const T& input) +{ + input.bark(); + input.bark(); + input.bark(); +} + +// Dikkat edersen tip parametresi hakkında birşey belirtilmedi. Derleyici bunları üretecek +// ve her parametre geçişinde tip-kontrolü yapacaktır, bu nedenle de fonksiyon herhangi bir T +// tipi için çalışacaktır! + +Dog fluffy; +fluffy.setName("Fluffy") +barkThreeTimes(fluffy); // Üç kere "Fluffy barks" yazdırır. + +// Şablonun parametresi sınıf olmak zorunda değildir: +template<int Y> +void printMessage() { + cout << "Learn C++ in " << Y << " minutes!" << endl; +} + +// Ve template'i daha etkili kod için dışarıdan özelleştirebilirsin. +// Tabiki gerçek-dünya kullanımlarında özelleştirme bunun kadar kolay değildir. +// Dikkat edersen, bütün parametreleri dıştan özelleştirmiş olsak bile +// hala fonksiyonu (veya sınıfı( template olarak tanımlamamız gerekli. +template<> +void printMessage<10>() { + cout << "Learn C++ faster in only 10 minutes!" << endl; +} + +printMessage<20>(); // "Learn C++ in 20 minutes!" yazdırır +printMessage<10>(); // "Learn C++ faster in only 10 minutes!" yazdırır + + +/////////////////////////////////////////////// +// İstisnai Durum Yönetimi (Exception Handling) +/////////////////////////////////////////////// + +// Standard kütüphane bazı istisnai tipler sağlar +// (bknz http://en.cppreference.com/w/cpp/error/exception) +// ama herhangi bir tip de istisnai durum fırlatabilir + +#include <exception> +#include <stdexcept> + +// _try_ bloğu içinde fırlatılan bütün istisnai durumlar, takip eden, _catch_ ile +// yakalanabilir. +try { + // _new_ kullanarak heap'ten istisnai durumlar için yer ayırma + throw std::runtime_error("A problem occurred"); +} + +// istisnai durumlar nesne ise const reference ile yakala +catch (const std::exception& ex) +{ + std::cout << ex.what(); +} + +// Bir önceki _catch_ bloğundan kaçan istisnai durum burda yakala +catch (...) +{ + std::cout << "Unknown exception caught"; + throw; // Tekrardan istisnai durum fırlatır +} + +/////// +// RAII +/////// + +// RAII, "Resource Acquisition Is Initialization" kelimelerinin kısaltmasıdır. +// Bu Türkçe, "Kaynak alımı aynı zamanda ilk değer atamasıdır." olarak çevrilebilir. +// Bunu basitçe constructor ile ayrılan hafızanın destructor ile iade edilmesi olarak +// düşünebiliriz. + +// Bunun ne şekilde kullanışlı olduğunu görmek için +// bir C dosyasının, dosya işleme biçimine bakabiliriz: +void doSomethingWithAFile(const char* filename) +{ + // Başlangıçta herşeyin yolunda gittiğini düşünelim + + FILE* fh = fopen(filename, "r"); // Dosyayı okuma modunda aç + + doSomethingWithTheFile(fh); + doSomethingElseWithIt(fh); + + fclose(fh); // Dosyayı kapat +} + +// Malesef hatalarla başa çıkmaya çalışırken işler hızlıca karmaşıklaşır. +// Mesela fopen'ın başarısız olduğunu varsayalım, ve doSoomethingWithTheFile ve +// doSomethingWithIt hata kodları gönderdi. +// (İstisnai durumlar yonetimi, hata koduna tercih ediler bir yöntemdir, ama bazı +// programcılar, özellikle C arkaplanı olanlar, aynı fikirde değildir. +// Bu durumda her bir fonksiyon çağrısını kontrol etmeli ve bir problem oluştuysa +// dosyayı kapatmalıyız. + +bool doSomethingWithAFile(const char* filename) +{ + FILE* fh = fopen(filename, "r"); // Dosyayı okuma modunda aç + if (fh == nullptr) // Başarısız olma durumunda dönen değer null olur + return false; // Başarısız olma durumunu çağırıcıya bildir + + // Başarısız olma durumunda her iki fonksiyonun da false döndürdüğünü kabul edelim + if (!doSomethingWithTheFile(fh)) { + fclose(fh); // Dosyayı kapatalım, akıntı olmasın. + return false; // Hatayı bildir + } + if (!doSomethingElseWithIt(fh)) { + fclose(fh); // Dosyayı kapatalım, akıntı olmasın. + return false; // Hatayı bildir + } + + fclose(fh); // Dosyayı kapat + return true; // Başarı durumunu ifade eder +} + +// C programcıları biraz goto kullanarak bu durumu temizler +bool doSomethingWithAFile(const char* filename) +{ + FILE* fh = fopen(filename, "r"); + if (fh == nullptr) + return false; + + if (!doSomethingWithTheFile(fh)) + goto failure; + + if (!doSomethingElseWithIt(fh)) + goto failure; + + fclose(fh); // Dosyayı kapat + return true; // Başarı durumunu ifade eder + +failure: + fclose(fh); + return false; // Hatayı bildir +} + +// Eğer fonksiyon istisnai durum yönetimi araçlarını kullanırsa +// işler daha temiz olur ama hala en iyi durumun altında kalır. +void doSomethingWithAFile(const char* filename) +{ + FILE* fh = fopen(filename, "r"); + if (fh == nullptr) + throw std::runtime_error("Could not open the file."); + + try { + doSomethingWithTheFile(fh); + doSomethingElseWithIt(fh); + } + catch (...) { + fclose(fh); // Hata durumunda dosyayı kapattığından emin ol + throw; // Sonra, tekrardan istisnai durum fırlat + } + + fclose(fh); // Dosyayı kapat + // Herşey başarılı +} + +// Şimdi aynı şeyi C++'ın dosya stream sınıfıyla (fstream) karşılaştıralım +// fstream, dosyayı kapatmak için kendi destructor'ını kullanır. +// Destructor'ın, nesne scope dışına çıktığında otomatik olarak çağrıldığını +// hatırlayın. +void doSomethingWithAFile(const std::string& filename) +{ + std::ifstream fh(filename); // Dosyayı aç + + // Dosyayla birşeyler yap + doSomethingWithTheFile(fh); + doSomethingElseWithIt(fh); + +} // Dosya, destructor tarafından otomatik olarak kapatıldı + +// Bunun _çok büyük_ avantajları var: +// 1. Ne olursa olursun, +// kaynak (bu örnekte dosya tutucusu) temizlenecektir. +// Destructor doğru yazıldığında, +// Tutucuyu kapatmayı unutma ve kaynak akıntısı _imkansız_dır. +// 2. Kodun çok daha temiz olduğuna dikkat edin. +// Destructor, dosyayı kapatma işini, endilenmemize gerek kalmadan +// arka planda halleder. +// 3. Kod, istisnai durumlara karşı korunaklıdır. +// İstisnai durum fonksiyonun herhangi bir yerinde fırlatılabilir ve +// temizleme işi gene de yapılır. + +// Bütün C++ kodu deyimleri RAII prensibini tüm kaynakları için kullanır. +// Ek örnekler şunlardır: +// - unique_ptr ve shared_ptr ile hafıza kullanımı +// - Tutucular - standard kütüphane linked list, +// vector (yani kendiliğinden boyu ayarlanan dizi), hash map vs. +// scope'un dışına çıktığında içerini otomatik olarak yok eden tüm yapılar. +// - lock_guard ve unique_lock kullanan mutex'ler + +/////////////////////////////////////// +// Lambda İfadeleri (C++11 ve yukarısı) +/////////////////////////////////////// + +// lambda'lar, tam olarak çağrıldığı yerde bir anonim fonksiyon tanımlamak +// veya fonksiyona argüman geçmek için uygun bir yoldur. + +// Mesela, pair'lardan oluşan bir vector'u, pair'ın ikinci değerine +// göre sıralamak isteyelim + +vector<pair<int, int> > tester; +tester.push_back(make_pair(3, 6)); +tester.push_back(make_pair(1, 9)); +tester.push_back(make_pair(5, 0)); + +// sort fonksiyonuna üçüncü argüman olarak lambda ifadesini geç +// sort, <algorithm> başlığında tanımlı + +sort(tester.begin(), tester.end(), [](const pair<int, int>& lhs, const pair<int, int>& rhs) { + return lhs.second < rhs.second; + }); + +// Lambda ifadesinin söz dizimine dikkat edin, +// lambda'daki [], değişkenleri "tutmak" için kullanılır +// "Tutma listesi", fonksiyon gövdesinde nelerin, ne şekilde erişilebilir olduğunu tanımlar +// Şunlardan biri olabilir: +// 1. bir değer : [x] +// 2. bir referans : [&x] +// 3. mevcut scope içindeki herhangi bir değişkene referans ile [&] +// 4. 3 ile aynı, ama değer ile [=] +// Mesela: +vector<int> dog_ids; +// number_of_dogs = 3; +for(int i = 0; i < 3; i++) { + dog_ids.push_back(i); +} + +int weight[3] = {30, 50, 10}; + +// Mesela dog_ids vector'unu dog'ların ağırlıklarına göre sıralamak isteyelim +// Yani en sonunda şöyle olmalı: [2, 0, 1] + +// Burada lambda ifadesi oldukça kullanışlıdır + +sort(dog_ids.begin(), dog_ids.end(), [&weight](const int &lhs, const int &rhs) { + return weight[lhs] < weight[rhs]; + }); +// Dikkat edersen "weight" dizisini referans ile aldık. +// C++'da lambdalar hakkında daha fazla bilgi için : http://stackoverflow.com/questions/7627098/what-is-a-lambda-expression-in-c11 + +////////////////////////////////// +// Akıllı For (C++11 ve yukarısı) +////////////////////////////////// + +// Akıllı for döngüsünü bir tutucuyu dolaşmak için kullanabilirsin +int arr[] = {1, 10, 3}; + +for(int elem: arr){ + cout << elem << endl; +} + +// Tutucunun elemanlarının tipi için endişe etmeden "auto" kullanabilirsin +// Mesela: + +for(auto elem: arr) { + // arr dizisinin elemanlarıyla ilgili bir şeyler yap +} + +//////////////// +// Güzel Şeyler +//////////////// + +// C++ dilinin bakış açısı yeni başlayanlar için (hatta dili iyi bilenler için bile) +// şaşırtıcı olabilir. +// Bu bölüm, ne yazık ki, büyük ölçüde tam değil; C++ kendi ayağına ateş edilebilecek kolay +// dillerden biridir. + +// private metodları override edebilirsin! +class Foo { + virtual void bar(); +}; +class FooSub : public Foo { + virtual void bar(); // Foo::bar fonksiyonu override edilir! +}; + + +// 0 == false == NULL (çoğu zaman)! +bool* pt = new bool; +*pt = 0; // 'pt'nin gösterdiği değere false atar. +pt = 0; // 'pt'ye null pointer atar. Her iki satır uyarısız derlenir. + +// nullptr'ın bu meselenin bazılarını çözmesi beklenmiştir: +int* pt2 = new int; +*pt2 = nullptr; // Derlenmez. +pt2 = nullptr; // pt2'ye null atar. + +// bool tipleri için bir istisna vardır. +// Bu null pointer'ları if(!ptr) ile test etmek içindir. +// ama sonuç olarak bir bool değerine nullptr atayabilirsin! +*pt = nullptr; // '*pt' değeri bir boll olmasına rağmen, hala derlenir! + + +// '=' != '=' != '='! +// Calls Foo::Foo(const Foo&) or some variant (see move semantics) copy +// Foo::Foo(const Foo&) çağrısını veya kopyalama constructor'ının bir çeşidinin çağrısınıyapar(taşıma semantiklerine bknz.) +Foo f2; +Foo f1 = f2; + +// Foo::operator=(Foo&) çağrısını yapar. +Foo f1; +f1 = f2; + + +/////////////////////////////////////// +// Tuple (C++11 ve yukarısı) +/////////////////////////////////////// + +#include<tuple> + +// Ana fikir olarak, Tuple, eski veri yapılarına (C'deki struct'lar) benzer ama isimli veri üyeleri yerine +// elemanlarına tuple içindeki sırasına göre erişilir. + +// Tuple'ı inşa ederek başlayalım +// değişkenleri tuple içinde paketliyoruz +auto first = make_tuple(10, 'A'); +const int maxN = 1e9; +const int maxL = 15; +auto second = make_tuple(maxN, maxL); + +// 'first' tuple'ının değerlerini yazdırma +cout << get<0>(first) << " " << get<1>(first) << "\n"; // 10 A yazdırır + +// 'second' tuple'ının değerlerini yazdırma +cout << get<0>(second) << " " << get<1>(second) << "\n"; // 1000000000 15 yazdırır + +// Değişkenleri tuple'dan çıkarma + +int first_int; +char first_char; +tie(first_int, first_char) = first; +cout << first_int << " " << first_char << "\n"; // 10 A yazdırır + +// Ayrıca şu şekide de tuple oluşturabiliriz. + +tuple<int, char, double> third(11, 'A', 3.14141); +// tuple_size, tuple'daki eleman sayısını (constexpr olarak) döndürür + +cout << tuple_size<decltype(third)>::value << "\n"; // 3 yazdırır + +// tuple_cat, tuple'daki tüm elemanları aynı sırada birleştirir. + +auto concatenated_tuple = tuple_cat(first, second, third); +// concatenated_tuple = (10, 'A', 1e9, 15, 11, 'A', 3.14141) olur + +cout << get<0>(concatenated_tuple) << "\n"; // 10 yazdırır +cout << get<3>(concatenated_tuple) << "\n"; // 15 yazdırır +cout << get<5>(concatenated_tuple) << "\n"; // 'A' yazdırır + + +///////////////////// +// Tutucular +///////////////////// + +// Tutucular veya Standard Şablon Kütüphanesi(STL) önceden tanımlanmış şablonlar sunar. +// Bunlar elemanları için ayrılan hafıza alanını yönetir +// ve onlara erişim ve değiştirmek için üye fonksiyonlar sağlar + +// Bazı tutucular şunlardır: + +// Vector (Dinamik Dizi) +// koşma anında nesne dizisi veya list oluşturmamızı sağlar +#include <vector> +string val; +vector<string> my_vector; // vector'ü tanımla +cin >> val; +my_vector.push_back(val); // val değerini my_vector vectörüne push edecektir +my_vector.push_back(val); // val değerini yeniden push edecektir (şu an iki elemanı var) + +// vector içinde dolaşmak için iki seçenek var: +// ya klasik döngüyle (0. index'ten son index'e kadar iterasyon yaparak) +for (int i = 0; i < my_vector.size(); i++) { + cout << my_vector[i] << endl; // vector'ün elemanlarına uşamak için [] operatörünü kullanabiliriz +} + +// ya da iteratör kulllanarak: +vector<string>::iterator it; // vector için iterator tanımla +for (it = my_vector.begin(); it != my_vector.end(); ++it) { + cout << *it << endl; +} + +// Set(Küme) +// Set'ler benzersiz(unique) elemanları belirli bir sırada saklayan tutuculardır. +// Set, benzersiz değerleri, herhangi bir fonksiyon veya kod gerektirmeksizin, sıralı olarak + +#include<set> +set<int> ST; // int tipi için set tanımlar +ST.insert(30); // ST kümesini 30 değerini dahil eder +ST.insert(10); // ST kümesini 10 değerini dahil eder +ST.insert(20); // ST kümesini 20 değerini dahil eder +ST.insert(30); // ST kümesini 30 değerini dahil eder +// Şimdi kümedeki elemanlar aşağıdaki gibidir +// 10 20 30 + +// Bir eleman silmek için: +ST.erase(20); // 20 değerine sahip elemanı siler +// Set ST: 10 30 +// Iterator kullanarak Set içinde iterasyon yapmak için: +set<int>::iterator it; +for(it=ST.begin();it<ST.end();it++) { + cout << *it << endl; +} +// Output: +// 10 +// 30 + +// Tutucuyu tamamen silmek için Tutucu_Adi.clear() kullanırız +ST.clear(); +cout << ST.size(); // ST kümesinin eleman sayısı(size)nı yazdırır. +// Output: 0 + +// NOTE: Aynı elemanlari içerebilen kümle için multiset kullanırız + +// Map(Harita) +// Map, elemanları anahtar değer, haritalanmış değer şeklinde özel bir sırada saklar. +// anahtar_değer -> haritalanmış_değer + +#include<map> +map<char, int> mymap; // Anahtar char ve değer int olacak şekilde map tanımlar + +mymap.insert(pair<char,int>('A',1)); +// 1 değeri için A anahtar değerini ekler +mymap.insert(pair<char,int>('Z',26)); +// 26 değeri için Z anahtar değerini ekler + +// Map'te dolaşma +map<char,int>::iterator it; +for (it=mymap.begin(); it!=mymap.end(); ++it) + std::cout << it->first << "->" << it->second << '\n'; +// Output: +// A->1 +// Z->26 + +// Anahtar'a atanmış değeri bulmak için +it = mymap.find('Z'); +cout << it->second; + +// Output: 26 + + +///////////////////////////////////////////// +// Mantıksal ve Bit seviyesindeki operatörler +///////////////////////////////////////////// + +// Pek çok C++ operatörleri diğer dillerdekiyle aynıdır + +// Mantıksal operatörler + +// C++, bool ifadelerinde Kısa-devre değerlendirmesini kullanır yani ikinci argüman yalnızca ilk argüman +// ifadenin değerine karar vermek için yeterli değilse çalıştırılır + +true && false // **mantıksal ve** işlemi yapılır ve yanlış sonucu üretilir +true || false // **mantıksal veya** işlemi yapılır ve true sonucu üretilir +! true // **mantıksal değil** işlemi yapılır ve yalnış sonucu üretilir + +// Sembolleri kullanmak yerine onlara karşılık gelen anahtar kelimeler kullanılabilir +true and false // **mantıksal ve** işlemi yapılır ve yanlış sonucu üretilir +true or false // **mantıksal veya** işlemi yapılır ve true sonucu üretilir +not true // **mantıksal değil** işlemi yapılır ve yalnış sonucu üretilir + +// Bit seviyesindeki operatörler + +// **<<** Sola kaydırma operatörü +// << bitleri sola kaydırır +4 << 1 // 4'ün bitlerini 1 sola kaydırır ve 8 sonucunu verir +// x << n, x * 2^n olarak düşünülebilir + + +// **>>** Sağa kaydırma operatörü +// >> bitleri sağa kaydırır +4 >> 1 // 4'ün bitlerini 1 sağa kaydırır ve 2 sonucunu verir +// x >> n, x / 2^n olarak düşünülebilir + +~4 // Bit seviyesinde değil işlemini gerçekleştirir +4 | 3 // Bit seviyesinde veya işlemini gerçekleştirir +4 & 3 // Bit seviyesinde ve işlemini gerçekleştirir +4 ^ 3 // Bit seviyesinde xor işlemini gerçekleştirir + +// Eşdeğer anahtar kelimeler +compl 4 // Bit seviyesinde değil işlemini gerçekleştirir +4 bitor 3 // Bit seviyesinde veya işlemini gerçekleştiri +4 bitand 3 // Bit seviyesinde ve işlemini gerçekleştirir +4 xor 3 // Bit seviyesinde xor işlemini gerçekleştirir + + +``` +İleri okuma: + +* Güncel bir referans [CPP Reference](http://cppreference.com/w/cpp) adresinde bulunabilir. +* Ek kaynaklar [CPlusPlus](http://cplusplus.com) adresinde bulunabilir. +* Dilin temellerini ve kodlama ortamını belirleyen bir öğretici [TheChernoProject - C ++](https://www.youtube.com/playlist?list=PLlrATfBNZ98dudnM48yfGUldqGD0S4FFb) adresinde bulunabilir. diff --git a/tr-tr/css-tr.html.markdown b/tr-tr/css-tr.html.markdown new file mode 100644 index 00000000..d13dadcc --- /dev/null +++ b/tr-tr/css-tr.html.markdown @@ -0,0 +1,304 @@ +--- +language: css +contributors: + - ["Mohammad Valipour", "https://github.com/mvalipour"] + - ["Marco Scannadinari", "https://github.com/marcoms"] + - ["Geoffrey Liu", "https://github.com/g-liu"] + - ["Connor Shea", "https://github.com/connorshea"] + - ["Deepanshu Utkarsh", "https://github.com/duci9y"] + - ["Brett Taylor", "https://github.com/glutnix"] + - ["Tyler Mumford", "https://tylermumford.com"] +filename: learncss-tr.css +translators: + - ["Fatih Turan", "http://fatihturan.com"] +lang: tr-tr +--- + +Web sayfaları bir sayfanın içeriğini belirleyen HTML ile inşa edilirler. CSS (Basamaklı Biçim Sayfaları) ise bir sayfanın **görünümünü** belirleyen ayrı bir dildir. + +CSS kodu statik *kurallardan* oluşur. Her kural bir ya da daha fazla *seçici* alır ve görsel *özelliklere* belirli *değerleri* verir. Sonrasında bu özellikler seçiciler tarafından belirlenen sayfa unsurlarına uygulanır. + +Bu rehber, CSS 3'ün yeni özellikleri ile genişletilen CSS 2 ile dikkate alınarak yazılmıştır. + +**NOT:** CSS görsel sonuçlar ürettiğinden dolayı, öğrenmek için herşeyi bir CSS oyun alanı içinde ([dabblet](http://dabblet.com) gibi) denemeniz gerekmektedir. Bu makale sözdizimi kuralları ve genel ipuçları üzerine odaklanmaktadır. + +## Sözdizimi + +```css +/* yorumlar bu satırdaki gibi taksim-yıldız içinde görünür +CSS'te "tek satırlık yorumlar" bulunmamaktadır; bu sadece tek bir yorum yazma stilidir */ + +/* #################### + ## SEÇİCİLER + #################### */ + +/* seçici bir sayfadaki unsuru hedeflemek için kullanılır. */ +seçici { özellik: değer; /* daha fazla özellikler...*/ } + +/* +İşte bir örnek: + +<div class='class1 class2' id='anID' attr='value' otherAttr='en-us foo bar' /> +*/ + +/* */ + +/* CSS sınıflarının birini kullanarak hedefleyebilirsiniz */ +.class1 { } + +/* veya her iki sınıfı birden!*/ +.class1.class2 { } + +/* veya sadece ögenin adını yazarak */ +div { } + +/* veya onun ID adını */ +#anID { } + +/* veya onun aldığı bir özelliği kullanarak! */ +[attr] { font-size:smaller; } + +/* veya onun aldığı özelliğin belirli bir değeri varsa */ +[attr='value'] { font-size:smaller; } + +/* bir değer ile başlıyorsa (CSS 3) */ +[attr^='val'] { font-size:smaller; } + +/* veya bir değer ile bitiyorsa (CSS 3)*/ +[attr$='ue'] { font-size:smaller; } + +/* veya boşlukla ayrılmış liste içinde bir değer içeriyorsa */ +[otherAttr~='foo'] { } +[otherAttr~='bar'] { } + +/* veya tire ile ayrılmış bir liste içinde bir değer içeriyorsa, örneğin: "-" (U+002D) */ +[otherAttr|='en'] { font-size:smaller; } + +/* Farklı seçicileri birleştirerek daha fazla odaklanmış bir seçici oluşturabilirsiniz. Seçiciler arasında boşluk bırakmayın. */ +div.some-class[attr$='ue'] { } + +/* Başka bir ögenin alt ögesi olan bir ögeyi seçebilirsiniz. */ +div.some-parent > .class-name { } + +/* veya bir başka ögeden türeyeni seçebilirsiniz. Alt ögeler onların ebeveynlerinin direkt türünden gelir, sadece ağacın bir alt ögeleridirler. Soyundan gelenler ağacın herhangi bir alt seviyesinde olabilir. */ + +div.some-parent .class-name { } + +/* Uyarı: Seçiciler arasında bir boşluk bırakmazsanız aynı seçicinin başka bir anlamı olur. +Ne olduğunu tahmin edebilir misiniz? */ + +div.some-parent.class-name { } + +/* Ayrıca bir ögenin bitişik kardeşini temel alarak bir ögeyi seçebilirsiniz. */ +.i-am-just-before + .this-element { } + +/* veya kendisinden önce gelen herhangi bir kardeş ögeyi */ +.i-am-any-element-before ~ .this-element { } + +/* Yalnızca belli bir durumda bir öge seçmek için kullanılan sahte sınıflar adı verilen bazı seçiciler vardır. */ + +/* Örneğin, imleç bir ögenin üzerine geldiğinde */ +selector:hover { } + +/* veya bir bağlantı ziyaret edildiğinde */ +selector:visited { } + +/* veya ziyaret edilmediğinde */ +selected:link { } + +/* veya bir ögeye odaklanıldığında */ +selected:focus { } + +/* Ebeveyninin ilk alt ögesi olan herhangi bir öge */ +selector:first-child {} + +/* Ebeveyninin son alt ögesi olan herhangi bir öge */ +selector:last-child {} + +/* Sahte sınıflar gibi sahte elementler de bir dokümanın belirli bir parçasına stil vermenize izin verir. */ + +/* Seçilen ögenin sanal ilk alt ögesiyle eşleşir. */ +selector::before {} + +/* Seçilen ögenin sanal son alt ögesiyle eşleşir. */ +selector::after {} + +/* Uygun yerlerde yıldız karakteri ile bütün ögeleri seçmek için joker olarak kullanılabilir. */ + +* { } /* Bütün ögeler */ +.parent * { } /* Tüm alt ögeler */ +.parent > * { } /* Tüm çocuk ögeler */ + +/* #################### + ## ÖZELLİKLER + #################### */ + +selector { + + /* Ölçü birimleri kesin veya göreceli olabilir.*/ + + /* Göreceli birimler */ + width: 50%; /* Ebeveyn elementin yüzdesel olarak genişliği */ + font-size: 2em; /* Öğenin özgün yazı tipi boyutunda katları */ + font-size: 2rem; /* veya kök ögenin yazı tipi boyutu */ + font-size: 2vw; /* Görüntüleme çerçevesinin genişliğinin %1 olarak katları (CSS 3) */ + font-size: 2vh; /* veya onun yüksekliğinin */ + font-size: 2vmin; /* Bir vh veya vw'nin hangisi küçükse */ + font-size: 2vmax; /* veya daha büyük... */ + + /* Kesin birimler */ + width: 200px; /* Piksel */ + font-size: 20pt; /* Nokta */ + width: 5cm; /* Santimetre */ + min-width: 50mm; /* Milimetre */ + max-width: 5in; /* İnç */ + + /* Renkler */ + color: #F6E; /* Kısa onaltılık (HEX) biçimi */ + color: #FF66EE; /* Uzun onaltılık (HEX) biçimi */ + color: tomato; /* Bir isim verilen renk */ + color: rgb(255, 255, 255); /* RGB değerleri verilen türde */ + color: rgb(10%, 20%, 50%); /* RGB yüzdeleri verilen türde */ + color: rgba(255, 0, 0, 0.3); /* RGBA değerleri verilen türde (CSS 3) Not: 0 <= a <= 1 */ + color: transparent; /* Şeffaflık değerinin sıfır olması ile eşdeğer */ + color: hsl(0, 100%, 50%); /* HSL yüzdeleri verilen türde (CSS 3) */ + color: hsla(0, 100%, 50%, 0.3); /* HSL ile beraber şeffaflık değeri verilen türde */ + + /* Kenarlıklar */ + border-width:5px; + border-style:solid; + border-color:red; /* background-color'ın ayarlanışına benzer şekilde */ + border: 5px solid red; /* Bu aynı şeyin kısayol ile yazılışıdır */ + border-radius:20px; /* Bu bir CSS3 özelliğidir */ + + /* Görseller ve Ögelerin Arkaplanları */ + background-image: url(/img-path/img.jpg); /* url() içindeki tırnak işaretleri isteğe bağlı */ + + /* Yazı tipleri */ + font-family: Arial; + /* Eğer yazı tipi ailesi isminde bir boşluk var ise tırnak işareti içine alınmalıdır. */ + font-family: "Courier New"; + /* Eğer ilk sıradaki bulunamazsa, tarayıcı bir sonrakini kullanır */ + font-family: "Courier New", Trebuchet, Arial, sans-serif; +} +``` + +## Kullanım + +CSS dosyasınızı `.css`uzantısı ile kaydedin. + +```html +<!-- CSS dosyanızı sayfanın içindeki <head> alanına dahil etmeniz gerekiyor. Bu önerilen yöntemdir. Bakın: http://stackoverflow.com/questions/8284365 --> +<link rel='stylesheet' type='text/css' href='path/to/style.css'> + +<!-- Bazı CSS kodları satır içi olarak yazabilirsiniz. --> +<style> + a { color: purple; } +</style> + +<!-- Veya ögenin üzerinde CSS özelliklerini direkt ayarlayabilirsiniz. --> +<div style="border: 1px solid red;"> +</div> +``` + +## Öncelik veya Basamak + +Bir öge birden çok seçici tarafından hedef alınabilir ve bir özellik kümesine birden fazla kez sahip olabilir. Bunun gibi durumlarda, kurallardan biri diğerlerine göre önceliklidir. Daha spesifik bir seçiciye sahip kurallar, daha az spesifik bir seçicinin önceliğini alır ve kural daha sonra stil sayfasında bir önceki kuralın üzerine yazar. + +Bu işleme geçiş denir ve olayısıyla Geçişli/Basamaklı Stil Sayfaları adı da buradan gelmiştir. + +Aşağıdaki CSS göz önüne alındığında: + +```css +/* A */ +p.class1[attr='değer'] + +/* B */ +p.class1 { } + +/* C */ +p.class2 { } + +/* D */ +p { } + +/* E */ +p { özellik: değer !important; } +``` + +ve aşağıdaki biçimlendirmeyi: + +```html +<p style='/*F*/ özellik:değer;' class='class1 class2' attr='değer'> +``` + +Stilin önceliği ise aşağıdaki gibidir. Unutmayın, öncelik **her bir özellik için ayrı ayrı geçerlidir**, tüm blok için geçerli değildir. + +* `E` `!important` kelimesi yüzünden en yüksek önceliğe sahiptir. Kullanımından kaçınmanız önerilir. +* `F` satıriçi stil olduğu için bir sonraki önceliğe sahiptir. +* `A` bir sonraki önceliğe sahiptir. Çünkü her şeyden daha "özgüdür". 