diff options
85 files changed, 6532 insertions, 1123 deletions
diff --git a/amd.html.markdown b/amd.html.markdown index b3237dc7..d7fb41ba 100644 --- a/amd.html.markdown +++ b/amd.html.markdown @@ -8,10 +8,10 @@ filename: learnamd.js ## Getting Started with AMD
-The **Asynchronous Module Definition** API specifies a mechanism for defining
-JavaScript modules such that the module and its dependencies can be asynchronously
-loaded. This is particularly well suited for the browser environment where
-synchronous loading of modules incurs performance, usability, debugging, and
+The **Asynchronous Module Definition** API specifies a mechanism for defining
+JavaScript modules such that the module and its dependencies can be asynchronously
+loaded. This is particularly well suited for the browser environment where
+synchronous loading of modules incurs performance, usability, debugging, and
cross-domain access problems.
### Basic concept
diff --git a/asymptotic-notation.html.markdown b/asymptotic-notation.html.markdown index e1f961f8..a516737e 100644 --- a/asymptotic-notation.html.markdown +++ b/asymptotic-notation.html.markdown @@ -72,45 +72,45 @@ for a given function. Say `f(n)` is your algorithm runtime, and `g(n)` is an arb you are trying to relate to your algorithm. `f(n)` is O(g(n)), if for any real constant c (c > 0), `f(n)` <= `c g(n)` for every input size n (n > 0). -*Example 1* +*Example 1* ``` -f(n) = 3log n + 100 +f(n) = 3log n + 100 g(n) = log n ``` -Is `f(n)` O(g(n))? -Is `3 log n + 100` O(log n)? +Is `f(n)` O(g(n))? +Is `3 log n + 100` O(log n)? Let's look to the definition of Big-O. ``` -3log n + 100 <= c * log n +3log n + 100 <= c * log n ``` -Is there some constant c that satisfies this for all n? +Is there some constant c that satisfies this for all n? ``` -3log n + 100 <= 150 * log n, n > 2 (undefined at n = 1) +3log n + 100 <= 150 * log n, n > 2 (undefined at n = 1) ``` Yes! The definition of Big-O has been met therefore `f(n)` is O(g(n)). -*Example 2* +*Example 2* ``` -f(n) = 3*n^2 +f(n) = 3*n^2 g(n) = n ``` -Is `f(n)` O(g(n))? -Is `3 * n^2` O(n)? +Is `f(n)` O(g(n))? +Is `3 * n^2` O(n)? Let's look at the definition of Big-O. ``` -3 * n^2 <= c * n +3 * n^2 <= c * n ``` -Is there some constant c that satisfies this for all n? +Is there some constant c that satisfies this for all n? No, there isn't. `f(n)` is NOT O(g(n)). ### Big-Omega diff --git a/bash.html.markdown b/bash.html.markdown index 08182c2c..191f916a 100644 --- a/bash.html.markdown +++ b/bash.html.markdown @@ -51,7 +51,7 @@ echo $Variable echo "$Variable" echo '$Variable' # When you use the variable itself — assign it, export it, or else — you write -# its name without $. If you want to use variable's value, you should use $. +# its name without $. If you want to use the variable's value, you should use $. # Note that ' (single quote) won't expand the variables! # String substitution in variables @@ -70,11 +70,11 @@ echo ${Foo:-"DefaultValueIfFooIsMissingOrEmpty"} # Builtin variables: # There are some useful builtin variables, like -echo "Last program return value: $?" +echo "Last program's return value: $?" echo "Script's PID: $$" -echo "Number of arguments: $#" -echo "Scripts arguments: $@" -echo "Scripts arguments separated in different variables: $1 $2..." +echo "Number of arguments passed to script: $#" +echo "All arguments passed to script: $@" +echo "Script's arguments separated into different variables: $1 $2..." # Reading a value from input: echo "What's your name?" @@ -108,8 +108,8 @@ fi # Expressions are denoted with the following format: echo $(( 10 + 5 )) -# Unlike other programming languages, bash is a shell — so it works in a context -# of current directory. You can list files and directories in the current +# Unlike other programming languages, bash is a shell so it works in the context +# of a current directory. You can list files and directories in the current # directory with the ls command: ls @@ -252,7 +252,7 @@ grep "^foo.*bar$" file.txt grep -c "^foo.*bar$" file.txt # if you literally want to search for the string, # and not the regex, use fgrep (or grep -F) -fgrep "^foo.*bar$" file.txt +fgrep "^foo.*bar$" file.txt # Read Bash shell builtins documentation with the bash 'help' builtin: diff --git a/c++.html.markdown b/c++.html.markdown index 26dfe111..6f4d0562 100644 --- a/c++.html.markdown +++ b/c++.html.markdown @@ -5,6 +5,7 @@ contributors: - ["Steven Basart", "http://github.com/xksteven"] - ["Matt Kline", "https://github.com/mrkline"] - ["Geoff Liu", "http://geoffliu.me"] + - ["Connor Waters", "http://github.com/connorwaters"] lang: en --- @@ -53,11 +54,11 @@ int main(int argc, char** argv) // However, C++ varies in some of the following ways: -// In C++, character literals are one byte. -sizeof('c') == 1 +// In C++, character literals are chars +sizeof('c') == sizeof(char) == 1 -// In C, character literals are the same size as ints. -sizeof('c') == sizeof(10) +// In C, character literals are ints +sizeof('c') == sizeof(int) // C++ has strict prototyping @@ -159,9 +160,9 @@ void foo() int main() { - // Includes all symbols from `namesapce Second` into the current scope. Note - // that simply `foo()` no longer works, since it is now ambiguous whether - // we're calling the `foo` in `namespace Second` or the top level. + // Includes all symbols from namespace Second into the current scope. Note + // that simply foo() no longer works, since it is now ambiguous whether + // we're calling the foo in namespace Second or the top level. using namespace Second; Second::foo(); // prints "This is Second::foo" @@ -244,7 +245,13 @@ cout << fooRef; // Prints "I am foo. Hi!" // Doesn't reassign "fooRef". This is the same as "foo = bar", and // foo == "I am bar" // after this line. +cout << &fooRef << endl; //Prints the address of foo fooRef = bar; +cout << &fooRef << endl; //Still prints the address of foo +cout << fooRef; // Prints "I am bar" + +//The address of fooRef remains the same, i.e. it is still referring to foo. + const string& barRef = bar; // Create a const reference to bar. // Like C, const values (and pointers and references) cannot be modified. @@ -256,8 +263,8 @@ string tempObjectFun() { ... } string retVal = tempObjectFun(); // What happens in the second line is actually: -// - a string object is returned from `tempObjectFun` -// - a new string is constructed with the returned object as arugment to the +// - a string object is returned from tempObjectFun +// - a new string is constructed with the returned object as argument to the // constructor // - the returned object is destroyed // The returned object is called a temporary object. Temporary objects are @@ -268,15 +275,15 @@ string retVal = tempObjectFun(); // code: foo(bar(tempObjectFun())) -// assuming `foo` and `bar` exist, the object returned from `tempObjectFun` is -// passed to `bar`, and it is destroyed before `foo` is called. +// assuming foo and bar exist, the object returned from tempObjectFun is +// passed to bar, and it is destroyed before foo is called. // Now back to references. The exception to the "at the end of the enclosing // expression" rule is if a temporary object is bound to a const reference, in // which case its life gets extended to the current scope: void constReferenceTempObjectFun() { - // `constRef` gets the temporary object, and it is valid until the end of this + // constRef gets the temporary object, and it is valid until the end of this // function. const string& constRef = tempObjectFun(); ... @@ -301,7 +308,7 @@ basic_string(basic_string&& other); // Idea being if we are constructing a new string from a temporary object (which // is going to be destroyed soon anyway), we can have a more efficient // constructor that "salvages" parts of that temporary string. You will see this -// concept referred to as the move semantic. +// concept referred to as "move semantics". ////////////////////////////////////////// // Classes and object-oriented programming @@ -349,7 +356,10 @@ public: // These are called when an object is deleted or falls out of scope. // This enables powerful paradigms such as RAII // (see below) - // Destructors must be virtual to allow classes to be derived from this one. + // The destructor should be virtual if a class is to be derived from; + // if it is not virtual, then the derived class' destructor will + // not be called if the object is destroyed through a base-class reference + // or pointer. virtual ~Dog(); }; // A semicolon must follow the class definition. @@ -492,9 +502,10 @@ int main () { ///////////////////// // Templates in C++ are mostly used for generic programming, though they are -// much more powerful than generics constructs in other languages. It also -// supports explicit and partial specialization, functional-style type classes, -// and also it's Turing-complete. +// much more powerful than generic constructs in other languages. They also +// support explicit and partial specialization and functional-style type +// classes; in fact, they are a Turing-complete functional language embedded +// in C++! // We start with the kind of generic programming you might be familiar with. To // define a class or function that takes a type parameter: @@ -506,7 +517,7 @@ public: }; // During compilation, the compiler actually generates copies of each template -// with parameters substituted, and so the full definition of the class must be +// with parameters substituted, so the full definition of the class must be // present at each invocation. This is why you will see template classes defined // entirely in header files. @@ -520,13 +531,13 @@ intBox.insert(123); Box<Box<int> > boxOfBox; boxOfBox.insert(intBox); -// Up until C++11, you must place a space between the two '>'s, otherwise '>>' -// will be parsed as the right shift operator. +// Until C++11, you had to place a space between the two '>'s, otherwise '>>' +// would be parsed as the right shift operator. // You will sometimes see // template<typename T> -// instead. The 'class' keyword and 'typename' keyword are _mostly_ -// interchangeable in this case. For full explanation, see +// instead. The 'class' keyword and 'typename' keywords are _mostly_ +// interchangeable in this case. For the full explanation, see // http://en.wikipedia.org/wiki/Typename // (yes, that keyword has its own Wikipedia page). @@ -582,12 +593,15 @@ try { // Do not allocate exceptions on the heap using _new_. throw std::runtime_error("A problem occurred"); } + // Catch exceptions by const reference if they are objects catch (const std::exception& ex) { - std::cout << ex.what(); + std::cout << ex.what(); +} + // Catches any exception not caught by previous _catch_ blocks -} catch (...) +catch (...) { std::cout << "Unknown exception caught"; throw; // Re-throws the exception @@ -597,8 +611,8 @@ catch (const std::exception& ex) // RAII /////// -// RAII stands for Resource Allocation Is Initialization. -// It is often considered the most powerful paradigm in C++, +// RAII stands for "Resource Acquisition Is Initialization". +// It is often considered the most powerful paradigm in C++ // and is the simple concept that a constructor for an object // acquires that object's resources and the destructor releases them. @@ -619,9 +633,9 @@ void doSomethingWithAFile(const char* filename) // Unfortunately, things are quickly complicated by error handling. // Suppose fopen can fail, and that doSomethingWithTheFile and // doSomethingElseWithIt return error codes if they fail. -// (Exceptions are the preferred way of handling failure, -// but some programmers, especially those with a C background, -// disagree on the utility of exceptions). +// (Exceptions are the preferred way of handling failure, +// but some programmers, especially those with a C background, +// disagree on the utility of exceptions). // We now have to check each call for failure and close the file handle // if a problem occurred. bool doSomethingWithAFile(const char* filename) @@ -735,21 +749,23 @@ class Foo { virtual void bar(); }; class FooSub : public Foo { - virtual void bar(); // overrides Foo::bar! + virtual void bar(); // Overrides Foo::bar! }; // 0 == false == NULL (most of the time)! bool* pt = new bool; -*pt = 0; // Sets the value points by 'pt' to false. +*pt = 0; // Sets the value points by 'pt' to false. pt = 0; // Sets 'pt' to the null pointer. Both lines compile without warnings. // nullptr is supposed to fix some of that issue: int* pt2 = new int; -*pt2 = nullptr; // Doesn't compile +*pt2 = nullptr; // Doesn't compile pt2 = nullptr; // Sets pt2 to null. -// But somehow 'bool' type is an exception (this is to make `if (ptr)` compile). +// There is an exception made for bools. +// This is to allow you to test for null pointers with if(!ptr), +// but as a consequence you can assign nullptr to a bool directly! *pt = nullptr; // This still compiles, even though '*pt' is a bool! @@ -776,12 +792,12 @@ vector<Foo> v; for (int i = 0; i < 10; ++i) v.push_back(Foo()); -// Following line sets size of v to 0, but destructors don't get called, +// Following line sets size of v to 0, but destructors don't get called // and resources aren't released! v.empty(); -v.push_back(Foo()); // New value is copied into the first Foo we inserted in the loop. +v.push_back(Foo()); // New value is copied into the first Foo we inserted -// Truly destroys all values in v. See section about temporary object for +// Truly destroys all values in v. See section about temporary objects for // explanation of why this works. v.swap(vector<Foo>()); diff --git a/c.html.markdown b/c.html.markdown index 8e631de4..db2ac930 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -130,7 +130,9 @@ int main(void) { // can be declared as well. The size of such an array need not be a compile // time constant: printf("Enter the array size: "); // ask the user for an array size - char buf[0x100]; + int size; + fscanf(stdin, "%d", &size); + char buf[size]; fgets(buf, sizeof buf, stdin); // strtoul parses a string to an unsigned integer diff --git a/chapel.html.markdown b/chapel.html.markdown index c8489371..7252a3e4 100644 --- a/chapel.html.markdown +++ b/chapel.html.markdown @@ -27,7 +27,7 @@ writeln( "There are ", 3, " commas (\",\") in this line of code" ); stdout.writeln( "This goes to standard output, just like plain writeln() does"); stderr.writeln( "This goes to standard error" ); -// Variables don't have to be explicitly typed as long as +// Variables don't have to be explicitly typed as long as // the compiler can figure out the type that it will hold. var myVar = 10; // 10 is an int, so myVar is implicitly an int myVar = -10; @@ -65,9 +65,9 @@ const almostPi: real = 22.0/7.0; param compileTimeConst: int = 16; // The config modifier allows values to be set at the command line -// and is much easier than the usual getOpts debacle +// and is much easier than the usual getOpts debacle // config vars and consts can be changed through the command line at run time -config var varCmdLineArg: int = -123; +config var varCmdLineArg: int = -123; config const constCmdLineArg: int = 777; // Set with --VarName=Value or --VarName Value at run time @@ -119,9 +119,9 @@ a *= thatInt; // Times-equals ( a = a * thatInt; ) b &&= thatBool; // Logical-and-equals ( b = b && thatBool; ) a <<= 3; // Left-bit-shift-equals ( a = a << 10; ) // and many, many more. -// Unlike other C family languages there are no +// Unlike other C family languages there are no // pre/post-increment/decrement operators like -// ++j, --j, j++, j-- +// ++j, --j, j++, j-- // Swap operator var old_this = thisInt; @@ -155,7 +155,7 @@ writeln( (a,b,thisInt,thatInt,thisBool,thatBool) ); // Type aliasing type chroma = int; // Type of a single hue -type RGBColor = 3*chroma; // Type representing a full color +type RGBColor = 3*chroma; // Type representing a full color var black: RGBColor = ( 0,0,0 ); var white: RGBColor = ( 255, 255, 255 ); @@ -198,7 +198,7 @@ select( inputOption ){ writeln( "Chose 'otherOption'" ); writeln( "Which has a body" ); } - otherwise { + otherwise { writeln( "Any other Input" ); writeln( "the otherwise case doesn't need a do if the body is one line" ); } @@ -221,7 +221,7 @@ do{ writeln( jSum ); // For loops are much like those in python in that they iterate over a range. -// Ranges themselves are types, and can be stuffed into variables +// Ranges themselves are types, and can be stuffed into variables // (more about that later) for i in 1..10 do write( i , ", ") ; writeln( ); @@ -240,28 +240,28 @@ for x in 1..10 { } // Ranges and Domains -// For-loops and arrays both use ranges and domains to +// For-loops and arrays both use ranges and domains to // define an index set that can be iterated over. // Ranges are single dimensional -// Domains can be multi-dimensional and can +// Domains can be multi-dimensional and can // represent indices of different types as well. // They are first-class citizen types, and can be assigned into variables var range1to10: range = 1..10; // 1, 2, 3, ..., 10 var range2to11 = 2..11; // 2, 3, 4, ..., 11 var rangeThistoThat: range = thisInt..thatInt; // using variables -var rangeEmpty: range = 100..-100 ; // this is valid but contains no indices +var rangeEmpty: range = 100..-100 ; // this is valid but contains no indices -// Ranges can be unbounded -var range1toInf: range(boundedType=BoundedRangeType.boundedLow) = 1.. ; +// Ranges can be unbounded +var range1toInf: range(boundedType=BoundedRangeType.boundedLow) = 1.. ; // 1, 2, 3, 4, 5, ... -// Note: the range(boundedType= ... ) is only +// Note: the range(boundedType= ... ) is only // necessary if we explicitly type the variable var rangeNegInfto1 = ..1; // ..., -4, -3, -2, -1, 0, 1 // Ranges can be strided using the 'by' operator. var range2to10by2: range(stridable=true) = 2..10 by 2; // 2, 4, 6, 8, 10 -// Note: the range(stridable=true) is only +// Note: the range(stridable=true) is only // necessary if we explicitly type the variable // Use by to create a reverse range @@ -275,9 +275,9 @@ var rangeCountBy: range(stridable=true) = -5..#12 by 2; // -5, -3, -1, 1, 3, 5 writeln( rangeCountBy ); // Can query properties of the range -// Print the first index, last index, number of indices, +// Print the first index, last index, number of indices, // stride, and ask if 2 is include in the range -writeln( ( rangeCountBy.first, rangeCountBy.last, rangeCountBy.length, +writeln( ( rangeCountBy.first, rangeCountBy.last, rangeCountBy.length, rangeCountBy.stride, rangeCountBy.member( 2 ) ) ); for i in rangeCountBy{ @@ -307,9 +307,9 @@ var stringSet: domain(string); // empty set of strings stringSet += "a"; stringSet += "b"; stringSet += "c"; -stringSet += "a"; // Redundant add "a" +stringSet += "a"; // Redundant add "a" stringSet -= "c"; // Remove "c" -writeln( stringSet ); +writeln( stringSet ); // Both ranges and domains can be sliced to produce a range or domain with the // intersection of indices @@ -332,13 +332,13 @@ var intArray2: [{1..10}] int; //equivalent for i in 1..10 do intArray[i] = -i; writeln( intArray ); -// We cannot access intArray[0] because it exists outside +// We cannot access intArray[0] because it exists outside // of the index set, {1..10}, we defined it to have. // intArray[11] is illegal for the same reason. var realDomain: domain(2) = {1..5,1..7}; var realArray: [realDomain] real; -var realArray2: [1..5,1..7] real; // Equivalent +var realArray2: [1..5,1..7] real; // Equivalent var realArray3: [{1..5,1..7}] real; // Equivalent for i in 1..5 { @@ -350,8 +350,8 @@ for i in 1..5 { } // Arrays have domains as members that we can iterate over -for idx in realArray.domain { // Again, idx is a 2*int tuple - realArray[idx] = 1 / realArray[idx[1],idx[2]]; // Access by tuple and list +for idx in realArray.domain { // Again, idx is a 2*int tuple + realArray[idx] = 1 / realArray[idx[1],idx[2]]; // Access by tuple and list } writeln( realArray ); @@ -377,7 +377,7 @@ var thatArray : [{0..5}] int; // Simply assign one to the other. // This copies thisArray into thatArray, instead of just creating a reference. // Modifying thisArray does not also modify thatArray. -thatArray = thisArray; +thatArray = thisArray; thatArray[1] = -1; writeln( (thisArray, thatArray) ); @@ -389,12 +389,12 @@ writeln( (thisArray, thatArray) ); var thisPlusThat = thisArray + thatArray; writeln( thisPlusThat ); -// Arrays and loops can also be expressions, where loop +// Arrays and loops can also be expressions, where loop // body's expression is the result of each iteration. var arrayFromLoop = for i in 1..10 do i; writeln( arrayFromLoop ); -// An expression can result in nothing, +// An expression can result in nothing, // such as when filtering with an if-expression var evensOrFives = for i in 1..10 do if (i % 2 == 0 || i % 5 == 0) then i; @@ -407,7 +407,7 @@ var evensOrFivesAgain = [ i in 1..10 ] if (i % 2 == 0 || i % 5 == 0) then i; // Or over the values of the array arrayFromLoop = [ value in arrayFromLoop ] value + 1; -// Note: this notation can get somewhat tricky. For example: +// Note: this notation can get somewhat tricky. For example: // evensOrFives = [ i in 1..10 ] if (i % 2 == 0 || i % 5 == 0) then i; // would break. // The reasons for this are explained in depth when discussing zipped iterators. @@ -431,7 +431,7 @@ proc addThree( n ) { doublePrint( addThree( fibonacci( 20 ) ) ); // Can also take 'unlimited' number of parameters -proc maxOf( x ...?k ) { +proc maxOf( x ...?k ) { // x refers to a tuple of one type, with k elements var maximum = x[1]; for i in 2..k do maximum = if (maximum < x[i]) then x[i] else maximum; @@ -439,7 +439,7 @@ proc maxOf( x ...?k ) { } writeln( maxOf( 1, -10, 189, -9071982, 5, 17, 20001, 42 ) ); -// The ? operator is called the query operator, and is used to take +// The ? operator is called the query operator, and is used to take // undetermined values (like tuple or array sizes, and generic types). // Taking arrays as parameters. @@ -463,7 +463,7 @@ writeln( defaultsProc( x=11 ) ); writeln( defaultsProc( x=12, y=5.432 ) ); writeln( defaultsProc( y=9.876, x=13 ) ); -// Intent modifiers on the arguments convey how +// Intent modifiers on the arguments convey how // those arguments are passed to the procedure // in: copy arg in, but not out // out: copy arg out, but not in @@ -489,18 +489,18 @@ writeln( "Outside After: ", (inVar, outVar, inoutVar, refVar) ); // Similarly we can define intents on the return type // refElement returns a reference to an element of array proc refElement( array : [?D] ?T, idx ) ref : T { - return array[ idx ]; // returns a reference to + return array[ idx ]; // returns a reference to } var myChangingArray : [1..5] int = [1,2,3,4,5]; writeln( myChangingArray ); -// Store reference to element in ref variable -ref refToElem = refElement( myChangingArray, 5 ); +// Store reference to element in ref variable +ref refToElem = refElement( myChangingArray, 5 ); writeln( refToElem ); refToElem = -2; // modify reference which modifies actual value in array writeln( refToElem ); writeln( myChangingArray ); -// This makes more practical sense for class methods where references to +// This makes more practical sense for class methods where references to // elements in a data-structure are returned via a method or iterator // We can query the type of arguments to generic procedures @@ -520,21 +520,21 @@ genericProc( 1.0+2.0i, 3.0+4.0i ); // We can also enforce a form of polymorphism with the 'where' clause // This allows the compiler to decide which function to use. -// Note: that means that all information needs to be known at compile-time. +// Note: that means that all information needs to be known at compile-time. // The param modifier on the arg is used to enforce this constraint. proc whereProc( param N : int ): void where ( N > 0 ) { - writeln( "N is greater than 0" ); + writeln( "N is greater than 0" ); } proc whereProc( param N : int ): void where ( N < 0 ) { - writeln( "N is less than 0" ); + writeln( "N is less than 0" ); } whereProc( 10 ); whereProc( -1 ); -// whereProc( 0 ) would result in a compiler error because there +// whereProc( 0 ) would result in a compiler error because there // are no functions that satisfy the where clause's condition. // We could have defined a whereProc without a where clause that would then have // served as a catch all for all the other cases (of which there is only one). @@ -543,7 +543,7 @@ whereProc( -1 ); // We can define the unary operators: // + - ! ~ // and the binary operators: -// + - * / % ** == <= >= < > << >> & | ˆ by +// + - * / % ** == <= >= < > << >> & | ˆ by // += -= *= /= %= **= &= |= ˆ= <<= >>= <=> // Boolean exclusive or operator @@ -569,14 +569,14 @@ Note: You could break everything if you get careless with your overloads. This here will break everything. Don't do it. proc +( left: int, right: int ): int{ return left - right; -} +} */ -// Iterators are a sisters to the procedure, and almost +// Iterators are a sisters to the procedure, and almost // everything about procedures also applies to iterators -// However, instead of returning a single value, +// However, instead of returning a single value, // iterators yield many values to a loop. -// This is useful when a complicated set or order of iterations is needed but +// This is useful when a complicated set or order of iterations is needed but // allows the code defining the iterations to be separate from the loop body. iter oddsThenEvens( N: int ): int { for i in 1..N by 2 do @@ -601,15 +601,15 @@ for i in absolutelyNothing( 10 ){ writeln( "Woa there! absolutelyNothing yielded ", i ); } -// We can zipper together two or more iterators (who have the same number -// of iterations) using zip() to create a single zipped iterator, where each -// iteration of the zipped iterator yields a tuple of one value yielded +// We can zipper together two or more iterators (who have the same number +// of iterations) using zip() to create a single zipped iterator, where each +// iteration of the zipped iterator yields a tuple of one value yielded // from each iterator. // Ranges have implicit iterators -for (positive, negative) in zip( 1..5, -5..-1) do +for (positive, negative) in zip( 1..5, -5..-1) do writeln( (positive, negative) ); -// Zipper iteration is quite important in the assignment of arrays, +// Zipper iteration is quite important in the assignment of arrays, // slices of arrays, and array/loop expressions. var fromThatArray : [1..#5] int = [1,2,3,4,5]; var toThisArray : [100..#5] int; @@ -629,11 +629,11 @@ for (i, j) in zip( toThisArray.domain, -100..#5 ){ } writeln( toThisArray ); -// This is all very important in undestanding why the statement +// This is all very important in undestanding why the statement // var iterArray : [1..10] int = [ i in 1..10 ] if ( i % 2 == 1 ) then j; // exhibits a runtime error. -// Even though the domain of the array and the loop-expression are -// the same size, the body of the expression can be though of as an iterator. +// Even though the domain of the array and the loop-expression are +// the same size, the body of the expression can be thought of as an iterator. // Because iterators can yield nothing, that iterator yields a different number // of things than the domain of the array or loop, which is not allowed. @@ -641,8 +641,8 @@ writeln( toThisArray ); // They currently lack privatization class MyClass { // Member variables - var memberInt : int; - var memberBool : bool = true; + var memberInt : int; + var memberBool : bool = true; // Classes have default constructors that don't need to be coded (see below) // Our explicitly defined constructor @@ -659,28 +659,28 @@ class MyClass { proc setMemberInt( val: int ){ this.memberInt = val; } - + proc setMemberBool( val: bool ){ this.memberBool = val; } - proc getMemberInt( ): int{ + proc getMemberInt( ): int{ return this.memberInt; } proc getMemberBool( ): bool { return this.memberBool; } - + } - + // Construct using default constructor, using default values var myObject = new MyClass( 10 ); myObject = new MyClass( memberInt = 10 ); // Equivalent writeln( myObject.getMemberInt( ) ); // ... using our values var myDiffObject = new MyClass( -1, true ); - myDiffObject = new MyClass( memberInt = -1, + myDiffObject = new MyClass( memberInt = -1, memberBool = true ); // Equivalent writeln( myDiffObject ); @@ -689,7 +689,7 @@ var myOtherObject = new MyClass( 1.95 ); myOtherObject = new MyClass( val = 1.95 ); // Equivalent writeln( myOtherObject.getMemberInt( ) ); -// We can define an operator on our class as well but +// We can define an operator on our class as well but // the definition has to be outside the class definition proc +( A : MyClass, B : MyClass) : MyClass { return new MyClass( memberInt = A.getMemberInt( ) + B.getMemberInt( ), @@ -715,46 +715,46 @@ class GenericClass { type classType; var classDomain: domain(1); var classArray: [classDomain] classType; - + // Explicit constructor proc GenericClass( type classType, elements : int ){ this.classDomain = {1..#elements}; } - + // Copy constructor - // Note: We still have to put the type as an argument, but we can + // Note: We still have to put the type as an argument, but we can // default to the type of the other object using the query (?) operator // Further, we can take advantage of this to allow our copy constructor // to copy classes of different types and cast on the fly - proc GenericClass( other : GenericClass(?otherType), + proc GenericClass( other : GenericClass(?otherType), type classType = otherType ) { this.classDomain = other.classDomain; // Copy and cast - for idx in this.classDomain do this[ idx ] = other[ idx ] : classType; + for idx in this.classDomain do this[ idx ] = other[ idx ] : classType; } - - // Define bracket notation on a GenericClass + + // Define bracket notation on a GenericClass // object so it can behave like a normal array // i.e. objVar[ i ] or objVar( i ) proc this( i : int ) ref : classType { return this.classArray[ i ]; } - - // Define an implicit iterator for the class + + // Define an implicit iterator for the class // to yield values from the array to a loop // i.e. for i in objVar do .... iter these( ) ref : classType { for i in this.classDomain do yield this[i]; } - + } var realList = new GenericClass( real, 10 ); -// We can assign to the member array of the object using the bracket +// We can assign to the member array of the object using the bracket // notation that we defined ( proc this( i: int ){ ... } ) for i in realList.classDomain do realList[i] = i + 1.0; -// We can iterate over the values in our list with the iterator +// We can iterate over the values in our list with the iterator // we defined ( iter these( ){ ... } ) for value in realList do write( value, ", " ); writeln( ); @@ -777,23 +777,23 @@ writeln( ); module OurModule { // We can use modules inside of other modules. use Time; // Time is one of the standard modules. - + // We'll use this procedure in the parallelism section. proc countdown( seconds: int ){ for i in 1..seconds by -1 { writeln( i ); sleep( 1 ); } - } - - // Submodules of OurModule + } + + // Submodules of OurModule // It is possible to create arbitrarily deep module nests. module ChildModule { proc foo(){ writeln( "ChildModule.foo()"); } } - + module SiblingModule { proc foo(){ writeln( "SiblingModule.foo()" ); @@ -806,7 +806,7 @@ module OurModule { use OurModule; // At this point we have not used ChildModule or SiblingModule so their symbols -// (i.e. foo ) are not available to us. +// (i.e. foo ) are not available to us. // However, the module names are, and we can explicitly call foo() through them. SiblingModule.foo(); // Calls SiblingModule.foo() @@ -821,13 +821,13 @@ foo(); // Less explicit call on ChildModule.foo() proc main(){ // Parallelism - // In other languages, parallelism is typically done with + // In other languages, parallelism is typically done with // complicated libraries and strange class structure hierarchies. // Chapel has it baked right into the language. - // A begin statement will spin the body of that statement off + // A begin statement will spin the body of that statement off // into one new task. - // A sync statement will ensure that the progress of the main + // A sync statement will ensure that the progress of the main // task will not progress until the children have synced back up. sync { begin { // Start of new task's body @@ -848,7 +848,7 @@ proc main(){ printFibb( 20 ); // new task printFibb( 10 ); // new task printFibb( 5 ); // new task - { + { // This is a nested statement body and thus is a single statement // to the parent statement and is executed by a single task writeln( "this gets" ); @@ -867,26 +867,26 @@ proc main(){ // NOTE! coforall should be used only for creating tasks! // Using it to iterating over a structure is very a bad idea! - // forall loops are another parallel loop, but only create a smaller number + // forall loops are another parallel loop, but only create a smaller number // of tasks, specifically --dataParTasksPerLocale=number of task forall i in 1..100 { write( i, ", "); } writeln( ); - // Here we see that there are sections that are in order, followed by + // Here we see that there are sections that are in order, followed by // a section that would not follow ( e.g. 1, 2, 3, 7, 8, 9, 4, 5, 6, ). // This is because each task is taking on a chunk of the range 1..10 // (1..3, 4..6, or 7..9) doing that chunk serially, but each task happens // in parallel. // Your results may depend on your machine and configuration - // For both the forall and coforall loops, the execution of the + // For both the forall and coforall loops, the execution of the // parent task will not continue until all the children sync up. // forall loops are particularly useful for parallel iteration over arrays. // Lets run an experiment to see how much faster a parallel loop is use Time; // Import the Time module to use Timer objects - var timer: Timer; + var timer: Timer; var myBigArray: [{1..4000,1..4000}] real; // Large array we will write into // Serial Experiment @@ -906,7 +906,7 @@ proc main(){ timer.stop( ); // Stop timer writeln( "Parallel: ", timer.elapsed( ) ); // Print elapsed time timer.clear( ); - // You may have noticed that (depending on how many cores you have) + // You may have noticed that (depending on how many cores you have) // that the parallel loop went faster than the serial loop // The bracket style loop-expression described @@ -926,15 +926,15 @@ proc main(){ writeln( uranium.read() ); var replaceWith = 239; - var was = uranium.exchange( replaceWith ); + var was = uranium.exchange( replaceWith ); writeln( "uranium was ", was, " but is now ", replaceWith ); var isEqualTo = 235; if ( uranium.compareExchange( isEqualTo, replaceWith ) ) { - writeln( "uranium was equal to ", isEqualTo, + writeln( "uranium was equal to ", isEqualTo, " so replaced value with ", replaceWith ); } else { - writeln( "uranium was not equal to ", isEqualTo, + writeln( "uranium was not equal to ", isEqualTo, " so value stays the same... whatever it was" ); } @@ -960,13 +960,13 @@ proc main(){ begin { // Reader task writeln( "Reader: waiting to read." ); var read_sync = someSyncVar$; - writeln( "value is ", read_sync ); + writeln( "Reader: value is ", read_sync ); } begin { // Writer task writeln( "Writer: will write in..." ); countdown( 3 ); - someSyncVar$ = 123; + someSyncVar$ = 123; } } @@ -989,14 +989,14 @@ proc main(){ } } - // Heres an example of using atomics and a synch variable to create a + // Heres an example of using atomics and a synch variable to create a // count-down mutex (also known as a multiplexer) var count: atomic int; // our counter var lock$: sync bool; // the mutex lock count.write( 2 ); // Only let two tasks in at a time. lock$.writeXF( true ); // Set lock$ to full (unlocked) - // Note: The value doesnt actually matter, just the state + // Note: The value doesnt actually matter, just the state // (full:unlocked / empty:locked) // Also, writeXF() fills (F) the sync var regardless of its state (X) @@ -1005,10 +1005,10 @@ proc main(){ do{ lock$; // Read lock$ (wait) }while ( count.read() < 1 ); // Keep waiting until a spot opens up - + count.sub(1); // decrement the counter lock$.writeXF( true ); // Set lock$ to full (signal) - + // Actual 'work' writeln( "Task #", task, " doing work." ); sleep( 2 ); @@ -1027,13 +1027,13 @@ proc main(){ // 'maxloc' gives max value and index of the max value // Note: We have to zip the array and domain together with the zip iterator - var (theMaxValue, idxOfMax) = maxloc reduce zip(listOfValues, + var (theMaxValue, idxOfMax) = maxloc reduce zip(listOfValues, listOfValues.domain); - + writeln( (sumOfValues, maxValue, idxOfMax, listOfValues[ idxOfMax ] ) ); // Scans apply the operation incrementally and return an array of the - // value of the operation at that index as it progressed through the + // value of the operation at that index as it progressed through the // array from array.domain.low to array.domain.high var runningSumOfValues = + scan listOfValues; var maxScan = max scan listOfValues; @@ -1046,14 +1046,14 @@ Who is this tutorial for? ------------------------- 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. +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 details. Occasionally check back here and on the [Chapel site](http://chapel.cray.com) to see if more topics have been added or more tutorials created. ### What this tutorial is lacking: - * Exposition of the standard modules + * Exposition of the [standard modules](http://chapel.cray.com/docs/latest/modules/modules.html) * Multiple Locales (distributed memory system) * Records * Parallel iterators @@ -1061,11 +1061,11 @@ Occasionally check back here and on the [Chapel site](http://chapel.cray.com) to Your input, questions, and discoveries are important to the developers! ----------------------------------------------------------------------- -The Chapel language is still in-development (version 1.11.0), so there are occasional hiccups with performance and language features. +The Chapel language is still in-development (version 1.12.0), 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). -If you're really interested in the development of the compiler or contributing to the project, +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). It is under the [Apache 2.0 License](http://www.apache.org/licenses/LICENSE-2.0). @@ -1074,14 +1074,14 @@ Installing the Compiler 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 its as easy as +and it's as easy as - 1. `tar -xvf chapel-1.11.0.tar.gz` - 2. `cd chapel-1.11.0` + 1. `tar -xvf chapel-1.12.0.tar.gz` + 2. `cd chapel-1.12.0` 3. `make` 4. `source util/setchplenv.bash # or .sh or .csh or .fish` -You will need to `source util/setchplenv.EXT` from within the Chapel directory (`$CHPL_HOME`) every time your terminal starts so its suggested that you drop that command in a script that will get executed on startup (like .bashrc). +You will need to `source util/setchplenv.EXT` from within the Chapel directory (`$CHPL_HOME`) every time your terminal starts so it's suggested that you drop that command in a script that will get executed on startup (like .bashrc). Chapel is easily installed with Brew for OS X @@ -1100,4 +1100,4 @@ Notable arguments: * `--fast`: enables a number of optimizations and disables array bounds checks. Should only enable when application is stable. * `--set <Symbol Name>=<Value>`: set config param `<Symbol Name>` to `<Value>` at compile-time. * `--main-module <Module Name>`: use the main() procedure found in the module `<Module Name>` as the executable's main. - * `--module-dir <Directory>`: includes `<Directory>` in the module search path.
