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diff --git a/ldpl.html.markdown b/ldpl.html.markdown new file mode 100644 index 00000000..cc95f5fb --- /dev/null +++ b/ldpl.html.markdown @@ -0,0 +1,183 @@ +--- +language: LDPL +filename: learnLDPL.ldpl +contributors: + - ["Martín del Río", "https://github.com/lartu"] +--- + +**LDPL** is a powerful, C++ transpiled, open-source programming language designed +from the ground up to be excessively expressive, readable, fast and easy to learn. +It mimics plain English, in the likeness of older programming languages like COBOL, +with the desire that it can be understood by anybody. It's very portable and runs on a +plethora of different architectures and operating systems and it even supports UTF-8 +out of the box. + +[Read more here.](https://github.com/lartu/ldpl) + +```coffeescript +# This is a single line comment in LDPL. +# LDPL doesn't have multi-line comments. + +# LDPL is a case-insensitive language: dIsPlaY and DISPLAY are the same +# statement, and foo and FOO name the same variable. + +# An LDPL source file is divided in two sections, the DATA section and +# the PROCEDURE section. + +DATA: +# Within the DATA section, variables are declared. + +myNumber is number # Defines a real number. +myString is text # Defines a string. +myList is number list # Defines a list of numbers. +myMap is number map # Defines a map of numbers. + +# LDPL understands four data types: two scalar types (NUMBER, TEXT) +# and two container types (LISTs and MAPs). +# LISTs can be TEXT LISTs or NUMBER LISTs, while MAPs can be +# TEXT MAPs and NUMBER MAPs. You can also chain many containers +# to create larger data types: +textListList is text list list +myMulticontainer is number list list map +# Defines a map of lists of lists of numbers. + +PROCEDURE: +# Within the PROCEDURE section, your code is written. + +store -19.2 in myNumber # Use the STORE statement to assign values +store "Hi there" in myString # to variables. +push 890 to myList # Use PUSH - TO to append values to lists. +push 100 to myList +push 500 to myList +store 45 in myMap:"someIndex" # Use the : operator to index containers. + +push list to textListList # Push an empty list into a list of lists. +push "LDPL is nice!" to textListList:0 #Push text to the pushed list. + +display "Hello World!" # Use the DISPLAY statement to print values. +# The display statement can receive multiple values separated by spaces. +display crlf "How are you today?" myNumber myString crlf +# CRLF is the standard line break value in LDPL. +display textListList:0:0 " Isn't it?" crlf + +# IF statements in LDPL are extremely verbose: +if myNumber is equal to -19.2 and myList:0 is less than 900 then + display "Yes!" crlf +else if myMap:"someIndex" is not equal to 45 then + display "This is an else if!" crlf +else + display "Else!" crlf +end if +# Valid LDPL comparisson operators are +# - IS EQUAL TO +# - IS NOT EQUAL TO +# - IS LESS THAN +# - IS GREATER THAN +# - IS LESS THAN OR EQUAL TO +# - IS GREATER THAN OR EQUAL TO +if "Hi there!" is not equal to "Bye bye!" then + display "Yep, those weren't equal." crlf +end if +# LDPL normally doesn't understand inline expressions, so you +# cannot do stuff like: +# if myNumber - 9 * 2 is equal to 10 then +# LDPL will set your computer on fire and burst your screen if you do so. + +# WHILE loops follow the same rules +store 0 in myNumber +while myNumber is less than 10 do + display "Loop number " myNumber "..." crlf + in myNumber solve myNumber + 1 # You can do math like this. +repeat +# You can use 'break' and 'continue' inside loops just like any other language. + +# LDPL also has FOR loops and FOR EACH loops +for myNumber from 0 to 100 step 2 do + display myNumber crlf +repeat + +for each myNumber in myList do + display myNumber +repeat + +display "Enter your name: " +accept myString # Use ACCEPT to let the user input values. +display "Hi there, " myString crlf +display "How old are you?: " +accept myNumber +if myNumber is greater than 200 then + display "Woah, you are so old!" crlf +end if + +wait 1000 milliseconds # Pause the program for a whole second. + +# Let's do some math +store 1.2 in myNumber +in myNumber solve myNumber * (10 / 7.2) # Operators are separated by spaces. +floor myNumber +display myNumber crlf +get random in myNumber # get a random number between 0 and 1 + # and store it in myNumber + +# Functions in LDPL are called sub-procedures. Sub-procedures, like source +# files, are divided in sections. The sections found in sub-procedures are +# the PARAMETERS section, the LOCAL DATA section and the PROCEDURE section. +# All sections except the PROCEDURE section can be skipped if they aren't +# used. If no PARAMTERS nor LOCAL DATA sections are used, the PROCEDURE +# keyword may be omited. +sub myFunction + parameters: + a is number # LDPL is pass by reference + b is number + result is number # Thus you can return values through a parameter. + local data: + c is number + procedure: + get random in c + in result solve a + b * c +end sub + +sub sayHello + display "Hi there!" crlf + return + display "This won't be displayed :(" +end sub + +call myFunction with 1 2 myNumber +display myNumber crlf +call sayHello +call sayBye # sub-procedures may be called before they are declared + +sub sayBye + display "Bye!" +end sub + +# One of the greatest features of LDPL is the ability to create your +# own statements. + +create statement "say hi" executing sayHello +say hi + +create statement "random add $ and $ in $" executing myFunction +random add 1 and 2 in myNumber +display myNumber crlf + +exit +``` + +## Topics Not Covered + + * [Command line arguments](https://docs.ldpl-lang.org/variables-in-ldpl/command-line-arguments) + * [Error variables](https://docs.ldpl-lang.org/variables-in-ldpl/errorcode-and-errortext) + * [Import other files](https://docs.ldpl-lang.org/structure-of-ldpl-source-code/importing-other-sources) + * [Identifier naming schemes](https://docs.ldpl-lang.org/naming-rules) + * [Text Statements](https://docs.ldpl-lang.org/text-statements/join-and-in) + * [List Statements](https://docs.ldpl-lang.org/list-statements/push-to) + * [Map Statements](https://docs.ldpl-lang.org/vector-statements/clear) + * [File loading / writing](https://docs.ldpl-lang.org/i-o-statements/load-file-in) + * [Executing commands](https://docs.ldpl-lang.org/i-o-statements/execute) + * [Extending LDPL with C++](https://docs.ldpl-lang.org/extensions/c++-extensions) + +## Further Reading + + * [LDPL Docs](https://docs.ldpl-lang.org) |