3 belirteci vardır: `p` ögesinin adı, sınıf` class1`, bir öznitelik `attr = 'değer'. +* `C`, `B` ile aynı özdeşliğe sahip olsa da, bundan sonra geldiğinden dolayı öncelik hakkına sahiptir. +* `B` bir sonraki önceliğe sahiptir. +* Sonuncu önceliğe sahip olan`D`'dir. + +## Medya Sorguları + +CSS Medya Sorguları, CSS 3'te belirli CSS kurallarının ne zaman uygulanması gerektiğini (örneğin basılan zaman veya belirli boyutlar veya piksel yoğunluğu olan bir ekranda olduğunda) belirlemenize izin veren bir özelliktir. Medya Sorguları, seçicilere önceliğk eklemez. + +```css +/* Tüm cihazlarda kullanılacak olan bir kural */ +h1 { + font-size: 2em; + color: white; + background-color: black; +} + +/* h1 ögesini değiştirip bir yazıcıda daha az mürekkep kullanın*/ +@media print { + h1 { + color: black; + background-color: white; + } +} + +/* En az 480 piksel genişliğinde bir ekran gösterildiğinde font yüksekliğini daha büyük yap */ +@media screen and (min-width: 480px) { + h1 { + font-size: 3em; + font-weight: normal; + } +} +``` + +Medya sorguları aşağıdaki bu özellikleri içerebilir: +`width`, `height`, `device-width`, `device-height`, `orientation`, `aspect-ratio`, `device-aspect-ratio`, `color`, `color-index`, `monochrome`, `resolution`, `scan`, `grid`. Bu özelliklerin birçoğunu `min-` veya `max-` öneki ile kullanabilirsiniz. + +`resolution` özelliği eski cihazlarda desteklenmediğinden ötürü `device-pixel-ratio` kullanın. + +Eğer `viewport` meta etiketi sağlanmadıkça birçok akıllı telefon ve tabletler, sayfayı masaüstü bilgisayardaymış gibi göstermeye çalışacaktır. + +```html +<head> + <meta name="viewport" content="width=device-width; initial-scale=1.0"> +</head> +``` + +## Uyumluluk + +CSS 2'deki çoğu özellik (ve CSS 3'deki birçoğu) bütün tarayıcılar ve cihazlar için bulunmaktadır. Ancak yeni bir özelliği kullanmadan önce kontrol etmek her zaman iyi bir uygulamadır. + +## Kaynaklar + +* [CanIUse](http://caniuse.com) (Detaylı uyumluluk bilgileri) +* [Dabblet](http://dabblet.com/) (CSS oyun alanı) +* [Mozilla Geliştirici Ağının CSS belgelendirmesi](https://developer.mozilla.org/en-US/docs/Web/CSS) (Eğitseller ve referanslar) +* [Codrops' CSS Referansı](http://tympanus.net/codrops/css_reference/) (Referans) + +## Daha Fazla Okuma + +* [Understanding Style Precedence in CSS: Specificity, Inheritance, and the Cascade](http://www.vanseodesign.com/css/css-specificity-inheritance-cascaade/) +* [Selecting elements using attributes](https://css-tricks.com/almanac/selectors/a/attribute/) +* [QuirksMode CSS](http://www.quirksmode.org/css/) +* [Z-Index - The stacking context](https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Understanding_z_index/The_stacking_context) +* [SASS](http://sass-lang.com/) and [LESS](http://lesscss.org/) for CSS pre-processing +* [CSS-Tricks](https://css-tricks.com) diff --git a/tr-tr/dynamic-programming-tr.html.markdown b/tr-tr/dynamic-programming-tr.html.markdown index 606ecf04..e6a734a7 100644 --- a/tr-tr/dynamic-programming-tr.html.markdown +++ b/tr-tr/dynamic-programming-tr.html.markdown @@ -8,24 +8,28 @@ translators: lang: tr-tr --- -Dinamik Programlama -Giriş +# Dinamik Programlama + +## Giriş + Dinamik Programlama, göreceğimiz gibi belirli bir problem sınıfını çözmek için kullanılan güçlü bir tekniktir. Fikir çok basittir, verilen girdiyle ilgili bir sorunu çözdüyseniz, aynı sorunun tekrar çözülmesini önlemek için sonucunu gelecekte referans olarak kaydedilmesine dayanır. Her zaman hatırla! "Geçmiş hatırlayamayanlar, aynı şeyleri tekrar yaşamaya mahkumlardır!" -Bu tür sorunların çözüm yolları +## Bu tür sorunların çözüm yolları -1-Yukarıdan aşağıya: +1. Yukarıdan aşağıya: Verilen problemi çözerek çözmeye başlayın. Sorunun zaten çözüldüğünü görürseniz, kaydedilen cevabı döndürmeniz yeterlidir. Çözülmemişse, çözünüz ve cevabı saklayınız. Bu genellikle düşünmek kolaydır ve çok sezgiseldir. Buna Ezberleştirme denir. -2-Aşağıdan yukarıya: +2. Aşağıdan yukarıya: Sorunu analiz edin ve alt problemlerin çözülme sırasını görün ve önemsiz alt sorundan verilen soruna doğru başlayın. Bu süreçte, problemi çözmeden önce alt problemlerin çözülmesi gerekmektedir. Buna Dinamik Programlama denir. -Örnek -En Uzun Artan Subsequence problemi belirli bir dizinin en uzun artan alt dizini bulmaktır. S = {a1, a2, a3, a4, ............., an-1} dizisi göz önüne alındığında, en uzun bir alt kümeyi bulmak zorundayız, böylece tüm j ve i, j için <I, aj <ai alt kümesinde. Her şeyden önce, en son alt dizgenin (LSi) değerini dizinin son elemanı olan ai'nin her indeksinde bulmalıyız. Daha sonra en büyük LSi, verilen dizideki en uzun alt dizin olacaktır. Başlamak için, ai, dizinin elemanı olduğundan (Son öğe) LSi atanır. Sonra tüm j için j <i ve aj <ai gibi, En Büyük LSj'yi buluruz ve LSi'ye ekleriz. Sonra algoritma O (n2) zaman alır. +## Örnek + +En Uzun Artan Subsequence problemi belirli bir dizinin en uzun artan alt dizini bulmaktır. `S = {a1, a2, a3, a4, ............., an-1}` dizisi göz önüne alındığında, en uzun bir alt kümeyi bulmak zorundayız, böylece tüm j ve i, `j<I` için , `aj<ai` alt kümesinde. Her şeyden önce, en son alt dizgenin (LSi) değerini dizinin son elemanı olan ai'nin her indeksinde bulmalıyız. Daha sonra en büyük LSi, verilen dizideki en uzun alt dizin olacaktır. Başlamak için, ai, dizinin elemanı olduğundan (Son öğe) LSi atanır. Sonra tüm j için `j<i` ve `aj<ai` gibi, En Büyük LSj'yi buluruz ve LSi'ye ekleriz. Sonra algoritma `O(n2)` zaman alır. -En uzun artan alt dizinin uzunluğunu bulmak için sözde kod: Bu algoritmaların karmaşıklığı dizi yerine daha iyi veri yapısı kullanılarak azaltılabilir. Büyük dizin ve dizin gibi selefi dizi ve değişkeni saklama çok zaman kazandıracaktır. +En uzun artan alt dizinin uzunluğunu bulmak için sözde kod: +Bu algoritmaların karmaşıklığı dizi yerine daha iyi veri yapısı kullanılarak azaltılabilir. Büyük dizin ve dizin gibi selefi dizi ve değişkeni saklama çok zaman kazandıracaktır. Yönlendirilmiş asiklik grafiğinde en uzun yolu bulmak için benzer bir kavram uygulanabilir. @@ -40,10 +44,12 @@ for i=0 to n-1 ``` -Bazı Ünlü Dinamik Programlama Problemleri --Floyd Warshall Algorithm - Tutorial and C Program source code:http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs—floyd-warshall-algorithm-with-c-program-source-code --Integer Knapsack Problem - Tutorial and C Program source code: http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming—the-integer-knapsack-problem --Longest Common Subsequence - Tutorial and C Program source code : http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming—longest-common-subsequence +### Bazı Ünlü Dinamik Programlama Problemleri + +- Floyd Warshall Algorithm - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-all-to-all-shortest-paths-in-graphs---floyd-warshall-algorithm-with-c-program-source-code]() +- Integer Knapsack Problem - Tutorial and C Program source code: [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---the-integer-knapsack-problem]() +- Longest Common Subsequence - Tutorial and C Program source code : [http://www.thelearningpoint.net/computer-science/algorithms-dynamic-programming---longest-common-subsequence]() + +## Online Kaynaklar -Online Kaynaklar -https://www.codechef.com/wiki/tutorial-dynamic-programming +- [codechef](https://www.codechef.com/wiki/tutorial-dynamic-programming) diff --git a/tr-tr/git-tr.html.markdown b/tr-tr/git-tr.html.markdown new file mode 100644 index 00000000..87c1820c --- /dev/null +++ b/tr-tr/git-tr.html.markdown @@ -0,0 +1,596 @@ +--- +category: tool +lang: tr-tr +tool: git +contributors: + - ["Jake Prather", "http://github.com/JakeHP"] + - ["Leo Rudberg" , "http://github.com/LOZORD"] + - ["Betsy Lorton" , "http://github.com/schbetsy"] + - ["Bruno Volcov", "http://github.com/volcov"] + - ["Andrew Taylor", "http://github.com/andrewjt71"] + - ["Jason Stathopulos", "http://github.com/SpiritBreaker226"] + - ["Milo Gilad", "http://github.com/Myl0g"] + - ["Adem Budak", "https://github.com/p1v0t"] + +filename: LearnGit-tr.txt +--- + +Git dağınık versiyon kontrol ve kaynak kod yönetim sistemidir. + +Bunu projenin bir seri anlık durumunu kaydederek yapar ve bu anlık durumları +kullanarak versiyon ve kaynak kodu yönetmeni sağlar. + +## Versiyonlama Konseptleri + +### Versiyon kontrol nedir? + +Versiyon kontrol, zaman içerisinde dosya(lar)daki değişikliği kaydeden sistemdir. + +### Merkezi Versiyonlama vs. Dağınık Versiyonlama + +* Merkezi versiyon kontrolü dosyaların eşitlenmesine, takibine ve yedeklenmesine odaklanır. +* Dağınık versiyon kontrolü değişimin paylaşılmasına odaklanır. Her değişiminin benzersiz bir adı vardır. +* Dağınık sistemlerin belirlenmiş bir yapısı yoktur. Git ile kolayca SVN'deki gibi merkezi bir sistem elde edebilirsin. + +[Daha fazla bilgi](http://git-scm.com/book/en/Getting-Started-About-Version-Control) + +### Neden Git? + +* Çevrimdışı çalışabilir +* Diğerleriyle beraber çalışmak kolaydır! +* Dallanma kolaydır! +* Dallanma hızlıdır! +* Git hızlıdır +* Git esnektir + +## Git Mimarisi + +### Repository + +Bir grup dosya, dizin, geriye dönük kayıt, commit, head. Bunları kaynak kodun veri +yapısı gibi düşünebilirsin, herbir kaynak kod "elemanı" seni kendi revizyon geçmişine +eriştirir. + +Bir git repo'su .git dizini ve çalışma ağacından oluşur. + +### .git Dizini (repository bileşeni) + +.git dizini bütün konfigrasyon, log, dallanma, HEAD ve daha fazlasını tutar. +[detaylı liste](http://gitready.com/advanced/2009/03/23/whats-inside-your-git-directory.html) + +### Çalışma Ağacı (repository bileşeni) + +Temelde repo'daki dizinlerin ve dosyalarındır. Sıkça çalışma ağacın olarak anılır. + +### Index (.git dizininin birleşeni) + +Index git'in evreleme alanıdır (staging area). Temelde çalışma ağacını Git repo'sundan +ayıran bir katmandır. Bu geliştiricilere neyin Git repo'suna gönderileceği hakkında daha +fazla güç verir. + +### Commit + +Bir git commit'i Çalışma Ağacındaki bir takım değişiklerdir. Mesela 5 tane dosya +eklemişsindir ve diğer 2 tanesini silmişindir, bu değişikler commit'te (anlık kayıtta) +tutulacaktır. Bu commit daha sonra diğer repo'lara bastırılabilir (pushed) ve bastırılmaz! + +### Branch + +Bir branch esasen yaptığın son commit'e göstericidir(pointer). Commit'lemeye devam ettiğinde, +bu gösterici otomatik olarak son commit'e güncellenir. + +### Tag + +Bir tag, tarihteki belirli bir noktanın işaretidir. İnsanlar bunu genelde +sürüm notları için kullanır (v1.0 vs.) + +### HEAD ve head (.git dizininin birleşenleri) + +HEAD mevcut branch'a bir göstericidir. Bir repository yalnızca 1 *aktif* +HEAD'e sahiptir. +head, commit'e bir göstericidir. Bir repository herhangi bir sayıda head'e sahip olabilir. + +### Git'in Stage'leri +* Modified - Dosyada değişikler yapıldı ama henüz Git Veritabanına commit yapılmadı. +* Staged - Modified edilmiş bir dosyayı, sonraki commit'e gitmek üzere işaretler. +* Committed - Dosyalar Git Veritabanına commit'lendi. + +### Kavramsal Kaynaklar + +* [Bilgisayar Bilimciler için Git](http://eagain.net/articles/git-for-computer-scientists/) +* [Tasarımcılar için Git](http://hoth.entp.com/output/git_for_designers.html) + +## Komutlar + +### init + +Boş bir Git repository'si oluştur. Git repository'sinin ayarları, depolanmış +bilgileri ve daha fazlası ".git" adlı dizinde (bir klasör) tutulur. + +```bash +$ git init +``` + +### config + +Ayarları yapılandırmak için. Repository, sistemin kendisi veya global yapılandırmalar +için olarabilir. (global yapılandırma dosyası `~/.gitconfig`). + +```bash +# Print & Set Some Basic Config Variables (Global) +$ git config --global user.email "MyEmail@Zoho.com" +$ git config --global user.name "My Name" +``` + +[git config hakkında daha fazla bilgi için.](http://git-scm.com/docs/git-config) + +### help + +Her bir komutun detaylı kılavuzuna hızlı bir erişim için. Ya da sadece bazı şeylerin +anlamı için hızlı bir hatırlatıcı için. + +```bash +# Quickly check available commands +$ git help + +# Check all available commands +$ git help -a + +# Command specific help - user manual +# git help <command_here> +$ git help add +$ git help commit +$ git help init +# or git <command_here> --help +$ git add --help +$ git commit --help +$ git init --help +``` + +### dosyaları ignore etme + +git'in bazı dosya(ları) ve klasör(leri) kasıtlı olarak takip etmemesi için. Genel +olarak,repository'de ne de olsa paylaşılacak, private ve temp dosyaları için. + +```bash +$ echo "temp/" >> .gitignore +$ echo "private_key" >> .gitignore +``` + +### status + +index dosyası(temelde çalıştığın repo) ve mevcut HEAD commit arasındaki farkı göstermek için. + +```bash +# Will display the branch, untracked files, changes and other differences +$ git status + +# To learn other "tid bits" about git status +$ git help status +``` + +### add + +Dosyaları staging area'ya eklemek için. Eğer yeni dosyaları staging area'ya `git add` +yapmazsanız, commit'lere eklenmez! + +```bash +# add a file in your current working directory +$ git add HelloWorld.java + +# add a file in a nested dir +$ git add /path/to/file/HelloWorld.c + +# Regular Expression support! +$ git add ./*.java + +# You can also add everything in your working directory to the staging area. +$ git add -A +``` +Bu yalnızca dosyayı staging area'a/index'e ekler, çalışılan dizine/repo'ya commit etmez. + +### branch + +Branch'ları yönetir. Bu komutu kullanarak, branch'ları görebilir, düzenleyebilir, oluşturabilir, silebilirsin. + +```bash +# list existing branches & remotes +$ git branch -a + +# create a new branch +$ git branch myNewBranch + +# delete a branch +$ git branch -d myBranch + +# rename a branch +# git branch -m <oldname> <newname> +$ git branch -m myBranchName myNewBranchName + +# edit a branch's description +$ git branch myBranchName --edit-description +``` + +### tag + +tag'leri yönetir + +```bash +# List tags +$ git tag + +# Create a annotated tag +# The -m specifies a tagging message, which is stored with the tag. +# If you don’t specify a message for an annotated tag, +# Git launches your editor so you can type it in. +$ git tag -a v2.0 -m 'my version 2.0' + +# Show info about tag +# That shows the tagger information, the date the commit was tagged, +# and the annotation message before showing the commit information. +$ git show v2.0 + +# Push a single tag to remote +$ git push origin v2.0 + +# Push a lot of tags to remote +$ git push origin --tags +``` + +### checkout + +index'in versiyonun eşlemek için çalışma ağacındaki,veya belirtilen ağactaki, tüm dosyaları günceller. + +```bash +# Checkout a repo - defaults to master branch +$ git checkout + +# Checkout a specified branch +$ git checkout branchName + +# Create a new branch & switch to it +# equivalent to "git branch <name>; git checkout <name>" + +$ git checkout -b newBranch +``` + +### clone + +Varolan bir repository'i yeni bir dizine clone'lar veya kopyalar. +Ayrıca clone'lanmış repodaki her bir branch için, uzak branch'a bastırmana izin veren, +uzak takip branch'ları ekler. + +```bash +# Clone learnxinyminutes-docs +$ git clone https://github.com/adambard/learnxinyminutes-docs.git + +# shallow clone - faster cloning that pulls only latest snapshot +$ git clone --depth 1 https://github.com/adambard/learnxinyminutes-docs.git + +# clone only a specific branch +$ git clone -b master-cn https://github.com/adambard/learnxinyminutes-docs.git --single-branch +``` + +### commit + +index'in mevcut içeriğini yeni bir "commit"te saklar. Bu commit, kullanıcının oluşturduğu +bir mesajı ve yapılan değişiklikleri saklar. + +```bash +# commit with a message +$ git commit -m "Added multiplyNumbers() function to HelloWorld.c" + +# signed commit with a message (user.signingkey must have been set +# with your GPG key e.g. git config --global user.signingkey 5173AAD5) +$ git commit -S -m "signed commit message" + +# automatically stage modified or deleted files, except new files, and then commit +$ git commit -a -m "Modified foo.php and removed bar.php" + +# change last commit (this deletes previous commit with a fresh commit) +$ git commit --amend -m "Correct message" +``` + +### diff + +Shows differences between a file in the working directory, index and commits. +Bir dosyanın, çalışma ağacı, index ve commit'ler arasındaki farklarını göster. + +```bash +# Show difference between your working dir and the index +$ git diff + +# Show differences between the index and the most recent commit. +$ git diff --cached + +# Show differences between your working dir and the most recent commit +$ git diff HEAD +``` + +### grep + +Bir repository'de hızlıca arama yapmana izin verir. + +İsteğe Bağlı Yapılandırmalar: + +```bash +# Thanks to Travis Jeffery for these +# Set line numbers to be shown in grep search results +$ git config --global grep.lineNumber true + +# Make search results more readable, including grouping +$ git config --global alias.g "grep --break --heading --line-number" +``` + +```bash +# Search for "variableName" in all java files +$ git grep 'variableName' -- '*.java' + +# Search for a line that contains "arrayListName" and, "add" or "remove" +$ git grep -e 'arrayListName' --and \( -e add -e remove \) +``` + +Daha fazla örnek için +[Git Grep Ninja](http://travisjeffery.com/b/2012/02/search-a-git-repo-like-a-ninja) + +### log + +Repository'deki commitleri gösterir. + +```bash +# Show all commits +$ git log + +# Show only commit message & ref +$ git log --oneline + +# Show merge commits only +$ git log --merges + +# Show all commits represented by an ASCII graph +$ git log --graph +``` + +### merge + +Dış commit'lerdeki değişiklikleri mevcut branch'a "merge" et (birleştir). + +```bash +# Merge the specified branch into the current. +$ git merge branchName + +# Always generate a merge commit when merging +$ git merge --no-ff branchName +``` + +### mv + +Bir dosyayı yeniden taşı veya yeniden adlandır + +```bash +# Renaming a file +$ git mv HelloWorld.c HelloNewWorld.c + +# Moving a file +$ git mv HelloWorld.c ./new/path/HelloWorld.c + +# Force rename or move +# "existingFile" already exists in the directory, will be overwritten +$ git mv -f myFile existingFile +``` + +### pull + +Bir repository'den çeker ve diğer branch'a merge eder. + +```bash +# Update your local repo, by merging in new changes +# from the remote "origin" and "master" branch. +# git pull <remote> <branch> +$ git pull origin master + +# By default, git pull will update your current branch +# by merging in new changes from its remote-tracking branch +$ git pull + +# Merge in changes from remote branch and rebase +# branch commits onto your local repo, like: "git fetch <remote> <branch>, git +# rebase <remote>/<branch>" +$ git pull origin master --rebase +``` + +### push + +Bir branch'taki değişikleri, uzak branch'a bastır ve birleştir. + +```bash +# Push and merge changes from a local repo to a +# remote named "origin" and "master" branch. +# git push <remote> <branch> +$ git push origin master + +# By default, git push will push and merge changes from +# the current branch to its remote-tracking branch +$ git push + +# To link up current local branch with a remote branch, add -u flag: +$ git push -u origin master +# Now, anytime you want to push from that same local branch, use shortcut: +$ git push +``` + +### stash + +Stash'leme çalışma dizinindeki kirli durumu alır ve bitmemiş değişiklikler +yığınına kaydeder. Bu değişikleri istediğin zaman tekrar uygulayabilirsin. + +Mesela git repo'nda bazı işler yaptın ama remote'dan pull yapmak istiyorsun. +Bazı dosyalarında kirli (commit'lenmemiş) değişiklikler olduğundan `git pull` +yapamazsın. Onun yerine önce `git stash` ile değişikliklerini yığına kaydet! + +(stash, sözlük anlamı: bir şeyi, özel bir yere güvenli biçimde saklamak) + +```bash +$ git stash +Saved working directory and index state \ + "WIP on master: 049d078 added the index file" + HEAD is now at 049d078 added the index file + (To restore them type "git stash apply") +``` + +Şimdi pull yapabilirsin! + +```bash +git pull +``` +`...changes apply...` + +Herşeyin tamam olduğunu kontrol et + +```bash +$ git status +# On branch master +nothing to commit, working directory clean +``` +Şu ana kadar neleri stash'lediğini `git stash list` kullanarak görebilirsin. +Stash'lenen şeyler Son-Giren-İlk-Çıkar şeklinde tutulduğundan en son değişim +en üste olacaktır. + +```bash +$ git stash list +stash@{0}: WIP on master: 049d078 added the index file +stash@{1}: WIP on master: c264051 Revert "added file_size" +stash@{2}: WIP on master: 21d80a5 added number to log +``` +Şimdi de kirli değişiklileri yığından çıkarıp uygulayalım. + +```bash +$ git stash pop +# On branch master +# Changes not staged for commit: +# (use "git add <file>..." to update what will be committed) +# +# modified: index.html +# modified: lib/simplegit.rb +# +``` + +`git stash apply` da aynı şeyi yapar + +Şimdi kendi işine dönmeye hazırsın! + +[Ek Okuma.](http://git-scm.com/book/en/v1/Git-Tools-Stashing) + +### rebase (dikkat) + +Branch'ta commit'lenen tüm değişimleri al ve onları başka bir branch'ta tekrar oynat +*Public repo'ya push edilmiş commit'leri rebase etme* + +```bash +# Rebase experimentBranch onto master +# git rebase <basebranch> <topicbranch> +$ git rebase master experimentBranch +``` + +[Ek Okuma.](http://git-scm.com/book/en/Git-Branching-Rebasing) + +### reset (dikkat) + +Reset the current HEAD to the specified state. This allows you to undo merges, +pulls, commits, adds, and more. It's a great command but also dangerous if you +don't know what you are doing. + +HEAD'i belirtilen duruma resetle. Bu merge'leri, pull'ları, commit'leri, add'leri +ve daha fazlasını geriye almanı sağlar. Muhteşem bir komuttur ama aynı zamanda, ne +yaptığını bilmiyorsan, tehlikelidir. + +```bash +# Reset the staging area, to match the latest commit (leaves dir unchanged) +$ git reset + +# Reset the staging area, to match the latest commit, and overwrite working dir +$ git reset --hard + +# Moves the current branch tip to the specified commit (leaves dir unchanged) +# all changes still exist in the directory. +$ git reset 31f2bb1 + +# Moves the current branch tip backward to the specified commit +# and makes the working dir match (deletes uncommitted changes and all commits +# after the specified commit). +$ git reset --hard 31f2bb1 +``` + +### reflog (dikkat) + +Reflog, verilen zaman içinde,default olarak 90 gündür, yaptığın git komutlarını listeler. + +Bu sana beklemediğin şekilde yanlış giden komutları geriye çevirme şansı verir. +(mesela, eğer bir rebase uygulamanı kırdıysa) + +Şu şekilde yapıbilirsin: + +1. `git reflog` rebase için tüm git komutlarını listele + +``` +38b323f HEAD@{0}: rebase -i (finish): returning to refs/heads/feature/add_git_reflog +38b323f HEAD@{1}: rebase -i (pick): Clarify inc/dec operators +4fff859 HEAD@{2}: rebase -i (pick): Update java.html.markdown +34ed963 HEAD@{3}: rebase -i (pick): [yaml/en] Add more resources (#1666) +ed8ddf2 HEAD@{4}: rebase -i (pick): pythonstatcomp spanish translation (#1748) +2e6c386 HEAD@{5}: rebase -i (start): checkout 02fb96d +``` +2. Nereye reset'leyeceğini seç, şu durumda `2e6c386` veya `HEAD@{5}` +3. 'git reset --hard HEAD@{5}' bu repo'nu seçilen head'e eşitler +4. Rebase'e yeniden başlayabilir veya onu yalnız bırakabilirsin. + +[Ek Okuma.](https://git-scm.com/docs/git-reflog) + +### revert + +Revert commit'leri geri almada kullanılır. Projenin durumunu önceki bir noktaya +alan reset ile karıştırılmamalıdır. Revert, belirtilen commit'in tersine yeni bir +commit ekleyecektir. + +```bash +# Revert a specified commit +$ git revert <commit> +``` + +### rm + +git add'in tersine, git rm çalışma ağacından dosyaları kaldırır. + +```bash +# remove HelloWorld.c +$ git rm HelloWorld.c + +# Remove a file from a nested dir +$ git rm /pather/to/the/file/HelloWorld.c +``` + +## Daha Fazla Bilgi + +* [tryGit - Git'i öğrenmek için eğlenceli interaktif bir yol](http://try.github.io/levels/1/challenges/1) + +* [Git Dallanmayı Öğren - Git'i web üzerinde öğrenmek için en görsel ve interaktif yol](http://learngitbranching.js.org/) + +* [Udemy Git Tutorial: Kapsayıcı bir kılavuz](https://blog.udemy.com/git-tutorial-a-comprehensive-guide/) + +* [Git Immersion - Git'in temelinden başlayan bir tur](http://gitimmersion.com/) + +* [git-scm - Video Tutorial](http://git-scm.com/videos) + +* [git-scm - Dökümantasyon](http://git-scm.com/docs) + +* [Atlassian Git - Tutorial & Workflow](https://www.atlassian.com/git/) + +* [SalesForce Kopya Kağıdı](http://res.cloudinary.com/hy4kyit2a/image/upload/SF_git_cheatsheet.pdf) + +* [GitGuys](http://www.gitguys.com/) + +* [Git - Basit bir kılavuz](http://rogerdudler.github.io/git-guide/index.html) + +* [Pro Git](http://www.git-scm.com/book/en/v2) + +* [Yeni başlayanlar için Git ve Github](http://product.hubspot.com/blog/git-and-github-tutorial-for-beginners) diff --git a/tr-tr/markdown-tr.html.markdown b/tr-tr/markdown-tr.html.markdown index b8f11e39..6caba1da 100644 --- a/tr-tr/markdown-tr.html.markdown +++ b/tr-tr/markdown-tr.html.markdown @@ -11,7 +11,7 @@ filename: markdown-tr.md Markdown, 2004 yılında John Gruber tarafından oluşturuldu. Asıl amacı kolay okuma ve yazmayı sağlamakla beraber kolayca HTML (artık bir çok diğer formatlara) dönüşüm sağlamaktır. -```markdown +```md <!-- Markdown, HTML'i kapsar, yani her HTML dosyası geçerli bir Markdown dosyasıdır, bu demektir ki Markdown içerisinde HTML etiketleri kullanabiliriz, örneğin bu yorum elementi, ve markdown işleyicisinde etki etmezler. Fakat, markdown dosyası içerisinde HTML elementi oluşturursanız, diff --git a/tr-tr/python3-tr.html.markdown b/tr-tr/python3-tr.html.markdown index e53d5568..b78d517f 100644 --- a/tr-tr/python3-tr.html.markdown +++ b/tr-tr/python3-tr.html.markdown @@ -4,7 +4,7 @@ contributors: - ["Louie Dinh", "http://pythonpracticeprojects.com"] - ["Steven Basart", "http://github.com/xksteven"] - ["Andre Polykanine", "https://github.com/Oire"] - - ["Andre Polykanine", "https://github.com/Oire"] + - ["Batuhan Osman T.", "https://github.com/BTaskaya"] translators: - ["Eray AYDIN", "http://erayaydin.me/"] lang: tr-tr @@ -484,7 +484,7 @@ filter(lambda x: x > 5, [3, 4, 5, 6, 7]) # => [6, 7] # Sınıf oluşturmak için objeden alt sınıf oluşturacağız. -class Insan(obje): +class Insan(object): # Sınıf değeri. Sınıfın tüm nesneleri tarafından kullanılabilir tur = "H. sapiens" @@ -499,7 +499,7 @@ class Insan(obje): # Bir metot. Bütün metotlar ilk parametre olarak "self "alır. def soyle(self, mesaj): - return "{isim}: {mesaj}".format(isim=self.name, mesaj=mesaj) + return "{isim}: {mesaj}".format(isim=self.isim, mesaj=mesaj) # Bir sınıf metotu bütün nesnelere paylaştırılır # İlk parametre olarak sınıf alırlar diff --git a/typescript.html.markdown b/typescript.html.markdown index 44fd791a..9158f123 100644 --- a/typescript.html.markdown +++ b/typescript.html.markdown @@ -9,7 +9,7 @@ TypeScript is a language that aims at easing development of large scale applicat TypeScript adds common concepts such as classes, modules, interfaces, generics and (optional) static typing to JavaScript. It is a superset of JavaScript: all JavaScript code is valid TypeScript code so it can be added seamlessly to any project. The TypeScript compiler emits JavaScript. -This article will focus only on TypeScript extra syntax, as opposed to [JavaScript](javascript.html.markdown). +This article will focus only on TypeScript extra syntax, as opposed to [JavaScript](/docs/javascript). To test TypeScript's compiler, head to the [Playground] (http://www.typescriptlang.org/Playground) where you will be able to type code, have auto completion and directly see the emitted JavaScript. @@ -29,7 +29,7 @@ let notSure: any = 4; notSure = "maybe a string instead"; notSure = false; // okay, definitely a boolean -// Use const keyword for constant variables +// Use const keyword for constants const numLivesForCat = 9; numLivesForCat = 1; // Error @@ -113,6 +113,13 @@ class Point { static origin = new Point(0, 0); } +// Classes can be explicitly marked as implementing an interface. +// Any missing properties will then cause an error at compile-time. +class PointPerson implements Person { + name: string + move() {} +} + let p1 = new Point(10, 20); let p2 = new Point(25); //y will be 0 @@ -178,6 +185,37 @@ let greeting = `Hi ${name}, how are you?` let multiline = `This is an example of a multiline string`; +// READONLY: New Feature in TypeScript 3.1 +interface Person { + readonly name: string; + readonly age: number; +} + +var p1: Person = { name: "Tyrone", age: 42 }; +p1.age = 25; // Error, p1.x is read-only + +var p2 = { name: "John", age: 60 }; +var p3: Person = p2; // Ok, read-only alias for p2 +p3.x = 35; // Error, p3.x is read-only +p2.x = 45; // Ok, but also changes p3.x because of aliasing + +class Car { + readonly make: string; + readonly model: string; + readonly year = 2018; + + constructor() { + this.make = "Unknown Make"; // Assignment permitted in constructor + this.model = "Unknown Model"; // Assignment permitted in constructor + } +} + +let numbers: Array<number> = [0, 1, 2, 3, 4]; +let moreNumbers: ReadonlyArray<number> = numbers; +moreNumbers[5] = 5; // Error, elements are read-only +moreNumbers.push(5); // Error, no push method (because it mutates array) +moreNumbers.length = 3; // Error, length is read-only +numbers = moreNumbers; // Error, mutating methods are missing ``` ## Further Reading diff --git a/uk-ua/java-ua.html.markdown b/uk-ua/java-ua.html.markdown index 1d600400..40d56988 100644 --- a/uk-ua/java-ua.html.markdown +++ b/uk-ua/java-ua.html.markdown @@ -30,7 +30,7 @@ JavaDoc-коментар виглядає так. Використовуєтьс // Імпорт класу ArrayList з пакета java.util import java.util.ArrayList; -// Імпорт усіх класів з пакета java.security +// Імпорт усіх класів з пакета java.security import java.security.