\ No newline at end of file + * `--module-dir <Directory>`: includes `<Directory>` in the module search path. diff --git a/clojure-macros.html.markdown b/clojure-macros.html.markdown index 9e907a7f..d74f77cf 100644 --- a/clojure-macros.html.markdown +++ b/clojure-macros.html.markdown @@ -142,11 +142,11 @@ You'll want to be familiar with Clojure. Make sure you understand everything in ### Further Reading -Writing Macros from [Clojure for the Brave and True](http://www.braveclojure.com/) +Writing Macros from [Clojure for the Brave and True](http://www.braveclojure.com/) [http://www.braveclojure.com/writing-macros/](http://www.braveclojure.com/writing-macros/) -Official docs +Official docs [http://clojure.org/macros](http://clojure.org/macros) -When to use macros? +When to use macros? [http://dunsmor.com/lisp/onlisp/onlisp_12.html](http://dunsmor.com/lisp/onlisp/onlisp_12.html) diff --git a/coffeescript.html.markdown b/coffeescript.html.markdown index 4c080bc6..89a29677 100644 --- a/coffeescript.html.markdown +++ b/coffeescript.html.markdown @@ -6,8 +6,8 @@ contributors: filename: coffeescript.coffee --- -CoffeeScript is a little language that compiles one-to-one into the equivalent JavaScript, and there is no interpretation at runtime. -As one of the succeeders of JavaScript, CoffeeScript tries its best to output readable, pretty-printed and smooth-running JavaScript codes working well in every JavaScript runtime. +CoffeeScript is a little language that compiles one-to-one into the equivalent JavaScript, and there is no interpretation at runtime. +As one of the successors to JavaScript, CoffeeScript tries its best to output readable, pretty-printed and smooth-running JavaScript code, which works well in every JavaScript runtime. See also [the CoffeeScript website](http://coffeescript.org/), which has a complete tutorial on CoffeeScript. @@ -54,35 +54,35 @@ math = square: square cube: (x) -> x * square x #=> var math = { -# "root": Math.sqrt, -# "square": square, -# "cube": function(x) { return x * square(x); } -#} +# "root": Math.sqrt, +# "square": square, +# "cube": function(x) { return x * square(x); } +# }; # Splats: race = (winner, runners...) -> print winner, runners #=>race = function() { -# var runners, winner; -# winner = arguments[0], runners = 2 <= arguments.length ? __slice.call(arguments, 1) : []; -# return print(winner, runners); -#}; +# var runners, winner; +# winner = arguments[0], runners = 2 <= arguments.length ? __slice.call(arguments, 1) : []; +# return print(winner, runners); +# }; # Existence: alert "I knew it!" if elvis? #=> if(typeof elvis !== "undefined" && elvis !== null) { alert("I knew it!"); } # Array comprehensions: -cubes = (math.cube num for num in list) +cubes = (math.cube num for num in list) #=>cubes = (function() { -# var _i, _len, _results; -# _results = []; +# var _i, _len, _results; +# _results = []; # for (_i = 0, _len = list.length; _i < _len; _i++) { -# num = list[_i]; -# _results.push(math.cube(num)); -# } -# return _results; -# })(); +# num = list[_i]; +# _results.push(math.cube(num)); +# } +# return _results; +# })(); foods = ['broccoli', 'spinach', 'chocolate'] eat food for food in foods when food isnt 'chocolate' diff --git a/common-lisp.html.markdown b/common-lisp.html.markdown index f9f64d68..63183c1e 100644 --- a/common-lisp.html.markdown +++ b/common-lisp.html.markdown @@ -175,7 +175,8 @@ nil ; for false - and the empty list :age 5)) *rover* ; => #S(DOG :NAME "rover" :BREED "collie" :AGE 5) -(dog-p *rover*) ; => t ;; ewww) +(dog-p *rover*) ; => true #| -p signifies "predicate". It's used to + check if *rover* is an instance of dog. |# (dog-name *rover*) ; => "rover" ;; Dog-p, make-dog, and dog-name are all created by defstruct! @@ -260,7 +261,7 @@ nil ; for false - and the empty list (defparameter *adjvec* (make-array '(3) :initial-contents '(1 2 3) :adjustable t :fill-pointer t)) - + *adjvec* ; => #(1 2 3) ;; Adding new element: diff --git a/csharp.html.markdown b/csharp.html.markdown index 479b7f01..02650038 100644 --- a/csharp.html.markdown +++ b/csharp.html.markdown @@ -25,7 +25,7 @@ Multi-line comments look like this //public void MethodOrClassOrOtherWithParsableHelp() {} // Specify the namespaces this source code will be using -// The namespaces below are all part of the standard .NET Framework Class Libary +// The namespaces below are all part of the standard .NET Framework Class Libary using System; using System.Collections.Generic; using System.Dynamic; @@ -48,7 +48,7 @@ namespace Learning.CSharp public class LearnCSharp { // BASIC SYNTAX - skip to INTERESTING FEATURES if you have used Java or C++ before - public static void Syntax() + public static void Syntax() { // Use Console.WriteLine to print lines Console.WriteLine("Hello World"); @@ -236,7 +236,8 @@ on a new line! ""Wow!"", the masses cried"; // Ternary operators // A simple if/else can be written as follows // <condition> ? <true> : <false> - string isTrue = (true) ? "True" : "False"; + int toCompare = 17; + string isTrue = toCompare == 17 ? "True" : "False"; // While loop int fooWhile = 0; @@ -370,11 +371,11 @@ on a new line! ""Wow!"", the masses cried"; // // INTERESTING FEATURES // - + // DEFAULT METHOD SIGNATURES public // Visibility - static // Allows for direct call on class without object + static // Allows for direct call on class without object int // Return Type, MethodSignatures( int maxCount, // First variable, expects an int @@ -382,7 +383,7 @@ on a new line! ""Wow!"", the masses cried"; int another = 3, params string[] otherParams // captures all other parameters passed to method ) - { + { return -1; } @@ -399,8 +400,8 @@ on a new line! ""Wow!"", the masses cried"; // The classes for TKey and TValue is specified by the user calling this function. // This method emulates the SetDefault of Python public static TValue SetDefault<TKey, TValue>( - IDictionary<TKey, TValue> dictionary, - TKey key, + IDictionary<TKey, TValue> dictionary, + TKey key, TValue defaultItem) { TValue result; @@ -409,7 +410,7 @@ on a new line! ""Wow!"", the masses cried"; return result; } - // You can narrow down the objects that are passed in + // You can narrow down the objects that are passed in public static void IterateAndPrint<T>(T toPrint) where T: IEnumerable<int> { // We can iterate, since T is a IEnumerable @@ -449,13 +450,13 @@ on a new line! ""Wow!"", the masses cried"; // GENERICS // - var phonebook = new Dictionary<string, string>() { + var phonebook = new Dictionary<string, string>() { {"Sarah", "212 555 5555"} // Add some entries to the phone book }; // Calling SETDEFAULT defined as a generic above Console.WriteLine(SetDefault<string,string>(phonebook, "Shaun", "No Phone")); // No Phone - // nb, you don't need to specify the TKey and TValue since they can be + // nb, you don't need to specify the TKey and TValue since they can be // derived implicitly Console.WriteLine(SetDefault(phonebook, "Sarah", "No Phone")); // 212 555 5555 @@ -490,26 +491,26 @@ on a new line! ""Wow!"", the masses cried"; // DISPOSABLE RESOURCES MANAGEMENT - let you handle unmanaged resources easily. // Most of objects that access unmanaged resources (file handle, device contexts, etc.) - // implement the IDisposable interface. The using statement takes care of + // implement the IDisposable interface. The using statement takes care of // cleaning those IDisposable objects for you. using (StreamWriter writer = new StreamWriter("log.txt")) { writer.WriteLine("Nothing suspicious here"); // At the end of scope, resources will be released. // Even if an exception is thrown. - } + } // PARALLEL FRAMEWORK // http://blogs.msdn.com/b/csharpfaq/archive/2010/06/01/parallel-programming-in-net-framework-4-getting-started.aspx - var websites = new string[] { - "http://www.google.com", "http://www.reddit.com", + var websites = new string[] { + "http://www.google.com", "http://www.reddit.com", "http://www.shaunmccarthy.com" }; var responses = new Dictionary<string, string>(); - + // Will spin up separate threads for each request, and join on them // before going to the next step! - Parallel.ForEach(websites, + Parallel.ForEach(websites, new ParallelOptions() {MaxDegreeOfParallelism = 3}, // max of 3 threads website => { @@ -533,7 +534,7 @@ on a new line! ""Wow!"", the masses cried"; (introduceTo) => string.Format("Hey {0}, this is {1}", student.FirstName, introduceTo)); Console.WriteLine(student.Introduce("Beth")); - // IQUERYABLE<T> - almost all collections implement this, which gives you a lot of + // IQUERYABLE<T> - almost all collections implement this, which gives you a lot of // very useful Map / Filter / Reduce style methods var bikes = new List<Bicycle>(); bikes.Sort(); // Sorts the array @@ -555,8 +556,8 @@ on a new line! ""Wow!"", the masses cried"; // ASPARALLEL // And this is where things get wicked - combines linq and parallel operations var threeWheelers = bikes.AsParallel().Where(b => b.Wheels == 3).Select(b => b.Name); - // this will happen in parallel! Threads will automagically be spun up and the - // results divvied amongst them! Amazing for large datasets when you have lots of + // this will happen in parallel! Threads will automagically be spun up and the + // results divvied amongst them! Amazing for large datasets when you have lots of // cores // LINQ - maps a store to IQueryable<T> objects, with delayed execution @@ -574,9 +575,9 @@ on a new line! ""Wow!"", the masses cried"; .Select(b => b.Name); // still no query run // Now the query runs, but opens a reader, so only populates are you iterate through - foreach (string bike in query) + foreach (string bike in query) Console.WriteLine(result); - + } @@ -628,7 +629,7 @@ on a new line! ""Wow!"", the masses cried"; private set; // You can set modifiers on the get/set methods } - int _speed; // Everything is private by default: Only accessible from within this class. + int _speed; // Everything is private by default: Only accessible from within this class. // can also use keyword private public string Name { get; set; } @@ -675,7 +676,7 @@ on a new line! ""Wow!"", the masses cried"; // Constructors are a way of creating classes // This is a default constructor - public Bicycle() + public Bicycle() { this.Gear = 1; // you can access members of the object with the keyword this Cadence = 50; // but you don't always need it @@ -687,13 +688,13 @@ on a new line! ""Wow!"", the masses cried"; // This is a specified constructor (it contains arguments) public Bicycle(int startCadence, int startSpeed, int startGear, - string name, bool hasCardsInSpokes, BikeBrand brand) + string name, bool hasCardsInSpokes, BikeBrand brand) : base() // calls base first { - Gear = startGear; + Gear = startGear; Cadence = startCadence; _speed = startSpeed; - Name = name; + Name = name; _hasCardsInSpokes = hasCardsInSpokes; Brand = brand; } @@ -856,7 +857,7 @@ on a new line! ""Wow!"", the masses cried"; } /// <summary> - /// Used to connect to DB for LinqToSql example. + /// Used to connect to DB for LinqToSql example. /// EntityFramework Code First is awesome (similar to Ruby's ActiveRecord, but bidirectional) /// http://msdn.microsoft.com/en-us/data/jj193542.aspx /// </summary> @@ -881,7 +882,7 @@ on a new line! ""Wow!"", the masses cried"; * ASP.NET Web Forms (old) * WebMatrix (tool) * Desktop Development - * Windows Presentation Foundation (WPF) (new) + * Windows Presentation Foundation (WPF) (new) * Winforms (old) ## Further Reading diff --git a/css.html.markdown b/css.html.markdown index 7224d80a..811767e6 100644 --- a/css.html.markdown +++ b/css.html.markdown @@ -4,22 +4,23 @@ 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"] filename: learncss.css --- -In the early days of the web there were no visual elements, just pure text. But with the -further development of browsers, fully visual web pages also became common. -CSS is the standard language that exists to keep the separation between +In the early days of the web there were no visual elements, just pure text. But with the +further development of browsers, fully visual web pages also became common. +CSS is the standard language that exists to keep the separation between the content (HTML) and the look-and-feel of web pages. -In short, what CSS does is to provide a syntax that enables you to target +In short, what CSS does is to provide a syntax that enables you to target different elements on an HTML page and assign different visual properties to them. -Like any other languages, CSS has many versions. Here we focus on CSS2.0, +Like any other languages, CSS has many versions. Here we focus on CSS2.0, which is not the most recent version, but is the most widely supported and compatible version. -**NOTE:** Because the outcome of CSS consists of visual effects, in order to -learn it, you need try everything in a +**NOTE:** Because the outcome of CSS consists of visual effects, in order to +learn it, you need try everything in a CSS playground like [dabblet](http://dabblet.com/). The main focus of this article is on the syntax and some general tips. @@ -77,8 +78,8 @@ div { } [otherAttr|='en'] { font-size:smaller; } -/* and more importantly you can combine these together -- there shouldn't be -any space between different parts because that makes it to have another +/* and more importantly you can combine these together -- there shouldn't be +any space between different parts because that makes it to have another meaning. */ div.some-class[attr$='ue'] { } @@ -88,22 +89,22 @@ div.some-class[attr$='ue'] { } div.some-parent > .class-name {} /* or any of its parents in the tree - the following basically means any element that has class "class-name" + the following basically means any element that has class "class-name" and is child of a div with class name "some-parent" IN ANY DEPTH */ div.some-parent .class-name {} -/* warning: the same selector without space has another meaning. +/* warning: the same selector without space has another meaning. can you say what? */ div.some-parent.class-name {} -/* you also might choose to select an element based on its direct +/* you also might choose to select an element based on its direct previous sibling */ .i-am-before + .this-element { } /* or any sibling before this */ .i-am-any-before ~ .this-element {} -/* There are some pseudo classes that allows you to select an element +/* There are some pseudo classes that allows you to select an element based on its page behaviour (rather than page structure) */ /* for example for when an element is hovered */ @@ -124,7 +125,7 @@ selected:focus {} #################### */ selector { - + /* Units */ width: 50%; /* in percent */ font-size: 2em; /* times current font-size */ @@ -137,7 +138,7 @@ selector { width: 0.4vw; /* times horizontal width of browser viewport (CSS3) */ min-height: 0.1vmin; /* the lesser of vertical, horizontal dimensions of browser viewport (CSS3) */ max-width: 0.3vmax; /* same as above, except the greater of the dimensions (CSS3) */ - + /* Colors */ background-color: #F6E; /* in short hex */ background-color: #F262E2; /* in long hex format */ @@ -149,10 +150,10 @@ selector { background-color: hsl(0, 100%, 50%); /* hsl format (CSS3). */ background-color: hsla(0, 100%, 50%, 0.3); /* Similar to RGBA, specify opacity at end (CSS3) */ - + /* Images */ background-image: url(/path-to-image/image.jpg); /* quotes inside url() optional */ - + /* Fonts */ font-family: Arial; font-family: "Courier New"; /* if name has space it appears in single or double quotes */ @@ -170,13 +171,13 @@ Save any CSS you want in a file with extension `.css`. <!-- you need to include the css file in your page's <head>: --> <link rel='stylesheet' type='text/css' href='path/to/style.css' /> -<!-- you can also include some CSS inline in your markup. However it is highly +<!-- you can also include some CSS inline in your markup. However it is highly recommended to avoid this. --> <style> a { color: purple; } </style> -<!-- or directly set CSS properties on the element. +<!-- or directly set CSS properties on the element. This has to be avoided as much as you can. --> <div style="border: 1px solid red;"> </div> @@ -185,8 +186,8 @@ This has to be avoided as much as you can. --> ## Precedence -As you noticed an element may be targetted by more than one selector. -and may have a property set on it in more than one. +As you noticed an element may be targetted by more than one selector. +and may have a property set on it in more than one. In these cases, one of the rules takes precedence over others. Given the following CSS: @@ -216,32 +217,35 @@ and the following markup: </p> ``` -The precedence of style is as followed: +The precedence of style is as followed: Remember, the precedence is for each **property**, not for the entire block. -* `E` has the highest precedence because of the keyword `!important`. +* `E` has the highest precedence because of the keyword `!important`. It is recommended to avoid this unless it is strictly necessary to use. * `F` is next, because it is inline style. -* `A` is next, because it is more "specific" than anything else. - more specific = more specifiers. here 3 specifiers: 1 tagname `p` + +* `A` is next, because it is more "specific" than anything else. + more specific = more specifiers. here 3 specifiers: 1 tagname `p` + class name `class1` + 1 attribute `attr='value'` -* `C` is next. although it has the same specificness as `B` +* `C` is next. although it has the same specificness as `B` but it appears last. * Then is `B` * and lastly is `D`. ## Compatibility -Most of the features in CSS2 (and gradually in CSS3) are compatible across -all browsers and devices. But it's always vital to have in mind the compatibility +Most of the features in CSS2 (and gradually in CSS3) are compatible across +all browsers and devices. But it's always vital to have in mind the compatibility of what you use in CSS with your target browsers. [QuirksMode CSS](http://www.quirksmode.org/css/) is one of the best sources for this. -To run a quick compatibility check, [CanIUse](http://caniuse.com) is a great resource. +To run a quick compatibility check, [Can I Use...](http://caniuse.com) is a great resource. ## Further Reading +* [Mozilla Developer Network's CSS documentation](https://developer.mozilla.org/en-US/docs/Web/CSS) +* [Codrops' CSS Reference](http://tympanus.net/codrops/css_reference/) * [Understanding Style Precedence in CSS: Specificity, Inheritance, and the Cascade](http://www.vanseodesign.com/css/css-specificity-inheritance-cascaade/) * [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) +* [SCSS](http://sass-lang.com/) and [LESS](http://lesscss.org/) for CSS pre-processing diff --git a/d.html.markdown b/d.html.markdown index daba8020..ba24b60f 100644 --- a/d.html.markdown +++ b/d.html.markdown @@ -1,6 +1,6 @@ --- -language: D -filename: learnd.d +language: D +filename: learnd.d contributors: - ["Nick Papanastasiou", "www.nickpapanastasiou.github.io"] lang: en @@ -18,9 +18,9 @@ void main(string[] args) { } ``` -If you're like me and spend way too much time on the internet, odds are you've heard +If you're like me and spend way too much time on the internet, odds are you've heard about [D](http://dlang.org/). The D programming language is a modern, general-purpose, -multi-paradigm language with support for everything from low-level features to +multi-paradigm language with support for everything from low-level features to expressive high-level abstractions. D is actively developed by Walter Bright and Andrei Alexandrescu, two super smart, really cool @@ -37,7 +37,7 @@ void main() { } auto n = 1; // use auto for type inferred variables - + // Numeric literals can use _ as a digit seperator for clarity while(n < 10_000) { n += n; @@ -49,7 +49,7 @@ void main() { // For and while are nice, but in D-land we prefer foreach // The .. creates a continuous range, excluding the end - foreach(i; 1..1_000_000) { + foreach(i; 1..1_000_000) { if(n % 2 == 0) writeln(i); } @@ -72,12 +72,12 @@ we can use templates to parameterize all of these on both types and values! // Here, T is a type parameter. Think <T> from C++/C#/Java struct LinkedList(T) { T data = null; - LinkedList!(T)* next; // The ! is used to instaniate a parameterized type. Again, think <T> + LinkedList!(T)* next; // The ! is used to instaniate a parameterized type. Again, think <T> } class BinTree(T) { T data = null; - + // If there is only one template parameter, we can omit parens BinTree!T left; BinTree!T right; @@ -101,7 +101,7 @@ alias NumTree = BinTree!double; // We can create function templates as well! T max(T)(T a, T b) { - if(a < b) + if(a < b) return b; return a; @@ -114,7 +114,7 @@ void swap(T)(ref T a, ref T b) { auto temp = a; a = b; - b = temp; + b = temp; } // With templates, we can also parameterize on values, not just types @@ -145,13 +145,13 @@ class MyClass(T, U) { class MyClass(T, U) { T _data; U _other; - + // Constructors are always named `this` this(T t, U u) { data = t; other = u; } - + // getters @property T data() { return _data; @@ -161,7 +161,7 @@ class MyClass(T, U) { return _other; } - // setters + // setters @property void data(T t) { _data = t; } @@ -177,7 +177,7 @@ void main() { mc.data = 7; mc.other = "seven"; - + writeln(mc.data); writeln(mc.other); } @@ -193,7 +193,7 @@ and `override`ing methods. D does inheritance just like Java: Extend one class, implement as many interfaces as you please. We've seen D's OOP facilities, but let's switch gears. D offers -functional programming with first-class functions, `pure` +functional programming with first-class functions, `pure` functions, and immutable data. In addition, all of your favorite functional algorithms (map, filter, reduce and friends) can be found in the wonderful `std.algorithm` module! @@ -205,7 +205,7 @@ import std.range : iota; // builds an end-exclusive range void main() { // We want to print the sum of a list of squares of even ints // from 1 to 100. Easy! - + // Just pass lambda expressions as template parameters! // You can pass any old function you like, but lambdas are convenient here. auto num = iota(1, 101).filter!(x => x % 2 == 0) @@ -216,12 +216,12 @@ void main() { } ``` -Notice how we got to build a nice Haskellian pipeline to compute num? +Notice how we got to build a nice Haskellian pipeline to compute num? That's thanks to a D innovation know as Uniform Function Call Syntax. With UFCS, we can choose whether to write a function call as a method or free function call! Walter wrote a nice article on this -[here.](http://www.drdobbs.com/cpp/uniform-function-call-syntax/232700394) -In short, you can call functions whose first parameter +[here.](http://www.drdobbs.com/cpp/uniform-function-call-syntax/232700394) +In short, you can call functions whose first parameter is of some type A on any expression of type A as a method. I like parallelism. Anyone else like parallelism? Sure you do. Let's do some! diff --git a/dart.html.markdown b/dart.html.markdown index 34d1c6a8..f7601271 100644 --- a/dart.html.markdown +++ b/dart.html.markdown @@ -81,7 +81,7 @@ example5() { // Where classBody can include instance methods and variables, but also // class methods and variables. class Example6Class { - var example6InstanceVariable = "Example6 instance variable"; + var example6InstanceVariable = "Example6 instance variable"; sayIt() { print(example6InstanceVariable); } @@ -92,7 +92,7 @@ example6() { // Class methods and variables are declared with "static" terms. class Example7Class { - static var example7ClassVariable = "Example7 class variable"; + static var example7ClassVariable = "Example7 class variable"; static sayItFromClass() { print(example7ClassVariable); } @@ -111,7 +111,7 @@ example7() { // by default. But arrays and maps are not. They can be made constant by // declaring them "const". var example8A = const ["Example8 const array"], - example8M = const {"someKey": "Example8 const map"}; + example8M = const {"someKey": "Example8 const map"}; example8() { print(example8A[0]); print(example8M["someKey"]); @@ -245,7 +245,7 @@ example18() { // Strings with triple single-quotes or triple double-quotes span // multiple lines and include line delimiters. example19() { - print('''Example19 <a href="etc"> + print('''Example19 <a href="etc"> Example19 Don't can't I'm Etc Example19 </a>'''); } @@ -272,7 +272,7 @@ example20() { class Example21 { List<String> _names; Example21() { - _names = ["a", "b"]; + _names = ["a", "b"]; } List<String> get names => _names; set names(List<String> list) { diff --git a/de-de/csharp-de.html.markdown b/de-de/csharp-de.html.markdown index dc77dda0..8ad7d71f 100644 --- a/de-de/csharp-de.html.markdown +++ b/de-de/csharp-de.html.markdown @@ -248,7 +248,8 @@ zur nächsten Zeile, ""Wahnsinn!"", die Massen waren kaum zu bändigen"; // Ternärer Operator
// Anstatt eines einfachen if/else lässt sich auch folgendes schreiben:
// <condition> ? <true> : <false>
- string isTrue = true ? "Ja" : "Nein";
+ int zumVergleich = 17;
+ string isTrue = zumVergleich == 17 ? "Ja" : "Nein";
// while-Schleife
int fooWhile = 0;
@@ -886,4 +887,4 @@ zur nächsten Zeile, ""Wahnsinn!"", die Massen waren kaum zu bändigen"; * [ASP.NET Web Forms Tutorials](http://www.asp.net/web-forms/tutorials)
* [Windows Forms Programming in C#](http://www.amazon.com/Windows-Forms-Programming-Chris-Sells/dp/0321116208)
-[C# Coding Conventions](http://msdn.microsoft.com/de-de/library/vstudio/ff926074.aspx)
\ No newline at end of file +[C# Coding Conventions](http://msdn.microsoft.com/de-de/library/vstudio/ff926074.aspx)
diff --git a/de-de/git-de.html.markdown b/de-de/git-de.html.markdown index c7b6ad86..43939129 100644 --- a/de-de/git-de.html.markdown +++ b/de-de/git-de.html.markdown @@ -48,7 +48,7 @@ Ein Repository besteht in Git aus dem .git-Verzeichnis und dem Arbeitsverzeichni ### .git-Verzeichnis (Teil des Repositorys) -Das .git-Verzeichnis enth? alle Einstellung, Logs, Branches, den HEAD und mehr. +Das .git-Verzeichnis enthält alle Einstellung, Logs, Branches, den HEAD und mehr. [Ausführliche Übersicht](http://gitready.com/advanced/2009/03/23/whats-inside-your-git-directory.html) ### Arbeitsverzeichnis (Teil des Repositorys) diff --git a/de-de/go-de.html.markdown b/de-de/go-de.html.markdown index 83d59c8b..765372e0 100644 --- a/de-de/go-de.html.markdown +++ b/de-de/go-de.html.markdown @@ -312,7 +312,7 @@ Dokumentation lesen. Auch zu empfehlen ist die Spezifikation von Go, die nach heutigen Standards sehr kurz und auch gut verständlich formuliert ist. Auf der Leseliste von Go-Neulingen ist außerdem der Quelltext der [Go standard Bibliothek](http://golang.org/src/pkg/). -Gut documentiert, demonstriert sie leicht zu verstehendes und im idiomatischen Stil +Gut dokumentiert, demonstriert sie leicht zu verstehendes und im idiomatischen Stil verfasstes Go. Erreichbar ist der Quelltext auch durch das Klicken der Funktionsnamen in der [offiziellen Dokumentation von Go](http://golang.org/pkg/). diff --git a/de-de/javascript-de.html.markdown b/de-de/javascript-de.html.markdown index a295c1c2..f3917506 100644 --- a/de-de/javascript-de.html.markdown +++ b/de-de/javascript-de.html.markdown @@ -479,9 +479,6 @@ myNumber === myNumberObj; // = false if (0){
// Dieser Teil wird nicht ausgeführt, weil 0 'falsy' ist.
}
-if (Number(0)){
- // Dieser Teil des Codes wird ausgeführt, weil Number(0) zu wahr evaluiert.