*; // Кожний .java файл містить один зовнішній публічний клас, ім’я якого співпадає @@ -99,13 +99,13 @@ public class LearnJava { // Примітка: Java не має беззнакових типів. - // Float — 32-бітне число з рухомою комою одиничної точності за стандартом IEEE 754 + // Float — 32-бітне число з рухомою комою одиничної точності за стандартом IEEE 754 // 2^-149 <= float <= (2-2^-23) * 2^127 float fooFloat = 234.5f; // f або F використовується для позначення того, що змінна має тип float; // інакше трактується як double. - // Double — 64-бітне число з рухомою комою подвійної точності за стандартом IEEE 754 + // Double — 64-бітне число з рухомою комою подвійної точності за стандартом IEEE 754 // 2^-1074 <= x <= (2-2^-52) * 2^1023 double fooDouble = 123.4; @@ -130,13 +130,13 @@ public class LearnJava { // байтів, операції над ними виконуються функціями, які мають клас BigInteger // // BigInteger можна ініціалізувати, використовуючи масив байтів чи рядок. - + BigInteger fooBigInteger = new BigInteger(fooByteArray); // BigDecimal — Незмінні знакові дробові числа довільної точності // - // BigDecimal складається з двох частин: цілого числа довільної точності + // BigDecimal складається з двох частин: цілого числа довільної точності // з немасштабованим значенням та 32-бітного масштабованого цілого числа // // BigDecimal дозволяє розробникам контролювати десяткове округлення. @@ -147,10 +147,10 @@ public class LearnJava { // чи немасштабованим значенням (BigInteger) і масштабованим значенням (int). BigDecimal fooBigDecimal = new BigDecimal(fooBigInteger, fooInt); - + // Для дотримання заданої точності рекомендується використовувати - // конструктор, який приймає String - + // конструктор, який приймає String + BigDecimal tenCents = new BigDecimal("0.1"); @@ -295,7 +295,7 @@ public class LearnJava { // Виконається 10 разів, fooFor 0->9 } System.out.println("Значення fooFor: " + fooFor); - + // Вихід із вкладеного циклу через мітку outer: for (int i = 0; i < 10; i++) { @@ -306,7 +306,7 @@ public class LearnJava { } } } - + // Цикл For Each // Призначений для перебору масивів та колекцій int[] fooList = {1, 2, 3, 4, 5, 6, 7, 8, 9}; @@ -318,7 +318,7 @@ public class LearnJava { // Оператор вибору Switch Case // Оператор вибору працює з типами даних byte, short, char, int. - // Також працює з переліками Enum, + // Також працює з переліками Enum, // класом String та класами-обгортками примітивних типів: // Character, Byte, Short та Integer. int month = 3; @@ -334,7 +334,7 @@ public class LearnJava { break; } System.out.println("Результат Switch Case: " + monthString); - + // Починаючи з Java 7 і далі, вибір рядкових змінних здійснюється так: String myAnswer = "можливо"; switch(myAnswer) { @@ -398,7 +398,7 @@ public class LearnJava { // toString повертає рядкове представлення об’єкту. System.out.println("Інформація про об’єкт trek: " + trek.toString()); - + // У Java немає синтаксису для явного створення статичних колекцій. // Це можна зробити так: @@ -554,7 +554,7 @@ public interface Digestible { // Можна створити клас, що реалізує обидва інтерфейси. public class Fruit implements Edible, Digestible { - + @Override public void eat() { // ... @@ -592,7 +592,7 @@ public class ExampleClass extends ExampleClassParent implements InterfaceOne, // Позначення класу як абстрактного означає, що оголошені у ньому методи мають // бути реалізовані у дочірніх класах. Подібно до інтерфейсів, не можна створити екземпляри // абстракних класів, але їх можна успадковувати. Нащадок зобов’язаний реалізувати всі абстрактні -// методи. на відміну від інтерфейсів, абстрактні класи можуть мати як визначені, +// методи. На відміну від інтерфейсів, абстрактні класи можуть мати як визначені, // так і абстрактні методи. Методи в інтерфейсах не мають тіла, // за винятком статичних методів, а змінні неявно мають модифікатор final, на відміну від // абстрактного класу. Абстрактні класи МОЖУТЬ мати метод «main». @@ -694,41 +694,41 @@ public abstract class Mammal() public enum Day { SUNDAY, MONDAY, TUESDAY, WEDNESDAY, - THURSDAY, FRIDAY, SATURDAY + THURSDAY, FRIDAY, SATURDAY } // Перелік Day можна використовувати так: public class EnumTest { - + // Змінна того же типу, що й перелік Day day; - + public EnumTest(Day day) { this.day = day; } - + public void tellItLikeItIs() { switch (day) { case MONDAY: - System.out.println("Понеділкі важкі."); + System.out.println("Понеділки важкі."); break; - + case FRIDAY: System.out.println("П’ятниці краще."); break; - - case SATURDAY: + + case SATURDAY: case SUNDAY: System.out.println("Вихідні найліпші."); break; - + default: System.out.println("Середина тижня так собі."); break; } } - + public static void main(String[] args) { EnumTest firstDay = new EnumTest(Day.MONDAY); firstDay.tellItLikeItIs(); // => Понеділки важкі. @@ -737,7 +737,7 @@ public class EnumTest { } } -// Переліки набагато потужніші, ніж тут показано. +// Переліки набагато потужніші, ніж тут показано. // Тіло переліків може містити методи та інші змінні. // Дивіться більше тут: https://docs.oracle.com/javase/tutorial/java/javaOO/enum.html diff --git a/uk-ua/javascript-ua.html.markdown b/uk-ua/javascript-ua.html.markdown index 397b1c5e..6a64a623 100644 --- a/uk-ua/javascript-ua.html.markdown +++ b/uk-ua/javascript-ua.html.markdown @@ -45,7 +45,7 @@ doStuff() 3; // = 3 1.5; // = 1.5 -// Деякі прості арифметичні операції працють так, як ми очікуємо. +// Деякі прості арифметичні операції працюють так, як ми очікуємо. 1 + 1; // = 2 0.1 + 0.2; // = 0.30000000000000004 (а деякі - ні) 8 - 1; // = 7 @@ -106,7 +106,7 @@ null == undefined; // = true // ... але приведення не виконується при === "5" === 5; // = false -null === undefined; // = false +null === undefined; // = false // ... приведення типів може призвести до дивних результатів 13 + !0; // 14 @@ -171,7 +171,7 @@ myArray[3] = "світ"; // Об’єкти в JavaScript схожі на словники або асоціативні масиви в інших мовах var myObj = {key1: "Hello", key2: "World"}; -// Ключі - це рядки, але лапки не обов’язкі, якщо ключ задовольняє +// Ключі - це рядки, але лапки не обов’язкові, якщо ключ задовольняє // правилам формування назв змінних. Значення можуть бути будь-яких типів. var myObj = {myKey: "myValue", "my other key": 4}; @@ -258,7 +258,7 @@ function myFunction(thing) { return thing.toUpperCase(); } myFunction("foo"); // = "FOO" - + // Зверніть увагу, що значення яке буде повернено, повинно починатися на тому ж // рядку, що і ключове слово return, інакше завжди буде повертатися значення undefined // через автоматичну вставку крапки з комою @@ -332,7 +332,7 @@ var myObj = { }; myObj.myFunc(); // = "Hello, world!" -// Функції, що прикріплені до об’єктів мають доступ до поточного об’єкта за +// Функції, що прикріплені до об’єктів мають доступ до поточного об’єкта за // допомогою ключового слова this. myObj = { myString: "Hello, world!", @@ -348,7 +348,7 @@ myObj.myFunc(); // = "Hello, world!" var myFunc = myObj.myFunc; myFunc(); // = undefined -// Функція може бути присвоєна іншому об’єкту. Тоді вона матиме доступ до +// Функція може бути присвоєна іншому об’єкту. Тоді вона матиме доступ до // цього об’єкта через this var myOtherFunc = function() { return this.myString.toUpperCase(); @@ -371,7 +371,7 @@ Math.min(42, 6, 27); // = 6 Math.min([42, 6, 27]); // = NaN (Ой-ой!) Math.min.apply(Math, [42, 6, 27]); // = 6 -// Але call і apply — тимчасові. Коли ми хочемо зв’язати функцію і об’єкт +// Але call і apply — тимчасові. Коли ми хочемо зв’язати функцію і об’єкт // використовують bind var boundFunc = anotherFunc.bind(myObj); boundFunc(" Hello!"); // = "Hello world, Hello!" @@ -475,7 +475,7 @@ if (Object.create === undefined) { // не перезаписуємо метод // Створюємо правильний конструктор з правильним прототипом var Constructor = function(){}; Constructor.prototype = proto; - + return new Constructor(); } } diff --git a/uk-ua/python-ua.html.markdown b/uk-ua/python-ua.html.markdown new file mode 100644 index 00000000..2406678d --- /dev/null +++ b/uk-ua/python-ua.html.markdown @@ -0,0 +1,818 @@ +--- +language: python +lang: uk-ua +contributors: + - ["Louie Dinh", "http://ldinh.ca"] + - ["Amin Bandali", "https://aminb.org"] + - ["Andre Polykanine", "https://github.com/Oire"] + - ["evuez", "http://github.com/evuez"] + - ["asyne", "https://github.com/justblah"] + - ["habi", "http://github.com/habi"] +translators: + - ["Oleg Gromyak", "https://github.com/ogroleg"] +filename: learnpython-ua.py +--- + +Мову Python створив Гвідо ван Россум на початку 90-х. Наразі це одна з +найбільш популярних мов. Я закохався у Python завдяки простому і зрозумілому +синтаксису. Це майже як виконуваний псевдокод. + +З вдячністю чекаю ваших відгуків: [@louiedinh](http://twitter.com/louiedinh) +або louiedinh [at] [поштовий сервіс від Google] + +Примітка: Ця стаття стосується Python 2.7, проте має працювати і +у інших версіях Python 2.x. Python 2.7 підходить до кінця свого терміну, +його підтримку припинять у 2020, тож наразі краще починати вивчення Python +з версії 3.x. +Аби вивчити Python 3.x, звертайтесь до статті по Python 3. + +```python +# Однорядкові коментарі починаються з символу решітки. + +""" Текст, що займає декілька рядків, + може бути записаний з використанням 3 знаків " і + зазвичай використовується у якості + вбудованої документації +""" + +#################################################### +## 1. Примітивні типи даних та оператори +#################################################### + +# У вас є числа +3 # => 3 + +# Математика працює досить передбачувано +1 + 1 # => 2 +8 - 1 # => 7 +10 * 2 # => 20 +35 / 5 # => 7 + +# А ось з діленням все трохи складніше. Воно цілочисельне і результат +# автоматично округлюється у меншу сторону. +5 / 2 # => 2 + +# Аби правильно ділити, спершу варто дізнатися про числа +# з плаваючою комою. +2.0 # Це число з плаваючою комою +11.0 / 4.0 # => 2.75 ох... Так набагато краще + +# Результат цілочисельного ділення округлюється у меншу сторону +# як для додатніх, так і для від'ємних чисел. +5 // 3 # => 1 +5.0 // 3.0 # => 1.0 # Працює і для чисел з плаваючою комою +-5 // 3 # => -2 +-5.0 // 3.0 # => -2.0 + +# Зверніть увагу, що ми також можемо імпортувати модуль для ділення, +# див. розділ Модулі +# аби звичне ділення працювало при використанні лише '/'. +from __future__ import division + +11 / 4 # => 2.75 ...звичне ділення +11 // 4 # => 2 ...цілочисельне ділення + +# Залишок від ділення +7 % 3 # => 1 + +# Піднесення до степеня +2 ** 4 # => 16 + +# Приорітет операцій вказується дужками +(1 + 3) * 2 # => 8 + +# Логічні оператори +# Зверніть увагу: ключові слова «and» і «or» чутливі до регістру букв +True and False # => False +False or True # => True + +# Завважте, що логічні оператори також використовуються і з цілими числами +0 and 2 # => 0 +-5 or 0 # => -5 +0 == False # => True +2 == True # => False +1 == True # => True + +# Для заперечення використовується not +not True # => False +not False # => True + +# Рівність — це == +1 == 1 # => True +2 == 1 # => False + +# Нерівність — це != +1 != 1 # => False +2 != 1 # => True + +# Ще трохи порівнянь +1 < 10 # => True +1 > 10 # => False +2 <= 2 # => True +2 >= 2 # => True + +# Порівняння можуть бути записані ланцюжком! +1 < 2 < 3 # => True +2 < 3 < 2 # => False + +# Рядки позначаються символом " або ' +"Це рядок." +'Це теж рядок.' + +# І рядки також можна додавати! +"Привіт " + "світ!" # => "Привіт світ!" +# Рядки можна додавати і без '+' +"Привіт " "світ!" # => "Привіт світ!" + +# ... або множити +"Привіт" * 3 # => "ПривітПривітПривіт" + +# З рядком можна працювати як зі списком символів +"Це рядок"[0] # => 'Ц' + +# Ви можете дізнатися довжину рядка +len("Це рядок") # => 8 + +# Символ % використовується для форматування рядків, наприклад: +"%s можуть бути %s" % ("рядки", "інтерпольовані") + +# Новий спосіб форматування рядків — використання методу format. +# Це бажаний спосіб. +"{} є {}".format("Це", "заповнювач") +"{0} можуть бути {1}".format("рядки", "форматовані") +# Якщо ви не хочете рахувати, то можете скористатися ключовими словами. +"{name} хоче з'істи {food}".format(name="Боб", food="лазанью") + +# None - це об'єкт +None # => None + +# Не використовуйте оператор рівності '=='' для порівняння +# об'єктів з None. Використовуйте для цього «is» +"etc" is None # => False +None is None # => True + +# Оператор 'is' перевіряє ідентичність об'єктів. Він не +# дуже корисний при роботі з примітивними типами, проте +# незамінний при роботі з об'єктами. + +# None, 0 і порожні рядки/списки рівні False. +# Всі інші значення рівні True +bool(0) # => False +bool("") # => False + + +#################################################### +## 2. Змінні та колекції +#################################################### + +# В Python є оператор print +print "Я Python. Приємно познайомитись!" # => Я Python. Приємно познайомитись! + +# Отримати дані з консолі просто +input_string_var = raw_input( + "Введіть щось: ") # Повертає дані у вигляді рядка +input_var = input("Введіть щось: ") # Працює з даними як з кодом на python +# Застереження: будьте обережні при використанні методу input() + +# Оголошувати змінні перед ініціалізацією не потрібно. +some_var = 5 # За угодою використовується нижній_регістр_з_підкресленнями +some_var # => 5 + +# При спробі доступу до неініціалізованої змінної +# виникне виняткова ситуація. +# Див. розділ Потік управління, аби дізнатись про винятки більше. +some_other_var # Помилка в імені + +# if може використовуватися як вираз +# Такий запис еквівалентний тернарному оператору '?:' у мові С +"yahoo!" if 3 > 2 else 2 # => "yahoo!" + +# Списки зберігають послідовності +li = [] +# Можна одразу створити заповнений список +other_li = [4, 5, 6] + +# Об'єкти додаються у кінець списку за допомогою методу append +li.append(1) # li тепер дорівнює [1] +li.append(2) # li тепер дорівнює [1, 2] +li.append(4) # li тепер дорівнює [1, 2, 4] +li.append(3) # li тепер дорівнює [1, 2, 4, 3] +# І видаляються з кінця методом pop +li.pop() # => повертає 3 і li стає рівним [1, 2, 4] +# Повернемо елемент назад +li.append(3) # li тепер знову дорівнює [1, 2, 4, 3] + +# Поводьтесь зі списком як зі звичайним масивом +li[0] # => 1 +# Присвоюйте нові значення вже ініціалізованим індексам за допомогою = +li[0] = 42 +li[0] # => 42 +li[0] = 1 # Зверніть увагу: повертаємось до попереднього значення +# Звертаємось до останнього елементу +li[-1] # => 3 + +# Спроба вийти за границі масиву призводить до помилки в індексі +li[4] # помилка в індексі + +# Можна звертатися до діапазону, використовуючи так звані зрізи +# (Для тих, хто любить математику: це називається замкнуто-відкритий інтервал). +li[1:3] # => [2, 4] +# Опускаємо початок +li[2:] # => [4, 3] +# Опускаємо кінець +li[:3] # => [1, 2, 4] +# Вибираємо кожен другий елемент +li[::2] # => [1, 4] +# Перевертаємо список +li[::-1] # => [3, 4, 2, 1] +# Використовуйте суміш вищеназваного для більш складних зрізів +# li[початок:кінець:крок] + +# Видаляємо довільні елементи зі списку оператором del +del li[2] # li тепер [1, 2, 3] + +# Ви можете додавати списки +li + other_li # => [1, 2, 3, 4, 5, 6] +# Зверніть увагу: значення li та other_li при цьому не змінились. + +# Поєднувати списки можна за допомогою методу extend +li.extend(other_li) # Тепер li дорівнює [1, 2, 3, 4, 5, 6] + +# Видалити перше входження значення +li.remove(2) # Тепер li дорівнює [1, 3, 4, 5, 6] +li.remove(2) # Помилка значення, оскільки у списку li немає 2 + +# Вставити елемент за вказаним індексом +li.insert(1, 2) # li знову дорівнює [1, 2, 3, 4, 5, 6] + +# Отримати індекс першого знайденого елементу +li.index(2) # => 1 +li.index(7) # Помилка значення, оскільки у списку li немає 7 + +# Перевірити елемент на входження у список можна оператором in +1 in li # => True + +# Довжина списку обчислюється за допомогою функції len +len(li) # => 6 + +# Кортежі схожі на списки, лише незмінні +tup = (1, 2, 3) +tup[0] # => 1 +tup[0] = 3 # Виникає помилка типу + +# Все те ж саме можна робити і з кортежами +len(tup) # => 3 +tup + (4, 5, 6) # => (1, 2, 3, 4, 5, 6) +tup[:2] # => (1, 2) +2 in tup # => True + +# Ви можете розпаковувати кортежі (або списки) у змінні +a, b, c = (1, 2, 3) # a == 1, b == 2 и c == 3 +d, e, f = 4, 5, 6 # дужки можна опустити +# Кортежі створюються за замовчуванням, якщо дужки опущено +g = 4, 5, 6 # => (4, 5, 6) +# Дивіться, як легко обміняти значення двох змінних +e, d = d, e # тепер d дорівнює 5, а e дорівнює 4 + +# Словники містять асоціативні масиви +empty_dict = {} +# Ось так описується попередньо заповнений словник +filled_dict = {"one": 1, "two": 2, "three": 3} + +# Значення можна отримати так само, як і зі списку +filled_dict["one"] # => 1 + +# Можна отримати всі ключі у виді списку за допомогою методу keys +filled_dict.keys() # => ["three", "two", "one"] +# Примітка: збереження порядку ключів у словників не гарантується +# Ваші результати можуть не співпадати з цими. + +# Можна отримати і всі значення у вигляді списку, використовуйте метод values +filled_dict.values() # => [3, 2, 1] +# Те ж зауваження щодо порядку ключів діє і тут + +# Отримуйте всі пари ключ-значення у вигляді списку кортежів +# за допомогою "items()" +filled_dict.items() # => [("one", 1), ("two", 2), ("three", 3)] + +# За допомогою оператору in можна перевіряти ключі на входження у словник +"one" in filled_dict # => True +1 in filled_dict # => False + +# Спроба отримати значення за неіснуючим ключем викине помилку ключа +filled_dict["four"] # помилка ключа + +# Аби уникнути цього, використовуйте метод get() +filled_dict.get("one") # => 1 +filled_dict.get("four") # => None +# Метод get також приймає аргумент за замовчуванням, значення якого буде +# повернуто при відсутності вказаного ключа +filled_dict.get("one", 4) # => 1 +filled_dict.get("four", 4) # => 4 +# Зверніть увагу, що filled_dict.get("four") все ще => None +# (get не встановлює значення елементу словника) + +# Присвоюйте значення ключам так само, як і в списках +filled_dict["four"] = 4 # тепер filled_dict["four"] => 4 + +# Метод setdefault() вставляє пару ключ-значення лише +# за відсутності такого ключа +filled_dict.setdefault("five", 5) # filled_dict["five"] повертає 5 +filled_dict.setdefault("five", 6) # filled_dict["five"] все ще повертає 5 + + +# Множини містять... ну, загалом, множини +# (які схожі на списки, проте в них не може бути елементів, які повторюються) +empty_set = set() +# Ініціалізація множини набором значень +some_set = set([1,2,2,3,4]) # some_set тепер дорівнює set([1, 2, 3, 4]) + +# Порядок не гарантовано, хоча інколи множини виглядають відсортованими +another_set = set([4, 3, 2, 2, 1]) # another_set тепер set([1, 2, 3, 4]) + +# Починаючи з Python 2.7, ви можете використовувати {}, аби створити множину +filled_set = {1, 2, 2, 3, 4} # => {1, 2, 3, 4} + +# Додавання нових елементів у множину +filled_set.add(5) # filled_set тепер дорівнює {1, 2, 3, 4, 5} + +# Перетин множин: & +other_set = {3, 4, 5, 6} +filled_set & other_set # => {3, 4, 5} + +# Об'єднання множин: | +filled_set | other_set # => {1, 2, 3, 4, 5, 6} + +# Різниця множин: - +{1,2,3,4} - {2,3,5} # => {1, 4} + +# Симетрична різниця множин: ^ +{1, 2, 3, 4} ^ {2, 3, 5} # => {1, 4, 5} + +# Перевіряємо чи множина зліва є надмножиною множини справа +{1, 2} >= {1, 2, 3} # => False + +# Перевіряємо чи множина зліва є підмножиною множини справа +{1, 2} <= {1, 2, 3} # => True + +# Перевірка на входження у множину: in +2 in filled_set # => True +10 in filled_set # => False + + +#################################################### +## 3. Потік управління +#################################################### + +# Для початку створимо змінну +some_var = 5 + +# Так виглядає вираз if. Відступи у python дуже важливі! +# результат: «some_var менше, ніж 10» +if some_var > 10: + print("some_var набагато більше, ніж 10.") +elif some_var < 10: # Вираз elif є необов'язковим. + print("some_var менше, ніж 10.") +else: # Це теж необов'язково. + print("some_var дорівнює 10.") + + +""" +Цикли For проходять по спискам + +Результат: + собака — це ссавець + кішка — це ссавець + миша — це ссавець +""" +for animal in ["собака", "кішка", "миша"]: + # Можете використовувати оператор {0} для інтерполяції форматованих рядків + print "{0} — це ссавець".format(animal) + +""" +"range(число)" повертає список чисел +від нуля до заданого числа +Друкує: + 0 + 1 + 2 + 3 +""" +for i in range(4): + print(i) +""" +"range(нижня_границя, верхня_границя)" повертає список чисел +від нижньої границі до верхньої +Друкує: + 4 + 5 + 6 + 7 +""" +for i in range(4, 8): + print i + +""" +Цикли while продовжуються до тих пір, поки вказана умова не стане хибною. +Друкує: + 0 + 1 + 2 + 3 +""" +x = 0 +while x < 4: + print(x) + x += 1 # Короткий запис для x = x + 1 + +# Обробляйте винятки блоками try/except + +# Працює у Python 2.6 і вище: +try: + # Аби створити виняток, використовується raise + raise IndexError("Помилка у індексі!") +except IndexError as e: + pass # pass — оператор, який нічого не робить. Зазвичай тут відбувається + # відновлення після помилки. +except (TypeError, NameError): + pass # Винятки можна обробляти групами, якщо потрібно. +else: # Необов'язковий вираз. Має слідувати за останнім блоком except + print("Все добре!") # Виконається лише якщо не було ніяких винятків +finally: # Виконується у будь-якому випадку + print "Тут ми можемо звільнити ресурси" + +# Замість try/finally для звільнення ресурсів +# ви можете використовувати вираз with +with open("myfile.txt") as f: + for line in f: + print line + + +#################################################### +## 4. Функції +#################################################### + +# Використовуйте def для створення нових функцій +def add(x, y): + print "x дорівнює {0}, а y дорівнює {1}".format(x, y) + return x + y # Повертайте результат за допомогою ключового слова return + + +# Виклик функції з аргументами +add(5, 6) # => друкує «x дорівнює 5, а y дорівнює 6» і повертає 11 + +# Інший спосіб виклику функції — виклик з іменованими аргументами +add(y=6, x=5) # Іменовані аргументи можна вказувати у будь-якому порядку + + +# Ви можете визначити функцію, яка приймає змінну кількість аргументів, +# які будуть інтерпретовані як кортеж, за допомогою * +def varargs(*args): + return args + + +varargs(1, 2, 3) # => (1,2,3) + + +# А також можете визначити функцію, яка приймає змінне число +# іменованих аргументів, котрі будуть інтерпретовані як словник, за допомогою ** +def keyword_args(**kwargs): + return kwargs + + +# Давайте подивимось що з цього вийде +keyword_args(big="foot", loch="ness") # => {"big": "foot", "loch": "ness"} + +# Якщо хочете, можете використовувати обидва способи одночасно +def all_the_args(*args, **kwargs): + print(args) + print(kwargs) + + +""" +all_the_args(1, 2, a=3, b=4) друкує: + (1, 2) + {"a": 3, "b": 4} +""" + +# Коли викликаєте функції, то можете зробити навпаки! +# Використовуйте символ * аби розпакувати позиційні аргументи і +# ** для іменованих аргументів +args = (1, 2, 3, 4) +kwargs = {"a": 3, "b": 4} +all_the_args(*args) # еквівалентно foo(1, 2, 3, 4) +all_the_args(**kwargs) # еквівалентно foo(a=3, b=4) +all_the_args(*args, **kwargs) # еквівалентно foo(1, 2, 3, 4, a=3, b=4) + +# ви можете передавати довільне число позиційних або іменованих аргументів +# іншим функціям, які їх приймають, розпаковуючи за допомогою +# * або ** відповідно +def pass_all_the_args(*args, **kwargs): + all_the_args(*args, **kwargs) + print varargs(*args) + print keyword_args(**kwargs) + + +# Область визначення функцій +x = 5 + + +def set_x(num): + # Локальна змінна x - не те ж саме, що глобальна змінна x + x = num # => 43 + print x # => 43 + + +def set_global_x(num): + global x + print x # => 5 + x = num # глобальна змінна x тепер дорівнює 6 + print x # => 6 + + +set_x(43) +set_global_x(6) + +# В Python функції є об'єктами першого класу +def create_adder(x): + def adder(y): + return x + y + + return adder + + +add_10 = create_adder(10) +add_10(3) # => 13 + +# Також є і анонімні функції +(lambda x: x > 2)(3) # => True +(lambda x, y: x ** 2 + y ** 2)(2, 1) # => 5 + +# Присутні вбудовані функції вищого порядку +map(add_10, [1, 2, 3]) # => [11, 12, 13] +map(max, [1, 2, 3], [4, 2, 1]) # => [4, 2, 3] + +filter(lambda x: x > 5, [3, 4, 5, 6, 7]) # => [6, 7] + +# Для зручного відображення і фільтрації можна використовувати +# включення у вигляді списків +[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] +[x for x in [3, 4, 5, 6, 7] if x > 5] # => [6, 7] + +# Ви також можете скористатися включеннями множин та словників +{x for x in 'abcddeef' if x in 'abc'} # => {'a', 'b', 'c'} +{x: x ** 2 for x in range(5)} # => {0: 0, 1: 1, 2: 4, 3: 9, 4: 16} + + +#################################################### +## 5. Класи +#################################################### + +# Аби отримати клас, ми наслідуємо object. +class Human(object): + # Атрибут класу. Він розділяється всіма екземплярами цього класу. + species = "H. sapiens" + + # Звичайний конструктор, буде викликаний при ініціалізації екземпляру класу + # Зверніть увагу, що подвійне підкреслення на початку та наприкінці імені + # використовується для позначення об'єктів та атрибутів, + # які використовуються Python, але знаходяться у просторах імен, + # якими керує користувач. Не варто вигадувати для них імена самостійно. + def __init__(self, name): + # Присвоєння значення аргумента атрибуту класу name + self.name = name + + # Ініціалізуємо властивість + self.age = 0 + + # Метод екземпляру. Всі методи приймають self у якості першого аргументу + def say(self, msg): + return "%s: %s" % (self.name, msg) + + # Методи класу розділяються між усіма екземплярами + # Вони викликаються з вказанням викликаючого класу + # у якості першого аргументу + @classmethod + def get_species(cls): + return cls.species + + # Статичний метод викликається без посилання на клас або екземпляр + @staticmethod + def grunt(): + return "*grunt*" + + # Властивість. + # Перетворює метод age() в атрибут тільки для читання + # з таким же ім'ям. + @property + def age(self): + return self._age + + # Це дозволяє змінювати значення властивості + @age.setter + def age(self, age): + self._age = age + + # Це дозволяє видаляти властивість + @age.deleter + def age(self): + del self._age + + +# Створюємо екземпляр класу +i = Human(name="Данило") +print(i.say("привіт")) # Друкує: «Данило: привіт» + +j = Human("Меланка") +print(j.say("Привіт")) # Друкує: «Меланка: привіт» + +# Виклик методу класу +i.get_species() # => "H. sapiens" + +# Зміна розділюваного атрибуту +Human.species = "H. neanderthalensis" +i.get_species() # => "H. neanderthalensis" +j.get_species() # => "H. neanderthalensis" + +# Виклик статичного методу +Human.grunt() # => "*grunt*" + +# Оновлюємо властивість +i.age = 42 + +# Отримуємо значення +i.age # => 42 + +# Видаляємо властивість +del i.age +i.age # => виникає помилка атрибуту + +#################################################### +## 6. Модулі +#################################################### + +# Ви можете імпортувати модулі +import math + +print(math.sqrt(16)) # => 4 + +# Ви можете імпортувати окремі функції з модуля +from math import ceil, floor + +print(ceil(3.7)) # => 4.0 +print(floor(3.7)) # => 3.0 + +# Можете імпортувати всі функції модуля. +# Попередження: краще так не робіть +from math import * + +# Можете скорочувати імена модулів +import math as m + +math.sqrt(16) == m.sqrt(16) # => True +# Ви також можете переконатися, що функції еквівалентні +from math import sqrt + +math.sqrt == m.sqrt == sqrt # => True + +# Модулі в Python — це звичайні Python-файли. Ви +# можете писати свої модулі та імпортувати їх. Назва +# модуля співпадає з назвою файлу. + +# Ви можете дізнатися, які функції та атрибути визначені +# в модулі +import math + +dir(math) + + +# Якщо у вас є Python скрипт з назвою math.py у тій же папці, що +# і ваш поточний скрипт, то файл math.py +# може бути завантажено замість вбудованого у Python модуля. +# Так трапляється, оскільки локальна папка має перевагу +# над вбудованими у Python бібліотеками. + +#################################################### +## 7. Додатково +#################################################### + +# Генератори +# Генератор "генерує" значення тоді, коли вони запитуються, замість того, +# щоб зберігати все одразу + +# Метод нижче (*НЕ* генератор) подвоює всі значення і зберігає їх +# в `double_arr`. При великих розмірах може знадобитися багато ресурсів! +def double_numbers(iterable): + double_arr = [] + for i in iterable: + double_arr.append(i + i) + return double_arr + + +# Тут ми спочатку подвоюємо всі значення, потім повертаємо їх, +# аби перевірити умову +for value in double_numbers(range(1000000)): # `test_non_generator` + print value + if value > 5: + break + + +# Натомість ми можемо скористатися генератором, аби "згенерувати" +# подвійне значення, як тільки воно буде запитане +def double_numbers_generator(iterable): + for i in iterable: + yield i + i + + +# Той самий код, але вже з генератором, тепер дозволяє нам пройтися по +# значенням і подвоювати їх одне за одним якраз тоді, коли вони обробляються +# за нашою логікою, одне за одним. А як тільки ми бачимо, що value > 5, ми +# виходимо з циклу і більше не подвоюємо більшість значень, +# які отримали на вхід (НАБАГАТО ШВИДШЕ!) +for value in double_numbers_generator(xrange(1000000)): # `test_generator` + print value + if value > 5: + break + +# Між іншим: ви помітили використання `range` у `test_non_generator` і +# `xrange` у `test_generator`? +# Як `double_numbers_generator` є версією-генератором `double_numbers`, так +# і `xrange` є аналогом `range`, але у вигляді генератора. +# `range` поверне нам масив з 1000000 значень +# `xrange`, у свою чергу, згенерує 1000000 значень для нас тоді, +# коли ми їх запитуємо / будемо проходитись по ним. + +# Аналогічно включенням у вигляді списків, ви можете створювати включення +# у вигляді генераторів. +values = (-x for x in [1, 2, 3, 4, 5]) +for x in values: + print(x) # друкує -1 -2 -3 -4 -5 + +# Включення у вигляді генератора можна явно перетворити у список +values = (-x for x in [1, 2, 3, 4, 5]) +gen_to_list = list(values) +print(gen_to_list) # => [-1, -2, -3, -4, -5] + +# Декоратори +# Декоратор – це функція вищого порядку, яка приймає та повертає функцію. +# Простий приклад використання – декоратор add_apples додає елемент 'Apple' в +# список fruits, який повертає цільова функція get_fruits. +def add_apples(func): + def get_fruits(): + fruits = func() + fruits.append('Apple') + return fruits + return get_fruits + +@add_apples +def get_fruits(): + return ['Banana', 'Mango', 'Orange'] + +# Друкуємо список разом з елементом 'Apple', який знаходиться в ньому: +# Banana, Mango, Orange, Apple +print ', '.join(get_fruits()) + +# У цьому прикладі beg обертає say +# Beg викличе say. Якщо say_please дорівнюватиме True, то повідомлення, +# що повертається, буде змінено. +from functools import wraps + + +def beg(target_function): + @wraps(target_function) + def wrapper(*args, **kwargs): + msg, say_please = target_function(*args, **kwargs) + if say_please: + return "{} {}".format(msg, "Будь ласка! Я бідний :(") + return msg + + return wrapper + + +@beg +def say(say_please=False): + msg = "Ви можете купити мені пива?" + return msg, say_please + + +print say() # Ви можете купити мені пива? +print say(say_please=True) # Ви можете купити мені пива? Будь ласка! Я бідний :( +``` + +## Готові до більшого? + +### Безкоштовні онлайн-матеріали + +* [Learn Python The Hard Way](http://learnpythonthehardway.org/book/) +* [Dive Into Python](http://www.diveintopython.net/) +* [Официальная документация](http://docs.python.org/2.6/) +* [Hitchhiker's Guide to Python](http://docs.python-guide.org/en/latest/) +* [Python Module of the Week](http://pymotw.com/2/) +* [A Crash Course in Python for Scientists](http://nbviewer.ipython.org/5920182) + +### Платні + +* [Programming Python](http://www.amazon.com/gp/product/0596158106/ref=as_li_qf_sp_asin_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596158106&linkCode=as2&tag=homebits04-20) +* [Dive Into Python](http://www.amazon.com/gp/product/1441413022/ref=as_li_tf_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1441413022&linkCode=as2&tag=homebits04-20) +* [Python Essential Reference](http://www.amazon.com/gp/product/0672329786/ref=as_li_tf_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0672329786&linkCode=as2&tag=homebits04-20) + diff --git a/vi-vn/less-vi.html.markdown b/vi-vn/less-vi.html.markdown new file mode 100644 index 00000000..594ccc31 --- /dev/null +++ b/vi-vn/less-vi.html.markdown @@ -0,0 +1,395 @@ +--- +language: less +contributors: + - ["Saravanan Ganesh", "http://srrvnn.me"] +translators: + - ["Thanh Duy Phan", "https://github.com/thanhpd"] +filename: learnless-vi.less +lang: vi-vn +--- + +Less là một CSS pre-processor (bộ tiền xử lí CSS), nó thêm các tính năng như biến (variable), lồng (nesting), mixin và nhiều thứ khác. Less cùng với các CSS pre-processor khác như [Sass](http://sass-lang.com/) giúp lập trình viên viết được các đoạn CSS bảo trì được và không bị lặp lại (DRY - Don't Repeat Yourself). + +```css + + +// Comment (chú thích) một dòng sẽ bị xóa khi Less được biên dịch thành CSS + +/* Comment trên nhiều dòng sẽ được giữ lại */ + + + +/* Biến +==============================*/ + + +/* Ta có thể lưu giá trị CSS (ví dụ như color) vào một biến. + Sử dụng ký hiệu '@' để khai báo một biến. */ + +@primary-color: #a3a4ff; +@secondary-color: #51527f; +@body-font: 'Roboto', sans-serif; + +/* Sau khi khai báo biến, ta có thể sử dụng nó ở trong tệp stylesheet. + Nhờ sử dụng biến ta chỉ cần thay đổi một lần + tại 1 nơi để thay đổi tất cả những đoạn sử dụng biến */ + +body { + background-color: @primary-color; + color: @secondary-color; + font-family: @body-font; +} + +/* Đoạn code trên sẽ được biên dịch thành: */ + +body { + background-color: #a3a4ff; + color: #51527F; + font-family: 'Roboto', sans-serif; +} + + +/* Cách sử dụng này giúp ta dễ dàng bảo trì hơn + việc phải đổi giá trị mỗi lần nó xuất hiện + trong tệp stylesheet. */ + + + +/* Mixins +==============================*/ + + +/* Nếu đang viết một đoạn code cho nhiều hơn một + element, ta có thể sử dụng lại nó dễ dàng. */ + +.center { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; +} + +/* Ta có thể dùng mixin chỉ bằng việc thêm selector + vào trong nội dung style của element khác */ + +div { + .center; + background-color: @primary-color; +} + +/* Đoạn code trên sẽ được biên dịch thành: */ + +.center { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; +} +div { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; + background-color: #a3a4ff; +} + +/* Ta có thể ngăn không cho code mixin được biên dịch + bằng cách thêm cặp ngoặc tròn đằng sau selector */ + +.center() { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; +} + +div { + .center; + background-color: @primary-color; +} + +/* Đoạn code trên sẽ được biên dịch thành: */ +div { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; + background-color: #a3a4ff; +} + + + +/* Nesting - Lồng +==============================*/ + + +/* Less cho phép ta có thể lồng selector bên trong selector */ + +ul { + list-style-type: none; + margin-top: 2em; + + li { + background-color: #f00; + } +} + +/* Selector bắt đầu bằng ký tự '&' sẽ thay thế ký tự '&' + với selector cha. */ +/* Ta cũng có thể lồng các pseudo-class với nhau */ +/* Nên lưu ý không nên lồng quá nhiều lần sẽ làm code kém tính bảo trì. + Kinh nghiệm cho thấy không nên lồng quá 3 lần. + Ví dụ: */ + +ul { + list-style-type: none; + margin-top: 2em; + + li { + background-color: red; + + &:hover { + background-color: blue; + } + + a { + color: white; + } + } +} + +/* Biên dịch thành: */ + +ul { + list-style-type: none; + margin-top: 2em; +} + +ul li { + background-color: red; +} + +ul li:hover { + background-color: blue; +} + +ul li a { + color: white; +} + + + +/* Function +==============================*/ + + +/* Less cung cấp các function có thể được dùng để hoàn thành + các công việc khác nhau. */ + +/* Function được gọi sử dụng tên của nó và truyền vào + các tham số được yêu cầu. */ + +body { + width: round(10.25px); +} + +.header { + background-color: lighten(#000, 0.5); +} + +.footer { + background-color: fadeout(#000, 0.25) +} + +/* Biên dịch thành: */ + +body { + width: 10px; +} + +.header { + background-color: #010101; +} + +.footer { + background-color: rgba(0, 0, 0, 0.75); +} + +/* Ta có thể định nghĩa function mới. + Function khá tương tự với mixin bởi chúng đều có thể được tái + sử dụng. Khi lựa chọn giữa việc sử dụng function hay mixin, + hãy nhớ mixin được tối ưu cho việc tạo ra CSS trong khi + function sẽ được sử dụng tốt hơn cho logic sẽ được sử dụng + xuyên suốt Less code. Các ví dụ trong phần 'Toán tử' là ứng cử viên + sáng giá cho việc dùng function có thể tái sử dụng được. +*/ + +/* Function này tính giá trị trung bình của hai số: */ +.average(@x, @y) { + @average-result: ((@x + @y) / 2); +} + +div { + .average(16px, 50px); // gọi mixin + padding: @average-result; // sử dụng giá trị trả về của mixin +} + +/* Biên dịch thành: */ + +div { + padding: 33px; +} + + + +/* Mở rộng (Thừa kế) +==============================*/ + + +/* Mở rộng là cách để chia sẻ thuộc tính của một selector cho selector khác */ + +.display { + height: 50px; +} + +.display-success { + &:extend(.display); + border-color: #22df56; +} + +/* Biên dịch thành: */ +.display, +.display-success { + height: 50px; +} +.display-success { + border-color: #22df56; +} + +/* Nên mở rộng một khai báo CSS có trước thay vì tạo một mixin mới + bởi cách nó nhóm các lớp có chung một style gốc. + Nếu thực hiện với mixin, các thuộc tính sẽ bị trùng lặp + cho mỗi khai báo có sử dụng mixin. Mặc dù không ảnh hưởng đến luồng công việc nhưng nó + tạo ra các đoạn code CSS thừa sau khi được biên dịch. +*/ + + +/* Partials and Imports - Chia nhỏ và nhập vào +==============================*/ + + +/* Less cho phép ta tạo các partial file (tệp con). + Sử dụng nó giúp ta có thể tổ chức code Less theo mô-đun có hệ thống. + Các tệp con thường bắt đầu với ký tự gạch dưới '_', vd: _reset.less + và được nhập vào file Less chính để được biên dịch thành CSS */ + +/* Quan sát ví dụ sau, ta sẽ đặt đoạn code dưới đây vào tệp tên là _reset.less */ + +html, +body, +ul, +ol { + margin: 0; + padding: 0; +} + +/* Less cung cấp cú pháp @import cho phép nhập các partial vào một file. + Cú pháp này trong Less sẽ nhập các file và kết hợp chúng lại với + code CSS được sinh ra. Nó khác với cú pháp @import của CSS, + bản chất là tạo một HTTP request mới để tải về tệp tin được yêu cầu. */ + +@import 'reset'; + +body { + font-size: 16px; + font-family: Helvetica, Arial, Sans-serif; +} + +/* Biên dịch thành: */ + +html, body, ul, ol { + margin: 0; + padding: 0; +} + +body { + font-size: 16px; + font-family: Helvetica, Arial, Sans-serif; +} + + + +/* Toán học +==============================*/ + + +/* Less cung cấp các toán tử sau: +, -, *, / và %. + Điều này rất có ích cho việc tính toán giá trị trực tiếp + trong tệp Less thay vì phải tính toán thủ công. + Dưới đây là ví dụ về việc tạo một khung thiết kế đơn giản có hai cột. */ + +@content-area: 960px; +@main-content: 600px; +@sidebar-content: 300px; + +@main-size: @main-content / @content-area * 100%; +@sidebar-size: @sidebar-content / @content-area * 100%; +@gutter: 100% - (@main-size + @sidebar-size); + +body { + width: 100%; +} + +.main-content { + width: @main-size; +} + +.sidebar { + width: @sidebar-size; +} + +.gutter { + width: @gutter; +} + +/* Biên dịch thành: */ + +body { + width: 100%; +} + +.main-content { + width: 62.5%; +} + +.sidebar { + width: 31.25%; +} + +.gutter { + width: 6.25%; +} + + +``` + +## Tập sử dụng Less + +Nếu bạn cần xài thử Less trên trình duyệt, hãy ghé qua: +* [Codepen](http://codepen.io/) +* [LESS2CSS](http://lesscss.org/less-preview/) + +## Tính tương thích + +Less có thể được dùng trong bất kì dự án nào miễn là ta có chương trình để biên dịch nó thành CSS. Ta cần chắc chắn rằng đoạn CSS đang dùng tương thích với các phiên bản trình duyệt mong muốn. + +[QuirksMode CSS](http://www.quirksmode.org/css/) và [CanIUse](http://caniuse.com) là nguồn thông tin tin cậy để kiểm tra tính tương thích của mã CSS. + +## Tìm hiểu thêm +* [Tài liệu chính thức](http://lesscss.org/features/) +* [Less CSS - Hướng dẫn cho người mới bắt đầu](http://www.hongkiat.com/blog/less-basic/)
\ No newline at end of file diff --git a/vi-vn/markdown-vi.html.markdown b/vi-vn/markdown-vi.html.markdown new file mode 100644 index 00000000..89b59253 --- /dev/null +++ b/vi-vn/markdown-vi.html.markdown @@ -0,0 +1,325 @@ +--- +language: markdown +contributors: + - ["Dan Turkel", "http://danturkel.com/"] + - ["Jacob Ward", "http://github.com/JacobCWard/"] +translators: + - ["Thanh Duy Phan", "https://github.com/thanhpd"] +filename: markdown-vi.md +lang: vi-vn +--- + + +Ngôn ngữ Markdown được sáng lập bởi John Gruber vào năm 2004. Nó được tạo ra với mục đích dễ đọc với cú pháp có thể được dễ dàng chuyển đổi qua HTML và các ngôn ngữ khác + +Markdown có sự khác biệt trong cách cài đặt giữa các trình phân tích cú pháp. Hướng dẫn này sẽ đề cập, giải thích tới nếu tính năng có thể được sử dụng chung hay nó chỉ áp dụng cho một trình phân tích riêng biệt. + +- [Phần tử HTML](#html-elements) +- [Đầu mục](#headings) +- [Định dạng văn bản](#simple-text-styles) +- [Đoạn văn](#paragraphs) +- [Danh sách](#lists) +- [Khối code](#code-blocks) +- [Đường kẻ ngang](#horizontal-rule) +- [Liên kết](#links) +- [Ảnh](#images) +- [Khác](#miscellany) + +## Phần tử HTML +Markdown là tập cha của HTML, vì vậy bất cứ file HTML nào đều là Markdown đúng. + +```md +<!-- Điều này đồng nghĩa ta có thể sử dụng các phần tử HTML +trong Markdown, ví dụ như phần tử chú thích/comment. +Tuy nhiên, nếu sử dụng một phần tử HTML trong file Markdown, +ta không thể sử dụng cú pháp Markdown cho nội dung bên trong phần tử đó. --> +``` + +## Đầu mục + +Ta có thể tạo các phần tử đầu mục HTML từ `<h1>` cho đến `<h6>` dễ dàng +bằng cách thêm số lượng dấu thăng (#) đằng trước chuỗi cần tạo đầu mục. + +```md +# Đây là đầu mục <h1> +## Đây là đầu mục <h2> +### Đây là đầu mục <h3> +#### Đây là đầu mục <h4> +##### Đây là đầu mục <h5> +###### Đây là đầu mục <h6> +``` +Markdown còn cung cấp cách khác để tạo đầu mục hạng nhất h1 và hạng nhì h2. + +```md +Đây là đầu mục h1 +============= + +Đây là đầu mục h2 +------------- +``` + +## Định dạng văn bản + +Văn bản có thể được định dạng dễ dàng như in nghiêng hay làm đậm sử dụng Markdown. + +```md +*Đoạn văn bản này được in nghiêng.* +_Và đoạn này cũng như vậy._ + +**Đoạn văn bản này được in đậm.** +__Và đoạn này cũng vậy.__ + +***Đoạn văn bản này được in nghiêng và đậm.*** +**_Cách này cũng tương tự_** +*__Và cách này nữa__* +``` + +Trong cài đặt Markdown để hiển thị file của GitHub,ta còn có gạch ngang: + +```md +~~Đoạn văn bản này được gạch ngang.~~ +``` +## Đoạn văn + +Đoạn văn bao gồm một hay nhiều dòng văn bản liên tiếp nhau được phân cách +bởi một hay nhiều dòng trống. + +```md +Đây là đoạn văn thứ nhất. + +Đây là đoạn văn thứ hai. +Dòng này vẫn thuộc đoạn văn thứ hai, do không có cách dòng. + + +Đây là đoạn văn thứ ba. +``` + +Nếu cần chèn thêm thẻ ngắt dòng `<br />` của HTML, ta có thể kết thúc đoạn văn bản +bằng cách thêm vào từ 2 dấu cách (space) trở lên và bắt đầu đoạn văn bản mới. + +```md +Dòng này kết thúc với 2 dấu cách (highlight để nhìn thấy). + +Có phần tử <br /> ở bên trên. +``` + +Khối trích dẫn được sử dụng với kí tự > + +```md +> Đây là khối trích dẫn. Ta có thể +> ngắt dòng thủ công và thêm kí tự `>` trước mỗi dòng hoặc ta có thể để dòng tự ngắt nếu cần thiệt khi quá dài. +> Không có sự khác biệt nào, chỉ cần nó bắt đầu với kí tự `>` + +> Ta còn có thể dùng nhiều mức +>> của khối trích dẫn. +> Như vậy có tốt không? + +``` + +## Danh sách + +Danh sách không có thứ tự có thể được tạo sử dụng dấu sao, dấu cộng hay dấu trừ đầu dòng. + +```md +* Một mục +* Một mục +* Một mục nữa + +hoặc + ++ Một mục ++ Một mục ++ Một mục khác + +hay + +- Một mục +- Một mục +- Một mục sau +``` + +Danh sách có thứ tự được tạo bởi một số theo sau bằng một dấu chấm. + +```md +1. Mục thứ nhất +2. Mục thứ hai +3. Mục thứ ba +``` + +Ta không nhất thiết phải điền số thứ thự cho chỉ mục đúng mà Markdown sẽ tự hiển thị danh sách theo thứ tự đã được sắp xếp, tuy nhiên cách làm này không tốt! + +```md +1. Mục thứ nhất +1. Mục thứ hai +1. Mục thứ ba +``` +(Sẽ hiển thị như ví dụ trước đó) + +Ta còn có thể sử dụng danh sách con + +```md +1. Mục thứ nhất +2. Mục thứ hai +3. Mục thứ ba + * Mục nhỏ + * Mục nhỏ +4. Mục thứ tư +``` + +Markdown còn cung cấp danh mục (checklist). Nó sẽ hiển thị ra hộp đánh dấu dạng HTML. + +```md +Boxes below without the 'x' are unchecked HTML checkboxes. +- [ ] First task to complete. +- [ ] Second task that needs done +This checkbox below will be a checked HTML checkbox. +- [x] This task has been completed +``` + +## Khối code + +Ta có thể đánh dấu một đoạn code (tương tự sử dụng phần tử HTML `<code>`) bằng việc thụt đầu dòng sử dụng bốn dấu cách (space) hoặc một dấu nhảy (tab) + +```md + This is code + So is this +``` + +Ta còn có thể thêm dấu nhảy (hoặc thêm vào bốn dấu cách nữa) để căn chỉnh phần bên trong đoạn code + +```md + my_array.each do |item| + puts item + end +``` + +Code hiển thị cùng dòng có thể được đánh dấu sử dụng cặp ``. + +```md +John didn't even know what the `go_to()` function did! +``` + +Trong Markdown của GitHub, ta còn có thêm cách để hiển thị code: + +<pre> +<code class="highlight">```ruby +def foobar + puts "Hello world!" +end +```</code></pre> + +The above text doesn't require indenting, plus GitHub will use syntax +highlighting of the language you specify after the \`\`\` +Đoạn trên không cần sử dụng thụt đầu dòng, và GitHub sẽ tô sáng cú pháp sử dụng ngôn ngữ mà ta cung cấp sau đoạn kí tự \`\`\` + +## Kẻ ngang + +Dòng kẻ ngang (`<hr />`) có thể được thêm vào dễ dàng sử dụng từ 3 kí tự sao (*) hoặc gạch ngang (-), không quan trọng có khoảng cách giữa các kí tự hay không. + + +```md +*** +--- +- - - +**************** +``` + +## Liên kết + +Một trong những thứ tốt nhất khi làm việc với Markdown là khả năng tạo liên kết hết sức dễ dàng. Đoạn text hiển thị được đóng trong cặp ngoặc vuông [] kèm theo đường dẫn url trong cặp ngoặc tròn (). + +```md +[Click me!](http://test.com/) +``` +Ta còn có thể tạo tiêu đề cho liên kết sử dụng cặp ngoặc nháy bên trong cặp ngoặc tròn + +```md +[Click me!](http://test.com/ "Link to Test.com") +``` +Đường dẫn tương đối cũng hoạt động. + +```md +[Go to music](/music/). +``` + +Markdown còn hỗ trợ liên kết kiểu tham chiếu. + +<pre><code class="highlight">[<span class="nv">Nhấn vào đây</span>][<span class="ss">link1</span>] để xem thêm! +[<span class="nv">Ngoài ra nhấn vào đây</span>][<span class="ss">foobar</span>] nếu bạn muốn xem qua. + +[<span class="nv">link1</span>]: <span class="sx">http://test.com/</span> <span class="nn">"Tuyệt!"</span> +[<span class="nv">foobar</span>]: <span class="sx">http://foobar.biz/</span> <span class="nn">"Tốt!"</span></code></pre> + +Tiêu đề có thể được đóng trong dấu nháy hay ngoặc đơn, hoặc có thể được bỏ qua. Tham chiếu có thể được đặt bất kì đâu trong văn bản và ID của tham chiếu có thể là bất kì gì miễn là nó độc nhất. + +Ngoài ra còn có kiểu đặt tên ngầm cho phép ta sử dụng đường dẫn làm ID. + +<pre><code class="highlight">[<span class="nv">This</span>][] is a link. + +[<span class="nv">this</span>]: <span class="sx">http://thisisalink.com/</span></code></pre> + +Nhưng nó không được sử dụng rộng rãi. + +## Ảnh + +Hiển thị ảnh tương tự như liên kết nhưng có thêm dấu chấm than đằng trước + +```md + +``` + +Và kiểu tham chiếu cũng hoạt động như vậy. + +<pre><code class="highlight">![<span class="nv">Đây là thuộc tính alt.</span>][<span class="ss">myimage</span>] + +[<span class="nv">myimage</span>]: <span class="sx">relative/urls/cool/image.jpg</span> <span class="nn">"Đây là tiêu đề"</span></code></pre> + +## Khác + +### Tự động đặt liên kết + +```md +<http://testwebsite.com/> tương đương với +[http://testwebsite.com/](http://testwebsite.com/) +``` + +### Tự động đặt liên kết cho email + +```md +<foo@bar.com> +``` + +### Hiển thị Kí tự đặc biệt + +```md +Khi ta muốn viết *đoạn văn bản này có dấu sao bao quanh* nhưng ta không muốn nó bị in nghiêng, ta có thể sử dụng: \*đoạn văn bản này có dấu sao bao quanh\*. +``` + +### Phím bàn phím + +Trong Markdown của Github, ta có thể sử dụng thẻ `<kbd>` để thay cho phím trên bàn phím. + +```md +Máy treo? Thử bấm tổ hợp +<kbd>Ctrl</kbd>+<kbd>Alt</kbd>+<kbd>Del</kbd> +``` +### Bảng biểu + +Bảng biểu được hỗ trợ trên Markdown của GitHub, Jira, Trello, v.v và khá khó viết: + +```md +| Cột 1 | Cột2 | Cột 3 | +| :----------- | :------: | ------------: | +| Căn trái | Căn giữa | Căn phải | +| blah | blah | blah | +``` +Hoặc có thể sử dụng kết quả dưới đây + +```md +Cột 1 | Cột 2 | Cột 3 +:-- | :-: | --: +blah | blah | blah +``` + +--- +Để biết thêm thông tin, hãy ghé qua hướng dẫn chính thức về cú pháp của John Gruber [tại đây](http://daringfireball.net/projects/markdown/syntax) và cheatsheet của Adam Pritchard [tại đây](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet). diff --git a/vi-vn/sass-vi.html.markdown b/vi-vn/sass-vi.html.markdown new file mode 100644 index 00000000..313890d4 --- /dev/null +++ b/vi-vn/sass-vi.html.markdown @@ -0,0 +1,590 @@ +--- +language: sass +filename: learnsass-vi.scss +contributors: + - ["Laura Kyle", "https://github.com/LauraNK"] + - ["Sean Corrales", "https://github.com/droidenator"] + - ["Kyle Mendes", "https://github.com/pink401k"] + - ["Keith Miyake", "https://github.com/kaymmm"] +translators: + - ["Thanh Duy Phan", "https://github.com/thanhpd"] +lang: vi-vn +--- + +Less là một ngôn ngữ mở rộng CSS/ CSS pre-processor, thêm các tính năng như biến (variable), lồng (nesting), mixin và nhiều thứ khác. Sass cùng với các CSS pre-processor khác như [Less](http://lesscss.org/) giúp lập trình viên viết được các đoạn CSS bảo trì được và không bị lặp lại (DRY - Don't Repeat Yourself). + +Sass có hai lựa chọn sử dụng cú pháp khác nhau. Một là SCSS, sử dụng cú pháp giống như CSS nhưng bổ sung thêm các tính năng của Sass. Hai là Sass (cú pháp nguyên bản), sử dụng thụt đầu dòng - indention thay vì ngoặc nhọn và dấu chấm phẩy. +Bài hướng dẫn này sử dụng SCSS. + +Nếu bạn đọc đã quen thuộc với CSS3 thì sẽ tương đối nhanh chóng để nắm được Sass. Nó không cung cấp thuộc tính để style CSS mới nhưng đưa ra những công cụ để có thể viết CSS hiệu quả hơn và có thể bảo trì dễ dàng hơn. + +```sass + + +// Comment (chú thích) một dòng sẽ bị xóa khi Less được biên dịch thành CSS + +/* Comment trên nhiều dòng sẽ được giữ lại */ + + + +/* Variable - Biến +============================== */ + + + +/* Ta có thể lưu giá trị CSS (ví dụ như color) vào một biến. + Sử dụng ký hiệu '$' để khai báo một biến. */ + +$primary-color: #A3A4FF; +$secondary-color: #51527F; +$body-font: 'Roboto', sans-serif; + +/* Sau khi khai báo biến, ta có thể sử dụng nó ở trong tệp stylesheet. + Nhờ sử dụng biến ta chỉ cần thay đổi một lần + tại 1 nơi để thay đổi tất cả những đoạn sử dụng biến */ + +body { + background-color: $primary-color; + color: $secondary-color; + font-family: $body-font; +} + +/* Đoạn code trên sẽ được biên dịch thành: */ +body { + background-color: #A3A4FF; + color: #51527F; + font-family: 'Roboto', sans-serif; +} + +/* Cách sử dụng này giúp ta dễ dàng bảo trì hơn + việc phải đổi giá trị mỗi lần nó xuất hiện + trong tệp stylesheet. */ + + + +/* Control Directive - Chỉ thị +============================== */ + + +/* Sass cho phép sử dụng @if, @else, @for, @while và @each để quản lý luồng code sinh ra CSS */ + +/* Khối điều kiện @if/@else hoạt động như các ngôn ngữ khác */ + +$debug: true !default; + +@mixin debugmode { + @if $debug { + @debug "Debug mode enabled"; + + display: inline-block; + } + @else { + display: none; + } +} + +.info { + @include debugmode; +} + +/* Trong đoạn code trên, nếu $debug được đặt là true thì class .info sẽ được sinh ra và ngược lại. + Lưu ý: @debug sẽ sinh ra thông tin debug trên dòng lệnh (command line). + Chế độ này rất có ích khi thực hiện debug trên file SCSS. */ + +.info { + display: inline-block; +} + +/* @for là khối vòng lặp trên một khoảng các giá trị. + Nó rất có ích cho việc đặt style của một tập hợp các phần tử. + Có hai cách để lặp, "through" sẽ lặp tới kể cả giá trị cuối cùng, "to" sẽ lặp tới và dừng khi đến giá trị cuối cùng. */ + +// Lặp 3 lần (không kể 4) +@for $c from 1 to 4 { + div:nth-of-type(#{$c}) { + left: ($c - 1) * 900 / 3; + } +} + +// Lặp 3 lần (kể cả 3) +@for $c from 1 through 3 { + .myclass-#{$c} { + color: rgb($c * 255 / 3, $c * 255 / 3, $c * 255 / 3); + } +} + +/* Biên dịch thành */ + +div:nth-of-type(1) { + left: 0; +} + +div:nth-of-type(2) { + left: 300; +} + +div:nth-of-type(3) { + left: 600; +} + +.myclass-1 { + color: #555555; +} + +.myclass-2 { + color: #aaaaaa; +} + +.myclass-3 { + color: white; +// SASS tự động chuyển mã #FFFFFF thành white (trắng) +} + +/* Khối lặp @while rất cơ bản: */ + +$columns: 4; +$column-width: 80px; + +@while $columns > 0 { + .col-#{$columns} { + width: $column-width; + left: $column-width * ($columns - 1); + } + + $columns: $columns - 1; +} + +/* Sẽ được biên dịch thành: */ + +.col-4 { + width: 80px; + left: 240px; +} + +.col-3 { + width: 80px; + left: 160px; +} + +.col-2 { + width: 80px; + left: 80px; +} + +.col-1 { + width: 80px; + left: 0px; +} + +/* @each hoạt động giống như @for, nhưng sử dụng một danh sách (list) thay vì thứ tự số đếm. + List được khai báo như những biến khác, sử dụng dấu cách để làm dấu phân cách. */ + +$social-links: facebook twitter linkedin reddit; + +.social-links { + @each $sm in $social-links { + .icon-#{$sm} { + background-image: url("images/#{$sm}.png"); + } + } +} + +/* Sẽ sinh ra: */ + +.social-links .icon-facebook { + background-image: url("images/facebook.png"); +} + +.social-links .icon-twitter { + background-image: url("images/twitter.png"); +} + +.social-links .icon-linkedin { + background-image: url("images/linkedin.png"); +} + +.social-links .icon-reddit { + background-image: url("images/reddit.png"); +} + + +/* Mixin +==============================*/ + +/* Nếu đang viết một đoạn code cho nhiều hơn một + element, ta có thể sử dụng lại nó dễ dàng. + Sử dụng cú pháp '@mixin' kèm theo tên để tạo một mixin. */ + +@mixin center { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; +} + +/* Ta có thể dùng mixin bằng cú pháp '@include' kèm theo tên của mixin. */ + +div { + @include center; + background-color: $primary-color; +} + +/* Được biên dịch thành: */ +div { + display: block; + margin-left: auto; + margin-right: auto; + left: 0; + right: 0; + background-color: #A3A4FF; +} + +/* Ta có thể dùng mixin để tạo nhanh các thuộc tính. */ + +@mixin size($width, $height) { + width: $width; + height: $height; +} + +/* Trong ví dụ này ta có thể tạo nhanh 2 thuộc tính width và height + bằng cách sử dụng mixin size và truyền vào tham số cho width và height. */ + +.rectangle { + @include size(100px, 60px); +} + +.square { + @include size(40px, 40px); +} + +/* Biên dịch thành: */ +.rectangle { + width: 100px; + height: 60px; +} + +.square { + width: 40px; + height: 40px; +} + + + +/* Function - Hàm +============================== */ + + + +/* Less cung cấp các hàm có thể được dùng để hoàn thành + các công việc khác nhau. */ + +/* Hàm được gọi sử dụng tên của nó và truyền vào + các tham số được yêu cầu. */ +body { + width: round(10.25px); +} + +.footer { + background-color: fade_out(#000000, 0.25); +} + +/* Biên dịch thành: */ + +body { + width: 10px; +} + +.footer { + background-color: rgba(0, 0, 0, 0.75); +} + +/* Ta có thể định nghĩa hàm mới. + hàm khá tương tự với mixin bởi chúng đều có thể được tái + sử dụng. Khi lựa chọn giữa việc sử dụng hàm hay mixin, + hãy nhớ mixin được tối ưu cho việc tạo ra CSS trong khi + hàm sẽ được sử dụng tốt hơn cho logic sẽ được sử dụng + xuyên suốt Less code. Các ví dụ trong phần 'Toán tử toán học' là ứng cử viên + sáng giá cho việc dùng hàm có thể tái sử dụng được. +*/ + +/* Hàm này sẽ tính độ tương đối giữa hai giá trị kích