-}
// Das Wrapper-Objekt und die regulären, eingebauten Typen, teilen sich einen
// Prototyp; so ist es möglich zum Beispiel einem String weitere Funktionen
diff --git a/erlang.html.markdown b/erlang.html.markdown index 8b67a76a..d6ed7b86 100644 --- a/erlang.html.markdown +++ b/erlang.html.markdown @@ -25,6 +25,7 @@ filename: learnerlang.erl %% 1. Variables and pattern matching. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% In Erlang new variables are bound with an `=` statement. Num = 42. % All variable names must start with an uppercase letter. % Erlang has single-assignment variables; if you try to assign a different @@ -32,9 +33,11 @@ Num = 42. % All variable names must start with an uppercase letter. Num = 43. % ** exception error: no match of right hand side value 43 % In most languages, `=` denotes an assignment statement. In Erlang, however, -% `=` denotes a pattern-matching operation. `Lhs = Rhs` really means this: -% evaluate the right side (`Rhs`), and then match the result against the -% pattern on the left side (`Lhs`). +% `=` denotes a pattern-matching operation. When an empty variable is used on the +% left hand side of the `=` operator to is bound (assigned), but when a bound +% variable is used on the left hand side the following behaviour is observed. +% `Lhs = Rhs` really means this: evaluate the right side (`Rhs`), and then +% match the result against the pattern on the left side (`Lhs`). Num = 7 * 6. % Floating-point number. @@ -289,7 +292,7 @@ calculateArea() -> _ -> io:format("We can only calculate area of rectangles or circles.") end. - + % Compile the module and create a process that evaluates `calculateArea` in the % shell. c(calculateGeometry). @@ -299,6 +302,39 @@ CalculateArea ! {circle, 2}. % 12.56000000000000049738 % The shell is also a process; you can use `self` to get the current pid. self(). % <0.41.0> +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% 5. Testing with EUnit +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +% Unit tests can be written using EUnits's test generators and assert macros +-module(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 will automatically export to a test() function to allow running the tests +% in the erlang shell +fib:test() + +% The popular erlang build tool Rebar is also compatible with EUnit +% ``` +% rebar eunit +% ``` + ``` ## References diff --git a/es-es/c++-es.html.markdown b/es-es/c++-es.html.markdown new file mode 100644 index 00000000..bcc775e5 --- /dev/null +++ b/es-es/c++-es.html.markdown @@ -0,0 +1,829 @@ +--- +language: c++ +filename: learncpp.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"] +translators: + - ["Gerson Lázaro", "https://gersonlazaro.com"] +lang: es-es +--- + +C++ es un lenguaje de programación de sistemas que, +[de acuerdo a su inventor Bjarne Stroustrup](http://channel9.msdn.com/Events/Lang-NEXT/Lang-NEXT-2014/Keynote), +fue diseñado para + +- ser un "mejor C" +- soportar abstracción de datos +- soportar programación orientada a objetos +- soportar programación genérica + +Aunque su sintaxis puede ser más difícil o compleja que los nuevos lenguajes, +es ampliamente utilizado, ya que compila instrucciones nativas que pueden ser +directamente ejecutadas por el procesador y ofrece un estricto control sobre +el hardware (como C), mientras ofrece características de alto nivel como +genericidad, excepciones, y clases. Esta combinación de velocidad y +funcionalidad hace de C ++ uno de los lenguajes de programación más utilizados. + +```c++ +//////////////////// +// Comparación con C +//////////////////// + +// C ++ es _casi_ un superconjunto de C y comparte su sintaxis básica para las +// declaraciones de variables, tipos primitivos y funciones. + +// Al igual que en C, el punto de entrada de tu programa es una función llamada +// main con un retorno de tipo entero. +// Este valor sirve como código de salida del programa. +// Mira http://en.wikipedia.org/wiki/Exit_status para mayor información. +int main(int argc, char** argv) +{ + // Los argumentos de la línea de comandos se pasan por argc y argv de la + // misma manera que en C. + // argc indica el número de argumentos, + // y argv es un arreglo de strings de estilo C (char*) + // representando los argumentos. + // El primer argumento es el nombre con el que el programa es llamado. + // argc y argv pueden omitirse si no te preocupan los argumentos, + // dejando la definición de la función como int main () + + // Un estado de salida 0 indica éxito. + return 0; +} + +// Sin embargo, C ++ varía en algunas de las siguientes maneras: + +// En C++, los caracteres literales son caracteres +sizeof('c') == sizeof(char) == 1 + +// En C, los caracteres literales son enteros +sizeof('c') == sizeof(int) + + +// C++ tiene prototipado estricto +void func(); // función que no acepta argumentos + +// En C +void func(); // función que puede aceptar cualquier número de argumentos + +// Use nullptr en lugar de NULL en C++ +int* ip = nullptr; + +// Las cabeceras (headers) estándar de C están disponibles en C ++, +// pero tienen el prefijo "c" y no tienen sufijo .h. +#include <cstdio> + +int main() +{ + printf("Hola mundo!\n"); + return 0; +} + +////////////////////////// +// Sobrecarga de funciones +////////////////////////// + +// C++ soporta sobrecarga de funciones +// siempre que cada función tenga diferentes parámetros. + +void print(char const* myString) +{ + printf("String %s\n", myString); +} + +void print(int myInt) +{ + printf("Mi entero es %d", myInt); +} + +int main() +{ + print("Hello"); // Resolves to void print(const char*) + print(15); // Resolves to void print(int) +} + +//////////////////////////////////// +// Argumentos de función por defecto +//////////////////////////////////// + +// Puedes proporcionar argumentos por defecto para una función si no son +// proporcionados por quien la llama. + +void doSomethingWithInts(int a = 1, int b = 4) +{ + // Hacer algo con los enteros aqui +} + +int main() +{ + doSomethingWithInts(); // a = 1, b = 4 + doSomethingWithInts(20); // a = 20, b = 4 + doSomethingWithInts(20, 5); // a = 20, b = 5 +} + +// Los argumentos predeterminados deben estar al final de la lista de argumentos. + +void invalidDeclaration(int a = 1, int b) // Error! +{ +} + +///////////////////// +// Espacios de nombre +///////////////////// + +// Espacios de nombres proporcionan ámbitos separados para variable, función y +// otras declaraciones. +// Los espacios de nombres se pueden anidar. + +namespace First { + namespace Nested { + void foo() + { + printf("Esto es First::Nested::foo\n"); + } + } // fin del nombre de espacio Nested +} // fin del nombre de espacio First + +namespace Second { + void foo() + { + printf("Esto es Second::foo\n") + } +} + +void foo() +{ + printf("Este es global: foo\n"); +} + +int main() +{ + + // Incluye todos los símbolos del espacio de nombre Second en el ámbito + // actual. Tenga en cuenta que simplemente foo() no funciona, ya que ahora + // es ambigua si estamos llamando a foo en espacio de nombres Second o en + // el nivel superior. + using namespace Second; + + Second::foo(); // imprime "Esto es Second::foo" + First::Nested::foo(); // imprime "Esto es First::Nested::foo" + ::foo(); // imprime "Este es global: foo" +} + +///////////////// +// Entrada/Salida +///////////////// + +// La entrada y salida de C++ utiliza flujos (streams) +// cin, cout, y cerr representan a stdin, stdout, y stderr. +// << es el operador de inserción >> es el operador de extracción. + + +#include <iostream> // Incluir para el flujo de entrada/salida + +using namespace std; // Los streams estan en std namespace (libreria estandar) + +int main() +{ + int myInt; + + // Imprime a la stdout (o terminal/pantalla) + cout << "Ingresa tu número favorito:\n"; + // Toma una entrada + cin >> myInt; + + // cout puede también ser formateado + cout << "Tu número favorito es " << myInt << "\n"; + // imprime "Tu número favorito es <myInt>" + + cerr << "Usado para mensajes de error"; +} +//////////////////// +// Cadenas (Strings) +//////////////////// + +// Las cadenas en C++ son objetos y tienen muchas funciones +#include <string> + +using namespace std; // Strings también estan en namespace std + +string myString = "Hola"; +string myOtherString = " Mundo"; + +// + es usado para concatenar. +cout << myString + myOtherString; // "Hola Mundo" + +cout << myString + " Tu"; // "Hola Tu" + +// Las cadenas en C++ son mutables y tienen valor semántico. +myString.append(" Perro"); +cout << myString; // "Hola Perro" + + +////////////// +// Referencias +////////////// + +// Además de punteros como los de C, +// C++ tiene _references_. +// Estos tipos de puntero no pueden ser reasignados una vez establecidos +// Y no pueden ser nulos. +// También tienen la misma sintaxis que la propia variable: +// No es necesaria * para eliminar la referencia y +// & (dirección) no se utiliza para la asignación. + +using namespace std; + +string foo = "Yo soy foo"; +string bar = "Yo soy bar"; + +string& fooRef = foo; // Crea una referencia a foo. +fooRef += ". Hola!"; // Modifica foo través de la referencia +cout << fooRef; // Imprime "Yo soy foo. Hola!" + +// No trate de reasignar "fooRef". Esto es lo mismo que "foo = bar", y +// foo == "Yo soy bar" +// después de esta linea. +fooRef = bar; + +const string& barRef = bar; // Crea una referencia constante a bar. +// Como en C, los valores constantes (y punteros y referencias) no pueden ser +// modificados. +barRef += ". Hola!"; // Error, referencia constante no puede ser modificada. + +// Sidetrack: Antes de hablar más sobre referencias, hay que introducir un +// concepto llamado objeto temporal. Supongamos que tenemos el siguiente código: +string tempObjectFun() { ... } +string retVal = tempObjectFun(); + +// Lo que pasa en la segunda línea es en realidad: +// - Un objeto de cadena es retornado desde tempObjectFun +// - Una nueva cadena se construye con el objeto devuelto como argumento al +// constructor +// - El objeto devuelto es destruido +// El objeto devuelto se llama objeto temporal. Objetos temporales son +// creados cada vez que una función devuelve un objeto, y es destruido en el +// fin de la evaluación de la expresión que encierra (Bueno, esto es lo que la +// norma dice, pero los compiladores están autorizados a cambiar este +// comportamiento. Busca "return value optimization" para ver mas detalles). +// Así que en este código: +foo(bar(tempObjectFun())) + +// Suponiendo que foo y bar existen, el objeto retornado de tempObjectFun es +// pasado al bar, y se destruye antes de llamar foo. + +// Ahora, de vuelta a las referencias. La excepción a la regla "en el extremo +// de la expresión encerrada" es si un objeto temporal se une a una +// referencia constante, en cuyo caso su vida se extiende al ámbito actual: + +void constReferenceTempObjectFun() { + // ConstRef obtiene el objeto temporal, y es válido hasta el final de esta + // función. + const string& constRef = tempObjectFun(); + ... +} + +// Otro tipo de referencia introducida en C ++ 11 es específicamente para +// objetos temporales. No se puede tener una variable de este tipo, pero tiene +// prioridad en resolución de sobrecarga: + +void someFun(string& s) { ... } // Referencia regular +void someFun(string&& s) { ... } // Referencia a objeto temporal + +string foo; +someFun(foo); // Llama la función con referencia regular +someFun(tempObjectFun()); // Llama la versión con referencia temporal + +// Por ejemplo, puedes ver estas dos versiones de constructores para +// std::basic_string: +basic_string(const basic_string& other); +basic_string(basic_string&& other); + +// La idea es que si estamos construyendo una nueva cadena de un objeto temporal +// (que va a ser destruido pronto de todos modos), podemos tener un constructor +// mas eficiente que "rescata" partes de esa cadena temporal. Usted verá este +// Concepto denominado "movimiento semántico". + +//////////////////////////////////////////// +// Clases y programación orientada a objetos +//////////////////////////////////////////// + +// Primer ejemplo de clases +#include <iostream> + +// Declara una clase. +// Las clases son usualmente declaradas en archivos de cabeceras (.h o .hpp) +class Dog { + // Variables y funciones de la clase son privados por defecto. + std::string name; + int weight; + +// Todos los miembros siguientes de este son públicos +// Hasta que se encuentre "private" o "protected". +// All members following this are public +// until "private:" or "protected:" is found. +public: + + // Constructor por defecto + Dog(); + + // Declaraciones de funciones de la clase (implementaciones a seguir) + // Nota que usamos std::string aquí en lugar de colocar + // using namespace std; + // arriba. + // Nunca ponga una declaración "using namespace" en un encabezado. + void setName(const std::string& dogsName); + + void setWeight(int dogsWeight); + // Funciones que no modifican el estado del objeto + // Deben marcarse como const. + // Esto le permite llamarlas si se envia una referencia constante al objeto. + // También tenga en cuenta que las funciones deben ser declaradas + // explícitamente como _virtual_ para que sea reemplazada en las clases + // derivadas. + // Las funciones no son virtuales por defecto por razones de rendimiento. + virtual void print() const; + + // Las funciones también se pueden definir en el interior + // del cuerpo de la clase. + // Funciones definidas como tales están entre líneas automáticamente. + void bark() const { std::cout << name << " barks!\n"; } + + // Junto a los constructores, C++ proporciona destructores. + // Estos son llamados cuando un objeto se elimina o está fuera del ámbito. + // Esto permite paradigmas potentes como RAII + // (mira abajo) + // El destructor debe ser virtual si una clase es dervada desde el; + // Si no es virtual, entonces la clase derivada destructor + // No será llamada si el objeto se destruye a través de una referencia de + // la clase base o puntero. + virtual ~Dog(); + + + +}; // Un punto y coma debe seguir la definición de clase. + +// Las funciones de una clase son normalmente implementados en archivos .cpp. +Dog::Dog() +{ + std::cout << "Un perro ha sido construido\n"; +} + +// Objetos (tales como cadenas) deben ser pasados por referencia +// Si los estas modificando o referencia constante en caso contrario. +void Dog::setName(const std::string& dogsName) +{ + name = dogsName; +} + +void Dog::setWeight(int dogsWeight) +{ + weight = dogsWeight; +} + +// Nota que "virtual" sólo se necesita en la declaración, no en la definición. +void Dog::print() const +{ + std::cout << "El perro es " << name << " y pesa " << weight << "kg\n"; +} + +Dog::~Dog() +{ + cout << "Adiós " << name << "\n"; +} + +int main() { + Dog myDog; // imprime "Un perro ha sido construido" + myDog.setName("Barkley"); + myDog.setWeight(10); + myDog.print(); // imprime "El perro es Barkley y pesa 10 kg" + return 0; +} // imprime "Adiós Barkley" + +// Herencia: + +// Esta clase hereda todo lo público y protegido de la clase Dog +class OwnedDog : public Dog { + + void setOwner(const std::string& dogsOwner); + + // Reemplaza el comportamiento de la función de impresión + // de todos los OwnedDogs. Mira + // http://en.wikipedia.org/wiki/Polymorphism_(computer_science)#Subtyping + // Para una introducción más general si no está familiarizado con el + // polimorfismo de subtipo. + // La palabra clave override es opcional, pero asegura que estás + // reemplazando el método de una clase base. + void print() const override; + +private: + std::string owner; +}; + +// Mientras tanto, en el archivo .cpp correspondiente: + +void OwnedDog::setOwner(const std::string& dogsOwner) +{ + owner = dogsOwner; +} + +void OwnedDog::print() const +{ + Dog::print(); // Llama a la función de impresión en la clase base Dog + std::cout << "El perro es de " << owner << "\n"; + // Imprime "El perro es <name> y pesa <weight>" + // "El perro es de <owner>" +} + +//////////////////////////////////////////// +// Inicialización y sobrecarga de operadores +//////////////////////////////////////////// + +// En C ++ se puede sobrecargar el comportamiento +// de los operadores como +, -, *, /, etc. +// Esto se hace mediante la definición de una función que es llamada +// cada vez que se utiliza el operador. + +#include <iostream> +using namespace std; + +class Point { +public: + // Las variables de la clase pueden dar valores por defecto de esta manera. + double x = 0; + double y = 0; + + // Define un constructor por defecto que no hace nada + // pero inicializa el punto al valor por defecto (0, 0) + Point() { }; + + // The following syntax is known as an initialization list + // and is the proper way to initialize class member values + Point (double a, double b) : + x(a), + y(b) + { /* No hace nada excepto inicializar los valores */ } + + // Sobrecarga el operador + + Point operator+(const Point& rhs) const; + + // Sobrecarga el operador += + Point& operator+=(const Point& rhs); + + // También tendría sentido añadir los operadores - y -=, + // Pero vamos a omitirlos por razones de brevedad. +}; + +Point Point::operator+(const Point& rhs) const +{ + // Crea un nuevo punto que es la suma de este y rhs. + 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); + // Llama al operador + de Point + // Point llama la función + con right como parámetro + Point result = up + right; + // Prints "Result is upright (1,1)" + cout << "Result is upright (" << result.x << ',' << result.y << ")\n"; + return 0; +} + +///////////////////////// +// Plantillas (Templates) +///////////////////////// + +// Las plantillas en C++ se utilizan sobre todo en la programación genérica, +// a pesar de que son mucho más poderoso que los constructores genéricos +// en otros lenguajes. Ellos también soportan especialización explícita y +// parcial y clases de tipo estilo funcional; de hecho, son un lenguaje +// funcional Turing-completo incrustado en C ++! + +// Empezamos con el tipo de programación genérica que podría estar +// familiarizado. +// Para definir una clase o función que toma un parámetro de tipo: +template<class T> +class Box { +public: + // En este caso, T puede ser usado como cualquier otro tipo. + void insert(const T&) { ... } +}; + +// Durante la compilación, el compilador realmente genera copias de cada +// plantilla con parámetros sustituidos, por lo que la definición completa +// de la clase debe estar presente en cada invocación. +// Es por esto que usted verá clases de plantilla definidas +// Enteramente en archivos de cabecera. + +//Para crear una instancia de una clase de plantilla en la pila: +Box<int> intBox; + +y puedes utilizarlo como era de esperar: +intBox.insert(123); + +// Puedes, por supuesto, anidar plantillas: +Box<Box<int> > boxOfBox; +boxOfBox.insert(intBox); + +// Hasta C++11, había que colocar un espacio entre los dos '>'s, +// de lo contrario '>>' serían analizados como el operador de desplazamiento +// a la derecha. + + +// A veces verás +// template<typename T> +// en su lugar. La palabra clave "class" y las palabras clave "typename" son +// mayormente intercambiables en este caso. Para la explicación completa, mira +// http://en.wikipedia.org/wiki/Typename +// (sí, esa palabra clave tiene su propia página de Wikipedia). + +// Del mismo modo, una plantilla de función: +template<class T> +void barkThreeTimes(const T& input) +{ + input.bark(); + input.bark(); + input.bark(); +} + +// Observe que no se especifica nada acerca de los tipos de parámetros aquí. +// El compilador generará y comprobará cada invocación de la plantilla, +// por lo que la función anterior funciona con cualquier tipo "T" +// que tenga un método 'bark' constante! + + +Dog fluffy; +fluffy.setName("Fluffy") +barkThreeTimes(fluffy); // Imprime "Fluffy barks" 3 veces. + +Los parámetros de la plantilla no tienen que ser las clases: +template<int Y> +void printMessage() { + cout << "Aprende C++ en " << Y << " minutos!" << endl; +} + +// Y usted puede especializar explícitamente plantillas +// para código más eficiente. +// Por supuesto, la mayor parte del mundo real que utiliza una especialización +// no son tan triviales como esta. +// Tenga en cuenta que usted todavía tiene que declarar la función (o clase) +// como plantilla incluso si ha especificado de forma explícita todos +// los parámetros. + +template<> +void printMessage<10>() { + cout << "Aprende C++ rapido en solo 10 minutos!" << endl; +} + +printMessage<20>(); // Prints "Aprende C++ en 20 minutos!" +printMessage<10>(); // Prints "Aprende C++ rapido en solo 10 minutos!" + + +///////////////////// +// Manejador de excepciones +///////////////////// + +// La biblioteca estándar proporciona algunos tipos de excepción +// (mira http://en.cppreference.com/w/cpp/error/exception) +// pero cualquier tipo puede ser lanzado como una excepción +#include <exception> +#include <stdexcept> + +//Todas las excepciones lanzadas dentro del bloque _try_ pueden ser +// capturados por los siguientes manejadores _catch_. +try { + // No asignar excepciones en el heap usando _new_. + throw std::runtime_error("Ocurrió un problema"); +} + +// Captura excepciones por referencia const si son objetos +catch (const std::exception& ex) +{ + std::cout << ex.what(); +} +******************************************************************************** +// Captura cualquier excepción no capturada por bloques _catch_ anteriores +catch (...) +{ + std::cout << "Excepción desconocida capturada"; + throw; // Re-lanza la excepción +} + +/////// +// RAII +/////// + +// RAII significa "Resource Acquisition Is Initialization" +// (Adquisición de recursos es inicialización). +// A menudo se considera el paradigma más poderoso en C++ +// Y el concepto es simple: un constructor de un objeto +// Adquiere recursos de ese objeto y el destructor les libera. + +// Para entender cómo esto es útil, +// Considere una función que utiliza un identificador de archivo C: +void doSomethingWithAFile(const char* filename) +{ + // Para empezar, asuma que nada puede fallar. + + FILE* fh = fopen(filename, "r"); // Abre el archivo en modo lectura + + doSomethingWithTheFile(fh); + doSomethingElseWithIt(fh); + + fclose(fh); // Cierra el manejador de archivos +} + +// Por desgracia, las cosas se complican rápidamente por el control de errores. +// Supongamos que fopen puede fallar, y que doSomethingWithTheFile y +// DoSomethingElseWithIt retornan códigos de error si fallan. +// (Excepciones son la mejor forma de manejar los fallos, +// pero algunos programadores, especialmente los que tienen un fondo C, +// estan en desacuerdo sobre la utilidad de las excepciones). +// Ahora tenemos que comprobar cada llamado por fallos y cerrar el manejador +// del archivo si se ha producido un problema. +bool doSomethingWithAFile(const char* filename) +{ + FILE* fh = fopen(filename, "r"); // Abre el archivo en modo lectura + if (fh == nullptr) // El puntero retornado es nulo o falla. + return false; // Reporta el fallo a quien hizo el llamado. + + // Asume que cada función retorna falso si falla + if (!doSomethingWithTheFile(fh)) { + fclose(fh); // Cierre el manejador de archivo para que no se filtre. + return false; // Propaga el error. + } + if (!doSomethingElseWithIt(fh)) { + fclose(fh); // Cierre el manejador de archivo para que no se filtre. + return false; // Propaga el error. + } + + fclose(fh); // Cierre el archivo. + return true; // Indica que todo funcionó correctamente. +} + +// Programadores C suelen limpiar esto un poco usando goto: +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); // Cierre el archivo. + return true; // Indica que todo funcionó correctamente. + +failure: + fclose(fh); + return false; // Propagate el error +} + +// Si las funciones indican errores mediante excepciones, +// Las cosas son un poco más claras, pero pueden optimizarse mas. +void doSomethingWithAFile(const char* filename) +{ + FILE* fh = fopen(filename, "r"); // Abrir el archivo en modo lectura + if (fh == nullptr) + throw std::runtime_error("No puede abrirse el archivo."); + + try { + doSomethingWithTheFile(fh); + doSomethingElseWithIt(fh); + } + catch (...) { + fclose(fh); // Asegúrese de cerrar el archivo si se produce un error. + throw; // Luego vuelve a lanzar la excepción. + } + + fclose(fh); // Cierra el archivo +} + +// Compare esto con el uso de la clase de flujo de archivos de C++ (fstream) +// fstream utiliza su destructor para cerrar el archivo. +// Los destructores son llamados automáticamente +// cuando un objeto queda fuera del ámbito. +void doSomethingWithAFile(const std::string& filename) +{ + // ifstream es la abreviatura de el input file stream + std::ifstream fh(filename); // Abre el archivo + + // Hacer algo con el archivo + doSomethingWithTheFile(fh); + doSomethingElseWithIt(fh); + +} // El archivo se cierra automáticamente aquí por el destructor + + +// Esto tiene ventajas _enormes_: +// 1. No importa lo que pase, +// El recurso (en este caso el manejador de archivo) será limpiado. +// Una vez que escribes el destructor correctamente, +// Es _imposible_ olvidar cerrar el identificador y permitir +// fugas del recurso. +// 2. Tenga en cuenta que el código es mucho más limpio. +// El destructor se encarga de cerrar el archivo detrás de cámaras +// Sin que tenga que preocuparse por ello. +// 3. El código es seguro. +// Una excepción puede ser lanzado en cualquier lugar de la función +// y la limpieza ocurrirá. + +// Todo el código idiomático C++ utiliza RAII ampliamente para todos los +// recursos. +// Otros ejemplos incluyen +// - Memoria usando unique_ptr y shared_ptr +// - Contenedores (Containers) - la biblioteca estándar linked list, +// vector (es decir, array con auto-cambio de tamaño), hash maps, etc. +// Destruimos todos sus contenidos de forma automática +// cuando quedan fuera del ámbito. +// - Mutex utilizando lock_guard y unique_lock + + +///////////////////// +// Cosas divertidas +///////////////////// + +// Aspectos de C ++ que pueden sorprender a los recién llegados +// (e incluso algunos veteranos). +// Esta sección es, por desgracia, salvajemente incompleta; +// C++ es uno de los lenguajes con los que mas facil te disparas en el pie. + +// Tu puedes sobreescribir métodos privados! +class Foo { + virtual void bar(); +}; +class FooSub : public Foo { + virtual void bar(); // Sobreescribe Foo::bar! +}; + + +// 0 == false == NULL (La mayoria de las veces)! +bool* pt = new bool; +*pt = 0; // Establece los puntos de valor de 'pt' en falso. +pt = 0; // Establece 'pt' al apuntador nulo. Ambas lineas compilan sin error. + +// nullptr se supone que arregla un poco de ese tema: +int* pt2 = new int; +*pt2 = nullptr; // No compila +pt2 = nullptr; // Establece pt2 como null. + +// Hay una excepción para los valores bool. +// Esto es para permitir poner a prueba punteros nulos con if (!ptr), +// pero como consecuencia se puede asignar nullptr a un bool directamente! +*pt = nullptr; // Esto todavía compila, a pesar de que '*pt' es un bool! + +// '=' != '=' != '='! +// Llama Foo::Foo(const Foo&) o alguna variante (mira movimientos semanticos) +// copia del constructor. +Foo f2; +Foo f1 = f2; + +// Llama Foo::Foo(const Foo&) o variante, pero solo copia el 'Foo' parte de +// 'fooSub'. Cualquier miembro extra de 'fooSub' se descarta. Este +// comportamiento horrible se llama "Corte de objetos." +FooSub fooSub; +Foo f1 = fooSub; + +// Llama a Foo::operator=(Foo&) o variantes. +Foo f1; +f1 = f2; + + +// Cómo borrar realmente un contenedor: +class Foo { ... }; +vector<Foo> v; +for (int i = 0; i < 10; ++i) + v.push_back(Foo()); +// La siguiente línea establece el tamaño de v en 0, +// pero los destructores no son llamados y los recursos no se liberan! + +v.empty(); +v.push_back(Foo()); // Nuevo valor se copia en el primer Foo que insertamos + +// En verdad destruye todos los valores en v. +// Consulta la sección acerca de los objetos temporales para la +// explicación de por qué esto funciona. +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> diff --git a/es-es/git-es.html.markdown b/es-es/git-es.html.markdown index 73853a9d..18b544b4 100644 --- a/es-es/git-es.html.markdown +++ b/es-es/git-es.html.markdown @@ -11,15 +11,15 @@ lang: es-es --- Git es un sistema de control de versiones distribuido diseñado para manejar -cualquier tipo de proyecto ya sea largos o pequeños, con velocidad y eficiencia. +cualquier tipo de proyecto, ya sea grande o pequeño, con velocidad y eficiencia. Git realiza esto haciendo "snapshots" del proyecto, con ello permite versionar y administrar nuestro código fuente. ## Versionamiento, conceptos. -### Que es el control de versiones? -El control de versiones es un sistema que guarda todos los cambios realizados a +### Qué es el control de versiones? +El control de versiones es un sistema que guarda todos los cambios realizados en uno o varios archivos, a lo largo del tiempo. ### Versionamiento centralizado vs Versionamiento Distribuido. @@ -31,15 +31,15 @@ uno o varios archivos, a lo largo del tiempo. + El versionamiento distribuido no tiene una estructura definida, incluso se puede mantener el estilo de los repositorios SVN con git. -[Informacion adicional](http://git-scm.com/book/es/Empezando-Acerca-del-control-de-versiones) +[Información adicional](http://git-scm.com/book/es/Empezando-Acerca-del-control-de-versiones) -### Por que usar Git? +### Por qué usar Git? * Se puede trabajar sin conexion. -* Colaborar con otros es sencillo!. -* Derivar, Crear ramas del proyecto (aka: Branching) es facil!. +* ¡Colaborar con otros es sencillo!. +* Derivar, crear ramas del proyecto (aka: Branching) es fácil. * Combinar (aka: Merging) -* Git es rapido. +* Git es rápido. * Git es flexible. ## Arquitectura de Git. @@ -48,10 +48,10 @@ uno o varios archivos, a lo largo del tiempo. Un repositorio es un conjunto de archivos, directorios, registros, cambios (aka: comits), y encabezados (aka: heads). Imagina que un repositorio es una clase, -y que sus atributos otorgan acceso al historial del elemento, ademas de otras +y que sus atributos otorgan acceso al historial del elemento, además de otras cosas. -Un repositorio esta compuesto por la carpeta .git y un "arbol de trabajo". +Un repositorio esta compuesto por la carpeta .git y un "árbol de trabajo". ### Directorio .git (componentes del repositorio) @@ -62,38 +62,38 @@ y mas. ### Directorio de trabajo (componentes del repositorio) -Es basicamente los directorios y archivos dentro del repositorio. La mayorioa de +Es basicamente los directorios y archivos dentro del repositorio. La mayoría de las veces se le llama "directorio de trabajo". -### Inidice (componentes del directorio .git) +### Índice (componentes del directorio .git) -El inidice es la area de inicio en git. Es basicamente la capa que separa el -directorio de trabajo, del repositorio en git. Esto otorga a los desarrolladores -mas poder sobre lo que envia y recibe en el repositorio. +El índice es el área de inicio en git. Es basicamente la capa que separa el +directorio de trabajo del repositorio en git. Esto otorga a los desarrolladores +más poder sobre lo que se envía y se recibe del repositorio. ### Commit (aka: cambios) Un commit es una captura de un conjunto de cambios, o modificaciones hechas en -el directorio de trabajo. Por ejemplo, si se añaden 5 archivos, se remueven 2, -estos cambios se almacenaran en un commit (aka: captura). Este commit puede ser o +el directorio de trabajo. Por ejemplo, si se añaden 5 archivos, se eliminan 2, +estos cambios se almacenarán en un commit (aka: captura). Este commit puede ser o no ser enviado (aka: "pusheado") hacia un repositorio. ### Branch (rama) -Un "branch", es escencialmente un apuntador hacia el ultimo commit (cambio -registrado) que se ha realizado. A medida que se realizan mas commits, este -apuntador se actualizara automaticamente hacia el ultimo commit. +Un "branch", es escencialmente un apuntador hacia el último commit (cambio +registrado) que se ha realizado. A medida que se realizan más commits, este +apuntador se actualizará automaticamente hacia el ultimo commit. -### "HEAD" y "head" (component of .git dir) +### "HEAD" y "head" (componentes del directorio .git) "HEAD" es un apuntador hacia la rama (branch) que se esta utilizando. Un repositorio solo puede tener un HEAD activo. En cambio "head", es un apuntador a -cualquier commit realizado, un repositorio puede tener cualquier numero de +cualquier commit realizado, un repositorio puede tener cualquier número de "heads". ### conceptos - recursos. -* [Git para informaticos](http://eagain.net/articles/git-for-computer-scientists/) +* [Git para informáticos](http://eagain.net/articles/git-for-computer-scientists/) * [Git para diseñadores](http://hoth.entp.com/output/git_for_designers.html) @@ -102,8 +102,8 @@ cualquier commit realizado, un repositorio puede tener cualquier numero de ### init -Crear un repositorio de git vacio. Las configuraciones, informacion almacenada y -demas son almacenadas en el directorio ".git". +Crear un repositorio de git vacio. Las configuraciones, información almacenada y +demás son almacenadas en el directorio ".git". ```bash $ git init @@ -115,7 +115,7 @@ Se utiliza para configurar las opciones ya sea globalmente, o solamente en el repositorio. ```bash -# Imprime y guarda algunas variables de configuracion basicas. (Globalmente) +# Imprime y guarda algunas variables de configuracion básicas. (Globalmente) $ git config --global user.email $ git config --global user.name @@ -123,15 +123,15 @@ $ git config --global user.email "corre@gmail.com" $ git config --global user.name "nombre" ``` -[Mas sobre git config.](http://git-scm.com/book/es/Personalizando-Git-Configuración-de-Git) +[Más sobre git config.](http://git-scm.com/book/es/Personalizando-Git-Configuración-de-Git) ### help -Otorga un accceso rapido a una guia extremadamente detallada de cada comando en +Otorga un accceso rápido a una guía extremadamente detallada de cada comando en git. O puede ser usada simplemente como un recordatorio de estos. ```bash -# Una vista rapido de los comandos disponibles. +# Una vista rápida de los comandos disponibles. $ git help # Chequear todos los comandos disponibles @@ -146,12 +146,12 @@ $ git help init ### status -Muestra las diferencias entre el archivo indice y el commit al cual apunta el +Muestra las diferencias entre el archivo índice y el commit al cual apunta el HEAD actualmente. ```bash -# Mostrara el "branch", archivos sin añadir a la repo, cambios y otras +# Mostrará el "branch", archivos sin añadir al repo, cambios y otras # diferencias $ git status @@ -161,9 +161,9 @@ $ git help status ### add -Para añadir archivos al arbol (directorio, repositorio) de trabajo. Si no se -utiliza `git add`, los nuevos archivos no se añadiran al arbol de trabajo, por -lo que no se incluiran en los commits (cambios). +Para añadir archivos al árbol (directorio, repositorio) de trabajo. Si no se +utiliza `git add`, los nuevos archivos no se añadirán al arbol de trabajo, por +lo que no se incluirán en los commits (cambios). ```bash # Añade un archivo en el directorio de trabajo actual. @@ -178,31 +178,31 @@ $ git add ./*.py ### branch -Administra las ramas del repositorios ("branches"). Puedes ver, editar, crear y +Administra las ramas del repositorio ("branches"). Puedes ver, editar, crear y borrar ramas ("branches"), usando este comando. ```bash # lista todas las ramas (remotas y locales) $ git branch -a -# Añada una nueva rama ("branch"). +# Añadir una nueva rama ("branch"). $ git branch branchNueva # Eliminar una rama. $ git branch -d branchFoo -# Renombra una rama. +# Renombrar una rama. # git branch -m <anterior> <nuevo> $ git branch -m youngling padawan -# Edita la descripcion de la rama. +# Editar la descripcion de la rama. $ git branch master --edit-description ``` ### checkout Actualiza todos los archivos en el directorio de trabajo para que sean igual que -las versiones almacenadas en el indice, o en un arbol de trabajo especificado. +las versiones almacenadas en el índice, o en un árbol de trabajo especificado. ```bash # Despachar un repositorio. - Por defecto la master branch. (la rama principal llamada 'master') @@ -215,8 +215,8 @@ $ git checkout -b jdei ### clone -Clona, o copia, una repo existente en un nuevo directorio. Tambien añada el -seguimiento hacia las ramas existentes del repo que ha sido clonada, lo que +Clona, o copia, un repositorio existente en un nuevo directorio. También añade el +seguimiento hacia las ramas existentes del repositorio que ha sido clonado, lo que permite subir (push) los archivos hacia una rama remota. ```bash @@ -226,60 +226,60 @@ $ git clone https://github.com/jquery/jquery.git ### commit -Almacena los cambios que almacenados en el indice en un nuevo "commit". Este -commit contiene los cambios hechos mas un resumen hecho por el desarrollador. +Almacena el contenido actual del índice en un nuevo "commit". Este +commit contiene los cambios hechos más un resumen proporcionado por el desarrollador. ```bash -# commit with a message # realizar un commit y añadirle un mensaje. $ git commit -m "jedi anakin wil be - jedis.list" ``` ### diff -Muestra las diferencias entre un archivo en el directorio de trabajo, el indice -y commits. +Muestra las diferencias entre un archivo en el directorio de trabajo, el índice +y los commits. ```bash -# Muestra la diferencia entre un directorio de trabajo y el indice. +# Muestra la diferencia entre un directorio de trabajo y el índice. $ git diff -# Muestra la diferencia entre el indice y los commits mas recientes. +# Muestra la diferencia entre el índice y los commits más recientes. $ git diff --cached -# Muestra la diferencia entre el directorio de trabajo y el commit mas reciente. +# Muestra la diferencia entre el directorio de trabajo y el commit más reciente. $ git diff HEAD ``` ### grep -Permite realizar una busqueda rapida en un repositorio. +Permite realizar una busqueda rápida en un repositorio. -Configuracion opcionales: +Configuraciones opcionales: ```bash # Gracias a Travis Jeffery por compartir lo siguiente. # Permite mostrar numeros de lineas en la salida de grep. $ git config --global grep.lineNumber true -# Realiza una busqueda mas lejible, incluyendo agrupacion. +# Realiza una búsqueda mas legible, incluyendo agrupación. $ git config --global alias.g "grep --break --heading --line-number" ``` ```bash -# Busca por "unaVariable" en todos los archivos ,java +# Busca por "unaVariable" en todos los archivos .java $ git grep 'unaVariable' -- '*.java' -# Busca por una linea que contenga "nombreArreglo" y , "agregar" o "remover" +# Busca por una línea que contenga "nombreArreglo" y "agregar" o "remover" $ git grep -e 'nombreArreglo' --and \( -e agregar -e remover \) ``` -Mas ejemplos: -[Git Grep Ninja](http://travisjeffery.com/b/2012/02/search-a-git-repo-like-a-ninja) +Más ejemplos: + +- [Git Grep Ninja](http://travisjeffery.com/b/2012/02/search-a-git-repo-like-a-ninja) ### log -Muestra los commits (cambios) registrados en el repositotrio. +Muestra los commits (cambios) registrados en el repositorio. ```bash # Muestra todos los commits. @@ -288,7 +288,7 @@ $ git log # Muestra un numero x de commits. $ git log -n 10 -# Muestra solo los commits que se han combinado en el hisotrial +# Muestra solo los commits que se han combinado en el historial. $ git log --merges ``` @@ -301,7 +301,7 @@ que se trabaja. # Combina la rama especificada en la rama actual. $ git merge jediMaster -# Siempre genere un solo merge commit cuando se utilizar merge. +# Siempre genere un solo merge commit cuando se utiliza merge. $ git merge --no-ff jediMaster ``` @@ -310,7 +310,7 @@ $ git merge --no-ff jediMaster Renombra o mueve un archivo ```bash -# Renombrando un archivo +# Renombrando un archivo. $ git mv HolaMundo.c AdiosMundo.c # Moviendo un archivo. @@ -322,33 +322,31 @@ $ git mv -f archivoA archivoB ### pull -Sube (Empuja) de un repositorio y lo combina en otro en una rama diferente. +Trae los cambios de un repositorio y los combina en otro en una rama diferente. ```bash -# Actualiza el repositorio local, combinando los nuevos cambios. +# Actualiza el repositorio local, combinando los nuevos cambios # de las ramas remotas "origin" y "master". -# from the remote "origin" and "master" branch. # git pull <remota> <rama> $ git pull origin master ``` ### push -Push and merge changes from a branch to a remote & branch. +Envía y combina los cambios de un repositorio local a un repositorio y rama remotos. ```bash -# Push and merge changes from a local repo to a -# Empuja y combina cambios de un repositorio local hacian un repositorio remoto +# Envía y combina cambios de un repositorio local hacia un repositorio remoto # llamados "origin" y "master", respectivamente. # git push <remota> <rama> # git push => por defecto es lo mismo que poner => git push origin master $ git push origin master ``` +### rebase Toma todos los cambios que fueron registrados en una rama, y los repite dentro -de otra rama. -*No reescribe los commits que se han empujado antes a un repositorio publico* +de otra rama. *No reescribe los commits que se han empujado antes a un repositorio público.