thước. */ + +@function calculate-percentage($target-size, $parent-size) { + @return $target-size / $parent-size * 100%; +} + +$main-content: calculate-percentage(600px, 960px); + +.main-content { + width: $main-content; +} + +.sidebar { + width: calculate-percentage(300px, 960px); +} + +/* Biên dịch thành: */ + +.main-content { + width: 62.5%; +} + +.sidebar { + width: 31.25%; +} + + + +/* Mở rộng (Thừa kế) +============================== */ + + + +/* Mở rộng là cách để chia sẻ thuộc tính của một selector cho selector khác */ + +.display { + @include size(5em, 5em); + border: 5px solid $secondary-color; +} + +.display-success { + @extend .display; + border-color: #22df56; +} + +/* Biên dịch thành: */ +.display, .display-success { + width: 5em; + height: 5em; + border: 5px solid #51527F; +} + +.display-success { + border-color: #22df56; +} + +/* Nên mở rộng một khai báo CSS có trước thay vì tạo một mixin mới + bởi cách nó nhóm các lớp có chung một style gốc. + Nếu thực hiện với mixin, các thuộc tính sẽ bị trùng lặp + cho mỗi khai báo có sử dụng mixin. Mặc dù không ảnh hưởng đến luồng công việc nhưng nó + tạo ra các đoạn code CSS thừa sau khi được biên dịch. +*/ + + + +/* Nesting - Lồng +============================== */ + + + +/* Sass cho phép ta có thể lồng selector bên trong selector */ + +ul { + list-style-type: none; + margin-top: 2em; + + li { + background-color: #FF0000; + } +} + +/* Selector bắt đầu bằng ký tự '&' sẽ thay thế ký tự '&' + với selector cha. */ +/* Ta cũng có thể lồng các pseudo-class với nhau */ +/* Nên lưu ý không nên lồng quá nhiều lần sẽ làm code kém tính bảo trì. + Kinh nghiệm cho thấy không nên lồng quá 3 lần. + Ví dụ: */ + +ul { + list-style-type: none; + margin-top: 2em; + + li { + background-color: red; + + &:hover { + background-color: blue; + } + + a { + color: white; + } + } +} + +/* Biên dịch thành: */ + +ul { + list-style-type: none; + margin-top: 2em; +} + +ul li { + background-color: red; +} + +ul li:hover { + background-color: blue; +} + +ul li a { + color: white; +} + + + +/* Partials and Imports - Chia nhỏ thành tệp con và nhập vào +============================== */ + + +/* Less cho phép ta tạo các partial file (tệp con). + Sử dụng nó giúp ta có thể tổ chức code Less theo mô-đun có hệ thống. + Các tệp con thường bắt đầu với ký tự gạch dưới '_', vd: _reset.less + và được nhập vào file Less chính để được biên dịch thành CSS. + File con không được biên dịch thành file CSS riêng. */ + +/* Quan sát ví dụ sau, ta sẽ đặt đoạn code dưới đây vào tệp tên là _reset.less */ + +html, +body, +ul, +ol { + margin: 0; + padding: 0; +} + +/* Sass cung cấp cú pháp @import cho phép nhập các partial vào một file. + Cú pháp này trong Sass sẽ nhập các file và kết hợp chúng lại với + code CSS được sinh ra. Nó khác với cú pháp @import của CSS, + bản chất là tạo một HTTP request mới để tải về tệp tin được yêu cầu. */ + +@import 'reset'; + +body { + font-size: 16px; + font-family: Helvetica, Arial, Sans-serif; +} + +/* Biên dịch thành: */ + +html, body, ul, ol { + margin: 0; + padding: 0; +} + +body { + font-size: 16px; + font-family: Helvetica, Arial, Sans-serif; +} + + + +/* Placeholder Selectors - Selector trống +============================== */ + + + +/* Khai báo trống rất hữu dụng khi ta cần tạo một khai báo CSS cần được mở rộng. + Nếu bạn cần tạo một khai báo CSS gốc cho các lần mở rộng sau ta có thể + sử dụng một khai báo trống. Khai báo trống bắt đầu với kí tự '$' thay vì + sử dụng '.' hay '#'. Khai báo trống sẽ không xuất hiện trong code CSS được biên dịch. */ + +%content-window { + font-size: 14px; + padding: 10px; + color: #000; + border-radius: 4px; +} + +.message-window { + @extend %content-window; + background-color: #0000ff; +} + +/* Biên dịch thành: */ + +.message-window { + font-size: 14px; + padding: 10px; + color: #000; + border-radius: 4px; +} + +.message-window { + background-color: #0000ff; +} + + + +/* Toán tử toán học +============================== */ + + + +/* Sass cung cấp các toán tử sau: +, -, *, / và %. + Điều này rất có ích cho việc tính toán giá trị trực tiếp + trong tệp Sass thay vì phải tính toán thủ công. + Dưới đây là ví dụ về việc tạo một khung thiết kế đơn giản có hai cột. */ + +$content-area: 960px; +$main-content: 600px; +$sidebar-content: 300px; + +$main-size: $main-content / $content-area * 100%; +$sidebar-size: $sidebar-content / $content-area * 100%; +$gutter: 100% - ($main-size + $sidebar-size); + +body { + width: 100%; +} + +.main-content { + width: $main-size; +} + +.sidebar { + width: $sidebar-size; +} + +.gutter { + width: $gutter; +} + +/* Biên dịch thành: */ + +body { + width: 100%; +} + +.main-content { + width: 62.5%; +} + +.sidebar { + width: 31.25%; +} + +.gutter { + width: 6.25%; +} + +``` + +## SASS hay Sass? +Bạn đã bao giờ thắc mắc liệu Sass có phải là từ viết tắt hay không? Nhiều nguwòi lầm tưởng nó là từ viết tắt nhưng thực chất tên của ngôn ngữ này lại là một từ - Sass. +Do sự lầm tưởng như vậy và mọi người thường xuyên viết nó là "SASS", người sáng lập ra ngôn ngữ này đã đặt một cái tên hài hước cho nó là "Syntactically Awesome StyleSheets" (Thiết lập style có cú pháp một cách tuyệt vời đáng kinh ngạc). + + +## Tập sử dụng Sass +Nếu bạn muốn thử dùng Sass trên trình duyệt, hãy ghé qua [SassMeister](http://sassmeister.com/). Bạn có thể dùng cả hai cú pháp, hoặc mở cài đặt và chọn Sass hoặc SCSS. + +## Tính tương thích +Sass có thể được dùng trong bất kì dự án nào miễn là ta có chương trình để biên dịch nó thành CSS. Ta cần chắc chắn rằng đoạn CSS đang dùng tương thích với các phiên bản trình duyệt mong muốn. + +[QuirksMode CSS](http://www.quirksmode.org/css/) và [CanIUse](http://caniuse.com) là nguồn thông tin tin cậy để kiểm tra tính tương thích của mã CSS. + + +## Tìm hiểu thêm +* [Tài liệu chính thức](http://sass-lang.com/documentation/file.SASS_REFERENCE.html) +* [The Sass Way](http://thesassway.com/) cung cấp các hướng dẫn từ cơ bản đến nâng cao cùng với các tin tức. diff --git a/vi-vn/typescript-vi.html.markdown b/vi-vn/typescript-vi.html.markdown new file mode 100644 index 00000000..ba459c11 --- /dev/null +++ b/vi-vn/typescript-vi.html.markdown @@ -0,0 +1,193 @@ +--- +language: TypeScript +contributors: + - ["Philippe Vlérick", "https://github.com/pvlerick"] +translators: + - ["Thanh Duy Phan", "https://github.com/thanhpd"] +filename: learntypescript-vi.ts +lang: vi-vn +--- + +TypeScript là ngôn ngữ được viết nhằm tinh giản quá trình phát triển ứng dụng quy mô lớn được viết bằng JavaScript. +TypeScript bổ sung thêm các khái niệm phổ biến như Class, Module, Interface, Generic và Static typing (tùy chọn) vào JavaScript. +Ngôn ngữ này là tập lớn hơn của JavaScript: tất cả code JavaScript đều là code TypeScript đúng nên nó có thể được thêm vào các dự án một cách nhanh chóng. Trình biên dịch TypeScript sẽ sinh ra JavaScript. + +Bài viết này sẽ chỉ tập trung tới các cú pháp bổ sung mà TypeScript thêm vào thay vì nói đến cả các cú pháp [JavaScript](javascript-vi.html.markdown). + +Để thử dùng TypeScript với trình biên dịch, đi đến [Sân chơi TypeScript](http://www.typescriptlang.org/play) nơi mà bạn có thể nhập code, sử dụng chức năng hỗ trợ tự hoàn thành code - autocompletion và trực tiếp quan sát mã JavaScript được sinh ra. + +```ts +// Đây là 3 khai báo kiểu biến cơ bản trong TypeScript +// (JavaScript chỉ có kiểu của giá trị, không có kiểu của biến) +let isDone: boolean = false; +let lines: number = 42; +let name: string = "Anders"; + +// Bạn có thể bỏ khai báo kiểu của biến nếu như nó đã được suy ra từ kiểu giá trị cơ bản +let isDone = false; +let lines = 42; +let name = "Anders"; + +// Có kiểu biến "any" tương thích với mọi kiểu của biến, +// được dùng khi ta không chắc chắn về kiểu của biến khi được khai báo +let notSure: any = 4; +notSure = "có thể là một biến kiểu string"; +notSure = false; // cũng có thể là biến kiểu boolean + +// Dùng từ khóa const cho khái báo biến không thay đổi (constant variable) +const numLivesForCat = 9; +numLivesForCat = 1; // Có lỗi! + +// Khi khai báo tập hợp ta có thể dùng mảng có kiểu được khai báo trước - typed array +let list: number[] = [1, 2, 3]; +// Ta cũng có thể sử dụng mảng kiểu chung - generic array +let list: Array<number> = [1, 2, 3]; + +// Để dùng enumeration - danh sách của một tập hợp: +enum Color { Red, Green, Blue }; +let c: Color = Color.Green; + +// Nếu function không trả về kết quả, sử dụng "void" cho kết quả trả về +function bigHorribleAlert(): void { + alert("I'm a little annoying box!"); +} + +// Function trong TypeScript là first-class citizen (tạm dịch: phần tử hạng nhất), hỗ trợ thao tác tới các thực thể khác +// (vd: truyền vào như tham số, được trả về từ function, chỉnh sửa, gán vào một biến) +// TypeScript hỗ trợ sử dụng function với cú pháp lambda (mũi tên) và suy luận kiểu trả về + +// Các cú pháp dưới đây tương đương với nhau, +// trình biên dịch sẽ tự nhận biết và sinh ra mã JavaScript giống nhau +let f1 = function (i: number): number { return i * i; } +// Kiểu trả về nếu không khai báo được tự suy diễn +let f2 = function (i: number) { return i * i; } +// Cú pháp mũi tên (arrow syntax) +let f3 = (i: number): number => { return i * i; } +// Cú pháp mũi tên với kiểu trả về được suy diễn +let f4 = (i: number) => { return i * i; } +// Cú pháp mũi tên với kiểu trả về được suy diễn +// khi không sử dụng dấu ngoặc nhọn {} thì không cần sử dụng return +let f5 = (i: number) => i * i; + +// Interface mang tính cấu trúc, mọi thứ có các đặc điểm (property) đều tương thích +interface IPerson { + name: string; + // Đặc điểm có thể tùy chọn bằng sử dụng dấu "?" + age?: number; + // Có thể sử dụng function + move(): void; +} + +// Object sử dụng interface IPerson nói trên +// có thể được coi là 1 thực thể Person vì nó có đặc điểm name và chức năng move +let p: Person = { name: "Bobby", move: () => { } }; +// Object sử dụng property tùy chọn +let validPerson: Person = { name: "Bobby", age: 42, move: () => { } }; +// Khai báo dưới đây gây lỗi vì giá trị đặc điểm age không mang kiểu number +let invalidPerson: Person = { name: "Bobby", age: true }; + +// Interface cũng có thể mô tả đặc tả của function +interface SearchFunc { + (source: string, subString: string): boolean; +} +// Chỉ có kiểu của tham số là quan trọng còn tên không quan trọng +let mySearch: SearchFunc; +mySearch = function (src: string, sub: string) { + return src.search(sub) != -1; +} + +// Class - các khai báo mặc định là public +class Point { + // Property + x: number; + + // Constructor - sử dụng tham số với từ khóa public/private + // sẽ tạo ra property tương ứng (ví dụ với property y) + // Có thể khai báo giá trị mặc định + + constructor(x: number, public y: number = 0) { + this.x = x; + } + + // Function + dist() { return Math.sqrt(this.x * this.x + this.y * this.y); } + + // Biến Static + static origin = new Point(0, 0); +} + +let p1 = new Point(10, 20); +let p2 = new Point(25); // y sử dụng giá trị mặc định là 0 + +// Thừa kế - Inheritance +class Point3D extends Point { + constructor(x: number, y: number, public z: number = 0) { + super(x, y); // Bắt buộc phải gọi constructor của class cha + } + + // Overwrite/Polymorphism - Ghi đè/Đa hình + dist() { + let d = super.dist(); + return Math.sqrt(d * d + this.z * this.z); + } +} + +// module, "." có thể được dùng như những module con +module Geometry { + export class Square { + constructor(public sideLength: number = 0) { + } + area() { + return Math.pow(this.sideLength, 2); + } + } +} + +let s1 = new Geometry.Square(5); + +// Bí danh (alias) có thể được sử dụng để tham vấn module khác +import G = Geometry; + +let s2 = new G.Square(10); + +// Generic +// Class +class Tuple<T1, T2> { + constructor(public item1: T1, public item2: T2) { + } +} + +// Interface +interface Pair<T> { + item1: T; + item2: T; +} + +// Function +let pairToTuple = function <T>(p: Pair<T>) { + return new Tuple(p.item1, p.item2); +}; + +let tuple = pairToTuple({ item1: "hello", item2: "world" }); + +// Các thư viện viết bằng JavaScript thường đi kèm file định nghĩa kiểu để có thể sử dụng cho TypeScript +// Thêm vào tham vấn tới file định nghĩa: +/// <reference path="jquery.d.ts" /> + +// Template Strings - Chuỗi dạng mẫu (string sử dụng dấu `) +// String Interpolation - Nội suy chuỗi with với template string +let name = 'Tyrone'; +let greeting = `Chào ${name}, bạn khỏe không?` +// Chuỗi nhiều dòng với template string +let multiline = `Đây là ví dụ +cho chuỗi nhiều dòng`; + +``` + +## Tìm hiểu thêm + +* [Website TypeScript chính thức](http://www.typescriptlang.org/) +* [Đặc tả ngôn ngữ TypeScript] (https://github.com/Microsoft/TypeScript/blob/master/doc/spec.md) +* [Anders Hejlsberg - Introducing TypeScript on Channel 9] (http://channel9.msdn.com/posts/Anders-Hejlsberg-Introducing-TypeScript) +* [Mã nguồn trên GitHub] (https://github.com/Microsoft/TypeScript) +* [Definitely Typed - repository for type definitions] (http://definitelytyped.org/) diff --git a/vim.html.markdown b/vim.html.markdown index 7723136f..0eb2c37e 100644 --- a/vim.html.markdown +++ b/vim.html.markdown @@ -8,18 +8,20 @@ filename: LearnVim.txt [Vim](http://www.vim.org) -(Vi IMproved) is a clone of the popular vi editor for Unix. It is a text -editor designed for speed and increased productivity, and is ubiquitous in most -unix-based systems. It has numerous keybindings for speedy navigation to +(Vi IMproved) is a clone of the popular vi editor for Unix. It is a text +editor designed for speed and increased productivity, and is ubiquitous in most +unix-based systems. It has numerous keybindings for speedy navigation to specific points in the file, and for fast editing. ## Basics of navigating Vim ``` vim <filename> # Open <filename> in vim + :help <topic> # Open up built-in help docs about <topic> if any exists :q # Quit vim :w # Save current file :wq # Save file and quit vim + ZZ # Save file and quit vim :q! # Quit vim without saving file # ! *forces* :q to execute, hence quiting vim without saving :x # Save file and quit vim, shorter version of :wq @@ -32,6 +34,11 @@ specific points in the file, and for fast editing. k # Move up one line l # Move right one character + Ctrl+B # Move back one full screen + Ctrl+F # Move forward one full screen + Ctrl+D # Move forward 1/2 a screen + Ctrl+U # Move back 1/2 a screen + # Moving within the line 0 # Move to beginning of line @@ -47,16 +54,17 @@ specific points in the file, and for fast editing. :%s/foo/bar/g # Change 'foo' to 'bar' on every line in the file :s/foo/bar/g # Change 'foo' to 'bar' on the current line + :%s/\n/\r/g # Replace new line characters with new line characters # Jumping to characters f<character> # Jump forward and land on <character> - t<character> # Jump forward and land right before <character> + t<character> # Jump forward and land right before <character> - # For example, + # For example, f< # Jump forward and land on < t< # Jump forward and land right before < - + # Moving by word w # Move forward by one word @@ -73,19 +81,28 @@ specific points in the file, and for fast editing. L # Move to the bottom of the screen ``` +## Help docs: + +Vim has built in help documentation that can accessed with `:help <topic>`. +For example `:help navigation` will pull up documentation about how to navigate +your workspace! + +`:help` can also be used without an option. This will bring up a default help dialog +that aims to make getting started with vim more approachable! + ## Modes: Vim is based on the concept on **modes**. -Command Mode - vim starts up in this mode, used to navigate and write commands -Insert Mode - used to make changes in your file -Visual Mode - used to highlight text and do operations to them +Command Mode - vim starts up in this mode, used to navigate and write commands +Insert Mode - used to make changes in your file +Visual Mode - used to highlight text and do operations to them Ex Mode - used to drop down to the bottom with the ':' prompt to enter commands ``` i # Puts vim into insert mode, before the cursor position a # Puts vim into insert mode, after the cursor position - v # Puts vim into visual mode + v # Puts vim into visual mode : # Puts vim into ex mode <esc> # 'Escapes' from whichever mode you're in, into Command mode @@ -102,18 +119,18 @@ Ex Mode - used to drop down to the bottom with the ':' prompt to enter comm ## The 'Grammar' of vim -Vim can be thought of as a set of commands in a +Vim can be thought of as a set of commands in a 'Verb-Modifier-Noun' format, where: -Verb - your action -Modifier - how you're doing your action +Verb - your action +Modifier - how you're doing your action Noun - the object on which your action acts on A few important examples of 'Verbs', 'Modifiers', and 'Nouns': ``` # 'Verbs' - + d # Delete c # Change y # Yank (copy) @@ -135,7 +152,7 @@ A few important examples of 'Verbs', 'Modifiers', and 'Nouns': s # Sentence p # Paragraph b # Block - + # Sample 'sentences' or commands d2w # Delete 2 words @@ -157,6 +174,20 @@ A few important examples of 'Verbs', 'Modifiers', and 'Nouns': ddp # Swap position of consecutive lines, dd then p . # Repeat previous action :w !sudo tee % # Save the current file as root + :set syntax=c # Set syntax highlighting to 'c' + :sort # Sort all lines + :sort! # Sort all lines in reverse + :sort u # Sort all lines and remove duplicates + ~ # Toggle letter case of selected text + u # Selected text to lower case + U # Selected text to upper case + + # Fold text + zf # Create fold from selected text + zo # Open current fold + zc # Close current fold + zR # Open all folds + zM # Close all folds ``` ## Macros @@ -180,7 +211,7 @@ Here's a sample ~/.vimrc file: ``` " Example ~/.vimrc -" 2015.10 +" 2015.10 " Required for vim to be iMproved set nocompatible diff --git a/visualbasic.html.markdown b/visualbasic.html.markdown index cbeb36b5..63f224b7 100644 --- a/visualbasic.html.markdown +++ b/visualbasic.html.markdown @@ -5,7 +5,7 @@ contributors: filename: learnvisualbasic.vb --- -```vb +``` Module Module1 Sub Main() diff --git a/whip.html.markdown b/whip.html.markdown index e7e5e427..c692714a 100644 --- a/whip.html.markdown +++ b/whip.html.markdown @@ -3,6 +3,7 @@ language: whip contributors: - ["Tenor Biel", "http://github.com/L8D"] - ["Saurabh Sandav", "http://github.com/SaurabhSandav"] + - ["Paulo Henrique Rodrigues Pinheiro", "https://github.com/paulohrpinheiro"] author: Tenor Biel author_url: http://github.com/L8D filename: whip.lisp @@ -232,6 +233,7 @@ undefined ; user to indicate a value that hasn't been set (words "foobar nachos cheese") ; => ("foobar" "nachos" "cheese") ; Join list of strings together. (unwords ("foo" "bar")) ; => "foobar" +; Successor and Predecessor (pred 21) ; => 20 (succ 20) ; => 21 ``` diff --git a/yaml.html.markdown b/yaml.html.markdown index 3b32a069..8683971e 100644 --- a/yaml.html.markdown +++ b/yaml.html.markdown @@ -2,8 +2,8 @@ language: yaml filename: learnyaml.yaml contributors: - - ["Adam Brenecki", "https://github.com/adambrenecki"] - - ["Suhas SG", "https://github.com/jargnar"] +- [Adam Brenecki, 'https://github.com/adambrenecki'] +- [Suhas SG, 'https://github.com/jargnar'] --- YAML is a data serialisation language designed to be directly writable and @@ -11,9 +11,11 @@ readable by humans. It's a strict superset of JSON, with the addition of syntactically significant newlines and indentation, like Python. Unlike Python, however, -YAML doesn't allow literal tab characters at all. +YAML doesn't allow literal tab characters for indentation. ```yaml +--- # document start + # Comments in YAML look like this. ################ @@ -32,8 +34,10 @@ boolean: true null_value: null key with spaces: value # Notice that strings don't need to be quoted. However, they can be. -however: "A string, enclosed in quotes." -"Keys can be quoted too.": "Useful if you want to put a ':' in your key." +however: 'A string, enclosed in quotes.' +'Keys can be quoted too.': "Useful if you want to put a ':' in your key." +single quotes: 'have ''one'' escape pattern' +double quotes: "have many: \", \0, \t, \u263A, \x0d\x0a == \r\n, and more." # Multiple-line strings can be written either as a 'literal block' (using |), # or a 'folded block' (using '>'). @@ -59,12 +63,12 @@ folded_style: > # COLLECTION TYPES # #################### -# Nesting is achieved by indentation. +# Nesting uses indentation. 2 space indent is preferred (but not required). a_nested_map: - key: value - another_key: Another Value - another_nested_map: - hello: hello + key: value + another_key: Another Value + another_nested_map: + hello: hello # Maps don't have to have string keys. 0.25: a float key @@ -72,8 +76,8 @@ a_nested_map: # Keys can also be complex, like multi-line objects # We use ? followed by a space to indicate the start of a complex key. ? | - This is a key - that has multiple lines + This is a key + that has multiple lines : and this is its value # YAML also allows mapping between sequences with the complex key syntax @@ -81,24 +85,28 @@ a_nested_map: # An example ? - Manchester United - Real Madrid -: [ 2001-01-01, 2002-02-02 ] +: [2001-01-01, 2002-02-02] -# Sequences (equivalent to lists or arrays) look like this: +# Sequences (equivalent to lists or arrays) look like this +# (note that the '-' counts as indentation): a_sequence: - - Item 1 - - Item 2 - - 0.5 # sequences can contain disparate types. - - Item 4 - - key: value - another_key: another_value - - - - This is a sequence - - inside another sequence + - Item 1 + - Item 2 + - 0.5 # sequences can contain disparate types. + - Item 4 + - key: value + another_key: another_value + - + - This is a sequence + - inside another sequence + - - - Nested sequence indicators + - can be collapsed # Since YAML is a superset of JSON, you can also write JSON-style maps and # sequences: json_map: {"key": "value"} json_seq: [3, 2, 1, "takeoff"] +and quotes are optional: {key: [3, 2, 1, takeoff]} ####################### # EXTRA YAML FEATURES # @@ -111,15 +119,19 @@ other_anchor: *anchor_name # Anchors can be used to duplicate/inherit properties base: &base - name: Everyone has same name + name: Everyone has same name + +# The regexp << is called Merge Key Language-Independent Type. It is is used to +# indicate that all the keys of one or more specified maps should be inserted +# into the current map. foo: &foo - <<: *base - age: 10 + <<: *base + age: 10 bar: &bar - <<: *base - age: 20 + <<: *base + age: 20 # foo and bar would also have name: Everyone has same name @@ -147,25 +159,28 @@ date: 2002-12-14 # The !!binary tag indicates that a string is actually a base64-encoded # representation of a binary blob. gif_file: !!binary | - R0lGODlhDAAMAIQAAP//9/X17unp5WZmZgAAAOfn515eXvPz7Y6OjuDg4J+fn5 - OTk6enp56enmlpaWNjY6Ojo4SEhP/++f/++f/++f/++f/++f/++f/++f/++f/+ - +f/++f/++f/++f/++f/++SH+Dk1hZGUgd2l0aCBHSU1QACwAAAAADAAMAAAFLC - AgjoEwnuNAFOhpEMTRiggcz4BNJHrv/zCFcLiwMWYNG84BwwEeECcgggoBADs= + R0lGODlhDAAMAIQAAP//9/X17unp5WZmZgAAAOfn515eXvPz7Y6OjuDg4J+fn5 + OTk6enp56enmlpaWNjY6Ojo4SEhP/++f/++f/++f/++f/++f/++f/++f/++f/+ + +f/++f/++f/++f/++f/++SH+Dk1hZGUgd2l0aCBHSU1QACwAAAAADAAMAAAFLC + AgjoEwnuNAFOhpEMTRiggcz4BNJHrv/zCFcLiwMWYNG84BwwEeECcgggoBADs= # YAML also has a set type, which looks like this: set: - ? item1 - ? item2 - ? item3 + ? item1 + ? item2 + ? item3 +or: {item1, item2, item3} -# Like Python, sets are just maps with null values; the above is equivalent to: +# Sets are just maps with null values; the above is equivalent to: set2: - item1: null - item2: null - item3: null + item1: null + item2: null + item3: null + +... # document end ``` ### More Resources + [YAML official website](http://yaml.org/) -+ [Online YAML Validator](http://codebeautify.org/yaml-validator) ++ [Online YAML Validator](http://www.yamllint.com/) diff --git a/zh-cn/awk-cn.html.markdown b/zh-cn/awk-cn.html.markdown new file mode 100644 index 00000000..3fea782b --- /dev/null +++ b/zh-cn/awk-cn.html.markdown @@ -0,0 +1,326 @@ +--- +language: awk +contributors: + - ["Marshall Mason", "http://github.com/marshallmason"] +translators: + - ["Tian Zhipeng", "https://github.com/tianzhipeng-git"] +filename: learnawk-cn.awk +lang: zh-cn +--- + +AWK是POSIX兼容的UNIX系统中的标准工具. 它像简化版的Perl, 非常适用于文本处理任务和其他脚本类需求. +它有着C风格的语法, 但是没有分号, 没有手动内存管理, 没有静态类型. +他擅长于文本处理, 你可以通过shell脚本调用AWK, 也可以用作独立的脚本语言. + +为什么使用AWK而不是Perl, 大概是因为AWK是UNIX的一部分, 你总能依靠它, 而Perl已经前途未卜了. +AWK比Perl更易读. 对于简单的文本处理脚本, 特别是按行读取文件, 按分隔符分隔处理, AWK极可能是正确的工具. + +```awk +#!/usr/bin/awk -f + +# 注释使用井号 + +# AWK程序由一系列 模式(patterns) 和 动作(actions) 组成. +# 最重要的模式叫做 BEGIN. 动作由大括号包围. +BEGIN { + + # BEGIN在程序最开始运行. 在这里放一些在真正处理文件之前的准备和setup的代码. + # 如果没有文本文件要处理, 那就把BEGIN作为程序的主入口吧. + + # 变量是全局的. 直接赋值使用即可, 无需声明. + count = 0 + + # 运算符和C语言系一样 + a = count + 1 + b = count - 1 + c = count * 1 + d = count / 1 # 整数除法 + e = count % 1 # 取余 + f = count ^ 1 # 取幂 + + a += 1 + b -= 1 + c *= 1 + d /= 1 + e %= 1 + f ^= 1 + + # 自增1, 自减1 + a++ + b-- + + # 前置运算, 返回增加之后的值 + ++a + --b + + # 注意, 不需要分号之类的标点来分隔语句 + + # 控制语句 + if (count == 0) + print "Starting with count of 0" + else + print "Huh?" + + # 或者三目运算符 + print (count == 0) ? "Starting with count of 0" : "Huh?" + + # 多行的代码块用大括号包围 + while (a < 10) { + print "String concatenation is done" " with a series" " of" + " space-separated strings" + print a + + a++ + } + + for (i = 0; i < 10; i++) + print "Good ol' for loop" + + # 标准的比较运算符 + a < b # 小于 + a <= b # 小于或等于 + a != b # 不等于 + a == b # 等于 + a > b # 大于 + a >= b # 大于或等于 + + # 也有逻辑运算符 + a && b # 且 + a || b # 或 + + # 并且有超实用的正则表达式匹配 + if ("foo" ~ "^fo+$") + print "Fooey!" + if ("boo" !~ "^fo+$") + print "Boo!" + + # 数组 + arr[0] = "foo" + arr[1] = "bar" + # 不幸的是, 没有其他方式初始化数组. 必须像这样一行一行的赋值. + + # 关联数组, 类似map或dict的用法. + assoc["foo"] = "bar" + assoc["bar"] = "baz" + + # 多维数组. 但是有一些局限性这里不提了. + multidim[0,0] = "foo" + multidim[0,1] = "bar" + multidim[1,0] = "baz" + multidim[1,1] = "boo" + + # 可以检测数组包含关系 + if ("foo" in assoc) + print "Fooey!" + + # 可以使用in遍历数组 + for (key in assoc) + print assoc[key] + + # 命令行参数是一个叫ARGV的数组 + for (argnum in ARGV) + print ARGV[argnum] + + # 可以从数组中移除元素 + # 在 防止awk把文件参数当做数据来处理 时delete功能很有用. + delete ARGV[1] + + # 命令行参数的个数是一个叫ARGC的变量 + print ARGC + + # AWK有很多内置函数, 分为三类, 会在接下来定义的各个函数中介绍. + + return_value = arithmetic_functions(a, b, c) + string_functions() + io_functions() +} + +# 定义函数 +function arithmetic_functions(a, b, c, d) { + + # 或许AWK最让人恼火的地方是没有局部变量, 所有东西都是全局的, + # 对于短的脚本还好, 对于长一些的就会成问题. + + # 这里有一个技巧, 函数参数是对函数局部可见的, 并且AWK允许定义多余的参数, + # 因此可以像上面那样把局部变量插入到函数声明中. + # 为了方便区分普通参数(a,b,c)和局部变量(d), 可以多键入一些空格. + + # 现在介绍数学类函数 + + # 多数AWK实现中包含标准的三角函数 + localvar = sin(a) + localvar = cos(a) + localvar = atan2(a, b) # arc tangent of b / a + + # 对数 + localvar = exp(a) + localvar = log(a) + + # 平方根 + localvar = sqrt(a) + + # 浮点型转为整型 + localvar = int(5.34) # localvar => 5 + + # 随机数 + srand() # 接受随机种子作为参数, 默认使用当天的时间 + localvar = rand() # 0到1之间随机 + + # 函数返回 + return localvar +} + +function string_functions( localvar, arr) { + + # AWK, 作为字符处理语言, 有很多字符串相关函数, 其中大多数都严重依赖正则表达式. + + # 搜索并替换, 第一个出现的 (sub) or 所有的 (gsub) + # 都是返回替换的个数 + localvar = "fooooobar" + sub("fo+", "Meet me at the ", localvar) # localvar => "Meet me at the bar" + gsub("e+", ".", localvar) # localvar => "m..t m. at th. bar" + + # 搜索匹配正则的字符串 + # index() 也是搜索, 不支持正则 + match(localvar, "t") # => 4, 't'在4号位置. + # (译者注: awk是1开始计数的,不是常见的0-base) + + # 按分隔符分隔 + split("foo-bar-baz", arr, "-") # a => ["foo", "bar", "baz"] + + # 其他有用的函数 + sprintf("%s %d %d %d", "Testing", 1, 2, 3) # => "Testing 1 2 3" + substr("foobar", 2, 3) # => "oob" + substr("foobar", 4) # => "bar" + length("foo") # => 3 + tolower("FOO") # => "foo" + toupper("foo") # => "FOO" +} + +function io_functions( localvar) { + + # 你已经见过的print函数 + print "Hello world" + + # 也有printf + printf("%s %d %d %d\n", "Testing", 1, 2, 3) + + # AWK本身没有文件句柄, 当你使用需要文件的东西时会自动打开文件, + # 做文件I/O时, 字符串就是打开的文件句柄. 这看起来像Shell + print "foobar" >"/tmp/foobar.txt" + + # 现在"/tmp/foobar.txt"字符串是一个文件句柄, 你可以关闭它 + close("/tmp/foobar.txt") + + # 在shell里运行一些东西 + system("echo foobar") # => prints foobar + + # 从标准输入中读一行, 并存储在localvar中 + getline localvar + + # 从管道中读一行, 并存储在localvar中 + "echo foobar" | getline localvar # localvar => "foobar" + close("echo foobar") + + # 从文件中读一行, 并存储在localvar中 + getline localvar <"/tmp/foobar.txt" + close("/tmp/foobar.txt") +} + +# 正如开头所说, AWK程序由一系列模式和动作组成. 你已经看见了重要的BEGIN pattern, +# 其他的pattern在你需要处理来自文件或标准输入的的数据行时才用到. +# +# 当你给AWK程序传参数时, 他们会被视为要处理文件的文件名, 按顺序全部会处理. +# 可以把这个过程看做一个隐式的循环, 遍历这些文件中的所有行. +# 然后这些模式和动作就是这个循环里的switch语句一样 + +/^fo+bar$/ { + + # 这个动作会在匹配这个正则(/^fo+bar$/)的每一行上执行. 不匹配的则会跳过. + # 先让我们打印它: + print + + # 哦, 没有参数, 那是因为print有一个默认参数 $0. + # $0 是当前正在处理的行, 自动被创建好了. + + # 你可能猜到有其他的$变量了. + # 每一行在动作执行前会被分隔符分隔. 像shell中一样, 每个字段都可以用$符访问 + + # 这个会打印这行的第2和第4个字段 + print $2, $4 + + # AWK自动定义了许多其他的变量帮助你处理行. 最常用的是NF变量 + # 打印这一行的字段数 + print NF + + # 打印这一行的最后一个字段 + print $NF +} + +# 每一个模式其实是一个true/false判断, 上面那个正则其实也是一个true/false判断, 只不过被部分省略了. +# 没有指定时默认使用当前处理的整行($0)进行匹配. 因此, 完全版本是这样: + +$0 ~ /^fo+bar$/ { + print "Equivalent to the last pattern" +} + +a > 0 { + # 只要a是整数, 这块会在每一行上执行. +} + +# 就是这样, 处理文本文件, 一次读一行, 对行做一些操作. +# 按分隔符分隔, 这在UNIX中很常见, awk都帮你做好了. +# 你所需要做的是基于自己的需求写一些模式和动作. + +# 这里有一个快速的例子, 展示了AWK所擅长做的事. +# 它从标准输入读一个名字, 打印这个first name下所有人的平均年龄. +# 示例数据: +# +# Bob Jones 32 +# Jane Doe 22 +# Steve Stevens 83 +# Bob Smith 29 +# Bob Barker 72 +# +# 示例脚本: + +BEGIN { + + # 首先, 问用户要一个名字 + print "What name would you like the average age for?" + + # 从标准输入获取名字 + getline name <"/dev/stdin" +} + +# 然后, 用给定的名字匹配每一行的第一个字段. +$1 == name { + + # 这里我们要使用几个有用的变量, 已经提前为我们加载好的: + # $0 是整行 + # $3 是第三个字段, 就是我们所感兴趣的年龄 + # NF 字段数, 这里是3 + # NR 至此为止的行数 + # FILENAME 在处理的文件名 + # FS 在使用的字段分隔符, 这里是空格" " + # ...等等, 还有很多, 在帮助文档中列出. + + # 跟踪 总和以及行数 + sum += $3 + nlines++ +} + +# 另一个特殊的模式叫END. 它会在处理完所有行之后运行. 不像BEGIN, 它只会在有输入的时候运行. +# 它在所有文件依据给定的模式和动作处理完后运行, 目的通常是输出一些最终报告, 做一些数据聚合操作. + +END { + if (nlines) + print "The average age for " name " is " sum / nlines +} + +``` +更多: + +* [Awk 教程](http://www.grymoire.com/Unix/Awk.html) +* [Awk 手册](https://linux.die.net/man/1/awk) +* [The GNU Awk 用户指南](https://www.gnu.org/software/gawk/manual/gawk.html) GNU Awk在大多数Linux中预装 diff --git a/zh-cn/c++-cn.html.markdown b/zh-cn/c++-cn.html.markdown index 87951bc3..e0d6b6fe 100644 --- a/zh-cn/c++-cn.html.markdown +++ b/zh-cn/c++-cn.html.markdown @@ -567,6 +567,6 @@ void doSomethingWithAFile(const std::string& filename) ```
扩展阅读：
-<http://cppreference.com/w/cpp> 提供了最新的语法参考。
-
-可以在 <http://cplusplus.com> 找到一些补充资料。
+* [CPP Reference](http://cppreference.com/w/cpp) 提供了最新的语法参考。
+* 可以在 [CPlusPlus](http://cplusplus.com) 找到一些补充资料。
+* 可以在 [TheChernoProject - C ++](https://www.youtube.com/playlist?list=PLlrATfBNZ98dudnM48yfGUldqGD0S4FFb）上找到涵盖语言基础和设置编码环境的教程。
diff --git a/zh-cn/c-cn.html.markdown b/zh-cn/c-cn.html.markdown index 1e10416e..8566e811 100644 --- a/zh-cn/c-cn.html.markdown +++ b/zh-cn/c-cn.html.markdown @@ -41,7 +41,7 @@ enum days {SUN = 1, MON, TUE, WED, THU, FRI, SAT}; void function_1(char c); void function_2(void); -// 如果函数出现在main()之后，那么必须在main()之前 +// 如果函数调用在main()之后，那么必须声明在main()之前 // 先声明一个函数原型 int add_two_ints(int x1, int x2); // 函数原型 diff --git a/zh-cn/crystal-cn.html.markdown b/zh-cn/crystal-cn.html.markdown new file mode 100644 index 00000000..14805114 --- /dev/null +++ b/zh-cn/crystal-cn.html.markdown @@ -0,0 +1,567 @@ +--- +language: crystal +filename: learncrystal-cn.cr +contributors: + - ["Vitalii Elenhaupt", "http://veelenga.com"] + - ["Arnaud Fernandés", "https://github.com/TechMagister/"] +translators: + - ["Xuty", "https://github.com/xtyxtyx"] +lang: zh-cn +--- + +```crystal + +# 这是一行注释 + +# 一切都是对象(object) +nil.class #=> Nil +100.class #=> Int32 +true.class #=> Bool + +# nil, false 以及空指针是假值(falsey values) +!nil #=> true : Bool +!false #=> true : Bool +!0 #=> false : Bool + +# 整数类型 + +1.class #=> Int32 + +# 四种有符号整数 +1_i8.class #=> Int8 +1_i16.class #=> Int16 +1_i32.class #=> Int32 +1_i64.class #=> Int64 + +# 四种无符号整数 +1_u8.class #=> UInt8 +1_u16.class #=> UInt16 +1_u32.class #=> UInt32 +1_u64.class #=> UInt64 + +2147483648.class #=> Int64 +9223372036854775808.class #=> UInt64 + +# 二进制数 +0b1101 #=> 13 : Int32 + +# 八进制数 +0o123 #=> 83 : Int32 + +# 十六进制数 +0xFE012D #=> 16646445 : Int32 +0xfe012d #=> 16646445 : Int32 + +# 浮点数类型 + +1.0.class #=> Float64 + +# Crystal中有两种浮点数 +1.0_f32.class #=> Float32 +1_f32.class #=> Float32 + +1e10.class #=> Float64 +1.5e10.class #=> Float64 +1.5e-7.class #=> Float64 + +# 字符类型 + +'a'.class #=> Char + +# 八进制字符 +'\101' #=> 'A' : Char + +# Unicode字符 +'\u0041' #=> 'A' : Char + +# 字符串 + +"s".class #=> String + +# 字符串不可变(immutable) +s = "hello, " #=> "hello, " : String +s.object_id #=> 134667712 : UInt64 +s += "Crystal" #=> "hello, Crystal" : String +s.object_id #=> 142528472 : UInt64 + +# 支持字符串插值(interpolation) +"sum = #{1 + 2}" #=> "sum = 3" : String + +# 多行字符串 +"这是一个 + 多行字符串" + +# 书写带有引号的字符串 +%(hello "world") #=> "hello \"world\"" + +# 符号类型 +# 符号是不可变的常量，本质上是Int32类型 +# 符号通常被用来代替字符串，来高效地传递特定的值 + +:symbol.class #=> Symbol + +sentence = :question? # :"question?" : Symbol + +sentence == :question? #=> true : Bool +sentence == :exclamation! #=> false : Bool +sentence == "question?" #=> false : Bool + +# 数组类型(Array) + +[1, 2, 3].class #=> Array(Int32) +[1, "hello", 'x'].class #=> Array(Int32 | String | Char) + +# 必须为空数组指定类型 +[] # Syntax error: for empty arrays use '[] of ElementType' +[] of Int32 #=> [] : Array(Int32) +Array(Int32).new #=> [] : Array(Int32) + +# 数组可以通过下标访问 +array = [1, 2, 3, 4, 5] #=> [1, 2, 3, 4, 5] : Array(Int32) +array[0] #=> 1 : Int32 +array[10] # raises IndexError +array[-6] # raises IndexError +array[10]? #=> nil : (Int32 | Nil) +array[-6]? #=> nil : (Int32 | Nil) + +# 使用负位置编号，从后往前访问数组 +array[-1] #=> 5 + +# With a start index and size +# 使用起始位置编号+大小 +array[2, 3] #=> [3, 4, 5] + +# 使用范围(range)访问数组 +array[1..3] #=> [2, 3, 4] + +# 向尾部添加元素 +array << 6 #=> [1, 2, 3, 4, 5, 6] + +# 删除尾部元素 +array.pop #=> 6 +array #=> [1, 2, 3, 4, 5] + +# 删除首部元素 +array.shift #=> 1 +array #=> [2, 3, 4, 5] + +# 检查元素是否存在与数组之中 +array.includes? 3 #=> true + +# 一种特殊语法，用来创建字符串数组或符号数组 +%w(one two three) #=> ["one", "two", "three"] : Array(String) +%i(one two three) #=> [:one, :two, :three] : Array(Symbol) + +# 对于定义了`new`和`#<<`方法的类，可以用以下语法创建新对象 +set = Set{1, 2, 3} #=> [1, 2, 3] +set.class #=> Set(Int32) + +# 以下代码与上方等同 +set = Set(typeof(1, 2, 3)).new +set << 1 +set << 2 +set << 3 + +# 哈希表类型(Hash) + +{1 => 2, 3 => 4}.class #=> Hash(Int32, Int32) +{1 => 2, 'a' => 3}.class #=> Hash(Int32 | Char, Int32) + +# 必须为空哈希表指定类型 +{} # Syntax error +{} of Int32 => Int32 # {} +Hash(Int32, Int32).new # {} + +# 可以使用键(key)快速查询哈希表 +hash = {"color" => "green", "number" => 5} +hash["color"] #=> "green" +hash["no_such_key"] #=> Missing hash key: "no_such_key" (KeyError) +hash["no_such_key"]? #=> nil + +# 检查某一键哈希表中是否存在 +hash.has_key? "color" #=> true + +# 对于定义了`#[]=`方法的类，可以使用以下语法创建对象 +class MyType + def []=(key, value) + puts "do stuff" + end +end + +MyType{"foo" => "bar"} + +# 以上与下列代码等同 +tmp = MyType.new +tmp["foo"] = "bar" +tmp + +# 范围类型(Range) + +1..10 #=> Range(Int32, Int32) +Range.new(1, 10).class #=> Range(Int32, Int32) + +# 包含或不包含端点 +(3..5).to_a #=> [3, 4, 5] +(3...5).to_a #=> [3, 4] + +# 检查某一值是否在范围内 +(1..8).includes? 2 #=> true + +# 元组类型(Tuple) + +# 元组类型尺寸固定，不可变，储存在栈中 +# 元组可以有不同类型的对象组成 +{1, "hello", 'x'}.class #=> Tuple(Int32, String, Char) + +# 使用下标访问元组 +tuple = {:key1, :key2} +tuple[1] #=> :key2 +tuple[2] #=> syntax error : Index out of bound + +# 将元组中的元素赋值给变量 +a, b, c = {:a, 'b', "c"} +a #=> :a +b #=> 'b' +c #=> "c" + +# 命名元组类型(NamedTuple) + +tuple = {name: "Crystal", year: 2011} # NamedTuple(name: String, year: Int32) +tuple[:name] # => "Crystal" (String) +tuple[:year] # => 2011 (Int32) + +# 命名元组的键可以是字符串常量 +{"this is a key": 1} # => NamedTuple("this is a key": Int32) + +# 过程类型(Proc) +# 过程代表一个函数指针，以及可选的上下文(闭包) +# 过程通常使用字面值创建 +proc = ->(x : Int32) { x.to_s } +proc.class # Proc(Int32, String) + +# 或者使用`new`方法创建 +Proc(Int32, String).new { |x| x.to_s } + +# 使用`call`方法调用过程 +proc.call 10 #=> "10" + +# 控制语句(Control statements) + +if true + "if 语句" +elsif false + "else-if, 可选" +else + "else, 同样可选" +end + +puts "可以将if后置" if true + +# 将if作为表达式 +a = if 2 > 1 + 3 + else + 4 + end + +a #=> 3 + +# 条件表达式 +a = 1 > 2 ? 3 : 4 #=> 4 + +# `case`语句 +cmd = "move" + +action = case cmd + when "create" + "Creating..." + when "copy" + "Copying..." + when "move" + "Moving..." + when "delete" + "Deleting..." +end + +action #=> "Moving..." + +# 循环 +index = 0 +while index <= 3 + puts "Index: #{index}" + index += 1 +end +# Index: 0 +# Index: 1 +# Index: 2 +# Index: 3 + +index = 0 +until index > 3 + puts "Index: #{index}" + index += 1 +end +# Index: 0 +# Index: 1 +# Index: 2 +# Index: 3 + +# 更好的做法是使用`each` +(0..3).each do |index| + puts "Index: #{index}" +end +# Index: 0 +# Index: 1 +# Index: 2 +# Index: 3 + +# 变量的类型取决于控制语句中表达式的类型 +if a < 3 + a = "hello" +else + a = true +end +typeof a #=> (Bool | String) + +if a && b + # 此处`a`与`b`均为Nil +end + +if a.is_a? String + a.class #=> String +end + +# 函数(Functions) + +def double(x) + x * 2 +end + +# 函数(以及所有代码块)均将最末尾表达式的值作为返回值 +double(2) #=> 4 + +# 在没有歧义的情况下，括号可以省略 +double 3 #=> 6 + +double double 3 #=> 12 + +def sum(x, y) + x + y +end + +# 使用逗号分隔参数 +sum 3, 4 #=> 7 + +sum sum(3, 4), 5 #=> 12 + +# yield +# 所有函数都有一个默认生成、可选的代码块(block)参数 +# 在函数中可以使用yield调用此代码块 + +def surround + puts '{' + yield + puts '}' +end + +surround { puts "hello world" } + +# { +# hello world +# } + + +# 可将代码块作为参数传给函数 +# "&" 表示对代码块参数的引用 +def guests(&block) + block.call "some_argument" +end + +# 使用星号"*"将参数转换成元组 +def guests(*array) + array.each { |guest| puts guest } +end + +# 如果函数返回数组，可以将其解构 +def foods + ["pancake", "sandwich", "quesadilla"] +end +breakfast, lunch, dinner = foods +breakfast #=> "pancake" +dinner #=> "quesadilla" + +# 按照约定，所有返回布尔值的方法都以问号结尾 +5.even? # false +5.odd? # true + +# 以感叹号结尾的方法，都有一些破坏性(destructive)行为，比如改变调用接收者(receiver) +# 对于某些方法，带有感叹号的版本将改变调用接收者，而不带有感叹号的版本返回新值 +company_name = "Dunder Mifflin" +company_name.gsub "Dunder", "Donald" #=> "Donald Mifflin" +company_name #=> "Dunder Mifflin" +company_name.gsub! "Dunder", "Donald" +company_name #=> "Donald Mifflin" + + +# 使用`class`关键字来定义类(class) +class Human + + # 类变量，由类的所有实例所共享 + @@species = "H. sapiens" + + # `name`的类型为`String` + @name : String + + # 构造器方法(initializer) + # 其中@name、@age为简写，相当于 + # + # def initialize(name, age = 0) + # @name = name + # @age = age + # end + # + # `age`为可选参数，如果未指定，则使用默认值0 + def initialize(@name, @age = 0) + end + + # @name的setter方法 + def name=(name) + @name = name + end + + # @name的getter方法 + def name + @name + end + + # 上述getter与setter的定义可以用property宏简化 + property :name + + # 也可用getter与setter宏独立创建getter与setter + getter :name + setter :name + + # 此处的`self.`使`say`成为类方法 + def self.say(msg) + puts msg + end + + def species + @@species + end +end + + +# 将类实例化 +jim = Human.new("Jim Halpert") + +dwight = Human.new("Dwight K. Schrute") + +# 调用一些实例方法 +jim.species #=> "H. sapiens" +jim.name #=> "Jim Halpert" +jim.name = "Jim Halpert II" #=> "Jim Halpert II" +jim.name #=> "Jim Halpert II" +dwight.species #=> "H. sapiens" +dwight.name #=> "Dwight K. Schrute" + +# 调用类方法 +Human.say("Hi") #=> 输出 Hi ，返回 nil + +# 带有`@`前缀的变量为实例变量 +class TestClass + @var = "I'm an instance var" +end + +# 带有`@@`前缀的变量为类变量 +class TestClass + @@var = "I'm a class var" +end +# 首字母大写的变量为常量 +Var = "这是一个常量" +Var = "无法再次被赋值" # 常量`Var`已经被初始化 + +# 在crystal中类也是对象(object)，因此类也有实例变量(instance variable) +# 类变量的定义由类以及类的派生类所共有，但类变量的值是独立的 + +# 基类 +class Human + @@foo = 0 + + def self.foo + @@foo + end + + def self.foo=(value) + @@foo = value + end +end + +# 派生类 +class Worker < Human +end + +Human.foo #=> 0 +Worker.foo #=> 0 + +Human.foo = 2 #=> 2 +Worker.foo #=> 0 + +Worker.foo = 3 #=> 3 +Human.foo #=> 2 +Worker.foo #=> 3 + +module ModuleExample + def foo + "foo" + end +end + +# include <Module> 将模块(module)中的方法添加为实例方法 +# extend <Module> 将模块中的方法添加为类方法 + +class Person + include ModuleExample +end + +class Book + extend ModuleExample +end + +Person.foo # => undefined method 'foo' for Person:Class +Person.new.foo # => 'foo' +Book.foo # => 'foo' +Book.new.foo # => undefined method 'foo' for Book + + +# 异常处理 + +# 定义新的异常类(exception) +class MyException < Exception +end + +# 再定义一个异常类 +class MyAnotherException < Exception; end + +ex = begin + raise MyException.new +rescue ex1 : IndexError + "ex1" +rescue ex2 : MyException | MyAnotherException + "ex2" +rescue ex3 : Exception + "ex3" +rescue ex4 # 捕捉任何类型的异常 + "ex4" +end + +ex #=> "ex2" + +``` + +## 参考资料 + +- [官方网站](https://crystal-lang.org/) +- [官方文档](https://crystal-lang.org/docs/overview/) +- [在线运行代码](https://play.crystal-lang.org/#/cr) +- [Github仓库](https://github.com/crystal-lang/crystal) diff --git a/zh-cn/dart-cn.html.markdown b/zh-cn/dart-cn.html.markdown index 6a6562bc..b0287f0c 100644 --- a/zh-cn/dart-cn.html.markdown +++ b/zh-cn/dart-cn.html.markdown @@ -492,8 +492,8 @@ main() { Dart 有一个综合性网站。它涵盖了 API 参考、入门向导、文章以及更多， 还包括一个有用的在线试用 Dart 页面。 -http://www.dartlang.org/ -http://try.dartlang.org/ +* [https://www.dartlang.org](https://www.dartlang.org) +* [https://try.dartlang.org](https://try.dartlang.org) diff --git a/zh-cn/fortran95-cn.html.markdown b/zh-cn/fortran95-cn.html.markdown new file mode 100644 index 00000000..e28d309f --- /dev/null +++ b/zh-cn/fortran95-cn.html.markdown @@ -0,0 +1,435 @@ +--- +language: Fortran +filename: learnfortran-cn.f95 +contributors: + - ["Robert Steed", "https://github.com/robochat"] +translators: + - ["Corvusnest", "https://github.com/Corvusnest"] +lang: zh-cn +--- + +Fortran 是最古老的计算机语言之一。它由IBM开发于1950年用于数值运算（Fortran 为 "Formula +Translation" 的缩写）。虽然该语言已年代久远，但目前仍用于高性能计算，如天气预报。 +该语言仍在持续发展，并且基本保持向下兼容。知名的版本为 Fortran 77, Fortran 90, +Fortran 95, Fortran 2003, Fortran 2008 与 Fortran 2015。 + +这篇概要将讨论 Fortran 95 的一些特征。因为它是目前所广泛采用的标准版本，并且与最新版本的内容 +也基本相同（而 Fortran 77 则是一个非常不同的版本）。 + +```fortran + +! 这是一行注释 + + +program example !声明一个叫做 example 的程序 + + ! 代码只能放在程序、函数、子程序或者模块内部 + ! 推荐使用缩进，但不是必须的。 + + ! 声明变量 + ! =================== + + ! 所有的声明必须放在语句与表达式之前 + + implicit none !阻止变量的隐式声明 (推荐!) + ! Implicit none 必须在每一个 函数/程序/模块 中进行声明 + + ! 重要 - Fortran 对大小写不敏感 + real z + REAL Z2 + + real :: v,x ! 警告: 默认值取决于编译器! + real :: a = 3, b=2E12, c = 0.01 + integer :: i, j, k=1, m + real, parameter :: PI = 3.1415926535897931 !声明一个常量 + logical :: y = .TRUE. , n = .FALSE. !布尔值 + complex :: w = (0,1) !sqrt(-1) (译注: 定义复数，此为-1的平方根) + character (len=3) :: month !长度为3的字符串 + + real :: array(6) !声明长度为6的浮点数数组 + real, dimension(4) :: arrayb !声明数组的另一种方法 + integer :: arrayc(-10:10) !有着自定义索引的数组 + real :: array2d(3,2) !多维数组 + + ! 分隔符 '::' 并不总是必要的，但推荐使用 + + ! 还存在很多其他的变量特征: + real, pointer :: p !声明一个指针 + + integer, parameter :: LP = selected_real_kind(20) + real (kind = LP) :: d !长精度变量 + + ! 警告：在声明期间初始化变量将导致在函数内发生问题，因为这将自动具备了 “save” 属性， + ! 因此变量的值在函数的多次调用期间将被存储。一般来说，除了常量，应分开声明与初始化！ + + ! 字符串 + ! ======= + + character :: a_char = 'i' + character (len = 6) :: a_str = "qwerty" + character (len = 30) :: str_b + character (len = *), parameter :: a_long_str = "This is a long string." + !可以通过使用 (len=*) 来自动判断长度，但只对常量有效 + + str_b = a_str // " keyboard" !通过 // 操作符来连接字符串 + + + ! 任务与计算 + ! ======================= + + Z = 1 !向之前声明的变量 z 赋值 (大小写不敏感). + j = 10 + 2 - 3 + a = 11.54 / (2.3 * 3.1) + b = 2**3 !幂 + + + ! 控制流程语句 与 操作符 + ! =================================== + + !单行 if 语句 + if (z == a) b = 4 !判别句永远需要放在圆括号内 + + if (z /= a) then !z 不等于 a + ! 其他的比较运算符： < > <= >= == /= + b = 4 + else if (z .GT. a) then !z 大于(Greater) a + ! 文本形式的比较运算符: .LT. .GT. .LE. .GE. .EQ. .NE. + b = 6 + else if (z < a) then !'then' 必须放在该行 + b = 5 !执行部分必须放在新的一行里 + else + b = 10 + end if !结束语句需要 'if' (也可以用 'endif'). + + + if (.NOT. (x < c .AND. v >= a .OR. z == z)) then !布尔操作符 + inner: if (.TRUE.) then !可以为 if 结构命名 + b = 1 + endif inner !接下来必须命名 endif 语句. + endif + + + i = 20 + select case (i) + case (0) !当 i == 0 + j=0 + case (1:10) !当 i 为 1 到 10 之内 ( 1 <= i <= 10 ) + j=1 + case (11:) !当 i>=11 + j=2 + case default + j=3 + end select + + + month = 'jan' + ! 状态值可以为整数、布尔值或者字符类型 + ! Select 结构同样可以被命名 + monthly: select case (month) + case ("jan") + j = 0 + case default + j = -1 + end select monthly + + do i=2,10,2 !从2到10(包含2和10)以2为步进值循环 + innerloop: do j=1,3 !循环同样可以被命名 + exit !跳出循环 + end do innerloop + cycle !重复跳入下一次循环 + enddo + + + ! Goto 语句是存在的，但强烈不建议使用 + goto 10 + stop 1 !立即停止程序 (返回一个设定的状态码). +10 j = 201 !这一行被标注为 10 行 （line 10） + + + ! 数组 + ! ====== + array = (/1,2,3,4,5,6/) + array = [1,2,3,4,5,6] !当使用 Fortran 2003 版本. + arrayb = [10.2,3e3,0.41,4e-5] + array2d = reshape([1.0,2.0,3.0,4.0,5.0,6.0], [3,2]) + + ! Fortran 数组索引起始于 1 + ! (默认下如此，也可以为数组定义不同的索引起始) + v = array(1) !获取数组的第一个元素 + v = array2d(2,2) + + print *, array(3:5) !打印从第3到第五5之内的所有元素 + print *, array2d(1,:) !打印2维数组的第一列 + + array = array*3 + 2 !可为数组设置数学表达式 + array = array*array !数组操作支持元素级(操作) (element-wise) + !array = array*array2d !这两类数组并不是同一个维度的 + + ! 有很多内置的数组操作函数 + c = dot_product(array,array) !点乘 (点积) + ! 用 matmul() 来进行矩阵运算. + c = sum(array) + c = maxval(array) + print *, minloc(array) + c = size(array) + print *, shape(array) + m = count(array > 0) + + ! 遍历一个数组 (一般使用 Product() 函数). + v = 1 + do i = 1, size(array) + v = v*array(i) + end do + + ! 有条件地执行元素级操作 + array = [1,2,3,4,5,6] + where (array > 3) + array = array + 1 + elsewhere (array == 2) + array = 1 + elsewhere + array = 0 + end where + + ! 隐式DO循环可以很方便地创建数组 + array = [ (i, i = 1,6) ] !创建数组 [1,2,3,4,5,6] + array = [ (i, i = 1,12,2) ] !创建数组 [1,3,5,7,9,11] + array = [ (i**2, i = 1,6) ] !创建数组 [1,4,9,16,25,36] + array = [ (4,5, i = 1,3) ] !创建数组 [4,5,4,5,4,5] + + + ! 输入/输出 + ! ============ + + print *, b !向命令行打印变量 'b' + + ! 我们可以格式化输出 + print "(I6)", 320 !打印 ' 320' + print "(I6.4)", 3 !打印 ' 0003' + print "(F6.3)", 4.32 !打印 ' 4.320' + + + ! 该字母与数值规定了给定的数值与字符所用于打印输出的类型与格式 + ! 字母可为 I (整数), F (浮点数), E (工程格式), + ! L (逻辑/布尔值), A (字符) ... + print "(I3)", 3200 !如果数值无法符合格式将打印 '***' + + ! 可以同时设定多种格式 + print "(I5,F6.2,E6.2)", 120, 43.41, 43.41 + print "(3I5)", 10, 20, 30 !连续打印3个整数 (字段宽度 = 5). + print "(2(I5,F6.2))", 120, 43.42, 340, 65.3 !连续分组格式 + + ! 我们也可以从终端读取输入 + read *, v + read "(2F6.2)", v, x !读取2个数值 + + ! 读取文件 + open(unit=11, file="records.txt", status="old") + ! 文件被引用带有一个单位数 'unit', 为一个取值范围在9-99的整数 + ! 'status' 可以为 {'old','replace','new'} 其中之一 + read(unit=11, fmt="(3F10.2)") a, b, c + close(11) + + ! 写入一个文件 + open(unit=12, file="records.txt", status="replace") + write(12, "(F10.2,F10.2,F10.2)") c, b, a + close(12) + ! 在讨论范围之外的还有更多的细节与可用功能，并于老版本的 Fortran 保持兼容 + + + ! 内置函数 + ! ================== + + ! Fortran 拥有大约 200 个内置函数/子程序 + ! 例子 + call cpu_time(v) !以秒为单位设置时间 + k = ior(i,j) !2个整数的位或运算 + v = log10(x) !以10为底的log运算 + i = floor(b) !返回一个最接近的整数小于或等于x (地板数) + v = aimag(w) !复数的虚数部分 + + + ! 函数与子程序 + ! ======================= + + ! 一个子程序会根据输入值运行一些代码并会导致副作用 (side-effects) 或修改输入值 + ! (译者注: 副作用是指对子程序/函数外的环境产生影响，如修改变量) + + call routine(a,c,v) !调用子程序 + + ! 一个函数会根据输入的一系列数值来返回一个单独的值 + ! 但输入值仍然可能被修改以及产生副作用 + + m = func(3,2,k) !调用函数 + + ! 函数可以在表达式内被调用 + Print *, func2(3,2,k) + + ! 一个纯函数不会去修改输入值或产生副作用 + m = func3(3,2,k) + + +contains ! 用于定义程序内部的副程序(sub-programs)的区域 + + ! Fortran 拥有一些不同的方法去定义函数 + + integer function func(a,b,c) !一个返回一个整数的函数 + implicit none !最好也在函数内将含蓄模式关闭 (implicit none) + integer :: a,b,c !输入值类型定义在函数内部 + if (a >= 2) then + func = a + b + c !返回值默认为函数名 + return !可以在函数内任意时间返回当前值 + endif + func = a + c + ! 在函数的结尾不需要返回语句 + end function func + + + function func2(a,b,c) result(f) !将返回值声明为 'f' + implicit none + integer, intent(in) :: a,b !可以声明让变量无法被函数修改 + integer, intent(inout) :: c + integer :: f !函数的返回值类型在函数内声明 + integer :: cnt = 0 !注意 - 隐式的初始化变量将在函数的多次调用间被存储 + f = a + b - c + c = 4 !变动一个输入变量的值 + cnt = cnt + 1 !记录函数的被调用次数 + end function func2 + + + pure function func3(a,b,c) !一个没有副作用的纯函数 + implicit none + integer, intent(in) :: a,b,c + integer :: func3 + func3 = a*b*c + end function func3 + + + subroutine routine(d,e,f) + implicit none + real, intent(inout) :: f + real, intent(in) :: d,e + f = 2*d + 3*e + f + end subroutine routine + + +end program example ! 函数定义完毕 ----------------------- + +! 函数与子程序的外部声明对于生成程序清单来说，需要一个接口声明（即使它们在同一个源文件内）(见下) +! 使用 'contains' 可以很容易地在模块或程序内定义它们 + +elemental real function func4(a) result(res) +! 一个元函数(elemental function) 为一个纯函数使用一个标量输入值 +! 但同时也可以用在一个数组并对其中的元素分别处理，之后返回一个新的数组 + real, intent(in) :: a + res = a**2 + 1.0 +end function func4 + + +! 模块 +! ======= + +! 模块十分适合于存放与复用相关联的一组声明、函数与子程序 + +module fruit + real :: apple + real :: pear + real :: orange +end module fruit + + +module fruity + + ! 声明必须按照顺序: 模块、接口、变量 + ! (同样可在程序内声明模块和接口) + + use fruit, only: apple, pear ! 使用来自于 fruit 模块的 apple 和 pear + implicit none !在模块导入后声明 + + private !使得模块内容为私有(private)(默认为公共 public) + ! 显式声明一些变量/函数为公共 + public :: apple,mycar,create_mycar + ! 声明一些变量/函数为私有(在当前情况下没必要)(译注: 因为前面声明了模块全局 private) + private :: func4 + + ! 接口 + ! ========== + ! 在模块内显式声明一个外部函数/程序 + ! 一般最好将函数/程序放进 'contains' 部分内 + interface + elemental real function func4(a) result(res) + real, intent(in) :: a + end function func4 + end interface + + ! 重载函数可以通过已命名的接口来定义 + interface myabs + ! 可以通过使用 'module procedure' 关键词来包含一个已在模块内定义的函数 + module procedure real_abs, complex_abs + end interface + + ! 派生数据类型 + ! ================== + ! 可创建自定义数据结构 + type car + character (len=100) :: model + real :: weight !(公斤 kg) + real :: dimensions(3) !例: 长宽高(米) + character :: colour + end type car + + type(car) :: mycar !声明一个自定义类型的变量 + ! 用法具体查看 create_mycar() + + ! 注: 模块内没有可执行的语句 + +contains + + subroutine create_mycar(mycar) + ! 展示派生数据类型的使用 + implicit none + type(car),intent(out) :: mycar + + ! 通过 '%' 操作符来访问(派生数据)类型的元素 + mycar%model = "Ford Prefect" + mycar%colour = 'r' + mycar%weight = 1400 + mycar%dimensions(1) = 5.0 !索引默认起始值为 1 ! + mycar%dimensions(2) = 3.0 + mycar%dimensions(3) = 1.5 + + end subroutine + + real function real_abs(x) + real :: x + if (x<0) then + real_abs = -x + else + real_abs = x + end if + end function real_abs + + real function complex_abs(z) + complex :: z + ! 过长的一行代码可通过延续符 '&' 来换行 + complex_abs = sqrt(real(z)**2 + & + aimag(z)**2) + end function complex_abs + + +end module fruity + +``` + +### 更多资源 + +了解更多的 Fortran 信息: + ++ [wikipedia](https://en.wikipedia.org/wiki/Fortran) ++ [Fortran_95_language_features](https://en.wikipedia.org/wiki/Fortran_95_language_features) ++ [fortranwiki.org](http://fortranwiki.org) ++ [www.fortran90.org/](http://www.fortran90.org) ++ [list of Fortran 95 tutorials](http://www.dmoz.org/Computers/Programming/Languages/Fortran/FAQs%2C_Help%2C_and_Tutorials/Fortran_90_and_95/) ++ [Fortran wikibook](https://en.wikibooks.org/wiki/Fortran) ++ [Fortran resources](http://www.fortranplus.co.uk/resources/fortran_resources.pdf) ++ [Mistakes in Fortran 90 Programs That Might Surprise You](http://www.cs.rpi.edu/~szymansk/OOF90/bugs.html) diff --git a/zh-cn/go-cn.html.markdown b/zh-cn/go-cn.html.markdown index 75498367..37b4b137 100644 --- a/zh-cn/go-cn.html.markdown +++ b/zh-cn/go-cn.html.markdown @@ -142,6 +142,7 @@ func learnTypes() { func learnNamedReturns(x, y int) (z int) { z = x * y return // z is implicit here, because we named it earlier. +} // Go全面支持垃圾回收。Go有指针，但是不支持指针运算。 // 你会因为空指针而犯错，但是不会因为增加指针而犯错。 diff --git a/zh-cn/javascript-cn.html.markdown b/zh-cn/javascript-cn.html.markdown index bdef0099..360f7c65 100644 --- a/zh-cn/javascript-cn.html.markdown +++ b/zh-cn/javascript-cn.html.markdown @@ -12,12 +12,9 @@ translators: lang: zh-cn --- -Javascript于1995年由网景公司的Brendan Eich发明。 -最初发明的目的是作为一个简单的网站脚本语言，来作为 -复杂网站应用java的补充。但由于它与网页结合度很高并且由浏览器内置支持， -所以javascript变得比java在前端更为流行了。 +Javascript 于 1995 年由网景公司的 Brendan Eich 发明。最初它作为一种简单的，用于开发网站的脚本语言而被发明出来，是用于开发复杂网站的 Java 的补充。但由于它与网页结合度很高并且在浏览器中得到内置的支持，所以在网页前端领域 Javascript 变得比 Java 更流行了。 -不过 JavaScript 可不仅仅只用于浏览器： Node.js，一个基于Google Chrome V8引擎的独立运行时环境，也越来越流行。 +不过，Javascript 不仅用于网页浏览器，一个名为 Node.js 的项目提供了面向 Google Chrome V8 引擎的独立运行时环境，它正在变得越来越流行。 很欢迎来自您的反馈，您可以通过下列方式联系到我： [@adambrenecki](https://twitter.com/adambrenecki), 或者 diff --git a/zh-cn/julia-cn.html.markdown b/zh-cn/julia-cn.html.markdown index 1f91d52c..b350b6dc 100644 --- a/zh-cn/julia-cn.html.markdown +++ b/zh-cn/julia-cn.html.markdown @@ -2,16 +2,24 @@ language: Julia filename: learn-julia-zh.jl contributors: - - ["Jichao Ouyang", "http://oyanglul.us"] + - ["Leah Hanson", "http://leahhanson.us"] + - ["Pranit Bauva", "https://github.com/pranitbauva1997"] + - ["Daniel YC Lin", "https://github.com/dlintw"] translators: - ["Jichao Ouyang", "http://oyanglul.us"] + - ["woclass", "https://github.com/inkydragon"] lang: zh-cn --- -```ruby -# 单行注释只需要一个井号 +Julia 是一种新的同像函数式编程语言(homoiconic functional language)，它专注于科学计算领域。 +虽然拥有同像宏(homoiconic macros)、一级函数(first-class functions)和底层控制等全部功能，但 Julia 依旧和 Python 一样易于学习和使用。 + +示例代码基于 Julia 1.0.0 + +```julia +# 单行注释只需要一个井号「#」 #= 多行注释 - 只需要以 '#=' 开始 '=#' 结束 + 只需要以「#=」开始「=#」结束 还可以嵌套. =# @@ -19,41 +27,41 @@ lang: zh-cn ## 1. 原始类型与操作符 #################################################### -# Julia 中一切皆是表达式。 - -# 这是一些基本数字类型. -3 # => 3 (Int64) -3.2 # => 3.2 (Float64) -2 + 1im # => 2 + 1im (Complex{Int64}) -2//3 # => 2//3 (Rational{Int64}) - -# 支持所有的普通中缀操作符。 -1 + 1 # => 2 -8 - 1 # => 7 -10 * 2 # => 20 -35 / 5 # => 7.0 -5 / 2 # => 2.5 # 用 Int 除 Int 永远返回 Float -div(5, 2) # => 2 # 使用 div 截断小数点 -5 \ 35 # => 7.0 -2 ^ 2 # => 4 # 次方, 不是二进制 xor -12 % 10 # => 2 +# Julia 中一切皆为表达式 + +# 这是一些基本数字类型 +typeof(3) # => Int64 +typeof(3.2) # => Float64 +typeof(2 + 1im) # => Complex{Int64} +typeof(2 // 3) # => Rational{Int64} + +# 支持所有的普通中缀操作符 +1 + 1 # => 2 +8 - 1 # => 7 +10 * 2 # => 20 +35 / 5 # => 7.0 +10 / 2 # => 5.0 # 整数除法总是返回浮点数 +div(5, 2) # => 2 # 使用 div 可以获得整除的结果 +5 \ 35 # => 7.0 +2^2 # => 4 # 幂运算，不是异或 (xor) +12 % 10 # => 2 # 用括号提高优先级 (1 + 3) * 2 # => 8 -# 二进制操作符 -~2 # => -3 # 非 -3 & 5 # => 1 # 与 -2 | 4 # => 6 # 或 -2 $ 4 # => 6 # 异或 -2 >>> 1 # => 1 # 逻辑右移 -2 >> 1 # => 1 # 算术右移 -2 << 1 # => 4 # 逻辑/算术 右移 - -# 可以用函数 bits 查看二进制数。 -bits(12345) +# 位操作符 +~2 # => -3 # 按位非 (not) +3 & 5 # => 1 # 按位与 (and) +2 | 4 # => 6 # 按位或 (or) +xor(2, 4) # => 6 # 按位异或 (xor) +2 >>> 1 # => 1 # 逻辑右移 +2 >> 1 # => 1 # 算术右移 +2 << 1 # => 4 # 逻辑/算术左移 + +# 可以用函数 bitstring 查看二进制数。 +bitstring(12345) # => "0000000000000000000000000000000000000000000000000011000000111001" -bits(12345.0) +bitstring(12345.0) # => "0100000011001000000111001000000000000000000000000000000000000000" # 布尔值是原始类型 @@ -61,40 +69,50 @@ true false # 布尔操作符 -!true # => false -!false # => true -1 == 1 # => true -2 == 1 # => false -1 != 1 # => false -2 != 1 # => true -1 < 10 # => true -1 > 10 # => false -2 <= 2 # => true -2 >= 2 # => true -# 比较可以串联 +!true # => false +!false # => true +1 == 1 # => true +2 == 1 # => false +1 != 1 # => false +2 != 1 # => true +1 < 10 # => true +1 > 10 # => false +2 <= 2 # => true +2 >= 2 # => true + +# 链式比较 1 < 2 < 3 # => true 2 < 3 < 2 # => false -# 字符串可以由 " 创建 +# 字符串可以由「"」创建 "This is a string." -# 字符字面量可用 ' 创建 +# 字符字面量可用「'」创建 'a' +# 字符串使用 UTF-8 编码 # 可以像取数组取值一样用 index 取出对应字符 -"This is a string"[1] # => 'T' # Julia 的 index 从 1 开始 :( -# 但是对 UTF-8 无效, -# 因此建议使用遍历器 (map, for loops, 等). +ascii("This is a string")[1] +# => 'T': ASCII/Unicode U+0054 (category Lu: Letter, uppercase) +# Julia 的 index 从 1 开始 :( +# 但只有在字符串仅由 ASCII 字符构成时，字符串才能够被安全的引索 +# 因此建议使用遍历器 (map, for loops, 等) # $ 可用于字符插值: "2 + 2 = $(2 + 2)" # => "2 + 2 = 4" # 可以将任何 Julia 表达式放入括号。 -# 另一种格式化字符串的方式是 printf 宏. -@printf "%d is less than %f" 4.5 5.3 # 5 is less than 5.300000 +# 另一种输出格式化字符串的方法是使用标准库 Printf 中的 Printf 宏 +using Printf +@printf "%d is less than %f\n" 4.5 5.3 # => 5 is less than 5.300000 # 打印字符串很容易 -println("I'm Julia. Nice to meet you!") +println("I'm Julia. Nice to meet you!") # => I'm Julia. Nice to meet you! + +# 字符串可以按字典序进行比较 +"good" > "bye" # => true +"good" == "good" # => true +"1 + 2 = 3" == "1 + 2 = $(1 + 2)" # => true #################################################### ## 2. 