* ```bash # Integrar ramaExperimento dentro de la rama "master" @@ -356,47 +354,47 @@ de otra rama. $ git rebase master experimentBranch ``` -[Informacion adicional.](http://git-scm.com/book/es/Ramificaciones-en-Git-Procedimientos-básicos-para-ramificar-y-fusionar) +[Información adicional.](http://git-scm.com/book/es/Ramificaciones-en-Git-Procedimientos-básicos-para-ramificar-y-fusionar) -### reset (precaucion) +### reset (precaución) -Reinicia el cabezal actual hacia un estado especificado. Esto permite desacer -combinaciones (merges), pulls, commits, adds y mas. Es un comando util, pero -tambien peligrosa si no se sabe lo que se hace. +Reinicia el HEAD actual hacia un estado especificado. Esto permite deshacer +combinaciones (merges), pulls, commits, adds y más. Es un comando útil, pero +tambien peligroso si no se sabe lo que se hace. ```bash -# Reinica el area principal, con el ultimo cambio registrado. (deja los +# Reinicia el área principal, con el último cambio registrado. (deja los # directorios sin cambios) $ git reset -# Reinica el area principal, con el ultimo cambio registrado, y reescribe el +# Reinicia el área principal, con el último cambio registrado, y reescribe el # directorio de trabajo. $ git reset --hard # Mueve la rama actual hacia el commit especificado (no realiza cambios a los -# directorios), todos los cambios aun existen el directorio. +# directorios), todos los cambios aún existen el directorio. $ git reset 31f2bb1 -# Mueve la rama actual devuelta a un commit especificado asi como el -# directorios (borra todos los cambios que no fueron registros y todos los -# cambios realizados despues del commit especificado). +# Mueve la rama actual devuelta a un commit especificado, así como el +# directorio (borra todos los cambios que no fueron registrados y todos los +# cambios realizados después del commit especificado). $ git reset --hard 31f2bb1 ``` ### rm -Lo contrario de git add, git rm remueve los archivos del directorio de trabajo +Lo contrario de git add, git rm elimina los archivos del directorio de trabajo actual. ```bash -# Remueve FooBar.c +# Elimina FooBar.c $ git rm FooBar.c -# Remueve un archivo de un directorio. +# Elimina un archivo de un directorio. $ git rm /directorio/del/archivo/FooBar.c ``` -## Informacion Adicional +## Información Adicional * [tryGit - Una forma entretenida y rapida de aprender Git.](http://try.github.io/levels/1/challenges/1) diff --git a/es-es/javascript-es.html.markdown b/es-es/javascript-es.html.markdown index fd01e7b9..036d7082 100644 --- a/es-es/javascript-es.html.markdown +++ b/es-es/javascript-es.html.markdown @@ -478,9 +478,6 @@ miNumero === miNumeroObjeyo; // = false if (0){ // Este código no se ejecutara porque 0 es false. } -if (Number(0)){ - // Este código sí se ejecutara, puesto que Number(0) es true. -} // Aún así, los objetos que envuelven y los prototipos por defecto comparten // un prototipo. así que puedes agregar funcionalidades a un string de la diff --git a/es-es/julia-es.html.markdown b/es-es/julia-es.html.markdown index 95a16412..e4181609 100644 --- a/es-es/julia-es.html.markdown +++ b/es-es/julia-es.html.markdown @@ -45,7 +45,7 @@ Esto se basa en la versión `0.3.11`. # Los comentarios de una línea comienzan con una almohadilla (o signo de gato). #= - Los commentarios multilínea pueden escribirse + Los comentarios multilínea pueden escribirse usando '#=' antes de el texto y '=#' después del texto. También se pueden anidar. =# @@ -174,7 +174,7 @@ otraVariable_123! = 6 # => 6 otra_variable * Los nombres de los tipos comienzan con una letra mayúscula y separación de - palabras se muestra con CamelCase en vez de guion bajo: + palabras se muestra con CamelCase en vez de guión bajo: OtroTipo @@ -214,7 +214,7 @@ matrix = [1 2; 3 4] 3 4 =# -# Añadir cosas a la final de un arreglo con push! y append!. +# Añadir cosas al final de un arreglo con push! y append!. push!(a, 1) # => [1] push!(a, 2) # => [1,2] push!(a, 4) # => [1,2,4] @@ -237,7 +237,7 @@ a[end] # => 6 shift!(a) # => 1 y a es ahora: [2,4,3,4,5,6] unshift!(a, 7) # => [7,2,4,3,4,5,6] -# Los nombres de funciónes que terminan en exclamaciones indican que modifican +# Los nombres de funciones que terminan en exclamaciones indican que modifican # su o sus argumentos de entrada. arr = [5, 4, 6] # => 3-element Array{Int64,1}: [5,4,6] sort(arr) # => [4,5,6] y arr es todavía: [5,4,6] @@ -710,7 +710,7 @@ end # Sólo define una función del mismo nombre que el tipo y llama al constructor # existente para obtener un valor del tipo correcto. -# Este es un constructor externo porque es fuera de la definición del tipo. +# Este es un constructor externo porque está fuera de la definición del tipo. Leon(rugido::String) = Leon("verde", rugido) type Pantera <: Gato # Pantera también es un a subtipo de Gato @@ -730,10 +730,10 @@ end ######################## # En Julia, todas las funciones nombradas son funciones genéricas. -# Esto significa que se construyen a partir de muchos métodosmás pequeños. +# Esto significa que se construyen a partir de muchos métodos más pequeños. # Cada constructor de Leon es un método de la función genérica Leon. -# Por ejemplo, vamos a hacer métodos para para Leon, Pantera, y Tigre de una +# Por ejemplo, vamos a hacer métodos para Leon, Pantera, y Tigre de una # función genérica maullar: # acceso utilizando notación de puntos diff --git a/fa-ir/javascript.html.markdown b/fa-ir/javascript.html.markdown index 5c64d24a..fe3555af 100644 --- a/fa-ir/javascript.html.markdown +++ b/fa-ir/javascript.html.markdown @@ -499,9 +499,6 @@ myNumber === myNumberObj; // = false if (0){ // This code won't execute, because 0 is falsy. } -if (Number(0)){ - // This code *will* execute, because Number(0) is truthy. -} ``` diff --git a/forth.html.markdown b/forth.html.markdown index f7c0bf34..b4a5581b 100644 --- a/forth.html.markdown +++ b/forth.html.markdown @@ -117,7 +117,7 @@ one-to-12 \ 0 1 2 3 4 5 6 7 8 9 10 11 12 ok : threes ( n n -- ) ?do i . 3 +loop ; \ ok 15 0 threes \ 0 3 6 9 12 ok -\ Indefinite loops with `begin` <stuff to do> <flag> `unil`: +\ Indefinite loops with `begin` <stuff to do> <flag> `until`: : death ( -- ) begin ." Are we there yet?" 0 until ; \ ok \ ---------------------------- Variables and Memory ---------------------------- @@ -133,7 +133,7 @@ variable age \ ok age @ . \ 21 ok age ? \ 21 ok -\ Constants are quite simiar, except we don't bother with memory addresses: +\ Constants are quite similar, except we don't bother with memory addresses: 100 constant WATER-BOILING-POINT \ ok WATER-BOILING-POINT . \ 100 ok diff --git a/fr-fr/csharp-fr.html.markdown b/fr-fr/csharp-fr.html.markdown index e51eacc8..58b3f386 100644 --- a/fr-fr/csharp-fr.html.markdown +++ b/fr-fr/csharp-fr.html.markdown @@ -239,7 +239,8 @@ sur une nouvelle ligne! ""Wow!"", quel style"; // Opérateur ternaire // Un simple if/else peut s'écrire : // <condition> ? <valeur si true> : <valeur si false> - string isTrue = (true) ? "True" : "False"; + int toCompare = 17; + string isTrue = toCompare == 17 ? "True" : "False"; // Boucle while int fooWhile = 0; diff --git a/fr-fr/javascript-fr.html.markdown b/fr-fr/javascript-fr.html.markdown index 2e18d0be..15478cdb 100644 --- a/fr-fr/javascript-fr.html.markdown +++ b/fr-fr/javascript-fr.html.markdown @@ -469,9 +469,6 @@ myNumber === myNumberObj; // = false if (0){ // 0 est falsy, le code ne fonctionnera pas. } -if (Number(0)){ - // Parce que Number(0) est truthy, le code fonctionnera -} // Cependant, vous pouvez ajouter des fonctionnalités aux types de bases grâce à // cette particularité. diff --git a/fr-fr/php.html.markdown b/fr-fr/php.html.markdown new file mode 100644 index 00000000..f4eaf396 --- /dev/null +++ b/fr-fr/php.html.markdown @@ -0,0 +1,696 @@ +--- +language: PHP +contributors: + - ["Malcolm Fell", "http://emarref.net/"] + - ["Trismegiste", "https://github.com/Trismegiste"] +translators: + - ["Pascal Boutin", "http://pboutin.net/"] +lang: fr-fr +--- + +This document describes PHP 5+. + +```php + // Le code PHP doit être placé à l'intérieur de balises '<?php' + +// Si votre fichier php ne contient que du code PHP, il est +// généralement recommandé de ne pas fermer la balise '?>' + +// Deux barres obliques amorcent un commentaire simple. + +# Le dièse aussi, bien que les barres obliques soient plus courantes + +/* + Les barres obliques et les astérisques peuvent être utilisés + pour faire un commentaire multi-lignes. +*/ + +// Utilisez "echo" ou "print" afficher une sortie +print('Hello '); // Affiche "Hello " sans retour à la ligne + +// Les parenthèses sont facultatives pour print et echo +echo "World\n"; // Affiche "World" avec un retour à la ligne + +// toutes les instructions doivent se terminer par un point-virgule + +// Tout ce qui se trouve en dehors des <?php ?> est automatiquement +// affiché en sortie +Hello World Again! +<?php + + +/************************************ + * Types & Variables + */ + +// Les noms de variables débutent par le symbole $ +// 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 +$boolean = true; // ou TRUE ou True +$boolean = false; // ou FALSE ou False + +// Entiers (integers) +$int1 = 12; // => 12 +$int2 = -12; // => -12 +$int3 = 012; // => 10 (un 0 devant la valeur désigne une valeur octale) +$int4 = 0x0F; // => 15 (un 0x devant la valeur désigne une valeur hexadécimale) + +// Réels (floats, doubles) +$float = 1.234; +$float = 1.2e3; +$float = 7E-10; + +// Suppression d'une variable +unset($int1); + +// Arithmétique +$sum = 1 + 1; // 2 (addition) +$difference = 2 - 1; // 1 (soustraction) +$product = 2 * 2; // 4 (produit) +$quotient = 2 / 1; // 2 (division) + +// Arithmétique (raccourcis) +$number = 0; +$number += 2; // Incrémente $number de 2 +echo $number++; // Affiche 2 (incrémente après l'évaluation) +echo ++$number; // Affiche 4 (incrémente avant l'évaluation) +$number /= $float; // Divise et assigne le quotient à $number + +// Les chaînes de caractères (strings) doivent être à +// l'intérieur d'une paire d'apostrophes +$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 $String.' + +// Les caractères spéciaux sont seulement échappés avec des guillemets +$escaped = "This contains a \t tab character."; +$unescaped = 'This just contains a slash and a t: \t'; + +// En cas de besoin, placez la variable dans des accolades +$money = "I have $${number} in the bank."; + +// Depuis PHP 5.3, Nowdoc peut être utilisé pour faire des chaînes +// multi-lignes non-interprétées +$nowdoc = <<<'END' +Multi line +string +END; + +// Heredoc peut être utilisé pour faire des chaînes multi-lignes interprétées +$heredoc = <<<END +Multi line +$sgl_quotes +END; + +// La concaténation de chaînes se fait avec un . +echo 'This string ' . 'is concatenated'; + + +/******************************** + * Constantes + */ + +// Une constante est déclarée avec define() +// et ne peut jamais être changée durant l'exécution + +// un nom valide de constante commence par une lettre ou un souligné, +// suivi de n'importe quelle lettre, nombre ou soulignés. +define("FOO", "something"); + +// on peut accéder à une constante en utilisant directement son nom +echo 'This outputs '.FOO; + + +/******************************** + * Tableaux (array) + */ + +// Tous les tableaux en PHP sont associatifs (hashmaps), + +// Fonctionne dans toutes les versions de PHP +$associative = array('One' => 1, 'Two' => 2, 'Three' => 3); + +// PHP 5.4 a introduit une nouvelle syntaxe +$associative = ['One' => 1, 'Two' => 2, 'Three' => 3]; + +echo $associative['One']; // affiche 1 + +// Dans une liste simple, l'index est automatiquement attribué en tant que clé +$array = ['One', 'Two', 'Three']; +echo $array[0]; // => "One" + +// Ajoute un élément à la fin du tableau +$array[] = 'Four'; + +// Retrait d'un élément du tableau +unset($array[3]); + +/******************************** + * Affichage + */ + +echo('Hello World!'); +// Affiche Hello World! dans stdout. +// Stdout est la page web si on exécute depuis un navigateur. + +print('Hello World!'); // Pareil à "écho" + +// Pour écho, vous n'avez pas besoin des parenthèses +echo 'Hello World!'; +print 'Hello World!'; // Pour print non plus + +$paragraph = 'paragraph'; + +echo 100; // Affichez un scalaire directement +echo $paragraph; // ou des variables + +// Si le raccourci de sortie est configuré, ou si votre version de PHP est +// 5.4.0+, vous pouvez utiliser ceci: +?> +<p><?= $paragraph ?></p> +<?php + +$x = 1; +$y = 2; +$x = $y; // $x contient maintenant la même valeur que $y +$z = &$y; +// $z contient une référence vers $y. Changer la valeur de +// $z changerait également la valeur de $y, et vice-versa. +// $x resterait inchangé comme la valeur initiale de $y + +echo $x; // => 2 +echo $z; // => 2 +$y = 0; +echo $x; // => 2 +echo $z; // => 0 + +// Affiche le type et la valeur de la variable dans stdout +var_dump($z); // prints int(0) + +// Affiche la variable dans stdout dans un format plus convivial +print_r($array); // prints: Array ( [0] => One [1] => Two [2] => Three ) + +/******************************** + * Logique + */ +$a = 0; +$b = '0'; +$c = '1'; +$d = '1'; + +// assert affiche un avertissement dans son argument n'est pas vrai + +// Ces comparaisons vont toujours être vraies, même si leurs +// types ne sont pas les mêmes. +assert($a == $b); // égalité +assert($c != $a); // inégalité +assert($c <> $a); // inégalité (moins courant) +assert($a < $c); +assert($c > $b); +assert($a <= $b); +assert($c >= $d); + +// Ces comparaisons vont seulement être vraies si les types concordent. +assert($c === $d); +assert($a !== $d); +assert(1 === '1'); +assert(1 !== '1'); + +// Opérateur 'spaceship' depuis PHP 7 +$a = 100; +$b = 1000; + +echo $a <=> $a; // 0 car ils sont égaux +echo $a <=> $b; // -1 car $a < $b +echo $b <=> $a; // 1 car $b > $a + +// Les variables peuvent être transtypées dépendamment de leur usage. + +$integer = 1; +echo $integer + $integer; // => 2 + +$string = '1'; +echo $string + $string; // => 2 + +$string = 'one'; +echo $string + $string; // => 0 +// Donne 0 car l'opérateur + ne peut pas transtyper la chaîne 'one' en un nombre + +// On peut également transtyper manuellement pour utiliser +// une variable dans un autre type + +$boolean = (boolean) 1; // => true + +$zero = 0; +$boolean = (boolean) $zero; // => false + +// Il y a également des fonctions dédiées pour transtyper +$integer = 5; +$string = strval($integer); + +$var = null; // Valeur nulle + + +/******************************** + * Structures de contrôle + */ + +if (true) { + print 'Je suis affiché'; +} + +if (false) { + print 'Je ne le suis pas'; +} else { + print 'Je suis affiché'; +} + +if (false) { + print 'Je ne suis pas affiché'; +} elseif (true) { + print 'Je le suis'; +} + +// Opérateur ternaire +print (false ? 'N\'est pas affiché' : 'L\'est'); + +// Opérateur ternaire depuis PHP 5.3 +// équivalent de $x ? $x : 'Does' +$x = false; +print($x ?: 'Does'); + +// depuis PHP 7, on peut facilement vérifier si une valeur est nulle +$a = null; +$b = 'Hello World'; +echo $a ?? 'a is not set'; // Affiche 'a is not set' +echo $b ?? 'b is not set'; // Affiche 'Hello World' + + +$x = 0; +if ($x === '0') { + print 'Pas affiché'; +} elseif($x == '1') { + print 'Pas affiché'; +} else { + print 'Affiché'; +} + + +// Cette syntaxe alternative est particulièrement utile avec du HTML: +?> + +<?php if ($x): ?> +<p>Ceci est affiché si $x est vrai</p> +<?php else: ?> +<p>Ceci est affiché si $x est faux</p> +<?php endif; ?> + +<?php + +// On peut également utiliser une condition multiple (switch case) +switch ($x) { + case '0': + print 'Les switch font du transtypage implicite'; + break; // Il est important de déclaré un 'break', sinon les cas + // 'two' et 'three' seront évalués + case 'two': + case 'three': + // Si $x == 'two' || $x == 'three' + break; + default: + // Si aucun cas n'a été vrai +} + +// Structures itératives (for, while, do while) +$i = 0; +while ($i < 5) { + echo $i++; +}; // Affiche "01234" + +echo "\n"; + +$i = 0; +do { + echo $i++; +} while ($i < 5); // Affiche "01234" + +echo "\n"; + +for ($x = 0; $x < 10; $x++) { + echo $x; +} // Affiche "0123456789" + +echo "\n"; + +$wheels = ['bicycle' => 2, 'car' => 4]; + +// Les boucles 'foreach' sont utiles pour parcourir les tableaux +foreach ($wheels as $wheel_count) { + echo $wheel_count; +} // Affiche "24" + +echo "\n"; + +// Il est également possible d'accéder aux clés du tableau +foreach ($wheels as $vehicle => $wheel_count) { + echo "The $vehicle have $wheel_count wheels"; +} + +echo "\n"; + +$i = 0; +while ($i < 5) { + if ($i === 3) { + break; // Permet d'arrêter la boucle + } + echo $i++; +} // Affiche "012" + +for ($i = 0; $i < 5; $i++) { + if ($i === 3) { + continue; // Permet de passer immédiatement à l'itération suivante + } + echo $i; +} // Affiche "0124" + + +/******************************** + * Fonctions + */ + +// On peut déclarer une fonction avec le mot clé 'function' +function my_function () { + return 'Hello'; +} + +echo my_function(); // => "Hello" + + +// Les noms de fonction débutent par le symbole $ +// Un nom de variable valide commence par une lettre ou un souligné, +// suivi de n'importe quelle lettre, nombre ou de soulignés. + +function add ($x, $y = 1) { // $y est facultatif et sa valeur par défaut est 1 + $result = $x + $y; + return $result; +} + +echo add(4); // => 5 +echo add(4, 2); // => 6 + +// $result n'est pas accessible en dehors de la fonction +// print $result; // Retourne un avertissement + +// Depuis PHP 5.3 on peut déclarer des fonctions anonymes +$inc = function ($x) { + return $x + 1; +}; + +echo $inc(2); // => 3 + +function foo ($x, $y, $z) { + echo "$x - $y - $z"; +} + +// Une fonction peut retourner une fonction +function bar ($x, $y) { + // On peut utiliser 'use' pour passer des variables externes + return function ($z) use ($x, $y) { + foo($x, $y, $z); + }; +} + +$bar = bar('A', 'B'); +$bar('C'); // Affiche "A - B - C" + +// On peut exécuter une fonction par son nom en chaîne de caractères +$function_name = 'add'; +echo $function_name(1, 2); // => 3 +// Utile pour déterminer par programmation quelle fonction exécuter. + +// On peut également utiliser +call_user_func(callable $callback [, $parameter [, ... ]]); + +/******************************** + * Insertions + */ + +<?php +// Le PHP se trouvant dans un fichier inclus doit +// également commencer par une balise PHP. + +include 'my-file.php'; +// Le code se trouvant dans my-file.php est maintenant disponible dans +// le contexte courant. Si le fichier ne peut pas être inclus +// (ex. non trouvé), un avertissement sera émit. + +include_once 'my-file.php'; +// Si le code dans my-file.php a déjà été inclus ailleur, il ne va pas +// être inclus de nouveau. + +require 'my-file.php'; +require_once 'my-file.php'; +// Même comportement que include() mais déclenche une érreur fatale si le fichier ne peux pas être inclus. + +// Contenu de my-include.php: +<?php + +return 'Anything you like.'; +// Fin de my-include.php + +// include() et require() peuvent également retourner une valeur +$value = include('my-include.php'); + +// Les fichiers sont inclus depuis le chemin donné ou, si aucun chemin n'est donné, +// la configuration 'include_path'. Si le fichier n'est pas trouvé dans le 'include_path', +// include va finalement vérifier dans le répertoire courant avant d'échouer. + +/******************************** + * Classes + */ + +// Les classes sont définies avec le mot clé 'class' + +class MyClass +{ + const MY_CONST = 'value'; // Une constante + + static $staticVar = 'static'; + + // Variables statiques et leur visibilité + public static $publicStaticVar = 'publicStatic'; + // Accessible à l'intérieur de la classe seulement + private static $privateStaticVar = 'privateStatic'; + // Accessible à l'intérieur de la classe et des classes enfants + protected static $protectedStaticVar = 'protectedStatic'; + + // Les attributs doivent définir leur visibilité + public $property = 'public'; + public $instanceProp; + protected $prot = 'protected'; + private $priv = 'private'; + + // Déclaration d'un constructeur avec __construct + public function __construct($instanceProp) { + // Access instance variables with $this + $this->instanceProp = $instanceProp; + } + + // Les méthodes sont déclarés par des fonctions au sein de la classe + public function myMethod() + { + print 'MyClass'; + } + + // le mot clé 'final' rend la function impossible à surcharger + final function youCannotOverrideMe() + { + } + +/* + * Les attributs et méthodes statiques peuvent être accédés sans devoir + * instancier la classe. Les attributs statiques ne sont pas accessibles depuis + * une instance, même si les méthodes statiques le sont. + */ + + public static function myStaticMethod() + { + print 'I am static'; + } +} + +// Les constantes d'une classe peuvent toujours être utilisé de façon statique +echo MyClass::MY_CONST; // Outputs 'value'; + +echo MyClass::$staticVar; // Retourne 'static'; +MyClass::myStaticMethod(); // Retourne 'I am static'; + +// On peut instancier une classe en utilisant le mot clé 'new' +$my_class = new MyClass('An instance property'); + +// On peut accéder aux attributs/méthodes d'une instance avec -> +echo $my_class->property; // => "public" +echo $my_class->instanceProp; // => "An instance property" +$my_class->myMethod(); // => "MyClass" + + +// On peut hériter d'une classe en utilisant 'extends' +class MyOtherClass extends MyClass +{ + function printProtectedProperty() + { + echo $this->prot; + } + + // Surcharge d'une méthode + function myMethod() + { + parent::myMethod(); + print ' > MyOtherClass'; + } +} + +$my_other_class = new MyOtherClass('Instance prop'); +$my_other_class->printProtectedProperty(); // => Retourne "protected" +$my_other_class->myMethod(); // Retourne "MyClass > MyOtherClass" + +// On peut empêcher qu'une classe soit héritée +final class YouCannotExtendMe +{ +} + +// On peut utiliser des "méthodes magiques" pour se faire des accesseurs +class MyMapClass +{ + private $property; + + public function __get($key) + { + return $this->$key; + } + + public function __set($key, $value) + { + $this->$key = $value; + } +} + +$x = new MyMapClass(); +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'). + +// Une interface peut être déclarée avec le mot clé 'interface' + +interface InterfaceOne +{ + public function doSomething(); +} + +interface InterfaceTwo +{ + public function doSomethingElse(); +} + +// Les interfaces peuvent hériter d'autres interfaces +interface InterfaceThree extends InterfaceTwo +{ + public function doAnotherContract(); +} + +abstract class MyAbstractClass implements InterfaceOne +{ + public $x = 'doSomething'; +} + +class MyConcreteClass extends MyAbstractClass implements InterfaceTwo +{ + public function doSomething() + { + echo $x; + } + + public function doSomethingElse() + { + echo 'doSomethingElse'; + } +} + + +// Les classes peuvent implémenter plusieurs interfaces à la fois +class SomeOtherClass implements InterfaceOne, InterfaceTwo +{ + public function doSomething() + { + echo 'doSomething'; + } + + public function doSomethingElse() + { + echo 'doSomethingElse'; + } +} + +/******************************** + * Espaces de noms (namespaces) + */ + +// Cette section est séparée, car une déclaration d'espace de nom doit être +// la première chose que l'on retrouve dans un fichier PHP, +// imaginons que c'est le cas + +<?php + +// Par défaut, les classes existent dans l'espace de nom global et peuvent +// être appelé explicitement avec un antislash. + +$cls = new \MyClass(); + + + +// On peut spécifier l'espace de nom d'un fichier comme cela +namespace My\Namespace; + +class MyClass +{ +} + +// (depuis un autre fichier...) +$cls = new My\Namespace\MyClass; + +// Ou depuis un autre espace de nom +namespace My\Other\Namespace; + +use My\Namespace\MyClass; + +$cls = new MyClass(); + +// On peut également utiliser un alias sur un espace de nom + +namespace My\Other\Namespace; + +use My\Namespace as SomeOtherNamespace; + +$cls = new SomeOtherNamespace\MyClass(); + +*/ + +``` + +## Pour plus d'informations + +Visitez la [documentation officielle](http://www.php.net/manual/fr). + +Si vous êtes intéressé par les bonnes pratiques, visitez +[PHP The Right Way](http://www.phptherightway.com/) (anglais seulement). + +Si vous êtes habitué à utiliser de bons gestionaires de dépendances, regardez +[Composer](http://getcomposer.org/). + +Pour consulter les standards, visitez "the PHP Framework Interoperability Groups" +[PSR standards](https://github.com/php-fig/fig-standards). diff --git a/fr-fr/python-fr.html.markdown b/fr-fr/python-fr.html.markdown index 58a036ba..3f6dcabb 100644 --- a/fr-fr/python-fr.html.markdown +++ b/fr-fr/python-fr.html.markdown @@ -15,11 +15,11 @@ Je suis tombé amoureux de Python de par la clarté de sa syntaxe. C'est pratiqu Vos retours sont grandement appréciés. Vous pouvez me contacter sur Twitter [@louiedinh](http://twitter.com/louiedinh) ou par e-mail: louiedinh [at] [google's email service] NB: Cet artice s'applique spécifiquement à Python 2.7, mais devrait s'appliquer pour toute version Python 2.x -Vous pourrez bientôt trouver un article pour Python 3! +Vous pourrez bientôt trouver un article pour Python 3 en Français. Pour le moment vous pouvez jettez un coup d'oeil à l'article [Python 3 en Anglais](http://learnxinyminutes.com/docs/python3/). ```python # Une ligne simple de commentaire commence par un dièse -""" Les lignes de commenatires multipes peuvent être écrites +""" Les lignes de commentaires multipes peuvent être écrites en utilisant 3 guillemets ("), et sont souvent utilisées pour les commentaires """ diff --git a/fr-fr/scala.html.markdown b/fr-fr/scala.html.markdown index a43edf16..c6d06361 100644 --- a/fr-fr/scala.html.markdown +++ b/fr-fr/scala.html.markdown @@ -208,6 +208,7 @@ sSquared.reduce (_+_) // La fonction filter prend un prédicat (une fonction de type A -> Booléen) et // sélectionne tous les éléments qui satisfont ce prédicat List(1, 2, 3) filter (_ > 2) // List(3) +case class Person(name: String, age: Int) List( Person(name = "Dom", age = 23), Person(name = "Bob", age = 30) @@ -217,6 +218,7 @@ List( // Scala a une méthode foreach définie pour certaines collections // qui prend en argument une fonction renvoyant Unit (une méthode void) +val aListOfNumbers = List(1, 2, 3, 4, 10, 20, 100) aListOfNumbers foreach (x => println(x)) aListOfNumbers foreach println @@ -271,11 +273,12 @@ i // Montre la valeur de i. Notez que while est une boucle au sens classique. // mais utiliser des combinateurs et des compréhensions comme ci-dessus est plus // facile pour comprendre et pour faire la parallélisation +i = 0 // La boucle do while do { println("x is still less then 10"); - x += 1 -} while (x < 10) + i += 1 +} while (i < 10) // La récursivité est un moyen idiomatique de faire une chose répétitive en Scala. @@ -370,7 +373,7 @@ val email(user, domain) = "henry@zkpr.com" "Les chaînes de caractères Scala sont entourées de doubles guillements" 'a' // Un caractère de Scala -'Les simples guillemets n'existent pas en Scala // Erreur +// 'Les simples guillemets n'existent pas en Scala' // Erreur "Les chaînes de caractères possèdent les méthodes usuelles de Java".length "Il y a aussi quelques méthodes extra de Scala.".reverse diff --git a/fr-fr/yaml-fr.html.markdown b/fr-fr/yaml-fr.html.markdown index 43b1df54..1e8296d3 100644 --- a/fr-fr/yaml-fr.html.markdown +++ b/fr-fr/yaml-fr.html.markdown @@ -8,113 +8,117 @@ lang: fr-fr Proposé à l'origine par Clark Evans en Mai 2001, YAML est un un format de représentation de données par sérialisation, conçu pour être aisément -éditable et lisible par nous même, les humains. +modifiable et lisible par nous-mêmes, les humains. -YAML est plus concis que le XML auquel il est parfois comparé par ceux qui le découvre, plus lisible et clair que le CSV, et emprunte beaucoup au JSON dont il est un parent naturel. Toutefois, YAML emprunte également des idées et concepts de chez Python, et s'intègre bien avec bon nombre de langages. +YAML est plus concis que le XML auquel il est parfois comparé par ceux qui le +découvre, plus lisible et clair que le CSV, et emprunte beaucoup au JSON dont +il est un parent naturel. Toutefois, YAML emprunte également des idées et +concepts de Python, et s'intègre bien avec bon nombre de langages. +Contrairement à ce dernier, YAML interdit l'utilisation des tabulations. ```yaml -# les Commentaires sont précédés d'un signe "#", comme cette ligne. +# Les commentaires sont précédés d'un signe "#", comme cette ligne. ############# # SCALAIRES # ############# -# Les scalaires sont l'ensemble des types YAML qui ne sont pas des collections -# ( listes ou tableaux associatifs ). +# Les scalaires sont l'ensemble des types YAML qui ne sont pas des collections +# (listes ou tableaux associatifs). -# Notre objet root ( racine ), sera une map ( carte ) et englobera -# l'intégralité du document. Cette map est l'équivalent d'un dictionnaire, +# Notre objet root (racine), sera une map (carte) et englobera +# l'intégralité du document. Cette map est l'équivalent d'un dictionnaire, # hash ou objet dans d'autres langages. clé: valeur -aurtre_clé: une autre valeur +autre_clé: une autre valeur valeur_numérique: 100 notation_scientifique: 1e+12 -boolean: true +booléen: true valeur_null: null clé avec espaces: valeur -# Bien qu'il ne soit pas nécessaire d'enfermer les chaînes de caractères +# Bien qu'il ne soit pas nécessaire de mettre les chaînes de caractères # entre guillemets, cela reste possible, et parfois utile. toutefois: "Une chaîne, peut être contenue entre guillemets." -"Une clé entre guillemets.": "Utile si on veut utiliser ':' dans la clé." +"Une clé entre guillemets.": "Utile si l'on veut utiliser ':' dans la clé." -# Les chaînes couvrant plusieurs lignes, peuvent être écrites au choix, -# comme un 'bloc littéral' ( avec | ) ou bien 'bloc replié' avec ( > ). +# Les chaînes couvrant plusieurs lignes, peuvent être écrites au choix, +# comme un "bloc littéral" (avec '|') ou bien un "bloc replié" (avec '>'). bloc_littéral: | - Tout ce bloc de texte sera la valeur de la clé 'bloc_littéral', - avec préservation des retours à la ligne. ( chaque ligne vide à - l'intérieur du même bloc, sera remplacée par "\n\n" ) + Tout ce bloc de texte sera la valeur de la clé "bloc_littéral", + avec préservation des retours à la ligne. Le littéral continue jusqu'à ce que l'indentation soit annulée. - Toutes lignes qui serait "d'avantage indentées" conservent leur + Toutes lignes qui seraient "davantage indentées" conservent leur indentation, constituée de 4 espaces. bloc_replié: > - Tout ce bloc de texte sera la valeur de la clé 'bloc_replié', mais - cette fois ci, toutes les nouvelles lignes deviendront un simple espace. + Tout ce bloc de texte sera la valeur de la clé "bloc_replié", mais + cette fois-ci, toutes les nouvelles lignes deviendront un simple espace. - Les lignes vides, comme ci-dessus, seront converties en caractère "\n". + Les lignes vides, comme ci-dessus, seront converties en caractère de + nouvelle ligne. - Les lignes 'plus-indentées' gardent leurs retours à la ligne - + Les lignes "plus-indentées" gardent leurs retours à la ligne - ce texte apparaîtra sur deux lignes. ############### # COLLECTIONS # ############### -# l'Imbrication est créée par indentation. +# L'imbrication est créée par indentation. une_map_imbriquée: clé: valeur autre_clé: autre valeur autre_map_imbriquée: bonjour: bonjour -# les Clés des Maps ne sont pas nécessairement des chaînes de caractères. -0.25: une clé de type float +# Les clés des maps ne sont pas nécessairement des chaînes de caractères. +0.25: une clé de type flottant -# les Clés peuvent également être des objets s'étendant sur plusieurs lignes, +# Les clés peuvent également être des objets s'étendant sur plusieurs lignes, # en utilisant le signe "?" pour indiquer le début de la clé. ? | - ceci est une Clé + ceci est une clé sur de multiples lignes -: et ceci est sa Valeur +: et ceci est sa valeur # YAML autorise aussi l'usage des collections à l'intérieur des clés, # mais certains langages de programmation ne le tolère pas si bien. -# les Séquences (équivalent des listes ou tableaux) ressemblent à cela: +# Les séquences (équivalent des listes ou tableaux) ressemblent à cela : une_séquence: - - Item 1 - - Item 2 + - Objet 1 + - Objet 2 - 0.5 # les séquences peuvent contenir des types variés. - - Item 4 + - Objet 4 - clé: valeur autre_clé: autre_valeur - - Ceci est une séquence - dans une autre séquence -# YAML étant un proche parent de JSON, vous pouvez écrire directement +# YAML étant un proche parent de JSON, vous pouvez écrire directement # des maps et séquences façon JSON json_map: {"clé": "valeur"} json_seq: [1, 2, 3, "soleil"] -################################# +################################ # AUTRES FONCTIONNALITÉES YAML # -################################# +################################ -# YAML possède une fonctionnalité fort utile nommée 'ancres'. Celle-ci +# YAML possède une fonctionnalité fort utile nommée "ancres". Celle-ci # vous permet de dupliquer aisément du contenu au sein de votre document. -# Les deux clés suivantes auront la même valeur: +# Les deux clés suivantes auront la même valeur : contenu_ancré: &nom_ancre Cette chaîne sera la valeur des deux clés. autre_ancre: *nom_ancre -# Avec les Tags YAML, vous pouvez explicitement déclarer des types de données. +# Avec les tags YAML, vous pouvez explicitement déclarer des types de données. chaine_explicite: !!str 0.5 -# Certains parsers implémentent des tags spécifiques à d'autres langages, -# comme par exemple le "complex number" de Python. +# Certains analyseurs syntaxiques (parsers) implémentent des tags spécifiques à +# d'autres langages, comme par exemple celui des nombres complexes de Python. python_complex_number: !!python/complex 1+2j ##################### @@ -122,7 +126,7 @@ python_complex_number: !!python/complex 1+2j ##################### # YAML interprète également les données formatées ISO de type date et datetime, -# pas seulement les chaînes et nombres. +# pas seulement les chaînes et nombres. datetime: 2001-12-15T02:59:43.1Z datetime_avec_espaces: 2001-12-14 21:59:43.10 -5 date: 2002-12-14 @@ -135,14 +139,14 @@ fichier_gif: !!binary | +f/++f/++f/++f/++f/++SH+Dk1hZGUgd2l0aCBHSU1QACwAAAAADAAMAAAFLC AgjoEwnuNAFOhpEMTRiggcz4BNJHrv/zCFcLiwMWYNG84BwwEeECcgggoBADs= -# YAML a de même un type "set", qui ressemble à cela: +# YAML a de même un type "set", semblable à ceci : set: ? item1 ? item2 ? item3 # Comme dans Python, les sets ne sont que des maps contenant des valeurs null ; -# le set précédent est l'équivalent du suivant: +# le set précédent est l'équivalent du suivant : set2: item1: null item2: null @@ -152,6 +156,6 @@ set2: Quelques références et outils : -- Doc officielle [YAML 1.2](http://www.yaml.org/spec/1.2/spec.html) *anglais*, +- Documentation officielle [YAML 1.2](http://www.yaml.org/spec/1.2/spec.html) *anglais*, - Une [Introduction à YAML](http://sweetohm.net/html/introduction-yaml.html) très bien construite et claire, -- Un outil pour tester [live](http://yaml-online-parser.appspot.com/) la syntaxe YAML, avec des exemples. +- Un outil pour tester [en ligne](http://yaml-online-parser.appspot.com/) la syntaxe YAML, avec des exemples. diff --git a/fsharp.html.markdown b/fsharp.html.markdown index 49951c78..76318d7d 100644 --- a/fsharp.html.markdown +++ b/fsharp.html.markdown @@ -5,7 +5,7 @@ contributors: filename: learnfsharp.fs --- -F# is a general purpose functional/OO programming language. It's free and open source, and runs on Linux, Mac, Windows and more. +F# is a general purpose functional/OO programming language. It's free and open source, and runs on Linux, Mac, Windows and more. It has a powerful type system that traps many errors at compile time, but it uses type inference so that it reads more like a dynamic language. @@ -90,7 +90,7 @@ let simplePatternMatch = | _ -> printfn "x is something else" // underscore matches anything // F# doesn't allow nulls by default -- you must use an Option type -// and then pattern match. +// and then pattern match. // Some(..) and None are roughly analogous to Nullable wrappers let validValue = Some(99) let invalidValue = None @@ -115,39 +115,39 @@ printfn "A string %s, and something generic %A" "hello" [1;2;3;4] // into a string, similar to String.Format in C#. // ================================================ -// More on functions +// More on functions // ================================================ // F# is a true functional language -- functions are first -// class entities and can be combined easy to make powerful +// class entities and can be combined easily to make powerful // constructs // Modules are used to group functions together // Indentation is needed for each nested module. -module FunctionExamples = +module FunctionExamples = // define a simple adding function let add x y = x + y - + // basic usage of a function let a = add 1 2 printfn "1+2 = %i" a - + // partial application to "bake in" parameters let add42 = add 42 let b = add42 1 printfn "42+1 = %i" b - + // composition to combine functions let add1 = add 1 let add2 = add 2 let add3 = add1 >> add2 let c = add3 7 printfn "3+7 = %i" c - + // higher order functions [1..10] |> List.map add3 |> printfn "new list is %A" - + // lists of functions, and more let add6 = [add1; add2; add3] |> List.reduce (>>) let d = add6 7 @@ -158,54 +158,54 @@ module FunctionExamples = // ================================================ // There are three types of ordered collection: -// * Lists are most basic immutable collection. -// * Arrays are mutable and more efficient when needed. -// * Sequences are lazy and infinite (e.g. an enumerator). +// * Lists are most basic immutable collection. +// * Arrays are mutable and more efficient when needed. +// * Sequences are lazy and infinite (e.g. an enumerator). // // Other collections include immutable maps and sets // plus all the standard .NET collections -module ListExamples = +module ListExamples = - // lists use square brackets + // lists use square brackets let list1 = ["a";"b"] let list2 = "c" :: list1 // :: is prepending let list3 = list1 @ list2 // @ is concat - + // list comprehensions (aka generators) - let squares = [for i in 1..10 do yield i*i] + let squares = [for i in 1..10 do yield i*i] // prime number generator let rec sieve = function | (p::xs) -> p :: sieve [ for x in xs do if x % p > 0 then yield x ] | [] -> [] let primes = sieve [2..50] - printfn "%A" primes - + printfn "%A" primes + // pattern matching for lists - let listMatcher aList = + let listMatcher aList = match aList with - | [] -> printfn "the list is empty" - | [first] -> printfn "the list has one element %A " first - | [first; second] -> printfn "list is %A and %A" first second - | _ -> printfn "the list has more than two elements" + | [] -> printfn "the list is empty" + | [first] -> printfn "the list has one element %A " first + | [first; second] -> printfn "list is %A and %A" first second + | _ -> printfn "the list has more than two elements" listMatcher [1;2;3;4] listMatcher [1;2] listMatcher [1] - listMatcher [] + listMatcher [] // recursion using lists - let rec sum aList = + let rec sum aList = match aList with | [] -> 0 | x::xs -> x + sum xs sum [1..10] - - // ----------------------------------------- - // Standard library functions + + // ----------------------------------------- + // Standard library functions // ----------------------------------------- - + // map let add3 x = x + 3 [1..10] |> List.map add3 @@ -213,68 +213,68 @@ module ListExamples = // filter let even x = x % 2 = 0 [1..10] |> List.filter even - + // many more -- see documentation - -module ArrayExamples = + +module ArrayExamples = // arrays use square brackets with bar let array1 = [| "a";"b" |] let first = array1.[0] // indexed access using dot - + // pattern matching for arrays is same as for lists - let arrayMatcher aList = + let arrayMatcher aList = match aList with - | [| |] -> printfn "the array is empty" - | [| first |] -> printfn "the array has one element %A " first - | [| first; second |] -> printfn "array is %A and %A" first second - | _ -> printfn "the array has more than two elements" + | [| |] -> printfn "the array is empty" + | [| first |] -> printfn "the array has one element %A " first + | [| first; second |] -> printfn "array is %A and %A" first second + | _ -> printfn "the array has more than two elements" arrayMatcher [| 1;2;3;4 |] // Standard library functions just as for List - - [| 1..10 |] + + [| 1..10 |] |> Array.map (fun i -> i+3) |> Array.filter (fun i -> i%2 = 0) |> Array.iter (printfn "value is %i. ") - - -module SequenceExamples = + + +module SequenceExamples = // sequences use curly braces let seq1 = seq { yield "a"; yield "b" } - - // sequences can use yield and + + // sequences can use yield and // can contain subsequences let strange = seq { // "yield! adds one element yield 1; yield 2; - + // "yield!" adds a whole subsequence - yield! [5..10] + yield! [5..10] yield! seq { - for i in 1..10 do + for i in 1..10 do if i%2 = 0 then yield i }} - // test - strange |> Seq.toList - + // test + strange |> Seq.toList + // Sequences can be created using "unfold" // Here's the fibonacci series let fib = Seq.unfold (fun (fst,snd) -> Some(fst + snd, (snd, fst + snd))) (0,1) - // test + // test let fib10 = fib |> Seq.take 10 |> Seq.toList - printf "first 10 fibs are %A" fib10 - - + printf "first 10 fibs are %A" fib10 + + // ================================================ -// Data Types +// Data Types // ================================================ -module DataTypeExamples = +module DataTypeExamples = // All data is immutable by default @@ -282,33 +282,33 @@ module DataTypeExamples = // -- Use a comma to create a tuple let twoTuple = 1,2 let threeTuple = "a",2,true - + // Pattern match to unpack let x,y = twoTuple //sets x=1 y=2 - // ------------------------------------ - // Record types have named fields - // ------------------------------------ + // ------------------------------------ + // Record types have named fields + // ------------------------------------ // Use "type" with curly braces to define a record type type Person = {First:string; Last:string} - - // Use "let" with curly braces to create a record + + // Use "let" with curly braces to create a record let person1 = {First="John"; Last="Doe"} // Pattern match to unpack let {First=first} = person1 //sets first="john" - // ------------------------------------ + // ------------------------------------ // Union types (aka variants) have a set of choices // Only case can be valid at a time. - // ------------------------------------ + // ------------------------------------ // Use "type" with bar/pipe to define a union type - type Temp = + type Temp = | DegreesC of float | DegreesF of float - + // Use one of the cases to create one let temp1 = DegreesF 98.6 let temp2 = DegreesC 37.0 @@ -317,29 +317,29 @@ module DataTypeExamples = let printTemp = function | DegreesC t -> printfn "%f degC" t | DegreesF t -> printfn "%f degF" t - - printTemp temp1 + + printTemp temp1 printTemp temp2 - // ------------------------------------ + // ------------------------------------ // Recursive types - // ------------------------------------ + // ------------------------------------ - // Types can be combined recursively in complex ways + // Types can be combined recursively in complex ways // without having to create subclasses - type Employee = + type Employee = | Worker of Person | Manager of Employee list let jdoe = {First="John";Last="Doe"} let worker = Worker jdoe - - // ------------------------------------ + + // ------------------------------------ // Modelling with types - // ------------------------------------ - + // ------------------------------------ + // Union types are great for modelling state without using flags - type EmailAddress = + type EmailAddress = | ValidEmailAddress of string | InvalidEmailAddress of string @@ -350,40 +350,40 @@ module DataTypeExamples = // The combination of union types and record types together // provide a great foundation for domain driven design. - // You can create hundreds of little types that accurately + // You can create hundreds of little types that accurately // reflect the domain. type CartItem = { ProductCode: string; Qty: int } type Payment = Payment of float type ActiveCartData = { UnpaidItems: CartItem list } type PaidCartData = { PaidItems: CartItem list; Payment: Payment} - - type ShoppingCart = + + type ShoppingCart = | EmptyCart // no data | ActiveCart of ActiveCartData - | PaidCart of PaidCartData + | PaidCart of PaidCartData - // ------------------------------------ + // ------------------------------------ // Built in behavior for types - // ------------------------------------ + // ------------------------------------ // Core types have useful "out-of-the-box" behavior, no coding needed. // * Immutability // * Pretty printing when debugging // * Equality and comparison // * Serialization - + // Pretty printing using %A - printfn "twoTuple=%A,\nPerson=%A,\nTemp=%A,\nEmployee=%A" + printfn "twoTuple=%A,\nPerson=%A,\nTemp=%A,\nEmployee=%A" twoTuple person1 temp1 worker // Equality and comparison built in. // Here's an example with cards. type Suit = Club | Diamond | Spade | Heart - type Rank = Two | Three | Four | Five | Six | Seven | Eight - | Nine | Ten | Jack | Queen | King | Ace + type Rank = Two | Three | Four | Five | Six | Seven | Eight + | Nine | Ten | Jack | Queen | King | Ace - let hand = [ Club,Ace; Heart,Three; Heart,Ace; + let hand = [ Club,Ace; Heart,Three; Heart,Ace; Spade,Jack; Diamond,Two; Diamond,Ace ] // sorting @@ -391,27 +391,27 @@ module DataTypeExamples = List.max hand |> printfn "high card is %A" List.min hand |> printfn "low card is %A" - + // ================================================ // Active patterns // ================================================ -module ActivePatternExamples = +module ActivePatternExamples = - // F# has a special type of pattern matching called "active patterns" - // where the pattern can be parsed or detected dynamically. + // F# has a special type of pattern matching called "active patterns" + // where the pattern can be parsed or detected dynamically. // "banana clips" are the syntax for active patterns - + // for example, define an "active" pattern to match character types... - let (|Digit|Letter|Whitespace|Other|) ch = + let (|Digit|Letter|Whitespace|Other|) ch = if System.Char.IsDigit(ch) then Digit else if System.Char.IsLetter(ch) then Letter else if System.Char.IsWhiteSpace(ch) then Whitespace - else Other + else Other // ... and then use it to make parsing logic much clearer - let printChar ch = + let printChar ch = match ch with | Digit -> printfn "%c is a Digit" ch | Letter -> printfn "%c is a Letter" ch @@ -424,52 +424,52 @@ module ActivePatternExamples = // ----------------------------------- // FizzBuzz using active patterns // ----------------------------------- - + // You can create partial matching patterns as well // Just use undercore in the defintion, and return Some if matched. let (|MultOf3|_|) i = if i % 3 = 0 then Some MultOf3 else None let (|MultOf5|_|) i = if i % 5 = 0 then Some MultOf5 else None // the main function - let fizzBuzz i = + let fizzBuzz i = match i with - | MultOf3 & MultOf5 -> printf "FizzBuzz, " - | MultOf3 -> printf "Fizz, " - | MultOf5 -> printf "Buzz, " + | MultOf3 & MultOf5 -> printf "FizzBuzz, " + | MultOf3 -> printf "Fizz, " + | MultOf5 -> printf "Buzz, " | _ -> printf "%i, " i - + // test - [1..20] |> List.iter fizzBuzz - + [1..20] |> List.iter fizzBuzz + // ================================================ -// Conciseness +// Conciseness // ================================================ -module AlgorithmExamples = +module AlgorithmExamples = - // F# has a high signal/noise ratio, so code reads + // F# has a high signal/noise ratio, so code reads // almost like the actual algorithm // ------ Example: define sumOfSquares function ------ - let sumOfSquares n = + let sumOfSquares n = [1..n] // 1) take all the numbers from 1 to n |> List.map square // 2) square each one |> List.sum // 3) sum the results - // test - sumOfSquares 100 |> printfn "Sum of squares = %A" - - // ------ Example: define a sort function ------ + // test + sumOfSquares 100 |> printfn "Sum of squares = %A" + + // ------ Example: define a sort function ------ let rec sort list = match list with - // If the list is empty - | [] -> + // If the list is empty + | [] -> [] // return an empty list - // If the list is not empty - | firstElem::otherElements -> // take the first element - let smallerElements = // extract the smaller elements + // If the list is not empty + | firstElem::otherElements -> // take the first element + let smallerElements = // extract the smaller elements otherElements // from the remaining ones - |> List.filter (fun e -> e < firstElem) + |> List.filter (fun e -> e < firstElem) |> sort // and sort them let largerElements = // extract the larger ones otherElements // from the remaining ones @@ -479,13 +479,13 @@ module AlgorithmExamples = List.concat [smallerElements; [firstElem]; largerElements] // test - sort [1;5;23;18;9;1;3] |> printfn "Sorted = %A" + sort [1;5;23;18;9;1;3] |> printfn "Sorted = %A" // ================================================ // Asynchronous Code // ================================================ -module AsyncExample = +module AsyncExample = // F# has built-in features to help with async code // without encountering the "pyramid of doom" @@ -495,23 +495,23 @@ module AsyncExample = open System.Net open System open System.IO - open Microsoft.FSharp.Control.CommonExtensions + open Microsoft.FSharp.Control.CommonExtensions // Fetch the contents of a URL asynchronously - let fetchUrlAsync url = - async { // "async" keyword and curly braces + let fetchUrlAsync url = + async { // "async" keyword and curly braces // creates an "async" object - let req = WebRequest.Create(Uri(url)) - use! resp = req.AsyncGetResponse() + let req = WebRequest.Create(Uri(url)) + use! resp = req.AsyncGetResponse() // use! is async assignment - use stream = resp.GetResponseStream() + use stream = resp.GetResponseStream() // "use" triggers automatic close() // on resource at end of scope - use reader = new IO.StreamReader(stream) - let html = reader.ReadToEnd() - printfn "finished downloading %s" url + use reader = new IO.StreamReader(stream) + let html = reader.ReadToEnd() + printfn "finished downloading %s" url } - + // a list of sites to fetch let sites = ["http://www.bing.com"; "http://www.google.com"; @@ -520,7 +520,7 @@ module AsyncExample = "http://www.yahoo.com"] // do it - sites + sites |> List.map fetchUrlAsync // make a list of async tasks |> Async.Parallel // set up the tasks to run in parallel |> Async.RunSynchronously // start them off @@ -529,58 +529,58 @@ module AsyncExample = // .NET compatability // ================================================ -module NetCompatibilityExamples = +module NetCompatibilityExamples = // F# can do almost everything C# can do, and it integrates // seamlessly with .NET or Mono libraries. // ------- work with existing library functions ------- - + let (i1success,i1) = System.Int32.TryParse("123"); if i1success then printfn "parsed as %i" i1 else printfn "parse failed" // ------- Implement interfaces on the fly! ------- - + // create a new object that implements IDisposable - let makeResource name = - { new System.IDisposable + let makeResource name = + { new System.IDisposable with member this.Dispose() = printfn "%s disposed" name } - let useAndDisposeResources = + let useAndDisposeResources = use r1 = makeResource "first resource" - printfn "using first resource" + printfn "using first resource" for i in [1..3] do let resourceName = sprintf "\tinner resource %d" i - use temp = makeResource resourceName - printfn "\tdo something with %s" resourceName + use temp = makeResource resourceName + printfn "\tdo something with %s" resourceName use r2 = makeResource "second resource" - printfn "using second resource" - printfn "done." + printfn "using second resource" + printfn "done." // ------- Object oriented code ------- - + // F# is also a fully fledged OO language. // It supports classes, inheritance, virtual methods, etc. // interface with generic type - type IEnumerator<'a> = + type IEnumerator<'a> = abstract member Current : 'a - abstract MoveNext : unit -> bool + abstract MoveNext : unit -> bool // abstract base class with virtual methods [<AbstractClass>] - type Shape() = + type Shape() = //readonly properties abstract member Width : int with get abstract member Height : int with get //non-virtual method member this.BoundingArea = this.Height * this.Width //virtual method with base implementation - abstract member Print : unit -> unit + abstract member Print : unit -> unit default this.Print () = printfn "I'm a shape" - // concrete class that inherits from base class and overrides - type Rectangle(x:int, y:int) = + // concrete class that inherits from base class and overrides + type Rectangle(x:int, y:int) = inherit Shape() override this.Width = x override this.Height = y @@ -590,20 +590,20 @@ module NetCompatibilityExamples = let r = Rectangle(2,3) printfn "The width is %i" r.Width printfn "The area is %i" r.BoundingArea - r.Print() + r.Print() // ------- extension methods ------- - + //Just as in C#, F# can extend existing classes with extension methods. type System.String with member this.StartsWithA = this.StartsWith "A" //test let s = "Alice" - printfn "'%s' starts with an 'A' = %A" s s.StartsWithA - + printfn "'%s' starts with an 'A' = %A" s s.StartsWithA + // ------- events ------- - + type MyButton() = let clickEvent = new Event<_>() @@ -615,11 +615,11 @@ module NetCompatibilityExamples = // test let myButton = new MyButton() - myButton.OnClick.Add(fun (sender, arg) -> + myButton.OnClick.Add(fun (sender, arg) -> printfn "Click event with arg=%O" arg) myButton.TestEvent("Hello World!") - + ``` ## More Information diff --git a/git.html.markdown b/git.html.markdown index bf8fce0c..72079f6c 100644 --- a/git.html.markdown +++ b/git.html.markdown @@ -8,17 +8,17 @@ contributors: filename: LearnGit.txt --- -Git is a distributed version control and source code management system. +Git is a distributed version control and source code management system. -It does this through a series of snapshots of your project, and it works -with those snapshots to provide you with functionality to version and +It does this through a series of snapshots of your project, and it works +with those snapshots to provide you with functionality to version and manage your source code. ## Versioning Concepts ### What is version control? -Version control is a system that records changes to a file, or set of files, over time. +Version control is a system that records changes to a file(s), over time. ### Centralized Versioning VS Distributed Versioning @@ -42,8 +42,9 @@ Version control is a system that records changes to a file, or set of files, ove ### Repository -A set of files, directories, historical records, commits, and heads. Imagine it as a source code data structure, -with the attribute that each source code "element" gives you access to its revision history, among other things. +A set of files, directories, historical records, commits, and heads. Imagine it +as a source code data structure, with the attribute that each source code +"element" gives you access to its revision history, among other things. A git repository is comprised of the .git directory & working tree. @@ -54,32 +55,33 @@ The .git directory contains all the configurations, logs, branches, HEAD, and mo ### Working Tree (component of repository) -This is basically the directories and files in your repository. It is often referred to -as your working directory. +This is basically the directories and files in your repository. It is often +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 over what gets sent to the Git -repository. +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 pushed to other repositories, or not! +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 -A branch is essentially a pointer that points to the last commit you made. As you commit, -this pointer will automatically update and point to the latest commit. +A branch is essentially a pointer to the last commit you made. As you go on +committing, this pointer will automatically update to point the latest commit. ### 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 of heads. -###Stages of Git +### Stages of Git * 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 @@ -95,7 +97,7 @@ head is a pointer that points to any commit. A repository can have any number of ### init -Create an empty Git repository. The Git repository's settings, stored information, +Create an empty Git repository. The Git repository's settings, stored information, and more is stored in a directory (a folder) named ".git". ```bash @@ -104,15 +106,12 @@ $ git init ### config -To configure settings. Whether it be for the repository, the system itself, or global -configurations. +To configure settings. Whether it be for the repository, the system itself, +or global configurations ( global config file is `~/.gitconfig` ). ```bash # Print & Set Some Basic Config Variables (Global) -$ git config --global user.email -$ git config --global user.name - $ git config --global user.email "MyEmail@Zoho.com" $ git config --global user.name "My Name" ``` @@ -142,10 +141,20 @@ $ git commit --help $ git init --help ``` +### ignore files + +To intentionally untrack file(s) & folder(s) from git. Typically meant for +private & temp files which would otherwise be shared in the repository. +```bash +$ echo "temp/" >> .gitignore +$ echo "private_key" >> .gitignore +``` + + ### status -To show differences between the index file (basically your working copy/repo) and the current -HEAD commit. +To show differences between the index file (basically your working copy/repo) +and the current HEAD commit. ```bash @@ -172,7 +181,8 @@ $ git add /path/to/file/HelloWorld.c $ git add ./*.java ``` -This only adds a file to the staging area/index, it doesn't commit it to the working directory/repo. +This only adds a file to the staging area/index, it doesn't commit it to the +working directory/repo. ### branch @@ -205,7 +215,8 @@ Updates all files in the working tree to match the version in the index, or spec $ git checkout # Checkout a specified branch $ git checkout branchName -# Create a new branch & switch to it, like: "git branch <name>; git checkout <name>" +# Create a new branch & switch to it +# equivalent to "git branch <name>; git checkout <name>" $ git checkout -b newBranch ``` @@ -218,6 +229,10 @@ to a remote branch. ```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 @@ -231,6 +246,9 @@ $ git commit -m "Added multiplyNumbers() function to HelloWorld.c" # 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 @@ -268,7 +286,7 @@ $ git config --global alias.g "grep --break --heading --line-number" $ git grep 'variableName' -- '*.java' # Search for a line that contains "arrayListName" and, "add" or "remove" -$ git grep -e 'arrayListName' --and \( -e add -e remove \) +$ git grep -e 'arrayListName' --and \( -e add -e remove \) ``` Google is your friend; for more examples @@ -282,8 +300,8 @@ Display commits to the repository. # Show all commits $ git log -# Show X number of commits -$ git log -n 10 +# Show only commit message & ref +$ git log --oneline # Show merge commits only $ git log --merges @@ -303,7 +321,7 @@ $ git merge --no-ff branchName ### mv -Rename or move a file +Rename or move a file ```bash # Renaming a file @@ -338,7 +356,7 @@ $ git pull origin master --rebase Push and merge changes from a branch to a remote & branch. ```bash -# Push and merge changes from a local repo to a +# Push and merge changes from a local repo to a # remote named "origin" and "master" branch. # git push <remote> <branch> # git push => implicitly defaults to => git push origin master @@ -347,23 +365,25 @@ $ git push origin master # 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 +$ git push ``` ### stash -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. +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 from the remote. -Since you have dirty (uncommited) changes to some files, you are not able to run `git pull`. -Instead, you can run `git stash` to save your changes onto a stack! +Let's say you've been doing some work in your git repo, but you want to pull +from the remote. Since you have dirty (uncommited) changes to some files, you +are not able to run `git pull`. Instead, you can run `git stash` to save your +changes onto a stack! ```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") + (To restore them type "git stash apply") ``` Now you can pull! @@ -410,7 +430,7 @@ Now you're ready to get back to work on your stuff! [Additional Reading.](http://git-scm.com/book/en/v1/Git-Tools-Stashing) -### rebase (caution) +### rebase (caution) 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*. @@ -464,6 +484,8 @@ $ git rm /pather/to/the/file/HelloWorld.c * [Udemy Git Tutorial: A Comprehensive Guide](https://blog.udemy.com/git-tutorial-a-comprehensive-guide/) +* [Git Immersion - A Guided tour that walks through the fundamentals of git](http://gitimmersion.com/) + * [git-scm - Video Tutorials](http://git-scm.com/videos) * [git-scm - Documentation](http://git-scm.com/docs) diff --git a/go.html.markdown b/go.html.markdown index 34b855e3..646a5650 100644 --- a/go.html.markdown +++ b/go.html.markdown @@ -10,6 +10,7 @@ contributors: - ["Quint Guvernator", "https://github.com/qguv"] - ["Jose Donizetti", "https://github.com/josedonizetti"] - ["Alexej Friesen", "https://github.com/heyalexej"] + - ["Clayton Walker", "https://github.com/cwalk"] --- Go was created out of the need to get work done. It's not the latest trend @@ -115,7 +116,7 @@ can include line breaks.` // Same string type. fmt.Println(s) // Updated slice is now [1 2 3 4 5 6] // To append another slice, instead of list of atomic elements we can // pass a reference to a slice or a slice literal like this, with a - // trailing elipsis, meaning take a slice and unpack its elements, + // trailing ellipsis, meaning take a slice and unpack its elements, // appending them to slice s. s = append(s, []int{7, 8, 9}...) // Second argument is a slice literal. fmt.Println(s) // Updated slice is now [1 2 3 4 5 6 7 8 9] @@ -129,7 +130,7 @@ can include line breaks.` // Same string type. m["one"] = 1 // Unused variables are an error in Go. - // The underbar lets you "use" a variable but discard its value. + // The underscore lets you "use" a variable but discard its value. _, _, _, _, _, _, _, _, _, _ = str, s2, g, f, u, pi, n, a3, s4, bs // Output of course counts as using a variable. fmt.Println(s, c, a4, s3, d2, m) @@ -164,7 +165,7 @@ func expensiveComputation() float64 { } func learnFlowControl() { - // If statements require brace brackets, and do not require parens. + // If statements require brace brackets, and do not require parentheses. if true { fmt.Println("told ya") } @@ -407,6 +408,8 @@ func requestServer() { The root of all things Go is the [official Go web site](http://golang.org/). There you can follow the tutorial, play interactively, and read lots. +Aside from a tour, [the docs](https://golang.org/doc/) contain information on +how to write clean and effective Go code, package and command docs, and release history. The language definition itself is highly recommended. It's easy to read and amazingly short (as language definitions go these days.) diff --git a/groovy.html.markdown b/groovy.html.markdown index 519f36ce..492c1ba2 100644 --- a/groovy.html.markdown +++ b/groovy.html.markdown @@ -99,7 +99,7 @@ technologies.sort() // To sort without mutating original, you can do: sortedTechnologies = technologies.sort( false ) -/*** Manipulating Lists ***/ +/*** Manipulating Lists ***/e //Replace all elements in the list Collections.replaceAll(technologies, 'Gradle', 'gradle') @@ -200,6 +200,14 @@ def y = 10 def x = (y > 1) ? "worked" : "failed" assert x == "worked" +//Groovy supports 'The Elvis Operator' too! +//Instead of using the ternary operator: + +displayName = user.name ? user.name : 'Anonymous' + +//We can write it: +displayName = user.name ?: 'Anonymous' + //For loop //Iterate over a range def x = 0 @@ -422,6 +430,3 @@ Join a [Groovy user group](http://www.groovy-lang.org/usergroups.html) [1] http://roshandawrani.wordpress.com/2010/10/18/groovy-new-feature-closures-can-now-memorize-their-results/ [2] http://www.solutionsiq.com/resources/agileiq-blog/bid/72880/Programming-with-Groovy-Trampoline-and-Memoize [3] http://mrhaki.blogspot.mx/2011/05/groovy-goodness-cache-closure-results.html - - - diff --git a/hack.html.markdown b/hack.html.markdown index 632fc705..b3d19f8e 100644 --- a/hack.html.markdown +++ b/hack.html.markdown @@ -2,6 +2,7 @@ language: Hack contributors: - ["Stephen Holdaway", "https://github.com/stecman"] + - ["David Lima", "https://github.com/davelima"] filename: learnhack.hh --- @@ -50,7 +51,7 @@ function identity(?string $stringOrNull) : ?string class TypeHintedProperties { public ?string $name; - + protected int $id; private float $score = 100.0; @@ -90,7 +91,7 @@ function openBox(Box<int> $box) : int // Shapes -// +// // Hack adds the concept of shapes for defining struct-like arrays with a // guaranteed, type-checked set of keys type Point2D = shape('x' => int, 'y' => int); @@ -107,7 +108,7 @@ distance( // Type aliasing -// +// // Hack adds a bunch of type aliasing features for making complex types readable newtype VectorArray = array<int, Vector<int>>; @@ -141,7 +142,7 @@ function getRoadType() : RoadType // Constructor argument promotion -// +// // To avoid boilerplate property and constructor definitions that only set // properties, Hack adds a concise syntax for defining properties and a // constructor at the same time. @@ -152,7 +153,7 @@ class ArgumentPromotion private bool $isAwesome) {} } -class WithoutArugmentPromotion +class WithoutArgumentPromotion { public string $name; @@ -169,13 +170,13 @@ class WithoutArugmentPromotion } -// Co-oprerative multi-tasking -// -// Two new keywords "async" and "await" can be used to perform mutli-tasking +// Co-operative multi-tasking +// +// Two new keywords "async" and "await" can be used to perform multi-tasking // Note that this does not involve threads - it just allows transfer of control async function cooperativePrint(int $start, int $end) : Awaitable<void> { - for ($i = $start; $i <= $end; $i++) { + for ($i = $start; $i <= $end; $i++) { echo "$i "; // Give other tasks a chance to do something @@ -192,9 +193,9 @@ AwaitAllWaitHandle::fromArray([ // Attributes -// +// // Attributes are a form of metadata for functions. Hack provides some -// special built-in attributes that introduce useful behaviour. +// special built-in attributes that introduce useful behaviour. // The __Memoize special attribute causes the result of a function to be cached <<__Memoize>> @@ -247,7 +248,7 @@ class ConsistentBar extends ConsistentFoo class InvalidFooSubclass extends ConsistentFoo { // Not matching the parent constructor will cause a type checker error: - // + // // "This object is of type ConsistentBaz. It is incompatible with this object // of type ConsistentFoo because some of their methods are incompatible" // @@ -258,7 +259,7 @@ class InvalidFooSubclass extends ConsistentFoo // Using the __Override annotation on a non-overriden method will cause a // type checker error: - // + // // "InvalidFooSubclass::otherMethod() is marked as override; no non-private // parent definition found or overridden parent is defined in non-<?hh code" // diff --git a/haml.html.markdown b/haml.html.markdown index aed3dcae..847714e6 100644 --- a/haml.html.markdown +++ b/haml.html.markdown @@ -62,11 +62,11 @@ $ haml input_file.haml output_file.html %h1 Headline copy / To write multiline content, nest it instead -%p +%p This is a lot of content that we could probably split onto two separate lines. -/ +/ You can escape html by using the ampersand and equals sign ( &= ). This converts html-sensitive characters (&, /, :) into their html encoded equivalents. For example @@ -102,7 +102,7 @@ $ haml input_file.haml output_file.html / Inserting Ruby / ------------------------------------------- -/ +/ To output a Ruby value as the contents of a tag, use an equals sign followed by the Ruby code @@ -141,7 +141,7 @@ $ haml input_file.haml output_file.html / ------------------------------------------- / - Use the colon to define Haml filters, one example of a filter you can + Use the colon to define Haml filters, one example of a filter you can use is :javascript, which can be used for writing inline js :javascript diff --git a/hu-hu/ruby.html.markdown b/hu-hu/ruby.html.markdown new file mode 100644 index 00000000..169f2b8e --- /dev/null +++ b/hu-hu/ruby.html.markdown @@ -0,0 +1,555 @@ +--- +language: ruby +lang: hu-hu +filenev: learnruby.