变量与集合 @@ -106,12 +124,12 @@ some_var # => 5 # 访问未声明变量会抛出异常 try - some_other_var # => ERROR: some_other_var not defined + some_other_var # => ERROR: UndefVarError: some_other_var not defined catch e println(e) end -# 变量名需要以字母开头. +# 变量名必须以下划线或字母开头 # 之后任何字母，数字，下划线，叹号都是合法的。 SomeOtherVar123! = 6 # => 6 @@ -122,66 +140,93 @@ SomeOtherVar123! = 6 # => 6 # 注意 Julia 的命名规约: # -# * 变量名为小写，单词之间以下划线连接('\_')。 +# * 名称可以用下划线「_」分割。 +# 不过一般不推荐使用下划线，除非不用变量名就会变得难于理解 # -# * 类型名以大写字母开头，单词以 CamelCase 方式连接。 +# * 类型名以大写字母开头，单词以 CamelCase 方式连接，无下划线。 # # * 函数与宏的名字小写，无下划线。 # -# * 会改变输入的函数名末位为 !。 +# * 会改变输入的函数名末位为「!」。 # 这类函数有时被称为 mutating functions 或 in-place functions. -# 数组存储一列值，index 从 1 开始。 -a = Int64[] # => 0-element Int64 Array +# 数组存储一列值，index 从 1 开始 +a = Int64[] # => 0-element Array{Int64,1} + +# 一维数组可以以逗号分隔值的方式声明 +b = [4, 5, 6] # => 3-element Array{Int64,1}: [4, 5, 6] +b = [4; 5; 6] # => 3-element Array{Int64,1}: [4, 5, 6] +b[1] # => 4 +b[end] # => 6 -# 一维数组可以以逗号分隔值的方式声明。 -b = [4, 5, 6] # => 包含 3 个 Int64 类型元素的数组: [4, 5, 6] -b[1] # => 4 -b[end] # => 6 +# 二维数组以分号分隔维度 +matrix = [1 2; 3 4] # => 2×2 Array{Int64,2}: [1 2; 3 4] -# 二维数组以分号分隔维度。 -matrix = [1 2; 3 4] # => 2x2 Int64 数组: [1 2; 3 4] +# 指定数组的类型 +b = Int8[4, 5, 6] # => 3-element Array{Int8,1}: [4, 5, 6] # 使用 push! 和 append! 往数组末尾添加元素 -push!(a,1) # => [1] -push!(a,2) # => [1,2] -push!(a,4) # => [1,2,4] -push!(a,3) # => [1,2,4,3] -append!(a,b) # => [1,2,4,3,4,5,6] +push!(a, 1) # => [1] +push!(a, 2) # => [1,2] +push!(a, 4) # => [1,2,4] +push!(a, 3) # => [1,2,4,3] +append!(a, b) # => [1,2,4,3,4,5,6] -# 用 pop 弹出末尾元素 -pop!(b) # => 6 and b is now [4,5] +# 用 pop 弹出尾部的元素 +pop!(b) # => 6 +b # => [4,5] -# 可以再放回去 -push!(b,6) # b 又变成了 [4,5,6]. +# 再放回去 +push!(b, 6) # => [4,5,6] +b # => [4,5,6] -a[1] # => 1 # 永远记住 Julia 的 index 从 1 开始! +a[1] # => 1 # 永远记住 Julia 的引索从 1 开始！而不是 0！ -# 用 end 可以直接取到最后索引. 可用作任何索引表达式 +# 用 end 可以直接取到最后索引。它可以用在任何索引表达式中 a[end] # => 6 -# 还支持 shift 和 unshift -shift!(a) # => 返回 1，而 a 现在时 [2,4,3,4,5,6] -unshift!(a,7) # => [7,2,4,3,4,5,6] +# 数组还支持 popfirst! 和 pushfirst! +popfirst!(a) # => 1 +a # => [2,4,3,4,5,6] +pushfirst!(a, 7) # => [7,2,4,3,4,5,6] +a # => [7,2,4,3,4,5,6] # 以叹号结尾的函数名表示它会改变参数的值 -arr = [5,4,6] # => 包含三个 Int64 元素的数组: [5,4,6] -sort(arr) # => [4,5,6]; arr 还是 [5,4,6] -sort!(arr) # => [4,5,6]; arr 现在是 [4,5,6] +arr = [5,4,6] # => 3-element Array{Int64,1}: [5,4,6] +sort(arr) # => [4,5,6] +arr # => [5,4,6] +sort!(arr) # => [4,5,6] +arr # => [4,5,6] -# 越界会抛出 BoundsError 异常 +# 数组越界会抛出 BoundsError try - a[0] # => ERROR: BoundsError() in getindex at array.jl:270 - a[end+1] # => ERROR: BoundsError() in getindex at array.jl:270 + a[0] + # => ERROR: BoundsError: attempt to access 7-element Array{Int64,1} at + # index [0] + # => Stacktrace: + # => [1] getindex(::Array{Int64,1}, ::Int64) at .\array.jl:731 + # => [2] top-level scope at none:0 + # => [3] ... + # => in expression starting at ...\LearnJulia.jl:203 + a[end + 1] + # => ERROR: BoundsError: attempt to access 7-element Array{Int64,1} at + # index [8] + # => Stacktrace: + # => [1] getindex(::Array{Int64,1}, ::Int64) at .\array.jl:731 + # => [2] top-level scope at none:0 + # => [3] ... + # => in expression starting at ...\LearnJulia.jl:211 catch e println(e) end -# 错误会指出发生的行号，包括标准库 -# 如果你有 Julia 源代码，你可以找到这些地方 +# 报错时错误会指出出错的文件位置以及行号，标准库也一样 +# 你可以在 Julia 安装目录下的 share/julia 文件夹里找到这些标准库 # 可以用 range 初始化数组 -a = [1:5] # => 5-element Int64 Array: [1,2,3,4,5] +a = [1:5;] # => 5-element Array{Int64,1}: [1,2,3,4,5] +# 注意！分号不可省略 +a2 = [1:5] # => 1-element Array{UnitRange{Int64},1}: [1:5] # 可以切割数组 a[1:3] # => [1, 2, 3] @@ -189,11 +234,13 @@ a[2:end] # => [2, 3, 4, 5] # 用 splice! 切割原数组 arr = [3,4,5] -splice!(arr,2) # => 4 ; arr 变成了 [3,5] +splice!(arr, 2) # => 4 +arr # => [3,5] # 用 append! 连接数组 b = [1,2,3] -append!(a,b) # a 变成了 [1, 2, 3, 4, 5, 1, 2, 3] +append!(a, b) # => [1, 2, 3, 4, 5, 1, 2, 3] +a # => [1, 2, 3, 4, 5, 1, 2, 3] # 检查元素是否在数组中 in(1, a) # => true @@ -201,240 +248,258 @@ in(1, a) # => true # 用 length 获得数组长度 length(a) # => 8 -# Tuples 是 immutable 的 -tup = (1, 2, 3) # => (1,2,3) # an (Int64,Int64,Int64) tuple. +# 元组(Tuples)是不可变的 +tup = (1, 2, 3) # => (1,2,3) +typeof(tup) # => Tuple{Int64,Int64,Int64} tup[1] # => 1 -try: - tup[1] = 3 # => ERROR: no method setindex!((Int64,Int64,Int64),Int64,Int64) +try + tup[1] = 3 + # => ERROR: MethodError: no method matching + # setindex!(::Tuple{Int64,Int64,Int64}, ::Int64, ::Int64) catch e println(e) end -# 大多数组的函数同样支持 tuples +# 大多数组的函数同样支持元组 length(tup) # => 3 -tup[1:2] # => (1,2) -in(2, tup) # => true +tup[1:2] # => (1,2) +in(2, tup) # => true -# 可以将 tuples 元素分别赋给变量 -a, b, c = (1, 2, 3) # => (1,2,3) # a is now 1, b is now 2 and c is now 3 +# 可以将元组的元素解包赋给变量 +a, b, c = (1, 2, 3) # => (1,2,3) +a # => 1 +b # => 2 +c # => 3 # 不用括号也可以 -d, e, f = 4, 5, 6 # => (4,5,6) +d, e, f = 4, 5, 6 # => (4,5,6) +d # => 4 +e # => 5 +f # => 6 # 单元素 tuple 不等于其元素值 (1,) == 1 # => false -(1) == 1 # => true +(1) == 1 # => true # 交换值 -e, d = d, e # => (5,4) # d is now 5 and e is now 4 +e, d = d, e # => (5,4) +d # => 5 +e # => 4 -# 字典Dictionaries store mappings -empty_dict = Dict() # => Dict{Any,Any}() +# 字典用于储存映射(mappings)（键值对） +empty_dict = Dict() # => Dict{Any,Any} with 0 entries # 也可以用字面量创建字典 -filled_dict = ["one"=> 1, "two"=> 2, "three"=> 3] -# => Dict{ASCIIString,Int64} +filled_dict = Dict("one" => 1, "two" => 2, "three" => 3) +# => Dict{String,Int64} with 3 entries: +# => "two" => 2, "one" => 1, "three" => 3 # 用 [] 获得键值 filled_dict["one"] # => 1 # 获得所有键 keys(filled_dict) -# => KeyIterator{Dict{ASCIIString,Int64}}(["three"=>3,"one"=>1,"two"=>2]) +# => Base.KeySet for a Dict{String,Int64} with 3 entries. Keys: +# => "two", "one", "three" # 注意，键的顺序不是插入时的顺序 # 获得所有值 values(filled_dict) -# => ValueIterator{Dict{ASCIIString,Int64}}(["three"=>3,"one"=>1,"two"=>2]) +# => Base.ValueIterator for a Dict{String,Int64} with 3 entries. Values: +# => 2, 1, 3 # 注意，值的顺序也一样 # 用 in 检查键值是否已存在，用 haskey 检查键是否存在 -in(("one", 1), filled_dict) # => true -in(("two", 3), filled_dict) # => false -haskey(filled_dict, "one") # => true -haskey(filled_dict, 1) # => false +in(("one" => 1), filled_dict) # => true +in(("two" => 3), filled_dict) # => false +haskey(filled_dict, "one") # => true +haskey(filled_dict, 1) # => false # 获取不存在的键的值会抛出异常 try - filled_dict["four"] # => ERROR: key not found: four in getindex at dict.jl:489 + filled_dict["four"] # => ERROR: KeyError: key "four" not found catch e println(e) end # 使用 get 可以提供默认值来避免异常 # get(dictionary,key,default_value) -get(filled_dict,"one",4) # => 1 -get(filled_dict,"four",4) # => 4 +get(filled_dict, "one", 4) # => 1 +get(filled_dict, "four", 4) # => 4 -# 用 Sets 表示无序不可重复的值的集合 -empty_set = Set() # => Set{Any}() -# 初始化一个 Set 并定义其值 -filled_set = Set(1,2,2,3,4) # => Set{Int64}(1,2,3,4) +# Set 表示无序不可重复的值的集合 +empty_set = Set() # => Set(Any[]) +# 初始化一个带初值的 Set +filled_set = Set([1, 2, 2, 3, 4]) # => Set([4, 2, 3, 1]) -# 添加值 -push!(filled_set,5) # => Set{Int64}(5,4,2,3,1) +# 新增值 +push!(filled_set, 5) # => Set([4, 2, 3, 5, 1]) -# 检查是否存在某值 -in(2, filled_set) # => true -in(10, filled_set) # => false +# 检查 Set 中是否存在某值 +in(2, filled_set) # => true +in(10, filled_set) # => false # 交集，并集，差集 -other_set = Set(3, 4, 5, 6) # => Set{Int64}(6,4,5,3) -intersect(filled_set, other_set) # => Set{Int64}(3,4,5) -union(filled_set, other_set) # => Set{Int64}(1,2,3,4,5,6) -setdiff(Set(1,2,3,4),Set(2,3,5)) # => Set{Int64}(1,4) - +other_set = Set([3, 4, 5, 6]) # => Set([4, 3, 5, 6]) +intersect(filled_set, other_set) # => Set([4, 3, 5]) +union(filled_set, other_set) # => Set([4, 2, 3, 5, 6, 1]) +setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set([4, 1]) #################################################### -## 3. 控制流 +## 3. 控制语句 #################################################### # 声明一个变量 some_var = 5 -# 这是一个 if 语句，缩进不是必要的 +# 这是一个 if 语句块，其中的缩进不是必须的 if some_var > 10 println("some_var is totally bigger than 10.") -elseif some_var < 10 # elseif 是可选的. +elseif some_var < 10 # elseif 是可选的 println("some_var is smaller than 10.") -else # else 也是可选的. +else # else 也是可选的 println("some_var is indeed 10.") end -# => prints "some var is smaller than 10" +# => some_var is smaller than 10. # For 循环遍历 -# Iterable 类型包括 Range, Array, Set, Dict, 以及 String. -for animal=["dog", "cat", "mouse"] +# 可迭代的类型包括：Range, Array, Set, Dict 和 AbstractString +for animal = ["dog", "cat", "mouse"] println("$animal is a mammal") - # 可用 $ 将 variables 或 expression 转换为字符串into strings + # 你可以用 $ 将变量或表达式插入字符串中 end -# prints: -# dog is a mammal -# cat is a mammal -# mouse is a mammal +# => dog is a mammal +# => cat is a mammal +# => mouse is a mammal -# You can use 'in' instead of '='. +# 你也可以不用「=」而使用「in」 for animal in ["dog", "cat", "mouse"] println("$animal is a mammal") end -# prints: -# dog is a mammal -# cat is a mammal -# mouse is a mammal +# => dog is a mammal +# => cat is a mammal +# => mouse is a mammal -for a in ["dog"=>"mammal","cat"=>"mammal","mouse"=>"mammal"] - println("$(a[1]) is a $(a[2])") +for pair in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal") + from, to = pair + println("$from is a $to") end -# prints: -# dog is a mammal -# cat is a mammal -# mouse is a mammal +# => mouse is a mammal +# => cat is a mammal +# => dog is a mammal +# 注意！这里的输出顺序和上面的不同 -for (k,v) in ["dog"=>"mammal","cat"=>"mammal","mouse"=>"mammal"] +for (k, v) in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal") println("$k is a $v") end -# prints: -# dog is a mammal -# cat is a mammal -# mouse is a mammal +# => mouse is a mammal +# => cat is a mammal +# => dog is a mammal # While 循环 -x = 0 -while x < 4 - println(x) - x += 1 # x = x + 1 +let x = 0 + while x < 4 + println(x) + x += 1 # x = x + 1 的缩写 + end end -# prints: -# 0 -# 1 -# 2 -# 3 +# => 0 +# => 1 +# => 2 +# => 3 # 用 try/catch 处理异常 try - error("help") + error("help") catch e - println("caught it $e") + println("caught it $e") end # => caught it ErrorException("help") - #################################################### ## 4. 函数 #################################################### -# 用关键字 'function' 可创建一个新函数 -#function name(arglist) -# body... -#end +# 关键字 function 用于定义函数 +# function name(arglist) +# body... +# end function add(x, y) println("x is $x and y is $y") - # 最后一行语句的值为返回 + # 函数会返回最后一行的值 x + y end -add(5, 6) # => 在 "x is 5 and y is 6" 后会打印 11 +add(5, 6) +# => x is 5 and y is 6 +# => 11 + +# 更紧凑的定义函数 +f_add(x, y) = x + y # => f_add (generic function with 1 method) +f_add(3, 4) # => 7 + +# 函数可以将多个值作为元组返回 +fn(x, y) = x + y, x - y # => fn (generic function with 1 method) +fn(3, 4) # => (7, -1) # 还可以定义接收可变长参数的函数 function varargs(args...) return args - # 关键字 return 可在函数内部任何地方返回 + # 使用 return 可以在函数内的任何地方返回 end # => varargs (generic function with 1 method) varargs(1,2,3) # => (1,2,3) -# 省略号 ... 被称为 splat. +# 省略号「...」称为 splat # 刚刚用在了函数定义中 -# 还可以用在函数的调用 -# Array 或者 Tuple 的内容会变成参数列表 -Set([1,2,3]) # => Set{Array{Int64,1}}([1,2,3]) # 获得一个 Array 的 Set -Set([1,2,3]...) # => Set{Int64}(1,2,3) # 相当于 Set(1,2,3) +# 在调用函数时也可以使用它，此时它会把数组或元组解包为参数列表 +add([5,6]...) # 等价于 add(5,6) -x = (1,2,3) # => (1,2,3) -Set(x) # => Set{(Int64,Int64,Int64)}((1,2,3)) # 一个 Tuple 的 Set -Set(x...) # => Set{Int64}(2,3,1) +x = (5, 6) # => (5,6) +add(x...) # 等价于 add(5,6) - -# 可定义可选参数的函数 -function defaults(a,b,x=5,y=6) +# 可定义带可选参数的函数 +function defaults(a, b, x=5, y=6) return "$a $b and $x $y" end +# => defaults (generic function with 3 methods) -defaults('h','g') # => "h g and 5 6" -defaults('h','g','j') # => "h g and j 6" -defaults('h','g','j','k') # => "h g and j k" +defaults('h', 'g') # => "h g and 5 6" +defaults('h', 'g', 'j') # => "h g and j 6" +defaults('h', 'g', 'j', 'k') # => "h g and j k" try - defaults('h') # => ERROR: no method defaults(Char,) - defaults() # => ERROR: no methods defaults() + defaults('h') # => ERROR: MethodError: no method matching defaults(::Char) + defaults() # => ERROR: MethodError: no method matching defaults() catch e println(e) end -# 还可以定义键值对的参数 -function keyword_args(;k1=4,name2="hello") # note the ; - return ["k1"=>k1,"name2"=>name2] +# 还可以定义带关键字参数的函数 +function keyword_args(;k1=4, name2="hello") # 注意分号 ';' + return Dict("k1" => k1, "name2" => name2) end +# => keyword_args (generic function with 1 method) -keyword_args(name2="ness") # => ["name2"=>"ness","k1"=>4] -keyword_args(k1="mine") # => ["k1"=>"mine","name2"=>"hello"] -keyword_args() # => ["name2"=>"hello","k1"=>4] +keyword_args(name2="ness") # => ["name2"=>"ness", "k1"=>4] +keyword_args(k1="mine") # => ["name2"=>"hello", "k1"=>"mine"] +keyword_args() # => ["name2"=>"hello", "k1"=>4] -# 可以组合各种类型的参数在同一个函数的参数列表中 +# 可以在一个函数中组合各种类型的参数 function all_the_args(normal_arg, optional_positional_arg=2; keyword_arg="foo") println("normal arg: $normal_arg") println("optional arg: $optional_positional_arg") println("keyword arg: $keyword_arg") end +# => all_the_args (generic function with 2 methods) all_the_args(1, 3, keyword_arg=4) -# prints: -# normal arg: 1 -# optional arg: 3 -# keyword arg: 4 +# => normal arg: 1 +# => optional arg: 3 +# => keyword arg: 4 # Julia 有一等函数 function create_adder(x) @@ -443,14 +508,16 @@ function create_adder(x) end return adder end +# => create_adder (generic function with 1 method) # 这是用 "stabby lambda syntax" 创建的匿名函数 (x -> x > 2)(3) # => true -# 这个函数和上面的 create_adder 一模一样 +# 这个函数和上面的 create_adder 是等价的 function create_adder(x) y -> x + y end +# => create_adder (generic function with 1 method) # 你也可以给内部函数起个名字 function create_adder(x) @@ -459,18 +526,19 @@ function create_adder(x) end adder end +# => create_adder (generic function with 1 method) -add_10 = create_adder(10) -add_10(3) # => 13 - +add_10 = create_adder(10) # => (::getfield(Main, Symbol("#adder#11")){Int64}) + # (generic function with 1 method) +add_10(3) # => 13 # 内置的高阶函数有 -map(add_10, [1,2,3]) # => [11, 12, 13] -filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] +map(add_10, [1,2,3]) # => [11, 12, 13] +filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] -# 还可以使用 list comprehensions 替代 map -[add_10(i) for i=[1, 2, 3]] # => [11, 12, 13] -[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] +# 还可以使用 list comprehensions 让 map 更美观 +[add_10(i) for i = [1, 2, 3]] # => [11, 12, 13] +[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13] #################################################### ## 5. 类型 @@ -482,248 +550,315 @@ filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7] typeof(5) # => Int64 # 类型是一等值 -typeof(Int64) # => DataType -typeof(DataType) # => DataType +typeof(Int64) # => DataType +typeof(DataType) # => DataType # DataType 是代表类型的类型，也代表他自己的类型 -# 类型可用作文档化，优化，以及调度 -# 并不是静态检查类型 +# 类型可用于文档化代码、执行优化以及多重派分(dispatch) +# Julia 并不只是静态的检查类型 # 用户还可以自定义类型 -# 跟其他语言的 records 或 structs 一样 -# 用 `type` 关键字定义新的类型 +# 就跟其它语言的 record 或 struct 一样 +# 用 `struct` 关键字定义新的类型 -# type Name +# struct Name # field::OptionalType # ... # end -type Tiger - taillength::Float64 - coatcolor # 不附带类型标注的相当于 `::Any` +struct Tiger + taillength::Float64 + coatcolor # 不带类型标注相当于 `::Any` end -# 构造函数参数是类型的属性 -tigger = Tiger(3.5,"orange") # => Tiger(3.5,"orange") +# 默认构造函数的参数是类型的属性，按类型定义中的顺序排列 +tigger = Tiger(3.5, "orange") # => Tiger(3.5, "orange") # 用新类型作为构造函数还会创建一个类型 -sherekhan = typeof(tigger)(5.6,"fire") # => Tiger(5.6,"fire") +sherekhan = typeof(tigger)(5.6, "fire") # => Tiger(5.6, "fire") -# struct 类似的类型被称为具体类型 -# 他们可被实例化但不能有子类型 +# 类似 struct 的类型被称为具体类型 +# 它们可被实例化，但不能有子类型 # 另一种类型是抽象类型 -# abstract Name -abstract Cat # just a name and point in the type hierarchy +# 抽象类型名 +abstract type Cat end # 仅仅是指向类型结构层次的一个名称 -# 抽象类型不能被实例化，但是可以有子类型 +# 抽象类型不能被实例化，但可以有子类型 # 例如，Number 就是抽象类型 -subtypes(Number) # => 6-element Array{Any,1}: - # Complex{Float16} - # Complex{Float32} - # Complex{Float64} - # Complex{T<:Real} - # ImaginaryUnit - # Real -subtypes(Cat) # => 0-element Array{Any,1} - -# 所有的类型都有父类型; 可以用函数 `super` 得到父类型. +subtypes(Number) # => 2-element Array{Any,1}: + # => Complex + # => Real +subtypes(Cat) # => 0-element Array{Any,1} + +# AbstractString，类如其名，也是一个抽象类型 +subtypes(AbstractString) # => 4-element Array{Any,1}: + # => String + # => SubString + # => SubstitutionString + # => Test.GenericString + +# 所有的类型都有父类型。可以用函数 `supertype` 得到父类型 typeof(5) # => Int64 -super(Int64) # => Signed -super(Signed) # => Real -super(Real) # => Number -super(Number) # => Any -super(super(Signed)) # => Number -super(Any) # => Any -# 所有这些类型，除了 Int64, 都是抽象类型. - -# <: 是类型集成操作符 -type Lion <: Cat # Lion 是 Cat 的子类型 - mane_color - roar::String +supertype(Int64) # => Signed +supertype(Signed) # => Integer +supertype(Integer) # => Real +supertype(Real) # => Number +supertype(Number) # => Any +supertype(supertype(Signed)) # => Real +supertype(Any) # => Any +# 除了 Int64 外，其余的类型都是抽象类型 +typeof("fire") # => String +supertype(String) # => AbstractString +supertype(AbstractString) # => Any +supertype(SubString) # => AbstractString + +# <: 是子类型化操作符 +struct Lion <: Cat # Lion 是 Cat 的子类型 + mane_color + roar::AbstractString end # 可以继续为你的类型定义构造函数 -# 只需要定义一个同名的函数 -# 并调用已有的构造函数设置一个固定参数 -Lion(roar::String) = Lion("green",roar) -# 这是一个外部构造函数，因为他再类型定义之外 - -type Panther <: Cat # Panther 也是 Cat 的子类型 - eye_color - Panther() = new("green") - # Panthers 只有这个构造函数，没有默认构造函数 +# 只需要定义一个与类型同名的函数，并调用已有的构造函数得到正确的类型 +Lion(roar::AbstractString) = Lion("green", roar) # => Lion +# 这是一个外部构造函数，因为它在类型定义之外 + +struct Panther <: Cat # Panther 也是 Cat 的子类型 + eye_color + Panther() = new("green") + # Panthers 只有这个构造函数，没有默认构造函数 end -# 使用内置构造函数，如 Panther，可以让你控制 -# 如何构造类型的值 -# 应该尽可能使用外部构造函数而不是内部构造函数 +# 像 Panther 一样使用内置构造函数，让你可以控制如何构建类型的值 +# 应该尽量使用外部构造函数，而不是内部构造函数 #################################################### ## 6. 多分派 #################################################### -# 在Julia中, 所有的具名函数都是类属函数 -# 这意味着他们都是有很大小方法组成的 -# 每个 Lion 的构造函数都是类属函数 Lion 的方法 +# Julia 中所有的函数都是通用函数，或者叫做泛型函数(generic functions) +# 也就是说这些函数都是由许多小方法组合而成的 +# Lion 的每一种构造函数都是通用函数 Lion 的一个方法 # 我们来看一个非构造函数的例子 +# 首先，让我们定义一个函数 meow -# Lion, Panther, Tiger 的 meow 定义为 +# Lion, Panther, Tiger 的 meow 定义分别为 function meow(animal::Lion) - animal.roar # 使用点符号访问属性 + animal.roar # 使用点记号「.」访问属性 end +# => meow (generic function with 1 method) function meow(animal::Panther) - "grrr" + "grrr" end +# => meow (generic function with 2 methods) function meow(animal::Tiger) - "rawwwr" + "rawwwr" end +# => meow (generic function with 3 methods) # 试试 meow 函数 -meow(tigger) # => "rawwr" -meow(Lion("brown","ROAAR")) # => "ROAAR" +meow(tigger) # => "rawwwr" +meow(Lion("brown", "ROAAR")) # => "ROAAR" meow(Panther()) # => "grrr" -# 再看看层次结构 -issubtype(Tiger,Cat) # => false -issubtype(Lion,Cat) # => true -issubtype(Panther,Cat) # => true +# 回顾类型的层次结构 +Tiger <: Cat # => false +Lion <: Cat # => true +Panther <: Cat # => true -# 定义一个接收 Cats 的函数 +# 定义一个接收 Cat 类型的函数 function pet_cat(cat::Cat) - println("The cat says $(meow(cat))") + println("The cat says $(meow(cat))") end +# => pet_cat (generic function with 1 method) -pet_cat(Lion("42")) # => prints "The cat says 42" +pet_cat(Lion("42")) # => The cat says 42 try - pet_cat(tigger) # => ERROR: no method pet_cat(Tiger,) + pet_cat(tigger) # => ERROR: MethodError: no method matching pet_cat(::Tiger) catch e println(e) end # 在面向对象语言中，通常都是单分派 -# 这意味着分派方法是通过第一个参数的类型决定的 -# 在Julia中, 所有参数类型都会被考虑到 +# 这意味着使用的方法取决于第一个参数的类型 +# 而 Julia 中选择方法时会考虑到所有参数的类型 -# 让我们定义有多个参数的函数，好看看区别 -function fight(t::Tiger,c::Cat) - println("The $(t.coatcolor) tiger wins!") +# 让我们定义一个有更多参数的函数，这样我们就能看出区别 +function fight(t::Tiger, c::Cat) + println("The $(t.coatcolor) tiger wins!") end # => fight (generic function with 1 method) -fight(tigger,Panther()) # => prints The orange tiger wins! -fight(tigger,Lion("ROAR")) # => prints The orange tiger wins! +fight(tigger, Panther()) # => The orange tiger wins! +fight(tigger, Lion("ROAR")) # => fight(tigger, Lion("ROAR")) -# 让我们修改一下传入具体为 Lion 类型时的行为 -fight(t::Tiger,l::Lion) = println("The $(l.mane_color)-maned lion wins!") +# 让我们修改一下传入 Lion 类型时的行为 +fight(t::Tiger, l::Lion) = println("The $(l.mane_color)-maned lion wins!") # => fight (generic function with 2 methods) -fight(tigger,Panther()) # => prints The orange tiger wins! -fight(tigger,Lion("ROAR")) # => prints The green-maned lion wins! +fight(tigger, Panther()) # => The orange tiger wins! +fight(tigger, Lion("ROAR")) # => The green-maned lion wins! -# 把 Tiger 去掉 -fight(l::Lion,c::Cat) = println("The victorious cat says $(meow(c))") +# 我们不需要一只老虎参与战斗 +fight(l::Lion, c::Cat) = println("The victorious cat says $(meow(c))") # => fight (generic function with 3 methods) -fight(Lion("balooga!"),Panther()) # => prints The victorious cat says grrr +fight(Lion("balooga!"), Panther()) # => The victorious cat says grrr try - fight(Panther(),Lion("RAWR")) # => ERROR: no method fight(Panther,Lion) -catch + fight(Panther(), Lion("RAWR")) + # => ERROR: MethodError: no method matching fight(::Panther, ::Lion) + # => Closest candidates are: + # => fight(::Tiger, ::Lion) at ... + # => fight(::Tiger, ::Cat) at ... + # => fight(::Lion, ::Cat) at ... + # => ... +catch e + println(e) end -# 在试试让 Cat 在前面 -fight(c::Cat,l::Lion) = println("The cat beats the Lion") -# => Warning: New definition -# fight(Cat,Lion) at none:1 -# is ambiguous with -# fight(Lion,Cat) at none:2. -# Make sure -# fight(Lion,Lion) -# is defined first. -#fight (generic function with 4 methods) - -# 警告说明了无法判断使用哪个 fight 方法 -fight(Lion("RAR"),Lion("brown","rarrr")) # => prints The victorious cat says rarrr -# 结果在老版本 Julia 中可能会不一样 - -fight(l::Lion,l2::Lion) = println("The lions come to a tie") -fight(Lion("RAR"),Lion("brown","rarrr")) # => prints The lions come to a tie - - -# Under the hood -# 你还可以看看 llvm 以及生成的汇编代码 - -square_area(l) = l * l # square_area (generic function with 1 method) - -square_area(5) #25 - -# 给 square_area 一个整形时发生什么 -code_native(square_area, (Int32,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 # Prologue - # push RBP - # mov RBP, RSP - # Source line: 1 - # movsxd RAX, EDI # Fetch l from memory? - # imul RAX, RAX # Square l and store the result in RAX - # pop RBP # Restore old base pointer - # ret # Result will still be in RAX - -code_native(square_area, (Float32,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # Source line: 1 - # vmulss XMM0, XMM0, XMM0 # Scalar single precision multiply (AVX) - # pop RBP - # ret - -code_native(square_area, (Float64,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # Source line: 1 - # vmulsd XMM0, XMM0, XMM0 # Scalar double precision multiply (AVX) - # pop RBP - # ret - # -# 注意 只要参数中又浮点类型，Julia 就使用浮点指令 +# 试试把 Cat 放在前面 +fight(c::Cat, l::Lion) = println("The cat beats the Lion") +# => fight (generic function with 4 methods) + +# 由于无法判断该使用哪个 fight 方法，而产生了错误 +try + fight(Lion("RAR"), Lion("brown", "rarrr")) + # => ERROR: MethodError: fight(::Lion, ::Lion) is ambiguous. Candidates: + # => fight(c::Cat, l::Lion) in Main at ... + # => fight(l::Lion, c::Cat) in Main at ... + # => Possible fix, define + # => fight(::Lion, ::Lion) + # => ... +catch e + println(e) +end +# 在不同版本的 Julia 中错误信息可能有所不同 + +fight(l::Lion, l2::Lion) = println("The lions come to a tie") +# => fight (generic function with 5 methods) +fight(Lion("RAR"), Lion("brown", "rarrr")) # => The lions come to a tie + + +# 深入编译器之后 +# 你还可以看看 llvm 以及它生成的汇编代码 + +square_area(l) = l * l # => square_area (generic function with 1 method) +square_area(5) # => 25 + +# 当我们喂给 square_area 一个整数时会发生什么？ +code_native(square_area, (Int32,), syntax = :intel) + # .text + # ; Function square_area { + # ; Location: REPL[116]:1 # 函数序言 (Prologue) + # push rbp + # mov rbp, rsp + # ; Function *; { + # ; Location: int.jl:54 + # imul ecx, ecx # 求 l 的平方，并把结果放在 ECX 中 + # ;} + # mov eax, ecx + # pop rbp # 还原旧的基址指针(base pointer) + # ret # 返回值放在 EAX 中 + # nop dword ptr [rax + rax] + # ;} +# 使用 syntax 参数指定输出语法。默认为 AT&T 格式，这里指定为 Intel 格式 + +code_native(square_area, (Float32,), syntax = :intel) + # .text + # ; Function square_area { + # ; Location: REPL[116]:1 + # push rbp + # mov rbp, rsp + # ; Function *; { + # ; Location: float.jl:398 + # vmulss xmm0, xmm0, xmm0 # 标量双精度乘法 (AVX) + # ;} + # pop rbp + # ret + # nop word ptr [rax + rax] + # ;} + +code_native(square_area, (Float64,), syntax = :intel) + # .text + # ; Function square_area { + # ; Location: REPL[116]:1 + # push rbp + # mov rbp, rsp + # ; Function *; { + # ; Location: float.jl:399 + # vmulsd xmm0, xmm0, xmm0 # 标量双精度乘法 (AVX) + # ;} + # pop rbp + # ret + # nop word ptr [rax + rax] + # ;} + +# 注意！只要参数中有浮点数，Julia 就会使用浮点指令 # 让我们计算一下圆的面积 -circle_area(r) = pi * r * r # circle_area (generic function with 1 method) -circle_area(5) # 78.53981633974483 - -code_native(circle_area, (Int32,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # Source line: 1 - # vcvtsi2sd XMM0, XMM0, EDI # Load integer (r) from memory - # movabs RAX, 4593140240 # Load pi - # vmulsd XMM1, XMM0, QWORD PTR [RAX] # pi * r - # vmulsd XMM0, XMM0, XMM1 # (pi * r) * r - # pop RBP - # ret - # - -code_native(circle_area, (Float64,)) - # .section __TEXT,__text,regular,pure_instructions - # Filename: none - # Source line: 1 - # push RBP - # mov RBP, RSP - # movabs RAX, 4593140496 - # Source line: 1 - # vmulsd XMM1, XMM0, QWORD PTR [RAX] - # vmulsd XMM0, XMM1, XMM0 - # pop RBP - # ret - # +circle_area(r) = pi * r * r # => circle_area (generic function with 1 method) +circle_area(5) # => 78.53981633974483 + +code_native(circle_area, (Int32,), syntax = :intel) + # .text + # ; Function circle_area { + # ; Location: REPL[121]:1 + # push rbp + # mov rbp, rsp + # ; Function *; { + # ; Location: operators.jl:502 + # ; Function *; { + # ; Location: promotion.jl:314 + # ; Function promote; { + # ; Location: promotion.jl:284 + # ; Function _promote; { + # ; Location: promotion.jl:261 + # ; Function convert; { + # ; Location: number.jl:7 + # ; Function Type; { + # ; Location: float.jl:60 + # vcvtsi2sd xmm0, xmm0, ecx # 从内存中读取整数 r + # movabs rax, 497710928 # 读取 pi + # ;}}}}} + # ; Function *; { + # ; Location: float.jl:399 + # vmulsd xmm1, xmm0, qword ptr [rax] # pi * r + # vmulsd xmm0, xmm1, xmm0 # (pi * r) * r + # ;}} + # pop rbp + # ret + # nop dword ptr [rax] + # ;} + +code_native(circle_area, (Float64,), syntax = :intel) + # .text + # ; Function circle_area { + # ; Location: REPL[121]:1 + # push rbp + # mov rbp, rsp + # movabs rax, 497711048 + # ; Function *; { + # ; Location: operators.jl:502 + # ; Function *; { + # ; Location: promotion.jl:314 + # ; Function *; { + # ; Location: float.jl:399 + # vmulsd xmm1, xmm0, qword ptr [rax] + # ;}}} + # ; Function *; { + # ; Location: float.jl:399 + # vmulsd xmm0, xmm1, xmm0 + # ;} + # pop rbp + # ret + # nop dword ptr [rax + rax] + # ;} ``` + +## 拓展阅读材料 + +你可以在 [Julia 中文文档](http://docs.juliacn.com/latest/) / [Julia 文档(en)](https://docs.julialang.org/) +中获得关于 Julia 的更多细节。 + +如果有任何问题可以去 [Julia 中文社区](http://discourse.juliacn.com/) / [官方社区(en)](https://discourse.julialang.org/) 提问，大家对待新手都非常的友好。 diff --git a/zh-cn/kotlin-cn.html.markdown b/zh-cn/kotlin-cn.html.markdown index 5d655029..f6dcd847 100644 --- a/zh-cn/kotlin-cn.html.markdown +++ b/zh-cn/kotlin-cn.html.markdown @@ -22,7 +22,7 @@ package com.learnxinyminutes.kotlin /* Kotlin程序的入口点是一个"main"函数 -该函数传递一个包含任何命令行参数的数组。 +该函数传递一个包含所有命令行参数的数组。 */ fun main(args: Array<String>) { /* @@ -67,10 +67,10 @@ fun helloWorld(val name : String) { 模板表达式从一个美元符号($)开始。 */ val fooTemplateString = "$fooString has ${fooString.length} characters" - println(fooTemplateString) + println(fooTemplateString) // => 输出 My String Is Here! has 18 characters /* - 当某个变量的值可以为 null 的时候，我们必须被明确指定它是可为空的。 + 当某个变量的值可以为 null 的时候，我们必须明确指定它是可为空的。 在变量声明处的类型后面加上?来标识它是可为空的。 我们可以用?.操作符来访问可为空的变量。 我们可以用?:操作符来指定一个在变量为空时使用的替代值。 @@ -96,24 +96,24 @@ fun helloWorld(val name : String) { println(hello()) // => Hello, world! /* - 用"vararg"关键字来修饰一个函数的参数来允许可变参数传递给该函数 + 函数的可变参数可使用 "vararg" 关键字来修饰 */ fun varargExample(vararg names: Int) { println("Argument has ${names.size} elements") } - varargExample() // => Argument has 0 elements - varargExample(1) // => Argument has 1 elements - varargExample(1, 2, 3) // => Argument has 3 elements + varargExample() // => 传入 0 个参数 + varargExample(1) // => 传入 1 个参数 + varargExample(1, 2, 3) // => 传入 3 个参数 /* - 当函数只包含一个单独的表达式时，大括号可以被省略。 - 函数体可以被指定在一个=符号后面。 + 当函数只包含一个单独的表达式时，大括号可以省略。 + 函数体可以写在一个=符号后面。 */ fun odd(x: Int): Boolean = x % 2 == 1 println(odd(6)) // => false println(odd(7)) // => true - // 如果返回值类型可以被推断，那么我们不需要指定它。 + // 如果返回值类型可以推断，那么我们不需要指定它。 fun even(x: Int) = x % 2 == 0 println(even(6)) // => true println(even(7)) // => false @@ -122,15 +122,14 @@ fun helloWorld(val name : String) { fun not(f: (Int) -> Boolean) : (Int) -> Boolean { return {n -> !f.invoke(n)} } - // 命名函数可以用::运算符被指定为参数。 + // 普通函数可以用::运算符传入引用作为函数参数。 val notOdd = not(::odd) val notEven = not(::even) - // 匿名函数可以被指定为参数。 + // lambda 表达式可以直接作为参数传递。 val notZero = not {n -> n == 0} /* - 如果一个匿名函数只有一个参数 - 那么它的声明可以被省略（连同->）。 - 这个参数的名字是"it"。 + 如果一个 lambda 表达式只有一个参数 + 那么它的声明可以省略（连同->），内部以 "it" 引用。 */ val notPositive = not {it > 0} for (i in 0..4) { @@ -152,7 +151,7 @@ fun helloWorld(val name : String) { 注意，Kotlin没有"new"关键字。 */ val fooExampleClass = ExampleClass(7) - // 可以使用一个点号来调用成员函数。 + // 可以使用一个点号来调用成员方法。 println(fooExampleClass.memberFunction(4)) // => 11 /* 如果使用"infix"关键字来标记一个函数 @@ -162,7 +161,7 @@ fun helloWorld(val name : String) { /* 数据类是创建只包含数据的类的一个简洁的方法。 - "hashCode"、"equals"和"toString"方法将被自动生成。 + "hashCode"、"equals"和"toString"方法将自动生成。 */ data class DataClassExample (val x: Int, val y: Int, val z: Int) val fooData = DataClassExample(1, 2, 4) diff --git a/zh-cn/make-cn.html.markdown b/zh-cn/make-cn.html.markdown new file mode 100644 index 00000000..4cdf1e63 --- /dev/null +++ b/zh-cn/make-cn.html.markdown @@ -0,0 +1,262 @@ +--- +language: make +contributors: +- ["Robert Steed", "https://github.com/robochat"] +- ["Jichao Ouyang", "https://github.com/jcouyang"] +translators: +- ["Jichao Ouyang", "https://github.com/jcouyang"] +filename: Makefile-cn +lang: zh-cn +--- + +Makefile 用于定义如何创建目标文件, 比如如何从源码到可执行文件. 创建这一工具的目标是 +减少不必要的编译或者任务.是传说中的 Stuart Feldman 在 1976 年花了一个周末写出来的, +而今仍然使用广泛, 特别是在 Unix 和 Linux 系统上. + +虽然每个语言可能都有相应的或多或少提供 make 的功能, 比如 ruby 的 rake, node 的 gulp, broccoli +, scala 的 sbt 等等. 但是 make 的简洁与高效, 和只做一件事并做到极致的风格, 使其至今仍是无可替代的, +甚至与其他构建工具一起使用也并无冲突. + +尽管有许多的分支和变体, 这篇文章针对是标准的 GNU make. + +```make +# 这行表示注释 + +# 文件名一定要交 Makefile, 大小写区分, 使用 `make <target>` 生成 target +# 如果想要取别的名字, 可以用 `make -f "filename" <target>`. + +# 重要的事情 - 只认识 TAB, 空格是不认的, 但是在 GNU Make 3.82 之后, 可以通过 +# 设置参数 .RECIPEPREFIX 进行修改 + +#----------------------------------------------------------------------- +# 初级 +#----------------------------------------------------------------------- + +# 创建一个 target 的规则非常简单 +# targets : prerequisites +# recipe +# … +# prerequisites(依赖) 是可选的, recipe(做法) 也可以多个或者不给. + +# 下面这个任务没有给 prerequisites, 只会在目标文件 file0.txt 文件不存在是跑 +file0.txt: + echo "foo" > file0.txt + # 试试 `make file0.txt` + # 或者直接 `make`, 因为第一个任务是默认任务. + # 注意: 即使是这些注释, 如果前面有 TAB, 也会发送给 shell, 注意看 `make file0.txt` 输出 + +# 如果提供 prerequisites, 则只有 prerequisites 比 target 新时会执行 +# 比如下面这个任务只有当 file1.txt 比 file0.txt 新时才会执行. +file1.txt: file0.txt + cat file0.txt > file1.txt + # 这里跟shell里的命令式一毛一样的. + @cat file0.txt >> file1.txt + # @ 不会把命令往 stdout 打印. + -@echo 'hello' + # - 意思是发生错误了也没关系. + # 试试 `make file1.txt` 吧. + +# targets 和 prerequisites 都可以是多个, 以空格分割 +file2.txt file3.txt: file0.txt file1.txt + touch file2.txt + touch file3.txt + +# 如果声明重复的 target, make 会给一个 warning, 后面会覆盖前面的 +# 比如重复定义 file2.txt 会得到这样的 warning +# Makefile:46: warning: overriding commands for target `file2.txt' +# Makefile:40: warning: ignoring old commands for target `file2.txt' +file2.txt: file0.txt + touch file2.txt + +# 但是如果不定义任何 recipe, 就不会冲突, 只是多了依赖关系 +file2.txt: file0.txt file3.txt + +#----------------------------------------------------------------------- +# Phony(假的) Targets +#----------------------------------------------------------------------- + +# phony targets 意思是 tagets 并不是文件, 可以想象成一个任务的名字而已. +# 因为不是文件, 无法比对是否有更新, 所以每次make都会执行. +all: maker process + +# 依赖于 phony target 的 target 也会每次 make 都执行, 即使 target 是文件 +ex0.txt ex1.txt: maker + +# target 的声明顺序并不重要, 比如上面的 all 的依赖 maker 现在才声明 +maker: + touch ex0.txt ex1.txt + +# 如果定义的 phony target 与文件名重名, 可以用 .PHONY 显示的指明哪些 targets 是 phony +.PHONY: all maker process +# This is a special target. There are several others. + +# 常用的 phony target 有: all clean install ... + +#----------------------------------------------------------------------- +# 变量与通配符 +#----------------------------------------------------------------------- + +process: file*.txt | dir/a.foo.b # 可以用通配符匹配多个文件作为prerequisites + @echo $^ # $^ 是 prerequisites + @echo $@ # $@ 代表 target, 如果 target 为多个, $@ 代表当前执行的那个 + @echo $< # $< prerequisite 中的第一个 + @echo $? # $? 需要更新的 prerequisite 文件列表 + @echo $+ # $+ 所有依赖, 包括重复的 + @echo $| # $| 竖线后面的 order-only prerequisites + +a.%.b: + @echo $* # $* match 的target % 那部分, 包括路径, 比如 `make dir/a.foo.b` 会打出 `dir/foo` + +# 即便分开定义依赖, $^ 依然能拿到 +process: ex1.txt file0.txt +# 非常智能的, ex1.txt 会被找到, file0.txt 会被去重. + +#----------------------------------------------------------------------- +# 模式匹配 +#----------------------------------------------------------------------- + +# 可以让 make 知道如何转换某些文件到别格式 +# 比如 从 svg 到 png +%.png: %.svg + inkscape --export-png $^ + +# 一旦有需要 foo.png 这个任务就会运行 + +# 路径会被忽略, 所以上面的 target 能匹配所有 png +# 但是如果加了路径, make 会找到最接近的匹配, 如果 +# make small/foo.png (在这之前要先有 small/foo.svg 这个文件) +# 则会匹配下面这个规则 +small/%.png: %.svg + inkscape --export-png --export-dpi 30 $^ + +%.png: %.svg + @echo 重复定义会覆盖前面的, 现在 inkscape 没用了 + +# make 已经有一些内置的规则, 比如从 *.c 到 *.o + +#----------------------------------------------------------------------- +# 变量 +#----------------------------------------------------------------------- +# 其实是宏 macro + +# 变量都是字符串类型, 下面这俩是一样一样的 + +name = Ted +name2="Sarah" + +echo: + @echo $(name) + @echo ${name2} + @echo $name # 这个会被蠢蠢的解析成 $(n)ame. + @echo \"$(name3)\" # 为声明的变量或扩展成空字符串. + @echo $(name4) + @echo $(name5) +# 你可以通过4种方式设置变量. +# 按以下顺序由高到低: +# 1: 命令行参数. 比如试试 `make echo name3=JICHAO` +# 2: Makefile 里面的 +# 3: shell 中的环境变量 +# 4: make 预设的一些变量 + +name4 ?= Jean +# 问号意思是如果 name4 被设置过了, 就不设置了. + +override name5 = David +# 用 override 可以防止命令行参数设置的覆盖 + +name4 +=grey +# 用加号可以连接 (中间用空格分割). + +# 在依赖的地方设置变量 +echo: name2 = Sara2 + +# 还有一些内置的变量 +echo_inbuilt: + echo $(CC) + echo ${CXX)} + echo $(FC) + echo ${CFLAGS)} + echo $(CPPFLAGS) + echo ${CXXFLAGS} + echo $(LDFLAGS) + echo ${LDLIBS} + +#----------------------------------------------------------------------- +# 变量 2 +#----------------------------------------------------------------------- + +# 加个冒号可以声明 Simply expanded variables 即时扩展变量, 即只在声明时扩展一次 +# 之前的等号声明时 recursively expanded 递归扩展 + +var := hello +var2 := $(var) hello + +# 这些变量会在其引用的顺序求值 +# 比如 var3 声明时找不到 var4, var3 会扩展成 `and good luck` +var3 := $(var4) and good luck +# 但是一般的变量会在调用时递归扩展, 先扩展 var5, 再扩展 var4, 所以是正常的 +var5 = $(var4) and good luck +var4 := good night + +echoSEV: + @echo $(var) + @echo $(var2) + @echo $(var3) + @echo $(var4) + @echo $(var5) + +#----------------------------------------------------------------------- +# 函数 +#----------------------------------------------------------------------- + +# make 自带了一些函数. +# wildcard 会将后面的通配符变成一串文件路径 +all_markdown: + @echo $(wildcard *.markdown) +# patsubst 可以做替换, 比如下面会把所有 markdown +# 后缀的文件重命名为 md 后缀 +substitue: * + @echo $(patsubst %.markdown,%.md,$* $^) + +# 函数调用格式是 $(func arg0,arg1,arg2...) + +# 试试 +ls: * + @echo $(filter %.txt, $^) + @echo $(notdir $^) + @echo $(join $(dir $^),$(notdir $^)) + +#----------------------------------------------------------------------- +# Directives +#----------------------------------------------------------------------- + +# 可以用 include 引入别的 Makefile 文件 +# include foo.mk + +sport = tennis +# 一些逻辑语句 if else 什么的, 顶个写 +report: +ifeq ($(sport),tennis) + @echo 'game, set, match' +else + @echo "They think it's all over; it is now" +endif + +# 还有 ifneq, ifdef, ifndef + +foo = true + +# 不只是 recipe, 还可以写在外面哟 +ifdef $(foo) +bar = 'bar' +endif + +hellobar: + @echo bar +``` + +### 资源 + ++ GNU Make 官方文档 [HTML](https://www.gnu.org/software/make/manual/) [PDF](https://www.gnu.org/software/make/manual/make.pdf) ++ [software carpentry tutorial](http://swcarpentry.github.io/make-novice/) ++ learn C the hard way [ex2](http://c.learncodethehardway.org/book/ex2.html) [ex28](http://c.learncodethehardway.org/book/ex28.html) diff --git a/zh-cn/markdown-cn.html.markdown b/zh-cn/markdown-cn.html.markdown index 87ed46ad..e9a8aeb2 100644 --- a/zh-cn/markdown-cn.html.markdown +++ b/zh-cn/markdown-cn.html.markdown @@ -13,7 +13,7 @@ Markdown 由 John Gruber 于 2004年创立. 它旨在成为一门容易读写的 欢迎您多多反馈以及分支和请求合并。 -```markdown +```md <!-- Markdown 是 HTML 的父集，所以任何 HTML 文件都是有效的 Markdown。 这意味着我们可以在 Markdown 里使用任何 HTML 元素，比如注释元素， 且不会被 Markdown 解析器所影响。不过如果你在 Markdown 文件内创建了 HTML 元素， diff --git a/zh-cn/matlab-cn.html.markdown b/zh-cn/matlab-cn.html.markdown index 2fbccfc4..d215755c 100644 --- a/zh-cn/matlab-cn.html.markdown +++ b/zh-cn/matlab-cn.html.markdown @@ -10,9 +10,12 @@ lang: zh-cn ---
-MATLAB 是 MATrix LABoratory （矩阵实验室）的缩写，它是一种功能强大的数值计算语言，在工程和数学领域中应用广泛。
+MATLAB 是 MATrix LABoratory（矩阵实验室）的缩写。
+它是一种功能强大的数值计算语言，在工程和数学领域中应用广泛。
-如果您有任何需要反馈或交流的内容，请联系本教程作者[@the_ozzinator](https://twitter.com/the_ozzinator)、[osvaldo.t.mendoza@gmail.com](mailto:osvaldo.t.mendoza@gmail.com)。
+如果您有任何需要反馈或交流的内容，请联系本教程作者：
+[@the_ozzinator](https://twitter.com/the_ozzinator)
+或 [osvaldo.t.mendoza@gmail.com](mailto:osvaldo.t.mendoza@gmail.com)。
```matlab
% 以百分号作为注释符
@@ -45,7 +48,7 @@ edit('myfunction.m') % 在编辑器中打开指定函数或脚本 type('myfunction.m') % 在命令窗口中打印指定函数或脚本的源码
profile on % 打开 profile 代码分析工具
-profile of % 关闭 profile 代码分析工具
+profile off % 关闭 profile 代码分析工具
profile viewer % 查看 profile 代码分析工具的分析结果
help command % 在命令窗口中显示指定命令的帮助文档
@@ -113,7 +116,7 @@ b(2) % ans = 符 % 元组（cell 数组）
a = {'one', 'two', 'three'}
a(1) % ans = 'one' - 返回一个元组
-char(a(1)) % ans = one - 返回一个字符串
+a{1} % ans = one - 返回一个字符串
% 结构体
@@ -210,8 +213,8 @@ size(A) % 返回矩阵的行数和列数，ans = 3 3 A(1, :) =[] % 删除矩阵的第 1 行
A(:, 1) =[] % 删除矩阵的第 1 列
-transpose(A) % 矩阵转置，等价于 A'
-ctranspose(A) % 矩阵的共轭转置（对矩阵中的每个元素取共轭复数）
+transpose(A) % 矩阵（非共轭）转置，等价于 A.' （注意！有个点）
+ctranspose(A) % 矩阵的共轭转置（对矩阵中的每个元素取共轭复数），等价于 A'
% 元素运算 vs. 矩阵运算
@@ -219,18 +222,20 @@ ctranspose(A) % 矩阵的共轭转置（对矩阵中的每个元素取共轭复 % 在运算符加上英文句点就是对矩阵中的元素进行元素计算
% 示例如下：
A * B % 矩阵乘法，要求 A 的列数等于 B 的行数
-A .* B % 元素乘法，要求 A 和 B 形状一致（A 的行数等于 B 的行数， A 的列数等于 B 的列数）
-% 元素乘法的结果是与 A 和 B 形状一致的矩阵，其每个元素等于 A 对应位置的元素乘 B 对应位置的元素
+A .* B % 元素乘法，要求 A 和 B 形状一致，即两矩阵行列数完全一致
+ % 元素乘法的结果是与 A 和 B 形状一致的矩阵
+ % 其每个元素等于 A 对应位置的元素乘 B 对应位置的元素
% 以下函数中，函数名以 m 结尾的执行矩阵运算，其余执行元素运算：
exp(A) % 对矩阵中每个元素做指数运算
expm(A) % 对矩阵整体做指数运算
sqrt(A) % 对矩阵中每个元素做开方运算
-sqrtm(A) % 对矩阵整体做开放运算（即试图求出一个矩阵，该矩阵与自身的乘积等于 A 矩阵）
+sqrtm(A) % 对矩阵整体做开方运算（即试图求出一个矩阵，该矩阵与自身的乘积等于 A 矩阵）
% 绘图
-x = 0:.10:2*pi; % 生成一向量，其元素从 0 开始，以 0.1 的间隔一直递增到 2*pi（pi 就是圆周率）
+x = 0:0.1:2*pi; % 生成一向量，其元素从 0 开始，以 0.1 的间隔一直递增到 2*pi
+ % 其中 pi 为圆周率
y = sin(x);
plot(x,y)
xlabel('x axis')
@@ -288,7 +293,10 @@ clf clear % 清除图形窗口中的图像，并重置图像属性 % 也可以用 gcf 函数返回当前图像的句柄
h = plot(x, y); % 在创建图像时显式地保存图像句柄
set(h, 'Color', 'r')
-% 颜色代码：'y' 黄色，'m' 洋红色，'c' 青色，'r' 红色，'g' 绿色，'b' 蓝色，'w' 白色，'k' 黑色
+% 颜色代码：
+% 'y' 黄色，'m' 洋红，'c' 青色
+% 'r' 红色，'g' 绿色，'b' 蓝色
+% 'w' 白色，'k' 黑色
set(h, 'Color', [0.5, 0.5, 0.4])
% 也可以使用 RGB 值指定颜色
set(h, 'LineStyle', '--')
@@ -328,7 +336,8 @@ load('myFileName.mat') % 将指定文件中的变量载入到当前工作空间 % 与脚本文件类似，同样以 .m 作为后缀名
% 但函数文件可以接受用户输入的参数并返回运算结果
% 并且函数拥有自己的工作空间（变量域），不必担心变量名称冲突
-% 函数文件的名称应当与其所定义的函数的名称一致（比如下面例子中函数文件就应命名为 double_input.m）
+% 函数文件的名称应当与其所定义的函数的名称一致
+% 比如下面例子中函数文件就应命名为 double_input.m
% 使用 'help double_input.m' 可返回函数定义中第一行注释信息
function output = double_input(x)
% double_input(x) 返回 x 的 2 倍
@@ -463,14 +472,16 @@ triu(x) % 返回 x 的上三角这部分 tril(x) % 返回 x 的下三角这部分
cross(A, B) % 返回 A 和 B 的叉积（矢量积、外积）
dot(A, B) % 返回 A 和 B 的点积（数量积、内积），要求 A 和 B 必须等长
-transpose(A) % A 的转置，等价于 A'
+transpose(A) % 矩阵（非共轭）转置，等价于 A.' （注意！有个点）
fliplr(A) % 将一个矩阵左右翻转
flipud(A) % 将一个矩阵上下翻转
% 矩阵分解
-[L, U, P] = lu(A) % LU 分解：PA = LU，L 是下三角阵，U 是上三角阵，P 是置换阵
-[P, D] = eig(A) % 特征值分解：AP = PD，D 是由特征值构成的对角阵，P 的各列就是对应的特征向量
-[U, S, V] = svd(X) % 奇异值分解：XV = US，U 和 V 是酉矩阵，S 是由奇异值构成的半正定实数对角阵
+[L, U, P] = lu(A) % LU 分解：PA = LU，L 是下三角阵，U 是上三角阵，P 是置换阵
+[P, D] = eig(A) % 特征值分解：AP = PD
+ % D 是由特征值构成的对角阵，P 的各列就是对应的特征向量
+[U, S, V] = svd(X) % 奇异值分解：XV = US
+ % U 和 V 是酉矩阵，S 是由奇异值构成的半正定实数对角阵
% 常用向量函数
max % 最大值
@@ -489,5 +500,5 @@ perms(x) % x 元素的全排列 ## 相关资料
-* 官方网页：[http://http://www.mathworks.com/products/matlab/](http://www.mathworks.com/products/matlab/)
-* 官方论坛：[http://www.mathworks.com/matlabcentral/answers/](http://www.mathworks.com/matlabcentral/answers/)
+* 官方网页：[MATLAB - 技术计算语言 - MATLAB & Simulink](https://ww2.mathworks.cn/products/matlab.html)
+* 官方论坛：[MATLAB Answers - MATLAB Central](https://ww2.mathworks.cn/matlabcentral/answers/)
diff --git a/zh-cn/python3-cn.html.markdown b/zh-cn/python3-cn.html.markdown index 76455a46..fd962305 100644 --- a/zh-cn/python3-cn.html.markdown +++ b/zh-cn/python3-cn.html.markdown @@ -10,13 +10,13 @@ filename: learnpython3-cn.py lang: zh-cn --- -Python是由吉多·范罗苏姆(Guido Van Rossum)在90年代早期设计。它是如今最常用的编程 -语言之一。它的语法简洁且优美，几乎就是可执行的伪代码。 +Python 是由吉多·范罗苏姆(Guido Van Rossum)在 90 年代早期设计。 +它是如今最常用的编程语言之一。它的语法简洁且优美，几乎就是可执行的伪代码。 -欢迎大家斧正。英文版原作Louie Dinh [@louiedinh](http://twitter.com/louiedinh) -或着Email louiedinh [at] [谷歌的信箱服务]。中文翻译Geoff Liu。 +欢迎大家斧正。英文版原作 Louie Dinh [@louiedinh](http://twitter.com/louiedinh) +邮箱 louiedinh [at] [谷歌的信箱服务]。中文翻译 Geoff Liu。 -注意：这篇教程是特别为Python3写的。如果你想学旧版Python2，我们特别有另一篇教程。 +注意：这篇教程是基于 Python 3 写的。如果你想学旧版 Python 2，我们特别有[另一篇教程](http://learnxinyminutes.com/docs/python/)。 ```python @@ -70,15 +70,15 @@ not True # => False not False # => True # 逻辑运算符，注意and和or都是小写 -True and False #=> False -False or True #=> True +True and False # => False +False or True # => True # 整数也可以当作布尔值 -0 and 2 #=> 0 --5 or 0 #=> -5 -0 == False #=> True -2 == True #=> False -1 == True #=> True +0 and 2 # => 0 +-5 or 0 # => -5 +0 == False # => True +2 == True # => False +1 == True # => True # 用==判断相等 1 == 1 # => True @@ -113,10 +113,11 @@ False or True #=> True # 可以重复参数以节省时间 "{0} be nimble, {0} be quick, {0} jump over the {1}".format("Jack", "candle stick") -#=> "Jack be nimble, Jack be quick, Jack jump over the candle stick" +# => "Jack be nimble, Jack be quick, Jack jump over the candle stick" # 如果不想数参数，可以用关键字 -"{name} wants to eat {food}".format(name="Bob", food="lasagna") #=> "Bob wants to eat lasagna" +"{name} wants to eat {food}".format(name="Bob", food="lasagna") +# => "Bob wants to eat lasagna" # 如果你的Python3程序也要在Python2.5以下环境运行，也可以用老式的格式化语法 "%s can be %s the %s way" % ("strings", "interpolated", "old") @@ -132,8 +133,8 @@ None is None # => True # 所有其他值都是True bool(0) # => False bool("") # => False -bool([]) #=> False -bool({}) #=> False +bool([]) # => False +bool({}) # => False #################################################### @@ -233,7 +234,8 @@ filled_dict = {"one": 1, "two": 2, "three": 3} filled_dict["one"] # => 1 -# 用keys获得所有的键。因为keys返回一个可迭代对象，所以在这里把结果包在list里。我们下面会详细介绍可迭代。 +# 用 keys 获得所有的键。 +# 因为 keys 返回一个可迭代对象，所以在这里把结果包在 list 里。我们下面会详细介绍可迭代。 # 注意：字典键的顺序是不定的，你得到的结果可能和以下不同。 list(filled_dict.keys()) # => ["three", "two", "one"] @@ -261,7 +263,7 @@ filled_dict.setdefault("five", 5) # filled_dict["five"]设为5 filled_dict.setdefault("five", 6) # filled_dict["five"]还是5 # 字典赋值 -filled_dict.update({"four":4}) #=> {"one": 1, "two": 2, "three": 3, "four": 4} +filled_dict.update({"four":4}) # => {"one": 1, "two": 2, "three": 3, "four": 4} filled_dict["four"] = 4 # 另一种赋值方法 # 用del删除 @@ -362,7 +364,7 @@ else: # else语句是可选的，必须在所有的except之后 filled_dict = {"one": 1, "two": 2, "three": 3} our_iterable = filled_dict.keys() -print(our_iterable) # => range(1,10) 是一个实现可迭代接口的对象 +print(our_iterable) # => dict_keys(['one', 'two', 'three'])，是一个实现可迭代接口的对象 # 可迭代对象可以遍历 for i in our_iterable: @@ -376,17 +378,17 @@ our_iterator = iter(our_iterable) # 迭代器是一个可以记住遍历的位置的对象 # 用__next__可以取得下一个元素 -our_iterator.__next__() #=> "one" +our_iterator.__next__() # => "one" # 再一次调取__next__时会记得位置 -our_iterator.__next__() #=> "two" -our_iterator.__next__() #=> "three" +our_iterator.__next__() # => "two" +our_iterator.__next__() # => "three" # 当迭代器所有元素都取出后，会抛出StopIteration our_iterator.__next__() # 抛出StopIteration # 可以用list一次取出迭代器所有的元素 -list(filled_dict.keys()) #=> Returns ["one", "two", "three"] +list(filled_dict.keys()) # => Returns ["one", "two", "three"] @@ -568,13 +570,14 @@ def double_numbers(iterable): yield i + i # 生成器只有在需要时才计算下一个值。它们每一次循环只生成一个值，而不是把所有的 -# 值全部算好。这意味着double_numbers不会生成大于15的数字。 +# 值全部算好。 # # range的返回值也是一个生成器，不然一个1到900000000的列表会花很多时间和内存。 # # 如果你想用一个Python的关键字当作变量名，可以加一个下划线来区分。 range_ = range(1, 900000000) # 当找到一个 >=30 的结果就会停 +# 这意味着 `double_numbers` 不会生成大于30的数。 for i in double_numbers(range_): print(i) if i >= 30: diff --git a/zh-cn/swift-cn.html.markdown b/zh-cn/swift-cn.html.markdown index c25b2918..18bc52ed 100644 --- a/zh-cn/swift-cn.html.markdown +++ b/zh-cn/swift-cn.html.markdown @@ -110,7 +110,7 @@ anyObjectVar = "Changed value to a string, not good practice, but possible." // -// Mark: 数组与字典（关联数组） +// MARK: 数组与字典（关联数组） // /* @@ -214,9 +214,9 @@ func greet(name: String, day: String) -> String { } greet("Bob", day: "Tuesday") -// 第一个参数表示外部参数名和内部参数名使用同一个名称。 +// 第一个参数`_`表示不使用外部参数名，忽略`_`表示外部参数名和内部参数名使用同一个名称。 // 第二个参数表示外部参数名使用 `externalParamName` ，内部参数名使用 `localParamName` -func greet2(requiredName requiredName: String, externalParamName localParamName: String) -> String { +func greet2(_ requiredName: String, externalParamName localParamName: String) -> String { return "Hello \(requiredName), the day is \(localParamName)" } greet2(requiredName:"John", externalParamName: "Sunday") // 调用时，使用命名参数来指定参数的值 @@ -250,7 +250,7 @@ var increment = makeIncrementer() increment(7) // 强制进行指针传递 (引用传递)，使用 `inout` 关键字修饰函数参数 -func swapTwoInts(inout a: Int, inout b: Int) { +func swapTwoInts(a: inout Int, b: inout Int) { let tempA = a a = b b = tempA @@ -521,7 +521,7 @@ class MyShape: Rect { // 在 optional 属性，方法或下标运算符后面加一个问号，可以优雅地忽略 nil 值，返回 nil。 // 这样就不会引起运行时错误 (runtime error) - if let reshape = self.delegate?.canReshape?() where reshape { + if let reshape = self.delegate?.canReshape?() { // 注意语句中的问号 self.delegate?.reshape?() } @@ -575,10 +575,10 @@ print(foundAtIndex == 2) // true // 自定义运算符可以以下面的字符打头: // / = - + * % < > ! & | ^ . ~ // 甚至是 Unicode 的数学运算符等 -prefix operator !!! {} +prefix operator !!! // 定义一个前缀运算符，使矩形的边长放大三倍 -prefix func !!! (inout shape: Square) -> Square { +prefix func !!! (shape: inout Square) -> Square { shape.sideLength *= 3 return shape } @@ -591,8 +591,8 @@ print(mySquare.sideLength) // 4 print(mySquare.sideLength) // 12 // 运算符也可以是泛型 -infix operator <-> {} -func <-><T: Equatable> (inout a: T, inout b: T) { +infix operator <-> +func <-><T: Equatable> (a: inout T, b: inout T) { let c = a a = b b = c diff --git a/zh-cn/typescript-cn.html.markdown b/zh-cn/typescript-cn.html.markdown index 2651b1cb..5d6153da 100644 --- a/zh-cn/typescript-cn.html.markdown +++ b/zh-cn/typescript-cn.html.markdown @@ -9,97 +9,103 @@ filename: learntypescript-cn.ts lang: zh-cn --- -TypeScript是一门为开发大型JavaScript应用而设计的语言。TypeScript在JavaScript的基础上增加了类、模块、接口、泛型和静态类型（可选）等常见的概念。它是JavaScript的一个超集：所有JavaScript代码都是有效的TypeScript代码，所以任何JavaScript项目都可以无缝引入TypeScript. TypeScript编译器会把TypeScript代码编译成JavaScript代码。 +TypeScript 是一门为开发大型 JavaScript 应用而设计的语言。TypeScript 在 JavaScript 的基础上增加了类、模块、接口、泛型和静态类型（可选）等常见的概念。它是 JavaScript 的超集：所有 JavaScript 代码都是有效的 TypeScript 代码，因此任何 JavaScript 项目都可以无缝引入 TypeScript，TypeScript 编译器最终会把 TypeScript 代码编译成 JavaScript 代码。 -本文只关注TypeScript额外增加的区别于[JavaScript](../javascript-cn/)的语法，. +本文只关注 TypeScript 额外增加的区别于 [JavaScript](../javascript-cn/) 的语法，. -如需测试TypeScript编译器，你可以在[Playground](http://www.typescriptlang.org/Playground)码代码，它会自动编译成JavaScript代码然后直接显示出来。 +如需测试 TypeScript 编译器，你可以到 [Playground](https://www.typescriptlang.org/play/) 编写代码，它会自动将你编写的 TypeScript 代码编译成 JavaScript 代码后，在右侧即时展示出来。 -```js -// TypeScript有三种基本类型 -var isDone: boolean = false; -var lines: number = 42; -var name: string = "Anders"; +```ts +// TypeScript 有三种基本类型，布尔类型、数值类型、字符串类型 +let isDone: boolean = false; +let lines: number = 42; +let name: string = 'Anders'; -// 如果不知道是什么类型，可以使用"any"(任意)类型 -var notSure: any = 4; -notSure = "maybe a string instead"; -notSure = false; // 亦可，定义为布尔型 +// 如果不知道是什么类型，可以使用 "any" (任意)类型 +let notSure: any = 4; +notSure = '可以重新赋值，转换为字符串类型'; +notSure = false; // 亦可，重新定义为布尔类型 -// 对于集合的声明, 有类型化数组和泛型数组 -var list: number[] = [1, 2, 3]; -// 另外一种，使用泛型数组 -var list: Array<number> = [1, 2, 3]; +// 使用 const 关键字将一个字面量修饰为常量 +const numLivesForCat = 9; +numLivesForCat = 1; // 常量不能重新被赋值，所以这里会报错 + +// TypeScript 中的 collection 有两种表示形式, 一种是有类型的数组，另一种是泛型数组 +let list: number[] = [1, 2, 3]; +// 或者，使用泛型数组 +let list: Array<number> = [1, 2, 3]; // 枚举： -enum Color {Red, Green, Blue}; -var c: Color = Color.Green; +enum Color {Red, Green, Blue} +let c: Color = Color.Green; -// 最后，"void"用于函数没有任何返回的特殊情况下 +// 最后是 "void"，它用于表明函数没有任何返回值的特殊情况 function bigHorribleAlert(): void { - alert("I'm a little annoying box!"); + alert('我是个烦人的弹出框！'); } -// 函数是"第一等公民"(first class citizens), 支持使用箭头表达式和类型推断 - -// 以下是相等的，TypeScript编译器会把它们编译成相同的JavaScript代码 -var f1 = function(i: number): number { return i * i; } -// 返回推断类型的值 -var f2 = function(i: number) { return i * i; } -var f3 = (i: number): number => { return i * i; } -// 返回推断类型的值 -var f4 = (i: number) => { return i * i; } -// 返回推断类型的值, 单行程式可以不需要return关键字和大括号 -var f5 = (i: number) => i * i; - -// 接口是结构化的，任何具有这些属性的对象都与该接口兼容 +// 函数是"一等公民"(first class citizens), 支持使用 lambda 胖箭头表达式和类型推断 + +// 以下 f1-f5 五个函数是等价的，TypeScript 编译器会把它们编译成相同的 JavaScript 代码(可以到 Playground 验证) +// 一般的函数 +let f1 = function(i: number): number { return i * i; }; +// 根据返回值推断函数返回类型 +let f2 = function(i: number) { return i * i; }; +// 胖箭头表达式 +let f3 = (i: number): number => { return i * i; }; +// 根据返回值推断返回类型的胖箭头表达式 +let f4 = (i: number) => { return i * i; }; +// 根据返回值推断返回类型的胖箭头表达式, 省略花括号的同时，可以同时省去 return 关键字 +let f5 = (i: number) => i * i; + +// 接口是结构化的，任何具备接口中声明的全部属性的对象，都与该接口兼容 interface Person { name: string; - // 可选属性，使用"?"标识 + // 使用 "?" 标识，表明该属性是一个非必需属性 age?: number; // 函数 move(): void; } -// 实现"Person"接口的对象，当它有了"name"和"move"方法之后可被视为一个"Person" -var p: Person = { name: "Bobby", move: () => {} }; -// 带了可选参数的对象 -var validPerson: Person = { name: "Bobby", age: 42, move: () => {} }; -// 因为"age"不是"number"类型所以这不是一个"Person" -var invalidPerson: Person = { name: "Bobby", age: true }; +// 实现 "Person" 接口的对象，当它具备 "name" 属性和 "move" 方法之后可被视为一个 "Person" +let p: Person = { name: 'Bobby', move: () => {} }; +// 带可选属性的对象 +let validPerson: Person = { name: 'Bobby', age: 42, move: () => {} }; +// 由于该对象 "age" 属性的类型不是 "number" ，所以这不是一个 "Person" +let invalidPerson: Person = { name: 'Bobby', age: true }; // 接口同样可以描述一个函数的类型 interface SearchFunc { (source: string, subString: string): boolean; } -// 参数名并不重要，参数类型才是重要的 -var mySearch: SearchFunc; +// 参数名并不重要，参数类型才是最重要的 +let mySearch: SearchFunc; mySearch = function(src: string, sub: string) { - return src.search(sub) != -1; -} + return src.search(sub) !== -1; +}; -// 类 - 成员默认为公共的(public) +// 类 - 成员访问权限默认都是公共的 (public) class Point { - // 属性 + // 成员属性 x: number; - // 构造器 - 这里面的public/private关键字会为属性生成样板代码和初始化值 - // 这个例子中，y会被同x一样定义，不需要额外代码 - // 同样支持默认值 + // 构造器 - 在构造器中使用 public/private 关键字修饰的变量，会被声明为类的成员属性。 + // 下面这个例子中，y 会像 x 一样被声明定义为类成员属性，而不再需要额外代码 + // 声明时，同样支持指定默认值 constructor(x: number, public y: number = 0) { this.x = x; } - // 函数 + // 成员函数 dist() { return Math.sqrt(this.x * this.x + this.y * this.y); } // 静态成员 static origin = new Point(0, 0); } -var p1 = new Point(10 ,20); -var p2 = new Point(25); //y为0 +let p1 = new Point(10 , 20); +let p2 = new Point(25); // y 为构造器中指定的默认值：0 // 继承 class Point3D extends Point { @@ -107,14 +113,14 @@ class Point3D extends Point { super(x, y); // 必须显式调用父类的构造器 } - // 重写 + // 重写父类中的 dist() 函数 dist() { - var d = super.dist(); + let d = super.dist(); return Math.sqrt(d * d + this.z * this.z); } } -// 模块, "."可以作为子模块的分隔符 +// 模块, "." 符号可以作为子模块的分隔符 module Geometry { export class Square { constructor(public sideLength: number = 0) { @@ -125,12 +131,12 @@ module Geometry { } } -var s1 = new Geometry.Square(5); +let s1 = new Geometry.Square(5); -// 引入模块并定义本地别名 +// 为模块创建一个本地别名 import G = Geometry; -var s2 = new G.Square(10); +let s2 = new G.Square(10); // 泛型 // 类 @@ -146,21 +152,21 @@ interface Pair<T> { } // 以及函数 -var pairToTuple = function<T>(p: Pair<T>) { +let pairToTuple = function<T>(p: Pair<T>) { return new Tuple(p.item1, p.item2); }; -var tuple = pairToTuple({ item1:"hello", item2:"world"}); +let tuple = pairToTuple({ item1: 'hello', item2: 'world'}); // 引用定义文件 -// <reference path="jquery.d.ts" /> +/// <reference path="jquery.d.ts" /> // 模板字符串(使用反引号的字符串) // 嵌入变量的模板字符串 -var name = 'Tyrone'; -var greeting = `Hi ${name}, how are you?` +let name = 'Tyrone'; +let greeting = `Hi ${name}, how are you?`; // 有多行内容的模板字符串 -var multiline = `This is an example +let multiline = `This is an example of a multiline string`; ``` diff --git a/zh-cn/visualbasic-cn.html.markdown b/zh-cn/visualbasic-cn.html.markdown index 8bdfabc6..e30041b3 100644 --- a/zh-cn/visualbasic-cn.html.markdown +++ b/zh-cn/visualbasic-cn.html.markdown @@ -5,10 +5,10 @@ contributors: translators: - ["Abner Chou", "http://cn.abnerchou.me"] lang: zh-cn -filename: learnvisualbasic.vb-cn +filename: learnvisualbasic-cn.vb --- -```vb +``` Module Module1 Sub Main() diff --git a/zh-tw/pcre-tw.html.markdown b/zh-tw/pcre-tw.html.markdown new file mode 100644 index 00000000..c9cdc537 --- /dev/null +++ b/zh-tw/pcre-tw.html.markdown @@ -0,0 +1,83 @@ +--- +language: PCRE +filename: pcre-tw.txt +contributors: + - ["Sachin Divekar", "http://github.com/ssd532"] +translators: + - ["Michael Yeh", "https://hinet60613.github.io/"] +lang: zh-tw +--- + +正規表達式(regular expression，或縮寫為regex, regexp)是一種用來表示搜尋模式的特殊字串。例如，你可以用`/^[a-z]+:/`來從網址`http://github.com`中擷取出`http:`這段http協定名稱。 + +相容Perl正規表達式(Perl Compatible Regular Expressions, PCRE)是一個實作正規表達式的C語言函式庫。此函式庫在1997年被開發出來，在當時面對複雜字串處理時大多會選擇使用Perl。也因為如此，PCRE大多的正規表達式語法都很酷似Perl。PCRE語法被廣泛運用在許多大專案中，包括PHP、Apache、R等。 + +PCRE中的超字元(metacharacter)主要可以分為以下兩類: +* 在中括號外會被辨識的字元 +``` + \ 通用跳脫字元 + ^ 字串開頭 或 行首 + $ 字串結尾 或 行尾 + . 除了換行符號外的任何字元 + [ 字元集合定義開始 + | 支流開始 + ( 子串模式定義開始 + ) 子串模式定義結束 + ? extends the meaning of ( + 同時為數量0或1配對 + also quantifier minimizer + * 量詞 至少0個 至多無限個 + + 量詞 至少1個 至多無限個 + 同時為佔有型量詞 + { 最大/最小量詞開始 +``` + +* 在中括號內會被辨識的超字元，在中括號外會被視為字元集合使用 + +``` + + \ 通用跳脫字元 + ^ 非字元集合的字，但只會抓到第一個符合的字元 + - 字元範圍 + [ POSIX字元集合(若後面接POSIX格式) + ] 字元集合定義結束 + +``` + +PCRE提供了一些通用的字元類型，可被當作字元集合使用 +``` + \d 任何數字字元 + \D 任何非數字字元 + \h 任何水平空白字元 + \H 任何非水平空白字元 + \s 任何空白字元 + \S 任何非空白至元 + \v 任何垂直空白字元 + \V 任何非垂直空白字元 + \w 任何英文字 + \W 任何非英文字 +``` + +## 範例 + +我們以字串 `66.249.64.13 - - [18/Sep/2004:11:07:48 +1000] "GET /robots.txt HTTP/1.0" 200 468 "-" "Googlebot/2.1"` 作為範例，這是一個標準的Apache存取記錄。 + +| 正規表達式 | 結果 | 說明 | +| :---- | :-------------- | :------ | +| GET | GET | GET 抓取 GET 字串 (會分別大小寫) | +| \d+.\d+.\d+.\d+ | 66.249.64.13 | `\d+` 抓取數字字元，數量由 `+` 定義為至少一個至多無限個。 `\.` 抓取 `.` 字元 | +| (\d+\.){3}\d+ | 66.249.64.13 | `(\d+\.){3}` 會試著抓取剛好三次的 (`\d+\.`) | +| \[.+\] | [18/Sep/2004:11:07:48 +1000] | `.+` 抓取除了換行符號以外的任何字元， `.` 表示任意字元 | +| ^\S+ | 66.249.64.13 | `^` 為行首， `\S+` 抓取至少一個非空白字元 | +| \+[0-9]+ | +1000 | `\+` 抓取 `+` 字元。 `[0-9]` 字元集表示剛好一個數字字元。 可以用 `\+\d+` 達到相同效果。 | + +以上範例皆可在 https://regex101.com/ 測試，步驟如下: + +1. 複製範例字串到 `TEST STRING` 區域 +2. 複製正規表達式字串到 `Regular Expression` 區域 +3. 網頁會顯示自動表達式抓取結果 + + +## 更多資料 + + |