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"] + translators: + - ["Zsolt Prontvai", "https://github.com/prozsolt"] +--- + +```ruby +# Ez egy komment + +=begin +Ez egy többsoros komment +Senki sem használja +Neked sem kellene +=end + +# Először is: Minden objektum + +# A számok objektumok + +3.class #=> Fixnum + +3.to_s #=> "3" + + +# Néhány alapvető számtani művelet +1 + 1 #=> 2 +8 - 1 #=> 7 +10 * 2 #=> 20 +35 / 5 #=> 7 +2**5 #=> 32 + +# A számtani művelet csak szintaktikus cukor +# az objektumon történő függvény hívásra +1.+(3) #=> 4 +10.* 5 #=> 50 + +# A speciális értékek objektumok +nil # Nincs itt semmi látnivaló +true # igaz +false # hamis + +nil.class #=> NilClass +true.class #=> TrueClass +false.class #=> FalseClass + +# Egyenlőség +1 == 1 #=> true +2 == 1 #=> false + +# Egyenlőtlenség +1 != 1 #=> false +2 != 1 #=> true + +# A false-on kívül, nil az egyetlen hamis érték + +!nil #=> true +!false #=> true +!0 #=> false + +# Még több összehasonlítás +1 < 10 #=> true +1 > 10 #=> false +2 <= 2 #=> true +2 >= 2 #=> true + +# Logikai operátorok +true && false #=> false +true || false #=> true +!true #=> false + +# A logikai operátoroknak alternatív verziójuk is van sokkal kisebb +# precedenciával. Ezeket arra szánták, hogy több állítást összeláncoljanak +# amíg egyikük igaz vagy hamis értékkel nem tér vissza. + +# `csinalj_valami_mast` csak akkor fut le, ha `csinalj_valamit` igaz értékkel +# tért vissza. +csinalj_valamit() and csinalj_valami_mast() +# `log_error` csak akkor fut le, ha `csinalj_valamit` hamis értékkel +# tért vissza. +csinalj_valamit() or log_error() + + +# A sztringek objektumok + +'Én egy sztring vagyok'.class #=> String +"Én is egy sztring vagyok".class #=> String + +helykitolto = 'interpolációt használhatok' +"Sztring #{helykitolto}, ha dupla időzőjelben van a sztringem" +#=> "Sztring interpolációt használhatok, ha dupla időzőjelben van a sztringem" + +# A szimpla idézőjelet preferáljuk, ahol csak lehet, +# mert a dupla idézőjel extra számításokat végez. + +# Kombinálhatunk sztringeket, de nem számokkal +'hello ' + 'world' #=> "hello world" +'hello ' + 3 #=> TypeError: can't convert Fixnum into String +'hello ' + 3.to_s #=> "hello 3" + +# kiírás a kimenetre +puts "Írok" + +# Változók +x = 25 #=> 25 +x #=> 25 + +# Értékadás az adott értékkel tér vissza +# Ez azt jelenti, hogy használhatunk többszörös értékadást: + +x = y = 10 #=> 10 +x #=> 10 +y #=> 10 + +# Konvencióból, snake_case változó neveket használj +snake_case = true + +# Leíró változó neveket használj +ut_a_projekt_gyokerehez = '/jo/nev/' +ut = '/rossz/nev/' + +# A szimbólumok (objektumok) +# A szimbólumok megváltoztathatatlan, újra felhasználható konstans, +# mely belsőleg egész számként reprezentált. Sokszor sztring helyett használják, +# hogy effektíven közvetítsünk konkrét, értelmes értékeket + +:fuggoben.class #=> Symbol + +statusz = :fuggoben + +statusz == :fuggoben #=> true + +statusz == 'fuggoben' #=> false + +statusz == :jovahagyott #=> false + +# Tömbök + +# Ez egy tömb +tomb = [1, 2, 3, 4, 5] #=> [1, 2, 3, 4, 5] + +# A tömmbök különböző tipusú dolgokat tartalmazhat + +[1, 'hello', false] #=> [1, "hello", false] + +# Tömbök indexelhetőek +# Az elejéről +tomb[0] #=> 1 +tomb[12] #=> nil + +# Akárcsak a számtani műveletek [var] hozzáférés +# is csak szintaktikus cukor +# a [] függvény hívására az objektumon +tomb.[] 0 #=> 1 +tomb.[] 12 #=> nil + +# A végéről +tomb[-1] #=> 5 + +# Kezdőértékkel és hosszal +tomb[2, 3] #=> [3, 4, 5] + +# Tömb megfordítása +a=[1,2,3] +a.reverse! #=> [3,2,1] + +# Vagy tartománnyal +tomb[1..3] #=> [2, 3, 4] + +# Így adhatunk a tömbhöz +tomb << 6 #=> [1, 2, 3, 4, 5, 6] +# Vagy így +tomb.push(6) #=> [1, 2, 3, 4, 5, 6] + +# Ellenőrízük, hogy a tömb tartalmaz egy elemet +tomb.include?(1) #=> true + +# Hash-ek a ruby elsődleges szótárjai kulcs/érték párokkal +# Hash-eket kapcsos zárójellel jelöljük +hash = { 'szin' => 'zold', 'szam' => 5 } + +hash.keys #=> ['szin', 'szam'] + +# Hash-ekben könnyen kreshetünk a kulcs segítségével: +hash['szin'] #=> 'zold' +hash['szam'] #=> 5 + +# Nem létező kulcsra keresve nil-t kapunk: +hash['nincs itt semmi'] #=> nil + +# Ruby 1.9-től, egy külnleges szintaxist is használhatunk a szimbólumot +# használunk kulcsnak + +uj_hash = { defcon: 3, action: true } + +uj_hash.keys #=> [:defcon, :action] + +# Ellenőrizzük, hogy az adott kulcs és érték bene-e van a hash-ben +uj_hash.has_key?(:defcon) #=> true +uj_hash.has_value?(3) #=> true + +# Tip: A tömbök és hash-ek is felsorolhatóak +# Sok közös függvényük van, akár az each, map, count, és több + +# Kontroll Struktúrák + +if true + 'ha állítás' +elsif false + 'különben ha, opcionális' +else + 'különben, szintén opcionális' +end + +for szamlalo in 1..5 + puts "iteracio #{szamlalo}" +end +#=> iteracio 1 +#=> iteracio 2 +#=> iteracio 3 +#=> iteracio 4 +#=> iteracio 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 "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: +(1..5).each { |counter| puts "iteration #{counter}" } + +# The contents of data structures can also be iterated using each. +array.each do |element| + puts "#{element} is part of the array" +end +hash.each do |key, value| + puts "#{key} is #{value}" +end + +counter = 1 +while counter <= 5 do + puts "iteration #{counter}" + counter += 1 +end +#=> iteration 1 +#=> iteration 2 +#=> iteration 3 +#=> iteration 4 +#=> iteration 5 + +jegy = '4' + +case jegy +when '5' + puts 'Kitünő' +when '4' + puts 'Jó' +when '3' + puts 'Közepes' +when '2' + puts 'Elégsége' +when '1' + puts 'Elégtelen' +else + puts 'Alternatív értékelés, hm?' +end +#=> "Jó" + +# case-ek tartományokat is használhatnak +jegy = 82 +case jegy +when 90..100 + puts 'Hurrá!' +when 80...90 + puts 'Jó munka' +else + puts 'Megbuktál!' +end +#=> "Jó munka" + +# kivétel kezelés: +begin + # kód ami kivételt dobhat + raise NoMemoryError, 'Megtelt a memória' +rescue NoMemoryError => kivetel_valtozo + puts 'NoMemoryError-t dobott', kivetel_valtozo +rescue RuntimeError => mas_kivetel_valtozo + puts 'RuntimeError dobott most' +else + puts 'Ez akkor fut ha nem dob kivételt' +ensure + puts 'Ez a kód mindenképpen lefut' +end + +# Függvények + +def ketszeres(x) + x * 2 +end + +# Függvények (és egyébb blokkok) implicit viszatértnek az utolsó értékkel +ketszeres(2) #=> 4 + +# Zárójelezés opcionális, ha az eredmény félreérthetetlen +ketszeres 3 #=> 6 + +ketszeres ketszeres 3 #=> 12 + +def osszeg(x, y) + x + y +end + +# Függvény argumentumait vesszővel választjuk el. +osszeg 3, 4 #=> 7 + +osszeg osszeg(3, 4), 5 #=> 12 + +# yield +# Minden függvénynek van egy implicit, opcionális block paramétere +# 'yield' kulcsszóval hívhatjuk + +def korulvesz + puts '{' + yield + puts '}' +end + +korulvesz { puts 'hello world' } + +# { +# hello world +# } + + +# Fuggvénynek átadhatunk blokkot +# "&" jelöli az átadott blokk referenciáját +def vendegek(&block) + block.call 'valami_argumentum' +end + +# Argumentum lisát is átadhatunk, ami tömbé lesz konvertálva +# Erre való a splat operátor ("*") +def vendegek(*array) + array.each { |vendeg| puts vendeg } +end + +# Osztályt a class kulcsszóval definiálhatunk +class Ember + + # Az osztály változó. Az osztály minden példánnyával megvan osztva + @@faj = 'H. sapiens' + + # Alap inicializáló + def initialize(nev, kor = 0) + # Hozzárendeli az argumentumot a "nev" példány változóhoz + @nev = nev + # Ha nem adtunk meg kort akkor az alapértemezet értéket fogja használni + @kor = kor + end + + # Alap setter függvény + def nev=(nev) + @nev = nev + end + + # Alap getter függvény + def nev + @nev + end + + # A fönti funkcionalítást az attr_accessor függvénnyel is elérhetjük + attr_accessor :nev + + # Getter/setter függvények egyenként is kreálhatóak + attr_reader :nev + attr_writer :nev + + # Az osztály függvények "self"-et hasznalnak, hogy megkülönböztessék magukat a + # példány függvényektől + # Az osztályn hívhatóak, nem a példányon + def self.mond(uzenet) + puts uzenet + end + + def faj + @@faj + end +end + + +# Példányosítsuk az osztályt +jim = Ember.new('Jim Halpert') + +dwight = Ember.new('Dwight K. Schrute') + +# Hívjunk meg pár függvényt +jim.faj #=> "H. sapiens" +jim.nev #=> "Jim Halpert" +jim.nev = "Jim Halpert II" #=> "Jim Halpert II" +jim.nev #=> "Jim Halpert II" +dwight.faj #=> "H. sapiens" +dwight.nev #=> "Dwight K. Schrute" + +# Hívjuk meg az osztály függvényt +Ember.mond('Hi') #=> "Hi" + +# Változók szókjait az elnevezésük definiálja +# $ kezdetű változók globálisak +$var = "Én egy globális változó vagyok" +defined? $var #=> "global-variable" + +# Változók amik @-al kezdődnek példány szkópjuk van +@var = "Én egy példány változó vagyok" +defined? @var #=> "instance-variable" + +# Változók amik @@-al kezdődnek példány szkópjuk van +@@var = "Én egy osztály változó vagyok" +defined? @@var #=> "class variable" + +# Változók amik nagy betűvel kezdődnek a konstansok +Var = "Konstans vagyok" +defined? Var #=> "constant" + +# Az osztály is objetum. Tehát az osztálynak lehet példány változója +# Az osztályváltozón osztozik minden pédány és leszármazott + +# Ős osztály +class Ember + @@foo = 0 + + def self.foo + @@foo + end + + def self.foo=(ertek) + @@foo = ertek + end +end + +# Leszarmazott osztály +class Dolgozo < Ember +end + +Ember.foo # 0 +Dolgozo.foo # 0 + +Ember.foo = 2 # 2 +Dolgozo.foo # 2 + +# Az osztálynak példány változóját nem látja az osztály leszármazottja. + +class Ember + @bar = 0 + + def self.bar + @bar + end + + def self.bar=(ertek) + @bar = ertek + end +end + +class Doctor < Ember +end + +Ember.bar # 0 +Doctor.bar # nil + +module ModulePelda + def foo + 'foo' + end +end + +# Modulok include-olása a fügvényeiket az osztály példányaihoz köti. +# Modulok extend-elésa a fügvényeiket magához az osztályhoz köti. + +class Szemely + include ModulePelda +end + +class Konyv + extend ModulePelda +end + +Szemely.foo # => NoMethodError: undefined method `foo' for Szemely:Class +Szemely.new.foo # => 'foo' +Konyv.foo # => 'foo' +Konyv.new.foo # => NoMethodError: undefined method `foo' + +# Callback-ek végrehajtódnak amikor include-olunk és extend-elünk egy modult + +module ConcernPelda + 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 Valami + include ConcernPelda +end + +Valami.bar # => 'bar' +Valami.qux # => NoMethodError: undefined method `qux' +Valami.new.bar # => NoMethodError: undefined method `bar' +Valami.new.qux # => 'qux' +``` + +## Egyéb források + +- [Learn Ruby by Example with Challenges](http://www.learneroo.com/modules/61/nodes/338) +- [Official Documentation](http://www.ruby-doc.org/core-2.1.1/) +- [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/) - A régebbi [ingyenes változat](http://ruby-doc.com/docs/ProgrammingRuby/) elérhető online. +- [Ruby Style Guide](https://github.com/bbatsov/ruby-style-guide) diff --git a/id-id/json-id.html.markdown b/id-id/json-id.html.markdown new file mode 100644 index 00000000..52e61449 --- /dev/null +++ b/id-id/json-id.html.markdown @@ -0,0 +1,60 @@ +--- +language: json +filename: learnjson.json +contributors: + - ["Anna Harren", "https://github.com/iirelu"] + - ["Marco Scannadinari", "https://github.com/marcoms"] +translators + - ["Rizky Luthfianto", "https://github.com/rilut"] +--- + +JSON adalah format pertukaran data yang sangat simpel, kemungkinan besar, +ini adalah "Learn X in Y Minutes" yang paling singkat. + +Murninya, JSON tidak mempunyai fitur komentar, tapi kebanyakan parser akan +menerima komentar bergaya bahasa C (`//`, `/* */`). Namun, pada halaman ini, +hanya dicontohkan JSON yang 100% valid. + +```json +{ + "kunci": "nilai", + + "kunci": "harus selalu diapit tanda kutip", + "angka": 0, + "strings": "Halø, dunia. Semua karaktor unicode diperbolehkan, terumasuk \"escaping\".", + "punya tipe data boolean?": true, + "nilai kosong": null, + + "angka besar": 1.2e+100, + + "obyek": { + "komentar": "Most of your structure will come from objects.", + + "array": [0, 1, 2, 3, "Array bisa berisi apapun.", 5], + + "obyek lainnya": { + "komentar": "Obyek-obyek JSON dapat dibuat bersarang, sangat berguna." + } + }, + + "iseng-iseng": [ + { + "sumber potassium": ["pisang"] + }, + [ + [1, 0, 0, 0], + [0, 1, 0, 0], + [0, 0, 1, "neo"], + [0, 0, 0, 1] + ] + ], + + "gaya alternatif": { + "komentar": "lihat ini!" + , "posisi tanda koma": "tak masalah. selama sebelum nilai berikutnya, valid-valid saja" + , "komentar lainnya": "betapa asyiknya" + }, + + "singkat": "Dan Anda selesai! Sekarang Anda tahu apa saja yang disediakan oleh JSON." +} +``` diff --git a/id-id/xml-id.html.markdown b/id-id/xml-id.html.markdown new file mode 100644 index 00000000..c1e985aa --- /dev/null +++ b/id-id/xml-id.html.markdown @@ -0,0 +1,130 @@ +--- +language: xml +filename: learnxml.xml +contributors: + - ["João Farias", "https://github.com/JoaoGFarias"] +translators: + - ["Rizky Luthfianto", "https://github.com/rilut"] +lang: id-id +--- + +XML adalah bahasa markup yang dirancang untuk menyimpan dan mengirim data. + +Tidak seperti HTML, XML tidak menentukan bagaimana menampilkan atau format data, hanya membawanya. + +* Sintaks XML + +```xml +<!-- Komentar di XML seperti ini --> + +<?xml version="1.0" encoding="UTF-8"?> +<tokobuku> + <buku category="MEMASAK"> + <judul lang="en">Everyday Italian</judul> + <pengarang>Giada De Laurentiis</pengarang> + <tahun>2005</tahun> + <harga>30.00</harga> + </buku> + <buku category="ANAK"> + <judul lang="en">Harry Potter</judul> + <pengarang>J K. Rowling</pengarang> + <tahun>2005</tahun> + <harga>29.99</harga> + </buku> + <buku category="WEB"> + <judul lang="en">Learning XML</judul> + <pengarang>Erik T. Ray</pengarang> + <tahun>2003</tahun> + <harga>39.95</harga> + </buku> +</tokobuku> + +<!-- Di atas adalah contoh file XML biasa. + Dimulai dengan deklarasi, menginformasikan beberapa metadata (opsional). + + XML menggunakan struktur pohon. Di atas, simpul akar adalah 'tokobuku', + yang memiliki tiga node anak, para 'buku'. Node-node tersebut dapat memiliki + node-node anak, dan seterusnya ... + + Node dibuat menggunakan tag buka/tutup, dan node-node anak hanya + berada di antara tag buka dan tutup .--> + + +<!-- XML membawa dua jenis data: + 1 - Atribut -> Itu metadata tentang sebuah node. + Biasanya, parser XML menggunakan informasi ini untuk menyimpan data dengan + benar. Hal ini ditandai dengan muncul dengan format nama = "nilai" dalam pembukaan tag. + 2 - Elemen -> Itu data yang murni. + Itulah yang parser akan mengambil dari file XML. + Elemen muncul antara tag membuka dan menutup.--> + + +<!-- Di bawah ini, unsur dengan dua atribut--> +<file type="gif" id="4293">komputer.gif</file> + + +``` + +* Dokumen yang well-formated & Validasi + +Sebuah dokumen XML disebut well-formated jika sintaksisnya benar. +Namun, juga mungkin untuk mendefinisikan lebih banyak batasan dalam dokumen, +menggunakan definisi dokumen, seperti DTD dan XML Schema. + +Sebuah dokumen XML yang mengikuti definisi dokumen disebut valid, +jika sesuai dokumen itu. + +Dengan alat ini, Anda dapat memeriksa data XML di luar logika aplikasi. + +```xml + +<!-- Di bawah, Anda dapat melihat versi sederhana dari dokumen tokobuku, + dengan penambahan definisi DTD .--> + +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE catatan SYSTEM "tokobuku.dtd"> +<tokobuku> + <buku category="MEMASAK"> + <judul >Everyday Italian</judul> + <harga>30.00</harga> + </buku> +</tokobuku> + +<!-- This DTD could be something like:--> + +<!DOCTYPE catatan +[ +<!ELEMENT tokobuku (buku+)> +<!ELEMENT buku (judul,harga)> +<!ATTLIST buku category CDATA "Sastra"> +<!ELEMENT judul (#PCDATA)> +<!ELEMENT harga (#PCDATA)> +]> + + +<!-- DTD dimulai dengan deklarasi. + Berikut, node akar dinyatakan, membutuhkan 1 atau lebih anak node 'buku'. + Setiap 'buku' harus berisi tepat satu 'judul' dan 'harga' dan atribut + disebut 'kategori', dengan "Sastra" sebagai nilai default. + Node yang 'judul' dan 'harga' mengandung karakter data diurai .--> + +<!-- DTD dapat dideklarasikan di dalam file XML itu sendiri .--> + +<?xml version="1.0" encoding="UTF-8"?> + +<!DOCTYPE catatan +[ +<!ELEMENT tokobuku (buku+)> +<!ELEMENT buku (judul,harga)> +<!ATTLIST buku category CDATA "Sastra"> +<!ELEMENT judul (#PCDATA)> +<!ELEMENT harga (#PCDATA)> +]> + +<tokobuku> + <buku category="MEMASAK"> + <judul >Everyday Italian</judul> + <harga>30.00</harga> + </buku> +</tokobuku> +``` diff --git a/java.html.markdown b/java.html.markdown index 928eb39f..ba602d2e 100644 --- a/java.html.markdown +++ b/java.html.markdown @@ -5,6 +5,7 @@ contributors: - ["Jakukyo Friel", "http://weakish.github.io"] - ["Madison Dickson", "http://github.com/mix3d"] - ["Simon Morgan", "http://sjm.io/"] + - ["Zachary Ferguson", "http://github.com/zfergus2"] filename: LearnJava.java --- @@ -31,7 +32,7 @@ import java.security.*; // the file. public class LearnJava { - // A program must have a main method as an entry point. + // In order to run a java program, it must have a main method as an entry point. public static void main (String[] args) { // Use System.out.println() to print lines. @@ -45,12 +46,34 @@ public class LearnJava { System.out.print("Hello "); System.out.print("World"); + // Use System.out.printf() for easy formatted printing. + System.out.printf("pi = %.5f", Math.PI); // => pi = 3.14159 /////////////////////////////////////// - // Types & Variables + // Variables /////////////////////////////////////// + /* + * Variable Declaration + */ // Declare a variable using <type> <name> + int fooInt; + // Declare multiple variables of the same type <type> <name1>, <name2>, <name3> + int fooInt1, fooInt2, fooInt3; + + /* + * Variable Initialization + */ + + // Initialize a variable using <type> <name> = <val> + int fooInt = 1; + // Initialize multiple variables of same type with same value <type> <name1>, <name2>, <name3> = <val> + int fooInt1, fooInt2, fooInt3; + fooInt1 = fooInt2 = fooInt3 = 1; + + /* + * Variable types + */ // Byte - 8-bit signed two's complement integer // (-128 <= byte <= 127) byte fooByte = 100; @@ -73,7 +96,7 @@ public class LearnJava { // Float - Single-precision 32-bit IEEE 754 Floating Point float fooFloat = 234.5f; - // f is used to denote that this variable value is of type float; + // f or F is used to denote that this variable value is of type float; // otherwise it is treated as double. // Double - Double-precision 64-bit IEEE 754 Floating Point @@ -86,9 +109,12 @@ 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 to another object, final int HOURS_I_WORK_PER_WEEK = 9001; - + // but they can be initialized later. + final double E; + E = 2.71828; + // Strings String fooString = "My String Is Here!"; @@ -146,6 +172,7 @@ 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 (0.5 truncated down) + System.out.println("1/2 = " + (i1 / (i2*1.0))); // => 0.5 // Modulo System.out.println("11%3 = "+(11 % 3)); // => 2 @@ -158,12 +185,17 @@ public class LearnJava { System.out.println("2 <= 2? " + (2 <= 2)); // => true System.out.println("2 >= 2? " + (2 >= 2)); // => true + // Boolean operators + System.out.println("3 > 2 && 2 > 3? " + ((3 > 2) && (2 > 3))); // => false + System.out.println("3 > 2 || 2 > 3? " + ((3 > 2) || (2 > 3))); // => true + System.out.println("!(3 == 2)? " + (!(3 == 2))); // => true + // Bitwise operators! /* ~ Unary bitwise complement << Signed left shift - >> Signed right shift - >>> Unsigned right shift + >> Signed/Arithmetic right shift + >>> Unsigned/Logical right shift & Bitwise AND ^ Bitwise exclusive OR | Bitwise inclusive OR @@ -216,9 +248,8 @@ public class LearnJava { System.out.println("fooDoWhile Value: " + fooDoWhile); // For Loop - int fooFor; // for loop structure => for(<start_statement>; <conditional>; <step>) - for (fooFor = 0; fooFor < 10; fooFor++) { + for (int fooFor = 0; fooFor < 10; fooFor++) { System.out.println(fooFor); // Iterated 10 times, fooFor 0->9 } @@ -306,11 +337,39 @@ public class LearnJava { // toString returns this Object's string representation. System.out.println("trek info: " + trek.toString()); + // Double Brace Initialization + // The Java Language has no syntax for how to create static Collections + // in an easy way. Usually you end up in the following way: + + private static final Set<String> COUNTRIES = new HashSet<String>(); + static { + validCodes.add("DENMARK"); + validCodes.add("SWEDEN"); + validCodes.add("FINLAND"); + } + + // But there's a nifty way to achive the same thing in an + // easier way, by using something that is called Double Brace + // Initialization. + + private static final Set<String> COUNTRIES = HashSet<String>() {{ + add("DENMARK"); + add("SWEDEN"); + add("FINLAND"); + }} + + // The first brace is creating an new AnonymousInnerClass and the + // second one declares and instance initializer block. This block + // is called with the anonymous inner class is created. + // This does not only work for Collections, it works for all + // non-final classes. + } // End main method } // End LearnJava class -// You can include other, non-public outer-level classes in a .java file +// You can include other, non-public outer-level classes in a .java file, +// but it is good practice. Instead split classes into separate files. // Class Declaration Syntax: @@ -330,6 +389,8 @@ class Bicycle { // Constructors are a way of creating classes // This is a constructor public Bicycle() { + // You can also call another constructor: + // this(1, 50, 5, "Bontrager"); gear = 1; cadence = 50; speed = 5; @@ -345,13 +406,13 @@ class Bicycle { this.name = name; } - // Function Syntax: + // Method Syntax: // <public/private/protected> <return type> <function name>(<args>) // Java classes often implement getters and setters for their fields // Method declaration syntax: - // <scope> <return type> <method name>(<args>) + // <access modifier> <return type> <method name>(<args>) public int getCadence() { return cadence; } @@ -382,7 +443,7 @@ class Bicycle { } //Method to display the attribute values of this Object. - @Override + @Override // Inherited from the Object class. public String toString() { return "gear: " + gear + " cadence: " + cadence + " speed: " + speed + " name: " + name; @@ -417,26 +478,26 @@ class PennyFarthing extends Bicycle { // Example - Food: public interface Edible { - public void eat(); // Any class that implements this interface, must + public void eat(); // Any class that implements this interface, must // implement this method. } public interface Digestible { - public void digest(); + public void digest(); } // We can now create a class that implements both of these interfaces. public class Fruit implements Edible, Digestible { @Override - public void eat() { - // ... - } + public void eat() { + // ... + } @Override - public void digest() { - // ... - } + public void digest() { + // ... + } } // In Java, you can extend only one class, but you can implement many @@ -444,12 +505,119 @@ public class Fruit implements Edible, Digestible { public class ExampleClass extends ExampleClassParent implements InterfaceOne, InterfaceTwo { @Override - public void InterfaceOneMethod() { - } + public void InterfaceOneMethod() { + } + + @Override + public void InterfaceTwoMethod() { + } +} + +// Abstract Classes + +// Abstract Class declaration syntax +// <access-level> abstract <abstract-class-name> extends <super-abstract-classes> { +// // Constants and variables +// // Method declarations +// } + +// Marking a class as abstract means that it contains abstract methods 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. + +public abstract class Animal +{ + public abstract void makeSound(); + + // Method can have a body + public void eat() + { + System.out.println("I am an animal and I am Eating."); + // Note: We can access private variable here. + age = 30; + } + + // No need to initialize, however in an interface + // a variable is implicitly final and hence has + // to be initialized. + protected int age; + + public void printAge() + { + System.out.println(age); + } + + // Abstract classes can have main function. + public static void main(String[] args) + { + System.out.println("I am abstract"); + } +} + +class Dog extends Animal +{ + // Note still have to override the abstract methods in the + // abstract class. + @Override + public void makeSound() + { + System.out.println("Bark"); + // age = 30; ==> ERROR! age is private to Animal + } + // NOTE: You will get an error if you used the + // @Override annotation here, since java doesn't allow + // overriding of static methods. + // What is happening here is called METHOD HIDING. + // Check out this awesome SO post: http://stackoverflow.com/questions/16313649/ + public static void main(String[] args) + { + Dog pluto = new Dog(); + pluto.makeSound(); + pluto.eat(); + pluto.printAge(); + } +} + +// Final Classes + +// Final Class declaration syntax +// <access-level> final <final-class-name> { +// // Constants and variables +// // Method declarations +// } + +// Final classes are classes that cannot be inherited from and are therefore a +// final child. In a way, final classes are the opposite of abstract classes +// because abstract classes must be extended, but final classes cannot be +// extended. +public final class SaberToothedCat extends Animal +{ + // Note still have to override the abstract methods in the + // abstract class. @Override - public void InterfaceTwoMethod() { - } + public void makeSound() + { + System.out.println("Roar"); + } +} + +// Final Methods +public abstract class Mammal() +{ + // Final Method Syntax: + // <access modifier> final <return type> <function name>(<args>) + + // Final methods, like, final classes cannot be overridden by a child class, + // and are therefore the final implementation of the method. + public final boolean isWarmBlooded() + { + return true; + } } ``` diff --git a/javascript.html.markdown b/javascript.html.markdown index ba2e8ce4..6ea0b0bb 100644 --- a/javascript.html.markdown +++ b/javascript.html.markdown @@ -64,7 +64,7 @@ doStuff() // There are three special not-a-real-number values: Infinity; // result of e.g. 1/0 -Infinity; // result of e.g. -1/0 -NaN; // result of e.g. 0/0 +NaN; // result of e.g. 0/0, stands for 'Not a Number' // There's also a boolean type. true; @@ -189,7 +189,7 @@ myObj.myFourthKey; // = undefined /////////////////////////////////// // 3. Logic and Control Structures -// The syntax for this section is almost identical to Java's. +// The syntax for this section is almost identical to Java's. // The `if` structure works as you'd expect. var count = 1; @@ -218,6 +218,26 @@ for (var i = 0; i < 5; i++){ // will run 5 times } +//The For/In statement loops iterates over every property across the entire prototype chain +var description = ""; +var person = {fname:"Paul", lname:"Ken", age:18}; +for (var x in person){ + description += person[x] + " "; +} + +//If only want to consider properties attached to the object itself, +//and not its prototypes use hasOwnProperty() check +var description = ""; +var person = {fname:"Paul", lname:"Ken", age:18}; +for (var x in person){ + if (person.hasOwnProperty(x)){ + description += person[x] + " "; + } +} + +//for/in should not be used to iterate over an Array where the index order is important. +//There is no guarantee that for/in will return the indexes in any particular order + // && is logical and, || is logical or if (house.size == "big" && house.colour == "blue"){ house.contains = "bear"; @@ -231,8 +251,8 @@ var name = otherName || "default"; // The `switch` statement checks for equality with `===`. -// use 'break' after each case -// or the cases after the correct one will be executed too. +// use 'break' after each case +// or the cases after the correct one will be executed too. grade = 'B'; switch (grade) { case 'A': @@ -516,12 +536,12 @@ more about how to use JavaScript in web pages, start by learning about the [Document Object Model](https://developer.mozilla.org/en-US/docs/Using_the_W3C_DOM_Level_1_Core) -[Learn Javascript by Example and with Challenges](http://www.learneroo.com/modules/64/nodes/350) is a variant of this reference with built-in challenges. +[Learn Javascript by Example and with Challenges](http://www.learneroo.com/modules/64/nodes/350) is a variant of this reference with built-in challenges. [JavaScript Garden](http://bonsaiden.github.io/JavaScript-Garden/) is an in-depth guide of all the counter-intuitive parts of the language. -[JavaScript: The Definitive Guide](http://www.amazon.com/gp/product/0596805527/) is a classic guide / reference book. +[JavaScript: The Definitive Guide](http://www.amazon.com/gp/product/0596805527/) is a classic guide / reference book. In addition to direct contributors to this article, some content is adapted from Louie Dinh's Python tutorial on this site, and the [JS diff --git a/json.html.markdown b/json.html.markdown index f57b82b8..a1629137 100644 --- a/json.html.markdown +++ b/json.html.markdown @@ -10,13 +10,16 @@ As JSON is an extremely simple data-interchange format, this is most likely goin to be the simplest Learn X in Y Minutes ever. JSON in its purest form has no actual comments, but most parsers will accept -C-style (`//`, `/* */`) comments. For the purposes of this, however, everything is -going to be 100% valid JSON. Luckily, it kind of speaks for itself. +C-style (`//`, `/* */`) comments. Some parsers also tolerate a trailing comma +(i.e. a comma after the last element of an array or the after the last property of an object), +but they should be avoided for better compatibility. + +For the purposes of this, however, everything is going to be 100% valid JSON. Luckily, it kind of speaks for itself. ```json { "key": "value", - + "keys": "must always be enclosed in double quotes", "numbers": 0, "strings": "Hellø, wørld. All unicode is allowed, along with \"escaping\".", @@ -46,10 +49,10 @@ going to be 100% valid JSON. Luckily, it kind of speaks for itself. [0, 0, 0, 1] ] ], - + "alternative style": { "comment": "check this out!" - , "comma position": "doesn't matter - as long as its before the value, then its valid" + , "comma position": "doesn't matter - as long as it's before the value, then it's valid" , "another comment": "how nice" }, diff --git a/julia.html.markdown b/julia.html.markdown index 5ccd6484..c5089dc3 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -14,7 +14,7 @@ This is based on Julia 0.3. # Single line comments start with a hash (pound) symbol. #= Multiline comments can be written - by putting '#=' before the text and '=#' + by putting '#=' before the text and '=#' after the text. They can also be nested. =# @@ -81,10 +81,13 @@ 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' -# A string can be indexed like an array of characters +# 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). @@ -314,7 +317,7 @@ end # For loops iterate over iterables. -# Iterable types include Range, Array, Set, Dict, and String. +# Iterable types include Range, Array, Set, Dict, and AbstractString. for animal=["dog", "cat", "mouse"] println("$animal is a mammal") # You can use $ to interpolate variables or expression into strings @@ -537,6 +540,17 @@ subtypes(Number) # => 6-element Array{Any,1}: # 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. typeof(5) # => Int64 super(Int64) # => Signed @@ -546,17 +560,21 @@ super(Number) # => Any super(super(Signed)) # => Number super(Any) # => Any # All of these type, except for Int64, are abstract. +typeof("fire") # => ASCIIString +super(ASCIIString) # => DirectIndexString +super(DirectIndexString) # => AbstractString +# Likewise here with ASCIIString # <: is the subtyping operator type Lion <: Cat # Lion is a subtype of Cat mane_color - roar::String + 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::String) = 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 @@ -670,7 +688,7 @@ square_area(l) = l * l # square_area (generic function with 1 method) square_area(5) #25 # What happens when we feed square_area an integer? -code_native(square_area, (Int32,)) +code_native(square_area, (Int32,)) # .section __TEXT,__text,regular,pure_instructions # Filename: none # Source line: 1 # Prologue @@ -703,10 +721,10 @@ code_native(square_area, (Float64,)) # vmulsd XMM0, XMM0, XMM0 # Scalar double precision multiply (AVX) # pop RBP # ret - # + # # Note that julia will use floating point instructions if any of the # arguements are floats. -# Let's calculate the area of a circle +# 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 @@ -737,7 +755,7 @@ code_native(circle_area, (Float64,)) # vmulsd XMM0, XMM1, XMM0 # pop RBP # ret - # + # ``` ## Further Reading diff --git a/ko-kr/javascript-kr.html.markdown b/ko-kr/javascript-kr.html.markdown index 4ca3bb5c..9561e80c 100644 --- a/ko-kr/javascript-kr.html.markdown +++ b/ko-kr/javascript-kr.html.markdown @@ -387,9 +387,6 @@ myNumber === myNumberObj // = false if (0){ // 0은 거짓이라서 이 코드는 실행되지 않습니다. } -if (Number(0)){ - // Number(0)은 참이라서 이 코드는 *실행됩니다*. -} // 하지만 래퍼 객체와 일반 내장 함수는 프로토타입을 공유하기 때문에 // 가령 문자열에 실제로 기능을 추가할 수 있습니다. diff --git a/livescript.html.markdown b/livescript.html.markdown index e64f7719..9235f5ce 100644 --- a/livescript.html.markdown +++ b/livescript.html.markdown @@ -166,7 +166,7 @@ not false # => true ######################################################################## ## 3. Functions -######################################################################## +######################################################################## # Since LiveScript is functional, you'd expect functions to get a nice # treatment. In LiveScript it's even more apparent that functions are @@ -229,7 +229,7 @@ double-minus-one = (- 1) . (* 2) # Other than the usual `f . g` mathematical formulae, you get the `>>` # and `<<` operators, that describe how the flow of values through the -# functions. +# functions. double-minus-one = (* 2) >> (- 1) double-minus-one = (- 1) << (* 2) @@ -344,7 +344,7 @@ kitten.hug! # => "*Mei (a cat) is hugged*" ## Further reading There's just so much more to LiveScript, but this should be enough to -get you started writing little functional things in it. The +get you started writing little functional things in it. The [official website](http://livescript.net/) has a lot of information on the language, and a nice online compiler for you to try stuff out! diff --git a/make.html.markdown b/make.html.markdown index 75543dcd..563139d1 100644 --- a/make.html.markdown +++ b/make.html.markdown @@ -31,7 +31,7 @@ we are using GNU make which is the standard on Linux. file0.txt:
echo "foo" > file0.txt
# Even comments in these 'recipe' sections get passed to the shell.
- # Try `make file0.txt` or simply `make` - first rule is the default.
+ # Try `make file0.txt` or simply `make` - first rule is the default.
# This rule will only run if file0.txt is newer than file1.txt.
@@ -49,7 +49,7 @@ file2.txt file3.txt: file0.txt file1.txt touch file2.txt
touch file3.txt
-# Make will complain about multiple recipes for the same rule. Empty
+# Make will complain about multiple recipes for the same rule. Empty
# recipes don't count though and can be used to add new dependencies.
#-----------------------------------------------------------------------
@@ -115,7 +115,7 @@ small/%.png: %.svg %.png: %.ps
@echo this rule is not chosen if *.svg and *.ps are both present
-# make already has some pattern rules built-in. For instance, it knows
+# make already has some pattern rules built-in. For instance, it knows
# how to turn *.c files into *.o files.
# Older makefiles might use suffix rules instead of pattern rules
@@ -185,7 +185,7 @@ var := hello var2 ::= $(var) hello
#:= and ::= are equivalent.
-# These variables are evaluated procedurely (in the order that they
+# These variables are evaluated procedurely (in the order that they
# appear), thus breaking with the rest of the language !
# This doesn't work
diff --git a/markdown.html.markdown b/markdown.html.markdown index 6d19710f..2333110f 100644 --- a/markdown.html.markdown +++ b/markdown.html.markdown @@ -70,7 +70,7 @@ 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. --> -I end with two spaces (highlight me to see them). +I end with two spaces (highlight me to see them). There's a <br /> above me! @@ -97,7 +97,7 @@ or + Item + One more item -or +or - Item - Item @@ -129,7 +129,7 @@ render the numbers in order, but this may not be a good idea --> <!-- There are even task lists. This creates HTML checkboxes. --> Boxes below without the 'x' are unchecked HTML checkboxes. -- [ ] First task to complete. +- [ ] First task to complete. - [ ] Second task that needs done This checkbox below will be a checked HTML checkbox. - [x] This task has been completed @@ -160,7 +160,7 @@ def foobar end \`\`\` <!-- here too, no backslashes, just ``` --> -<-- The above text doesn't require indenting, plus Github will use syntax +<!-- The above text doesn't require indenting, plus Github will use syntax highlighting of the language you specify after the ``` --> <!-- Horizontal rule (<hr />) --> @@ -169,7 +169,7 @@ with or without spaces. --> *** --- -- - - +- - - **************** <!-- Links --> diff --git a/matlab.html.markdown b/matlab.html.markdown index 00f4c53a..0cbc6f57 100644 --- a/matlab.html.markdown +++ b/matlab.html.markdown @@ -3,10 +3,11 @@ language: Matlab contributors: - ["mendozao", "http://github.com/mendozao"] - ["jamesscottbrown", "http://jamesscottbrown.com"] + - ["Colton Kohnke", "http://github.com/voltnor"] --- -MATLAB stands for MATrix LABoratory. It is a powerful numerical computing language commonly used in engineering and mathematics. +MATLAB stands for MATrix LABoratory. It is a powerful numerical computing language commonly used in engineering and mathematics. If you have any feedback please feel free to reach me at [@the_ozzinator](https://twitter.com/the_ozzinator), or @@ -16,7 +17,7 @@ If you have any feedback please feel free to reach me at % Comments start with a percent sign. %{ -Multi line comments look +Multi line comments look something like this @@ -62,10 +63,10 @@ disp('text') % print "text" to the screen % Variables & Expressions myVariable = 4 % Notice Workspace pane shows newly created variable myVariable = 4; % Semi colon suppresses output to the Command Window -4 + 6 % ans = 10 -8 * myVariable % ans = 32 -2 ^ 3 % ans = 8 -a = 2; b = 3; +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 % Calling functions can be done in either of two ways: @@ -73,7 +74,7 @@ c = exp(a)*sin(pi/2) % c = 7.3891 load('myFile.mat', 'y') % arguments within parantheses, spererated by commas % Command syntax: load myFile.mat y % no parentheses, and spaces instead of commas -% Note the lack of quote marks in command form: inputs are always passed as +% Note the lack of quote marks in command form: inputs are always passed as % literal text - cannot pass variable values. Also, can't receive output: [V,D] = eig(A); % this has no equivalent in command form [~,D] = eig(A); % if you only want D and not V @@ -103,7 +104,7 @@ a(2) % ans = y % Cells -a = {'one', 'two', 'three'} +a = {'one', 'two', 'three'} a(1) % ans = 'one' - returns a cell char(a(1)) % ans = one - returns a string @@ -113,7 +114,7 @@ A.c = [1 2]; A.d.e = false; % Vectors -x = [4 32 53 7 1] +x = [4 32 53 7 1] x(2) % ans = 32, indices in Matlab start 1, not 0 x(2:3) % ans = 32 53 x(2:end) % ans = 32 53 7 1 @@ -123,7 +124,7 @@ x = [4; 32; 53; 7; 1] % Column vector x = [1:10] % x = 1 2 3 4 5 6 7 8 9 10 % Matrices -A = [1 2 3; 4 5 6; 7 8 9] +A = [1 2 3; 4 5 6; 7 8 9] % Rows are separated by a semicolon; elements are separated with space or comma % A = @@ -132,7 +133,7 @@ A = [1 2 3; 4 5 6; 7 8 9] % 7 8 9 A(2,3) % ans = 6, A(row, column) -A(6) % ans = 8 +A(6) % ans = 8 % (implicitly concatenates columns into vector, then indexes into that) @@ -171,7 +172,7 @@ A(1,:) % All columns in row 1 % 4 5 42 % 7 8 9 -% this is the same as +% this is the same as vertcat(A,A); @@ -183,7 +184,7 @@ vertcat(A,A); % 4 5 42 4 5 42 % 7 8 9 7 8 9 -% this is the same as +% this is the same as horzcat(A,A); @@ -201,21 +202,21 @@ 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 +ctranspose(A) % Hermitian transpose the matrix % (the transpose, followed by taking complex conjugate of each element) -% Element by Element Arithmetic vs. Matrix Arithmetic +% Element by Element Arithmetic vs. Matrix Arithmetic % On their own, the arithmetic operators act on whole matrices. When preceded % by a period, they act on each element instead. For example: A * B % Matrix multiplication A .* B % Multiple each element in A by its corresponding element in B -% There are several pairs of functions, where one acts on each element, and +% There are several pairs of functions, where one acts on each element, and % the other (whose name ends in m) acts on the whole matrix. -exp(A) % exponentiate each element +exp(A) % exponentiate each element expm(A) % calculate the matrix exponential sqrt(A) % take the square root of each element sqrtm(A) % find the matrix whose square is A @@ -233,7 +234,7 @@ axis([0 2*pi -1 1]) % x range from 0 to 2*pi, y range from -1 to 1 plot(x,y1,'-',x,y2,'--',x,y3,':') % For multiple functions on one plot legend('Line 1 label', 'Line 2 label') % Label curves with a legend -% Alternative method to plot multiple functions in one plot. +% Alternative method to plot multiple functions in one plot. % while 'hold' is on, commands add to existing graph rather than replacing it plot(x, y) hold on @@ -271,9 +272,9 @@ clf clear % clear current figure window, and reset most figure properties % Properties can be set and changed through a figure handle. % You can save a handle to a figure when you create it. -% The function gcf returns a handle to the current figure +% The function gcf returns a handle to the current figure h = plot(x, y); % you can save a handle to a figure when you create it -set(h, 'Color', 'r') +set(h, 'Color', 'r') % 'y' yellow; 'm' magenta, 'c' cyan, 'r' red, 'g' green, 'b' blue, 'w' white, 'k' black set(h, 'LineStyle', '--') % '--' is solid line, '---' dashed, ':' dotted, '-.' dash-dot, 'none' is no line @@ -298,8 +299,8 @@ cd /path/to/move/into % change directory % Variables can be saved to .mat files -save('myFileName.mat') % Save the variables in your Workspace -load('myFileName.mat') % Load saved variables into Workspace +save('myFileName.mat') % Save the variables in your Workspace +load('myFileName.mat') % Load saved variables into Workspace % M-file Scripts % A script file is an external file that contains a sequence of statements. @@ -312,11 +313,11 @@ load('myFileName.mat') % Load saved variables into Workspace % Also, they have their own workspace (ie. different variable scope). % Function name should match file name (so save this example as double_input.m). % 'help double_input.m' returns the comments under line beginning function -function output = double_input(x) +function output = double_input(x) %double_input(x) returns twice the value of x output = 2*x; end -double_input(6) % ans = 12 +double_input(6) % ans = 12 % You can also have subfunctions and nested functions. @@ -325,8 +326,8 @@ double_input(6) % ans = 12 % functions, and have access to both its workspace and their own workspace. % If you want to create a function without creating a new file you can use an -% anonymous function. Useful when quickly defining a function to pass to -% another function (eg. plot with fplot, evaluate an indefinite integral +% anonymous function. Useful when quickly defining a function to pass to +% another function (eg. plot with fplot, evaluate an indefinite integral % with quad, find roots with fzero, or find minimum with fminsearch). % Example that returns the square of it's input, assigned to to the handle sqr: sqr = @(x) x.^2; @@ -336,12 +337,12 @@ doc function_handle % find out more % User input a = input('Enter the value: ') -% Stops execution of file and gives control to the keyboard: user can examine +% Stops execution of file and gives control to the keyboard: user can examine % or change variables. Type 'return' to continue execution, or 'dbquit' to exit keyboard % Reading in data (also xlsread/importdata/imread for excel/CSV/image files) -fopen(filename) +fopen(filename) % Output disp(a) % Print out the value of variable a @@ -363,8 +364,8 @@ end for k = 1:5 disp(k) end - -k = 0; + +k = 0; while (k < 5) k = k + 1; end @@ -382,7 +383,7 @@ password = 'root'; driver = 'com.mysql.jdbc.Driver'; dburl = ['jdbc:mysql://localhost:8889/' dbname]; javaclasspath('mysql-connector-java-5.1.xx-bin.jar'); %xx depends on version, download available at http://dev.mysql.com/downloads/connector/j/ -conn = database(dbname, username, password, driver, dburl); +conn = database(dbname, username, password, driver, dburl); sql = ['SELECT * from table_name where id = 22'] % Example sql statement a = fetch(conn, sql) %a will contain your data @@ -394,7 +395,7 @@ tan(x) asin(x) acos(x) atan(x) -exp(x) +exp(x) sqrt(x) log(x) log10(x) @@ -426,7 +427,7 @@ pinv(A) % calculate the pseudo-inverse zeros(m,n) % m x n matrix of 0's ones(m,n) % m x n matrix of 1's diag(A) % Extracts the diagonal elements of a matrix A -diag(x) % Construct a matrix with diagonal elements listed in x, and zeroes elsewhere +diag(x) % Construct a matrix with diagonal elements listed in x, and zeroes elsewhere eye(m,n) % Identity matrix linspace(x1, x2, n) % Return n equally spaced points, with min x1 and max x2 inv(A) % Inverse of matrix A @@ -452,18 +453,71 @@ flipud(A) % Flip matrix up to down [U,S,V] = svd(X) % SVD: XV = US, U and V are unitary matrices, S has non-negative diagonal elements in decreasing order % Common vector functions -max % largest component -min % smallest component +max % largest component +min % smallest component length % length of a vector -sort % sort in ascending order -sum % sum of elements +sort % sort in ascending order +sum % sum of elements prod % product of elements mode % modal value -median % median value -mean % mean value +median % median value +mean % mean value std % standard deviation perms(x) % list all permutations of elements of x + +% Classes +% Matlab can support object-oriented programming. +% Classes must be put in a file of the class name with a .m extension. +% To begin, we create a simple class to store GPS waypoints. +% Begin WaypointClass.m +classdef WaypointClass % The class name. + properties % The properties of the class behave like Structures + latitude + longitude + end + methods + % This method that has the same name of the class is the constructor. + function obj = WaypointClass(lat, lon) + obj.latitude = lat; + obj.longitude = lon; + end + + % Other functions that use the Waypoint object + function r = multiplyLatBy(obj, n) + r = n*[obj.latitude]; + end + + % If we want to add two Waypoint objects together without calling + % a special function we can overload Matlab's arithmetic like so: + function r = plus(o1,o2) + r = WaypointClass([o1.latitude] +[o2.latitude], ... + [o1.longitude]+[o2.longitude]); + end + end +end +% End WaypointClass.m + +% We can create an object of the class using the constructor +a = WaypointClass(45.0, 45.0) + +% Class properties behave exactly like Matlab Structures. +a.latitude = 70.0 +a.longitude = 25.0 + +% Methods can be called in the same way as functions +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) + +% Matlab functions can be overloaded to handle objects. +% In the method above, we have overloaded how Matlab handles +% the addition of two Waypoint objects. +b = WaypointClass(15.0, 32.0) +c = a + b + ``` ## More on Matlab diff --git a/neat.html.markdown b/neat.html.markdown index e99d1e0e..f02461ee 100644 --- a/neat.html.markdown +++ b/neat.html.markdown @@ -47,18 +47,18 @@ void main(string[] args) { // There are no one-value tuples though. // So you can always use () in the mathematical sense. // (string) arg; <- is an error - + /* byte: 8 bit signed integer char: 8 bit UTF-8 byte component. short: 16 bit signed integer int: 32 bit signed integer long: 64 bit signed integer - + float: 32 bit floating point double: 64 bit floating point real: biggest native size floating point (80 bit on x86). - + bool: true or false */ int a = 5; @@ -139,14 +139,14 @@ void main(string[] args) { assert !(hewo is s); // same as assert (hewo !is s); - + // Allocate arrays using "new array length" int[] integers = new int[] 10; assert(integers.length == 10); assert(integers[0] == 0); // zero is default initializer integers = integers ~ 5; // This allocates a new array! assert(integers.length == 11); - + // This is an appender array. // Instead of (length, pointer), it tracks (capacity, length, pointer). // When you append to it, it will use the free capacity if it can. @@ -156,13 +156,13 @@ void main(string[] args) { appender ~= 2; appender ~= 3; appender.free(); // same as {mem.free(appender.ptr); appender = null;} - + // Scope variables are automatically freed at the end of the current scope. scope int[auto~] someOtherAppender; // This is the same as: int[auto~] someOtherAppender2; onExit { someOtherAppender2.free; } - + // You can do a C for loop too // - but why would you want to? for (int i = 0; i < 5; ++i) { } @@ -178,23 +178,23 @@ void main(string[] args) { assert(i == 5); break; // otherwise we'd go back up to do { } - + // This is a nested function. // Nested functions can access the surrounding function. string returnS() { return s; } writeln returnS(); - + // Take the address of a function using & // The type of a global function is ReturnType function(ParameterTypeTuple). void function() foop = &foo; - + // Similarly, the type of a nested function is ReturnType delegate(ParameterTypeTuple). string delegate() returnSp = &returnS; writeln returnSp(); // Class member functions and struct member functions also fit into delegate variables. // In general, delegates are functions that carry an additional context pointer. // ("fat pointers" in C) - + // Allocate a "snapshot" with "new delegate". // Snapshots are not closures! I used to call them closures too, // but then my Haskell-using friends yelled at me so I had to stop. @@ -232,8 +232,8 @@ void main(string[] args) { auto nestfun = λ() { } // There is NO semicolon needed here! // "}" can always substitute for "};". // This provides syntactic consistency with built-in statements. - - + + // This is a class. // Note: almost all elements of Neat can be used on the module level // or just as well inside a function. @@ -268,7 +268,7 @@ void main(string[] args) { E e = E:cd; // dynamic class cast! e.doE(); writeln "$e"; // all interfaces convert to Object implicitly. - + // Templates! // Templates are parameterized namespaces, taking a type as a parameter. template Templ(T) { diff --git a/nim.html.markdown b/nim.html.markdown index c9548a1c..79271732 100644 --- a/nim.html.markdown +++ b/nim.html.markdown @@ -235,7 +235,7 @@ proc ask(question: string): Answer = else: echo("Please be clear: yes or no") proc addSugar(amount: int = 2) = # Default amount is 2, returns nothing - assert(amount > 0 or amount < 9000, "Crazy Sugar") + assert(amount > 0 and amount < 9000, "Crazy Sugar") for a in 1..amount: echo(a, " sugar...") diff --git a/nl-nl/brainfuck-nl.html.markdown b/nl-nl/brainfuck-nl.html.markdown index cd12b1d0..6062b24c 100644 --- a/nl-nl/brainfuck-nl.html.markdown +++ b/nl-nl/brainfuck-nl.html.markdown @@ -15,7 +15,7 @@ minimalistische Turing-complete programmeertaal met maar acht commando's. ``` Elk karakter behalve "><+-.,[]" (en de quotes) wordt genegeerd. -Brainfuck wordt gerepresenteerd door een array met 30,000 cellen die initieel +Brainfuck wordt gerepresenteerd door een array met 30.000 cellen die initieel gevuld is met nullen en een pointer die wijst naar de huidige cel. Dit zijn de acht commando's: diff --git a/objective-c.html.markdown b/objective-c.html.markdown index 91b84b47..89901308 100644 --- a/objective-c.html.markdown +++ b/objective-c.html.markdown @@ -5,12 +5,13 @@ contributors: - ["Eugene Yagrushkin", "www.about.me/yagrushkin"] - ["Yannick Loriot", "https://github.com/YannickL"] - ["Levi Bostian", "https://github.com/levibostian"] + - ["Clayton Walker", "https://github.com/cwalk"] filename: LearnObjectiveC.m --- Objective-C is the main programming language used by Apple for the OS X and iOS operating systems and their respective frameworks, Cocoa and Cocoa Touch. -It is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. +It is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. ```objective_c // Single-line comments start with // @@ -40,15 +41,15 @@ int main (int argc, const char * argv[]) // Use NSLog to print lines to the console NSLog(@"Hello World!"); // Print the string "Hello World!" - + /////////////////////////////////////// // Types & Variables /////////////////////////////////////// - + // Primitive declarations int myPrimitive1 = 1; long myPrimitive2 = 234554664565; - + // Object declarations // Put the * in front of the variable names for strongly-typed object declarations MyClass *myObject1 = nil; // Strong typing @@ -56,15 +57,15 @@ int main (int argc, const char * argv[]) // %@ is an object // 'description' is a convention to display the value of the Objects NSLog(@"%@ and %@", myObject1, [myObject2 description]); // prints => "(null) and (null)" - + // String NSString *worldString = @"World"; - NSLog(@"Hello %@!", worldString); // prints => "Hello World!" + NSLog(@"Hello %@!", worldString); // prints => "Hello World!" // NSMutableString is a mutable version of the NSString object NSMutableString *mutableString = [NSMutableString stringWithString:@"Hello"]; [mutableString appendString:@" World!"]; NSLog(@"%@", mutableString); // prints => "Hello World!" - + // Character literals NSNumber *theLetterZNumber = @'Z'; char theLetterZ = [theLetterZNumber charValue]; // or 'Z' @@ -74,11 +75,11 @@ int main (int argc, const char * argv[]) NSNumber *fortyTwoNumber = @42; int fortyTwo = [fortyTwoNumber intValue]; // or 42 NSLog(@"%i", fortyTwo); - + NSNumber *fortyTwoUnsignedNumber = @42U; unsigned int fortyTwoUnsigned = [fortyTwoUnsignedNumber unsignedIntValue]; // or 42 NSLog(@"%u", fortyTwoUnsigned); - + NSNumber *fortyTwoShortNumber = [NSNumber numberWithShort:42]; short fortyTwoShort = [fortyTwoShortNumber shortValue]; // or 42 NSLog(@"%hi", fortyTwoShort); @@ -86,7 +87,7 @@ int main (int argc, const char * argv[]) NSNumber *fortyOneShortNumber = [NSNumber numberWithShort:41]; unsigned short fortyOneUnsigned = [fortyOneShortNumber unsignedShortValue]; // or 41 NSLog(@"%u", fortyOneUnsigned); - + NSNumber *fortyTwoLongNumber = @42L; long fortyTwoLong = [fortyTwoLongNumber longValue]; // or 42 NSLog(@"%li", fortyTwoLong); @@ -100,7 +101,7 @@ int main (int argc, const char * argv[]) float piFloat = [piFloatNumber floatValue]; // or 3.141592654f NSLog(@"%f", piFloat); // prints => 3.141592654 NSLog(@"%5.2f", piFloat); // prints => " 3.14" - + NSNumber *piDoubleNumber = @3.1415926535; double piDouble = [piDoubleNumber doubleValue]; // or 3.1415926535 NSLog(@"%f", piDouble); @@ -110,7 +111,7 @@ int main (int argc, const char * argv[]) NSDecimalNumber *oneDecNum = [NSDecimalNumber decimalNumberWithString:@"10.99"]; NSDecimalNumber *twoDecNum = [NSDecimalNumber decimalNumberWithString:@"5.002"]; // NSDecimalNumber isn't able to use standard +, -, *, / operators so it provides its own: - [oneDecNum decimalNumberByAdding:twoDecNum]; + [oneDecNum decimalNumberByAdding:twoDecNum]; [oneDecNum decimalNumberBySubtracting:twoDecNum]; [oneDecNum decimalNumberByMultiplyingBy:twoDecNum]; [oneDecNum decimalNumberByDividingBy:twoDecNum]; @@ -129,8 +130,8 @@ int main (int argc, const char * argv[]) NSArray *anArray = @[@1, @2, @3, @4]; NSNumber *thirdNumber = anArray[2]; NSLog(@"Third number = %@", thirdNumber); // prints => "Third number = 3" - // NSMutableArray is a mutable version of NSArray, allowing you to change - // the items in the array and to extend or shrink the array object. + // NSMutableArray is a mutable version of NSArray, allowing you to change + // the items in the array and to extend or shrink the array object. // Convenient, but not as efficient as NSArray. NSMutableArray *mutableArray = [NSMutableArray arrayWithCapacity:2]; [mutableArray addObject:@"Hello"]; @@ -160,7 +161,7 @@ int main (int argc, const char * argv[]) /////////////////////////////////////// // Operators /////////////////////////////////////// - + // The operators works like in the C language // For example: 2 + 5; // => 7 @@ -205,13 +206,13 @@ int main (int argc, const char * argv[]) NSLog(@"I print"); } break; } - + // While loops statements int ii = 0; while (ii < 4) { NSLog(@"%d,", ii++); // ii++ increments ii in-place, after using its value - } // prints => "0," + } // prints => "0," // "1," // "2," // "3," @@ -221,25 +222,25 @@ int main (int argc, const char * argv[]) for (jj=0; jj < 4; jj++) { NSLog(@"%d,", jj); - } // prints => "0," + } // prints => "0," // "1," // "2," // "3," - - // Foreach statements + + // Foreach statements NSArray *values = @[@0, @1, @2, @3]; for (NSNumber *value in values) { NSLog(@"%@,", value); - } // prints => "0," + } // prints => "0," // "1," // "2," // "3," // Object for loop statement. Can be used with any Objective-C object type - for (id item in values) { - NSLog(@"%@,", item); - } // prints => "0," + for (id item in values) { + NSLog(@"%@,", item); + } // prints => "0," // "1," // "2," // "3," @@ -250,7 +251,7 @@ int main (int argc, const char * argv[]) // Your statements here @throw [NSException exceptionWithName:@"FileNotFoundException" reason:@"File Not Found on System" userInfo:nil]; - } @catch (NSException * e) // use: @catch (id exceptionName) to catch all objects. + } @catch (NSException * e) // use: @catch (id exceptionName) to catch all objects. { NSLog(@"Exception: %@", e); } @finally @@ -259,17 +260,17 @@ int main (int argc, const char * argv[]) } // prints => "Exception: File Not Found on System" // "Finally. Time to clean up." - // NSError objects are useful for function arguments to populate on user mistakes. + // NSError objects are useful for function arguments to populate on user mistakes. NSError *error = [NSError errorWithDomain:@"Invalid email." code:4 userInfo:nil]; - + /////////////////////////////////////// // Objects /////////////////////////////////////// - + // Create an object instance by allocating memory and initializing it // An object is not fully functional until both steps have been completed MyClass *myObject = [[MyClass alloc] init]; - + // The Objective-C model of object-oriented programming is based on message // passing to object instances // In Objective-C one does not simply call a method; one sends a message @@ -280,7 +281,7 @@ int main (int argc, const char * argv[]) // End of @autoreleasepool } - + // End the program return 0; } @@ -301,9 +302,9 @@ int main (int argc, const char * argv[]) @interface MyClass : NSObject <MyProtocol> // NSObject is Objective-C's base object class. { // Instance variable declarations (can exist in either interface or implementation file) - int count; // Protected access by default. + int count; // Protected access by default. @private id data; // Private access (More convenient to declare in implementation file) - NSString *name; + NSString *name; } // Convenient notation for public access variables to auto generate a setter method // By default, setter method name is 'set' followed by @property variable name @@ -313,7 +314,7 @@ int main (int argc, const char * argv[]) @property (readonly) NSString *roString; // Use @synthesize in @implementation to create accessor // You can customize the getter and setter names instead of using default 'set' name: @property (getter=lengthGet, setter=lengthSet:) int length; - + // Methods +/- (return type)methodSignature:(Parameter Type *)parameterName; @@ -335,7 +336,7 @@ int main (int argc, const char * argv[]) // To access public variables from the implementation file, @property generates a setter method // automatically. Method name is 'set' followed by @property variable name: MyClass *myClass = [[MyClass alloc] init]; // create MyClass object instance -[myClass setCount:10]; +[myClass setCount:10]; NSLog(@"%d", [myClass count]); // prints => 10 // Or using the custom getter and setter method defined in @interface: [myClass lengthSet:32]; @@ -358,7 +359,7 @@ NSString *stringFromInstanceMethod = [myClass instanceMethodWithParameter:@"Hell // as a variable // SEL is the data type. @selector() returns a selector from method name provided // methodAParameterAsString:andAParameterAsNumber: is method name for method in MyClass -SEL selectorVar = @selector(methodAParameterAsString:andAParameterAsNumber:); +SEL selectorVar = @selector(methodAParameterAsString:andAParameterAsNumber:); if ([myClass respondsToSelector:selectorVar]) { // Checks if class contains method // Must put all method arguments into one object to send to performSelector function NSArray *arguments = [NSArray arrayWithObjects:@"Hello", @4, nil]; @@ -382,7 +383,7 @@ distance = 18; // References "long distance" from MyClass implementation @synthesize roString = _roString; // _roString available now in @implementation // Called before calling any class methods or instantiating any objects -+ (void)initialize ++ (void)initialize { if (self == [MyClass class]) { distance = 0; @@ -392,7 +393,7 @@ distance = 18; // References "long distance" from MyClass implementation // Counterpart to initialize method. Called when an object's reference count is zero - (void)dealloc { - [height release]; // If not using ARC, make sure to release class variable objects + [height release]; // If not using ARC, make sure to release class variable objects [super dealloc]; // and call parent class dealloc } @@ -407,7 +408,7 @@ distance = 18; // References "long distance" from MyClass implementation return self; } // Can create constructors that contain arguments: -- (id)initWithDistance:(int)defaultDistance +- (id)initWithDistance:(int)defaultDistance { distance = defaultDistance; return self; @@ -418,7 +419,7 @@ distance = 18; // References "long distance" from MyClass implementation return @"Some string"; } -+ (MyClass *)myClassFromHeight:(NSNumber *)defaultHeight ++ (MyClass *)myClassFromHeight:(NSNumber *)defaultHeight { height = defaultHeight; return [[self alloc] init]; @@ -434,7 +435,7 @@ distance = 18; // References "long distance" from MyClass implementation return @42; } -// Objective-C does not have private method declarations, but you can simulate them. +// Objective-C does not have private method declarations, but you can simulate them. // To simulate a private method, create the method in the @implementation but not in the @interface. - (NSNumber *)secretPrivateMethod { return @72; @@ -453,15 +454,15 @@ distance = 18; // References "long distance" from MyClass implementation // Categories /////////////////////////////////////// // A category is a group of methods designed to extend a class. They allow you to add new methods -// to an existing class for organizational purposes. This is not to be mistaken with subclasses. -// Subclasses are meant to CHANGE functionality of an object while categories instead ADD +// to an existing class for organizational purposes. This is not to be mistaken with subclasses. +// Subclasses are meant to CHANGE functionality of an object while categories instead ADD // functionality to an object. // Categories allow you to: // -- Add methods to an existing class for organizational purposes. // -- Allow you to extend Objective-C object classes (ex: NSString) to add your own methods. -// -- Add ability to create protected and private methods to classes. -// NOTE: Do not override methods of the base class in a category even though you have the ability -// to. Overriding methods may cause compiler errors later between different categories and it +// -- Add ability to create protected and private methods to classes. +// NOTE: Do not override methods of the base class in a category even though you have the ability +// to. Overriding methods may cause compiler errors later between different categories and it // ruins the purpose of categories to only ADD functionality. Subclass instead to override methods. // Here is a simple Car base class. @@ -493,8 +494,8 @@ distance = 18; // References "long distance" from MyClass implementation @end // Now, if we wanted to create a Truck object, we would instead create a subclass of Car as it would -// be changing the functionality of the Car to behave like a truck. But lets say we want to just add -// functionality to this existing Car. A good example would be to clean the car. So we would create +// be changing the functionality of the Car to behave like a truck. But lets say we want to just add +// functionality to this existing Car. A good example would be to clean the car. So we would create // a category to add these cleaning methods: // @interface filename: Car+Clean.h (BaseClassName+CategoryName.h) #import "Car.h" // Make sure to import base class to extend. @@ -518,7 +519,7 @@ distance = 18; // References "long distance" from MyClass implementation NSLog(@"Waxed."); } -@end +@end // Any Car object instance has the ability to use a category. All they need to do is import it: #import "Car+Clean.h" // Import as many different categories as you want to use. @@ -533,7 +534,7 @@ int main (int argc, const char * argv[]) { [mustang turnOn]; // Use methods from base Car class. [mustang washWindows]; // Use methods from Car's Clean category. } - return 0; + return 0; } // Objective-C does not have protected method declarations but you can simulate them. @@ -547,7 +548,7 @@ int main (int argc, const char * argv[]) { //To use protected methods, import the category, then implement the methods: #import "Car+Protected.h" // Remember, import in the @implementation file only. -@implementation Car +@implementation Car - (void)lockCar { NSLog(@"Car locked."); // Instances of Car can't use lockCar because it's not in the @interface. @@ -570,8 +571,8 @@ int main (int argc, const char * argv[]) { // You can override numOfSides variable or getNumOfSides method to edit them with an extension: // @implementation filename: Shape.m #import "Shape.h" -// Extensions live in the same file as the class @implementation. -@interface Shape () // () after base class name declares an extension. +// Extensions live in the same file as the class @implementation. +@interface Shape () // () after base class name declares an extension. @property (copy) NSNumber *numOfSides; // Make numOfSides copy instead of readonly. -(NSNumber)getNumOfSides; // Make getNumOfSides return a NSNumber instead of an int. @@ -579,7 +580,7 @@ int main (int argc, const char * argv[]) { @end // The main @implementation: -@implementation Shape +@implementation Shape @synthesize numOfSides = _numOfSides; @@ -603,14 +604,14 @@ int main (int argc, const char * argv[]) { @property BOOL engineOn; // Adopting class must @synthesize all defined @properties and - (void)turnOnEngine; // all defined methods. @end -// Below is an example class implementing the protocol. +// Below is an example class implementing the protocol. #import "CarUtilities.h" // Import the @protocol file. @interface Car : NSObject <CarUtilities> // Name of protocol goes inside <> // You don't need the @property or method names here for CarUtilities. Only @implementation does. - (void)turnOnEngineWithUtilities:(id <CarUtilities>)car; // You can use protocols as data too. @end -// The @implementation needs to implement the @properties and methods for the protocol. +// The @implementation needs to implement the @properties and methods for the protocol. @implementation Car : NSObject <CarUtilities> @synthesize engineOn = _engineOn; // Create a @synthesize statement for the engineOn @property. @@ -619,14 +620,14 @@ int main (int argc, const char * argv[]) { _engineOn = YES; // how you implement a method, it just requires that you do implement it. } // You may use a protocol as data as you know what methods and variables it has implemented. -- (void)turnOnEngineWithCarUtilities:(id <CarUtilities>)objectOfSomeKind { +- (void)turnOnEngineWithCarUtilities:(id <CarUtilities>)objectOfSomeKind { [objectOfSomeKind engineOn]; // You have access to object variables - [objectOfSomeKind turnOnEngine]; // and the methods inside. + [objectOfSomeKind turnOnEngine]; // and the methods inside. [objectOfSomeKind engineOn]; // May or may not be YES. Class implements it however it wants. } @end -// Instances of Car now have access to the protocol. +// Instances of Car now have access to the protocol. Car *carInstance = [[Car alloc] init]; [carInstance setEngineOn:NO]; [carInstance turnOnEngine]; @@ -655,10 +656,10 @@ if ([myClass conformsToProtocol:@protocol(CarUtilities)]) { // See the problem is that Sister relies on Brother, and Brother relies on Sister. #import "Sister.h" -@protocol Sister; // These lines stop the recursion, resolving the issue. +@protocol Sister; // These lines stop the recursion, resolving the issue. @protocol Brother <NSObject> - + - (void)beNiceToSister:(id <Sister>)sister; @end @@ -667,24 +668,24 @@ if ([myClass conformsToProtocol:@protocol(CarUtilities)]) { /////////////////////////////////////// // Blocks /////////////////////////////////////// -// Blocks are statements of code, just like a function, that are able to be used as data. +// 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. -void (^noParameterBlockVar)(void); // Example variable declaration of block with no arguments. +int (^addUp)(int n); // Declare a variable to store the 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. +// value passed to the block is the value of the variable when the block is created. int outsideVar = 17; // If we edit outsideVar after declaring addUp, outsideVar is STILL 17. __block long mutableVar = 3; // __block makes variables writable to blocks, unlike outsideVar. -addUp = ^(int n) { // Remove (int n) to have a block that doesn't take in any parameters. +addUp = ^(int n) { // Remove (int n) to have a block that doesn't take in any parameters. NSLog(@"You may have as many lines in a block as you would like."); NSSet *blockSet; // Also, you can declare local variables. mutableVar = 32; // Assigning new value to __block variable. - return n + outsideVar; // Return statements are optional. + return n + outsideVar; // Return statements are optional. } -int addUp = add(10 + 16); // Calls block code with arguments. +int addUp = add(10 + 16); // Calls block code with arguments. // Blocks are often used as arguments to functions to be called later, or for callbacks. -@implementation BlockExample : NSObject - +@implementation BlockExample : NSObject + - (void)runBlock:(void (^)(NSString))block { NSLog(@"Block argument returns nothing and takes in a NSString object."); block(@"Argument given to block to execute."); // Calling block. @@ -696,19 +697,19 @@ int addUp = add(10 + 16); // Calls block code with arguments. /////////////////////////////////////// // Memory Management /////////////////////////////////////// -/* +/* For each object used in an application, memory must be allocated for that object. When the application -is done using that object, memory must be deallocated to ensure application efficiency. -Objective-C does not use garbage collection and instead uses reference counting. As long as +is done using that object, memory must be deallocated to ensure application efficiency. +Objective-C does not use garbage collection and instead uses reference counting. As long as there is at least one reference to an object (also called "owning" an object), then the object -will be available to use (known as "ownership"). +will be available to use (known as "ownership"). When an instance owns an object, its reference counter is increments by one. When the object is released, the reference counter decrements by one. When reference count is zero, -the object is removed from memory. +the object is removed from memory. -With all object interactions, follow the pattern of: -(1) create the object, (2) use the object, (3) then free the object from memory. +With all object interactions, follow the pattern of: +(1) create the object, (2) use the object, (3) then free the object from memory. */ MyClass *classVar = [MyClass alloc]; // 'alloc' sets classVar's reference count to one. Returns pointer to object @@ -723,11 +724,11 @@ MyClass *newVar = [classVar retain]; // If classVar is released, object is still // Automatic Reference Counting (ARC) // Because memory management can be a pain, Xcode 4.2 and iOS 4 introduced Automatic Reference Counting (ARC). -// ARC is a compiler feature that inserts retain, release, and autorelease automatically for you, so when using ARC, +// ARC is a compiler feature that inserts retain, release, and autorelease automatically for you, so when using ARC, // you must not use retain, relase, or autorelease -MyClass *arcMyClass = [[MyClass alloc] init]; +MyClass *arcMyClass = [[MyClass alloc] init]; // ... code using arcMyClass -// Without ARC, you will need to call: [arcMyClass release] after you're done using arcMyClass. But with ARC, +// Without ARC, you will need to call: [arcMyClass release] after you're done using arcMyClass. But with ARC, // there is no need. It will insert this release statement for you // As for the 'assign' and 'retain' @property attributes, with ARC you use 'weak' and 'strong' @@ -747,4 +748,8 @@ __unsafe_unretained NSArray *unsafeArray; // Like __weak, but unsafeArray not se [Programming with Objective-C. Apple PDF book](https://developer.apple.com/library/ios/documentation/cocoa/conceptual/ProgrammingWithObjectiveC/ProgrammingWithObjectiveC.pdf) +[Programming with Objective-C for iOS](https://developer.apple.com/library/ios/documentation/General/Conceptual/DevPedia-CocoaCore/ObjectiveC.html) + +[Programming with Objective-C for Mac OSX](https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/Introduction/Introduction.html) + [iOS For High School Students: Getting Started](http://www.raywenderlich.com/5600/ios-for-high-school-students-getting-started) diff --git a/ocaml.html.markdown b/ocaml.html.markdown index b0027fea..02435e4d 100644 --- a/ocaml.html.markdown +++ b/ocaml.html.markdown @@ -34,13 +34,13 @@ For a source file you can use "ocamlc -i /path/to/file.ml" command to print all names and type signatures. ``` -$ cat sigtest.ml +$ cat sigtest.ml let inc x = x + 1 let add x y = x + y -let a = 1 +let a = 1 -$ ocamlc -i ./sigtest.ml +$ ocamlc -i ./sigtest.ml val inc : int -> int val add : int -> int -> int val a : int @@ -104,7 +104,7 @@ let fact_4 = factorial (5-1) ;; let sqr2 = sqr (-2) ;; (* Every function must have at least one argument. - Since some funcions naturally don't take any arguments, there's + Since some funcions naturally don't take any arguments, there's "unit" type for it that has the only one value written as "()" *) let print_hello () = print_endline "hello world" ;; @@ -301,7 +301,7 @@ let l = IntList (1, EmptyList) ;; (* Pattern matching is somewhat similar to switch statement in imperative languages, but offers a lot more expressive power. - Even though it may look complicated, it really boils down to matching + Even though it may look complicated, it really boils down to matching an argument against an exact value, a predicate, or a type constructor. The type system is what makes it so powerful. *) @@ -320,7 +320,7 @@ let is_one = function ;; (* Matching predicates, aka "guarded pattern matching". *) -let abs x = +let abs x = match x with | x when x < 0 -> -x | _ -> x diff --git a/perl.html.markdown b/perl.html.markdown index 4e172406..1b86f410 100644 --- a/perl.html.markdown +++ b/perl.html.markdown @@ -102,6 +102,8 @@ for (@elements) { print; } +# the Perlish post-condition way again +print for @elements; #### Regular expressions diff --git a/perl6.html.markdown b/perl6.html.markdown index 8d425f7d..0f015b45 100644 --- a/perl6.html.markdown +++ b/perl6.html.markdown @@ -7,11 +7,11 @@ contributors: - ["Nami-Doc", "http://github.com/Nami-Doc"] --- -Perl 6 is a highly capable, feature-rich programming language made for at +Perl 6 is a highly capable, feature-rich programming language made for at least the next hundred years. The primary Perl 6 compiler is called [Rakudo](http://rakudo.org), which runs on -the JVM and [the MoarVM](http://moarvm.com) and +the JVM and [the MoarVM](http://moarvm.com) and [prior to March 2015](http://pmthium.com/2015/02/suspending-rakudo-parrot/), [the Parrot VM](http://parrot.org/). @@ -75,7 +75,7 @@ say @array; #=> a 6 b # except they get "flattened" (hash context), removing duplicated keys. my %hash = 1 => 2, 3 => 4; -my %hash = autoquoted => "key", # keys get auto-quoted +my %hash = foo => "bar", # keys get auto-quoted "some other" => "value", # trailing commas are okay ; my %hash = <key1 value1 key2 value2>; # you can also create a hash @@ -96,7 +96,6 @@ say %hash<key2>; # If it's a string, you can actually use <> # (`{key1}` doesn't work, as Perl6 doesn't have barewords) ## * Subs (subroutines, or functions in most other languages). -# Stored in variable, they use `&`. sub say-hello { say "Hello, world" } sub say-hello-to(Str $name) { # You can provide the type of an argument @@ -107,8 +106,8 @@ sub say-hello-to(Str $name) { # You can provide the type of an argument ## It can also have optional arguments: sub with-optional($arg?) { # the "?" marks the argument optional - say "I might return `(Any)` if I don't have an argument passed, - or I'll return my argument"; + say "I might return `(Any)` (Perl's "null"-like value) if I don't have + an argument passed, or I'll return my argument"; $arg; } with-optional; # returns Any @@ -125,14 +124,14 @@ hello-to('You'); #=> Hello, You ! ## You can also, by using a syntax akin to the one of hashes (yay unified syntax !), ## pass *named* arguments to a `sub`. -# They're optional, and will default to "Any" (Perl's "null"-like value). +# They're optional, and will default to "Any". sub with-named($normal-arg, :$named) { say $normal-arg + $named; } with-named(1, named => 6); #=> 7 # There's one gotcha to be aware of, here: # If you quote your key, Perl 6 won't be able to see it at compile time, -# and you'll have a single Pair object as a positional paramater, +# and you'll have a single Pair object as a positional parameter, # which means this fails: with-named(1, 'named' => 6); @@ -143,7 +142,7 @@ sub with-mandatory-named(:$str!) { say "$str !"; } with-mandatory-named(str => "My String"); #=> My String ! -with-mandatory-named; # run time error: "Required named parameter not passed" +with-mandatory-named; # run time error: "Required named parameter not passed" with-mandatory-named(3); # run time error: "Too many positional parameters passed" ## If a sub takes a named boolean argument ... @@ -162,7 +161,7 @@ named-def; #=> 5 named-def(def => 15); #=> 15 # Since you can omit parenthesis to call a function with no arguments, -# you need "&" in the name to capture `say-hello`. +# you need "&" in the name to store `say-hello` in a variable. my &s = &say-hello; my &other-s = sub { say "Anonymous function !" } @@ -173,8 +172,8 @@ sub as-many($head, *@rest) { # `*@` (slurpy) will basically "take everything els say @rest.join(' / ') ~ " !"; } say as-many('Happy', 'Happy', 'Birthday'); #=> Happy / Birthday ! - # Note that the splat did not consume - # the parameter before. + # Note that the splat (the *) did not + # consume the parameter before. ## You can call a function with an array using the # "argument list flattening" operator `|` @@ -197,7 +196,7 @@ sub mutate($n is rw) { say "\$n is now $n !"; } -# If what you want is a copy instead, use `is copy`. +# If what you want a copy instead, use `is copy`. # A sub itself returns a container, which means it can be marked as rw: my $x = 42; @@ -234,7 +233,7 @@ say "Quite truthy" if True; # - Ternary conditional, "?? !!" (like `x ? y : z` in some other languages) my $a = $condition ?? $value-if-true !! $value-if-false; -# - `given`-`when` looks like other languages `switch`, but much more +# - `given`-`when` looks like other languages' `switch`, but much more # powerful thanks to smart matching and thanks to Perl 6's "topic variable", $_. # # This variable contains the default argument of a block, @@ -290,7 +289,7 @@ for @array -> $variable { # That means you can use `when` in a `for` just like you were in a `given`. for @array { say "I've got $_"; - + .say; # This is also allowed. # A dot call with no "topic" (receiver) is sent to `$_` by default $_.say; # the above and this are equivalent. @@ -378,9 +377,11 @@ say join(' ', @array[15..*]); #=> 15 16 17 18 19 # which is equivalent to: say join(' ', @array[-> $n { 15..$n }]); -# You can use that in most places you'd expect, even assigning to an array -my @numbers = ^20; -my @seq = 3, 9 ... * > 95; # 3 9 15 21 27 [...] 81 87 93 99 +# You can use that in most places you'd expect, even assigning to an array +my @numbers = ^20; + +# Here numbers increase by "6"; more on `...` operator later. +my @seq = 3, 9 ... * > 95; # 3 9 15 21 27 [...] 81 87 93 99; @numbers[5..*] = 3, 9 ... *; # even though the sequence is infinite, # only the 15 needed values will be calculated. say @numbers; #=> 0 1 2 3 4 3 9 15 21 [...] 81 87 @@ -525,7 +526,7 @@ map(sub ($a, $b) { $a + $b + 3 }, @array); # (here with `sub`) # The constructs for declaring types are "class", "role", # which you'll see later. -# For now, let us examinate "subset": +# For now, let us examine "subset": # a "subset" is a "sub-type" with additional checks. # For example: "a very big integer is an Int that's greater than 500" # You can specify the type you're subtyping (by default, Any), @@ -608,40 +609,39 @@ sub foo { bar(); # call `bar` in-place } sub bar { - say $*foo; # `$*a` will be looked in the call stack, and find `foo`'s, + say $*foo; # `$*foo` will be looked in the call stack, and find `foo`'s, # even though the blocks aren't nested (they're call-nested). #=> 1 } ### Object Model -## Perl 6 has a quite comprehensive object model # You declare a class with the keyword `class`, fields with `has`, -# methods with `method`. Every field to private, and is named `$!attr`, -# but you have `$.` to get a public (immutable) accessor along with it. -# (using `$.` is like using `$!` plus a `method` with the same name) +# methods with `method`. Every attribute that is private is named `$!attr`. +# Immutable public attributes are named `$.attr` +# (you can make them mutable with `is rw`) -# (Perl 6's object model ("SixModel") is very flexible, +# Perl 6's object model ("SixModel") is very flexible, # and allows you to dynamically add methods, change semantics, etc ... # (this will not be covered here, and you should refer to the Synopsis). class A { has $.field; # `$.field` is immutable. # From inside the class, use `$!field` to modify it. - has $.other-field is rw; # You can obviously mark a public field `rw`. + has $.other-field is rw; # You can mark a public attribute `rw`. has Int $!private-field = 10; method get-value { $.field + $!private-field; } - + method set-value($n) { # $.field = $n; # As stated before, you can't use the `$.` immutable version. $!field = $n; # This works, because `$!` is always mutable. - + $.other-field = 5; # This works, because `$.other-field` is `rw`. } - + method !private-method { say "This method is private to the class !"; } @@ -656,23 +656,22 @@ $a.other-field = 10; # This, however, works, because the public field # is mutable (`rw`). ## Perl 6 also has inheritance (along with multiple inheritance) -# (though considered a misfeature by many) class A { has $.val; - + submethod not-inherited { say "This method won't be available on B."; say "This is most useful for BUILD, which we'll see later"; } - + method bar { $.val * 5 } } class B is A { # inheritance uses `is` method foo { say $.val; } - + method bar { $.val * 10 } # this shadows A's `bar` } @@ -699,20 +698,20 @@ role PrintableVal { # you "import" a mixin (a "role") with "does": class Item does PrintableVal { has $.val; - + # When `does`-ed, a `role` literally "mixes in" the class: # the methods and fields are put together, which means a class can access # the private fields/methods of its roles (but not the inverse !): method access { say $!counter++; } - + # However, this: # method print {} # is ONLY valid when `print` isn't a `multi` with the same dispatch. # (this means a parent class can shadow a child class's `multi print() {}`, # but it's an error if a role does) - + # NOTE: You can use a role as a class (with `is ROLE`). In this case, methods # will be shadowed, since the compiler will consider `ROLE` to be a class. } @@ -751,7 +750,7 @@ fail "foo"; # We're not trying to access the value, so no problem. try { fail "foo"; CATCH { - default { say "It threw because we try to get the fail's value!" } + default { say "It threw because we tried to get the fail's value!" } } } @@ -763,7 +762,7 @@ try { ### Packages # Packages are a way to reuse code. Packages are like "namespaces", and any # element of the six model (`module`, `role`, `class`, `grammar`, `subset` -# and `enum`) are actually packages. (Packages are the lowest common denomitor) +# and `enum`) are actually packages. (Packages are the lowest common denominator) # Packages are important - especially as Perl is well-known for CPAN, # the Comprehensive Perl Archive Network. # You usually don't use packages directly: you use `class Package::Name::Here;`, @@ -773,7 +772,7 @@ module Hello::World { # Bracketed form # that can be redeclared as something else later. # ... declarations here ... } -module Parse::Text; # file-scoped form +unit module Parse::Text; # file-scoped form grammar Parse::Text::Grammar { # A grammar is a package, which you could `use` } @@ -797,10 +796,8 @@ my $actions = JSON::Tiny::Actions.new; # You've already seen `my` and `has`, we'll now explore the others. ## * `our` (happens at `INIT` time -- see "Phasers" below) -# Along with `my`, there are several others declarators you can use. -# The first one you'll want for the previous part is `our`. +# It's like `my`, but it also creates a package variable. # (All packagish things (`class`, `role`, etc) are `our` by default) -# it's like `my`, but it also creates a package variable: module Foo::Bar { our $n = 1; # note: you can't put a type constraint on an `our` variable our sub inc { @@ -812,7 +809,7 @@ module Foo::Bar { say "Can't access me from outside, I'm my !"; } } - + say ++$n; # lexically-scoped variables are still available } say $Foo::Bar::n; #=> 1 @@ -829,7 +826,7 @@ constant why-not = 5, 15 ... *; say why-not[^5]; #=> 5 15 25 35 45 ## * `state` (happens at run time, but only once) -# State variables are only executed one time +# State variables are only initialized one time # (they exist in other langages such as C as `static`) sub fixed-rand { state $val = rand; @@ -862,7 +859,7 @@ for ^5 -> $a { ## * Compile-time phasers BEGIN { say "[*] Runs at compile time, as soon as possible, only once" } -CHECK { say "[*] Runs at compile time, instead as late as possible, only once" } +CHECK { say "[*] Runs at compile time, as late as possible, only once" } ## * Run-time phasers INIT { say "[*] Runs at run time, as soon as possible, only once" } @@ -870,10 +867,13 @@ END { say "Runs at run time, as late as possible, only once" } ## * Block phasers ENTER { say "[*] Runs everytime you enter a block, repeats on loop blocks" } -LEAVE { say "Runs everytime you leave a block, even when an exception happened. Repeats on loop blocks." } +LEAVE { say "Runs everytime you leave a block, even when an exception + happened. Repeats on loop blocks." } -PRE { say "Asserts a precondition at every block entry, before ENTER (especially useful for loops)" } -POST { say "Asserts a postcondition at every block exit, after LEAVE (especially useful for loops)" } +PRE { say "Asserts a precondition at every block entry, + before ENTER (especially useful for loops)" } +POST { say "Asserts a postcondition at every block exit, + after LEAVE (especially useful for loops)" } ## * Block/exceptions phasers sub { @@ -891,12 +891,12 @@ for ^5 { ## * Role/class phasers COMPOSE { "When a role is composed into a class. /!\ NOT YET IMPLEMENTED" } -# They allow for cute trick or clever code ...: -say "This code took " ~ (time - CHECK time) ~ "s to run"; +# They allow for cute tricks or clever code ...: +say "This code took " ~ (time - CHECK time) ~ "s to compile"; # ... or clever organization: sub do-db-stuff { - ENTER $db.start-transaction; # New transaction everytime we enter the sub + $db.start-transaction; # start a new transaction KEEP $db.commit; # commit the transaction if all went well UNDO $db.rollback; # or rollback if all hell broke loose } @@ -1020,7 +1020,7 @@ sub circumfix:<[ ]>(Int $n) { $n ** $n } say [5]; #=> 3125 - # circumfix is around. Again, not whitespace. + # circumfix is around. Again, no whitespace. sub postcircumfix:<{ }>(Str $s, Int $idx) { # post-circumfix is @@ -1052,9 +1052,9 @@ postcircumfix:<{ }>(%h, $key, :delete); # (you can call operators like that) # Basically, they're operators that apply another operator. ## * Reduce meta-operator -# It's a prefix meta-operator that takes a binary functions and +# It's a prefix meta-operator that takes a binary function and # one or many lists. If it doesn't get passed any argument, -# it either return a "default value" for this operator +# it either returns a "default value" for this operator # (a meaningless value) or `Any` if there's none (examples below). # # Otherwise, it pops an element from the list(s) one at a time, and applies @@ -1075,8 +1075,8 @@ say [//] Nil, Any, False, 1, 5; #=> False # Default value examples: -say [*] (); #=> 1 -say [+] (); #=> 0 +say [*] (); #=> 1 +say [+] (); #=> 0 # meaningless values, since N*1=N and N+0=N. say [//]; #=> (Any) # There's no "default value" for `//`. @@ -1089,7 +1089,7 @@ say [[&add]] 1, 2, 3; #=> 6 # This one is an infix meta-operator than 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 runs the an array with all these new elements. +# until it runs out of elements. It returns an array with all of these new elements. (1, 2) Z (3, 4); # ((1, 3), (2, 4)), since by default, the function makes an array 1..3 Z+ 4..6; # (5, 7, 9), using the custom infix:<+> function @@ -1109,8 +1109,7 @@ say [[&add]] 1, 2, 3; #=> 6 # (and might include a closure), and on the right, a value or the predicate # that says when to stop (or Whatever for a lazy infinite list). my @list = 1, 2, 3 ... 10; # basic deducing -#my @list = 1, 3, 6 ... 10; # this throws you into an infinite loop, - # because Perl 6 can't figure out the end +#my @list = 1, 3, 6 ... 10; # this dies because Perl 6 can't figure out the end my @list = 1, 2, 3 ...^ 10; # as with ranges, you can exclude the last element # (the iteration when the predicate matches). my @list = 1, 3, 9 ... * > 30; # you can use a predicate @@ -1222,7 +1221,7 @@ so 'abbbbbbc' ~~ / a b ** 3..* c /; # `True` (infinite ranges are okay) # they use a more perl6-ish syntax: say 'fooa' ~~ / f <[ o a ]>+ /; #=> 'fooa' # You can use ranges: -say 'aeiou' ~~ / a <[ e..w ]> /; #=> 'aeiou' +say 'aeiou' ~~ / a <[ e..w ]> /; #=> 'ae' # Just like in normal regexes, if you want to use a special character, escape it # (the last one is escaping a space) say 'he-he !' ~~ / 'he-' <[ a..z \! \ ]> + /; #=> 'he-he !' @@ -1244,7 +1243,7 @@ so 'foo!' ~~ / <-[ a..z ] + [ f o ]> + /; # True (the + doesn't replace the left so 'abc' ~~ / a [ b ] c /; # `True`. The grouping does pretty much nothing so 'fooABCABCbar' ~~ / foo [ A B C ] + bar /; # The previous line returns `True`. -# We match the "abc" 1 or more time (the `+` was applied to the group). +# We match the "ABC" 1 or more time (the `+` was applied to the group). # But this does not go far enough, because we can't actually get back what # we matched. @@ -1287,10 +1286,12 @@ say $/[0][0].Str; #=> ~ # This stems from a very simple fact: `$/` does not contain strings, integers or arrays, # it only contains match objects. These contain the `.list`, `.hash` and `.Str` methods. -# (but you can also just use `match<key>` for hash access and `match[idx]` for array access) +# (but you can also just use `match<key>` for hash access +# and `match[idx]` for array access) say $/[0].list.perl; #=> (Match.new(...),).list - # We can see it's a list of Match objects. Those contain a bunch of infos: - # where the match started/ended, the "ast" (see actions later), etc. + # We can see it's a list of Match objects. Those contain + # a bunch of infos: where the match started/ended, + # the "ast" (see actions later), etc. # You'll see named capture below with grammars. ## Alternatives - the `or` of regexps @@ -1328,14 +1329,14 @@ so 'ayc' ~~ / a [ b | y ] c /; # `True`. Obviously enough ... ### Extra: the MAIN subroutime # The `MAIN` subroutine is called when you run a Perl 6 file directly. -# It's very powerful, because Perl 6 actually parses the argument +# It's very powerful, because Perl 6 actually parses the arguments # and pass them as such to the sub. It also handles named argument (`--foo`) # and will even go as far as to autogenerate a `--help` sub MAIN($name) { say "Hello, $name !" } # This produces: # $ perl6 cli.pl # Usage: -# t.pl <name> +# t.pl <name> # And since it's a regular Perl 6 sub, you can haz multi-dispatch: # (using a "Bool" for the named argument so that we can do `--replace` @@ -1346,9 +1347,9 @@ multi MAIN('add', $key, $value, Bool :$replace) { ... } multi MAIN('remove', $key) { ... } multi MAIN('import', File, Str :$as) { ... } # omitting parameter name # This produces: -# $ perl 6 cli.pl +# $ perl6 cli.pl # Usage: -# t.pl [--replace] add <key> <value> +# t.pl [--replace] add <key> <value> # t.pl remove <key> # t.pl [--as=<Str>] import (File) # As you can see, this is *very* powerful. @@ -1400,7 +1401,7 @@ for <well met young hero we shall meet later> { # (explained in details below). .say } - + if rand == 0 ff rand == 1 { # compare variables other than `$_` say "This ... probably will never run ..."; } @@ -1429,7 +1430,7 @@ for <well met young hero we shall meet later> { # A flip-flop can change state as many times as needed: for <test start print it stop not printing start print again stop not anymore> { .say if $_ eq 'start' ^ff^ $_ eq 'stop'; # exclude both "start" and "stop", - #=> "print this printing again" + #=> "print it print again" } # you might also use a Whatever Star, @@ -1461,4 +1462,3 @@ If you want to go further, you can: - Come along on `#perl6` at `irc.freenode.net`. The folks here are always helpful. - Check the [source of Perl 6's functions and classes](https://github.com/rakudo/rakudo/tree/nom/src/core). Rakudo is mainly written in Perl 6 (with a lot of NQP, "Not Quite Perl", a Perl 6 subset easier to implement and optimize). - Read [the language design documents](http://design.perl6.org). They explain P6 from an implementor point-of-view, but it's still very interesting. - diff --git a/php.html.markdown b/php.html.markdown index 52ea2a95..39ec5aef 100644 --- a/php.html.markdown +++ b/php.html.markdown @@ -215,6 +215,14 @@ assert($a !== $d); assert(1 === '1'); assert(1 !== '1'); +// spaceship operator since PHP 7 +$a = 100; +$b = 1000; + +echo $a <=> $a; // 0 since they are equal +echo $a <=> $b; // -1 since $a < $b +echo $b <=> $a; // 1 since $b > $a + // Variables can be converted between types, depending on their usage. $integer = 1; @@ -264,6 +272,18 @@ if (false) { // ternary operator print (false ? 'Does not get printed' : 'Does'); +// ternary shortcut operator since PHP 5.3 +// equivalent of "$x ? $x : 'Does'"" +$x = false; +print($x ?: 'Does'); + +// null coalesce operator since php 7 +$a = null; +$b = 'Does print'; +echo $a ?? 'a is not set'; // prints 'a is not set' +echo $b ?? 'b is not set'; // prints 'Does print' + + $x = 0; if ($x === '0') { print 'Does not print'; @@ -495,7 +515,9 @@ class MyClass } } +// Class constants can always be accessed statically echo MyClass::MY_CONST; // Outputs 'value'; + echo MyClass::$staticVar; // Outputs 'static'; MyClass::myStaticMethod(); // Outputs 'I am static'; @@ -671,8 +693,43 @@ use My\Namespace as SomeOtherNamespace; $cls = new SomeOtherNamespace\MyClass(); +/********************** +* Error Handling +* */ +// Simple error handling can be done with try catch block + +try { + // Do something +} catch ( Exception $e) { + // Handle exception +} + +// When using try catch blocks in a namespaced enviroment use the following + +try { + // Do something +} catch (\Exception $e) { + // Handle exception +} + +// Custom exceptions + +class MyException extends Exception {} + +try { + + $condition = true; + + if ($condition) { + throw new MyException('Something just happend'); + } + +} catch (MyException $e) { + // Handle my exception +} + ``` ## More Information diff --git a/pt-br/brainfuck-pt.html.markdown b/pt-br/brainfuck-pt.html.markdown index c7ce55ee..9e4b458d 100644 --- a/pt-br/brainfuck-pt.html.markdown +++ b/pt-br/brainfuck-pt.html.markdown @@ -5,10 +5,11 @@ contributors: - ["Mathias Bynens", "http://mathiasbynens.be/"] translators: - ["Suzane Sant Ana", "http://github.com/suuuzi"] + - ["Rodrigo Muniz", "http://github.com/muniz95"] lang: pt-br --- -Brainfuck (em letras minúsculas, eceto no início de frases) é uma linguagem de +Brainfuck (em letras minúsculas, exceto no início de frases) é uma linguagem de programação Turing-completa extremamente simples com apenas 8 comandos. ``` @@ -18,7 +19,7 @@ Brainfuck é representado por um vetor com 30 000 células inicializadas em zero e um ponteiro de dados que aponta para a célula atual. Existem 8 comandos: -+ : Incrementa o vaor da célula atual em 1. ++ : Incrementa o valor da célula atual em 1. - : Decrementa o valor da célula atual em 1. > : Move o ponteiro de dados para a célula seguinte (célula à direita). < : Move o ponteiro de dados para a célula anterior (célula à esquerda). diff --git a/pt-br/c++-pt.html.markdown b/pt-br/c++-pt.html.markdown index 61625ebe..61e267f5 100644 --- a/pt-br/c++-pt.html.markdown +++ b/pt-br/c++-pt.html.markdown @@ -304,7 +304,7 @@ void Dog::Dog() } // Objetos (como strings) devem ser passados por referência -// se você está modificando-os ou referência const se você não é. +// se você pretende modificá-los, ou com const caso contrário. void Dog::setName(const std::string& dogsName) { name = dogsName; diff --git a/pt-br/clojure-macros-pt.html.markdown b/pt-br/clojure-macros-pt.html.markdown new file mode 100644 index 00000000..dbc0c25c --- /dev/null +++ b/pt-br/clojure-macros-pt.html.markdown @@ -0,0 +1,154 @@ +--- +language: clojure +filename: learnclojure-pt.clj +contributors: + - ["Adam Bard", "http://adambard.com/"] +translators: + - ["Raphael Bezerra do Nascimento"] +lang: pt-br +--- + +Como todas as Lisps, a inerente [homoiconicity](https://en.wikipedia.org/wiki/Homoiconic) +do Clojure lhe dá acesso a toda a extensão da linguagem +para escrever rotinas de geração de código chamados "macros". Macros fornecem uma poderosa forma de adequar a linguagem +às suas necessidades. + +Pórem Tenha cuidado. É considerado má pratica escrever uma macro quando uma função vai fazer. Use uma macro apenas +quando você precisar do controle sobre quando ou se os argumentos para um formulário será avaliado. + +Você vai querer estar familiarizado com Clojure. Certifique-se de entender tudo em +[Clojure em Y Minutos](/docs/clojure/). + +```clojure +;; Defina uma macro utilizando defmacro. Sua macro deve ter como saida uma lista que possa +;; ser avaliada como codigo Clojure. +;; +;; Essa macro é a mesma coisa que se você escrever (reverse "Hello World") +(defmacro my-first-macro [] + (list reverse "Hello World")) + +;; Inspecione o resultado de uma macro utilizando macroexpand or macroexpand-1. +;; +;; Note que a chamada deve utilizar aspas simples. +(macroexpand '(my-first-macro)) +;; -> (#<core$reverse clojure.core$reverse@xxxxxxxx> "Hello World") + +;; Você pode avaliar o resultad de macroexpand diretamente: +(eval (macroexpand '(my-first-macro))) +; -> (\d \l \o \r \W \space \o \l \l \e \H) + +;; mas você deve usar esse mais suscinto, sintax como de função: +(my-first-macro) ; -> (\d \l \o \r \W \space \o \l \l \e \H) + +;; Você pode tornar as coisas mais faceis pra você, utilizando a sintaxe de citação mais suscinta +;; para criar listas nas suas macros: +(defmacro my-first-quoted-macro [] + '(reverse "Hello World")) + +(macroexpand '(my-first-quoted-macro)) +;; -> (reverse "Hello World") +;; Note que reverse não é mais uma função objeto, mas um simbolo. + +;; Macros podem ter argumentos. +(defmacro inc2 [arg] + (list + 2 arg)) + +(inc2 2) ; -> 4 + +;; Mas se você tentar fazer isso com uma lista entre aspas simples, você vai receber um erro, por que o +;; argumento irá entra aspas simples também. Para contornar isso, Clojure prover uma maneira de utilizar aspas simples +;; em macros: `. Dentro `, você pode usar ~ para chegar ao escopo externo. +(defmacro inc2-quoted [arg] + `(+ 2 ~arg)) + +(inc2-quoted 2) + +;; Você pode usar os argumentos de destruturação habituais. Expandir lista de variaveis usando ~@ +(defmacro unless [arg & body] + `(if (not ~arg) + (do ~@body))) ; Lembrar o do! + +(macroexpand '(unless true (reverse "Hello World"))) +;; -> +;; (if (clojure.core/not true) (do (reverse "Hello World"))) + +;; (unless) avalia e retorna seu corpo, se o primeiro argumento é falso. +;; caso contrario, retorna nil + +(unless true "Hello") ; -> nil +(unless false "Hello") ; -> "Hello" + +;; Usado sem cuidados, macros podem fazer muito mal por sobreporem suas variaveis +(defmacro define-x [] + '(do + (def x 2) + (list x))) + +(def x 4) +(define-x) ; -> (2) +(list x) ; -> (2) + +;;s Para evitar isso, use gensym para receber um identificador unico +(gensym 'x) ; -> x1281 (ou outra coisa) + +(defmacro define-x-safely [] + (let [sym (gensym 'x)] + `(do + (def ~sym 2) + (list ~sym)))) + +(def x 4) +(define-x-safely) ; -> (2) +(list x) ; -> (4) + +;; Você pode usar # dentro de ` para produzir uma gensym para cada simbolo automaticamente +(defmacro define-x-hygenically [] + `(do + (def x# 2) + (list x#))) + +(def x 4) +(define-x-hygenically) ; -> (2) +(list x) ; -> (4) + +;; É típico o uso de funções de auxilio com macros. Vamos criar um pouco +;; Vamos criar um pouco para nos ajudar a suportar uma sintaxe aritmética inline (estupida) +(declare inline-2-helper) +(defn clean-arg [arg] + (if (seq? arg) + (inline-2-helper arg) + arg)) + +(defn apply-arg + "Given args [x (+ y)], return (+ 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))) + +;; Podemos testar isso imediatamente, sem criar uma macro +(inline-2-helper '(a + (b - 2) - (c * 5))) ; -> (- (+ a (- b 2)) (* c 5)) + +; Entretanto, temos que tornar isso uma macro caso quisermos que isso seja rodado em tempo de compilação +(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 (Na verdade, 3N, desde que o numero ficou convertido em uma fração racional com / + +### Leitura adicional + +Escrevendo Macros de [Clojure para o Brave e True](http://www.braveclojure.com/) +[http://www.braveclojure.com/writing-macros/](http://www.braveclojure.com/writing-macros/) + +Documentos oficiais +[http://clojure.org/macros](http://clojure.org/macros) + +Quando utilizar macros? +[http://dunsmor.com/lisp/onlisp/onlisp_12.html](http://dunsmor.com/lisp/onlisp/onlisp_12.html) diff --git a/pt-br/hack-pt.html.markdown b/pt-br/hack-pt.html.markdown new file mode 100644 index 00000000..7c938149 --- /dev/null +++ b/pt-br/hack-pt.html.markdown @@ -0,0 +1,316 @@ +--- +language: Hack +contributors: + - ["Stephen Holdaway", "https://github.com/stecman"] + - ["David Lima", "https://github.com/davelima"] +translators: + - ["David Lima", "https://github.com/davelima"] +lang: pt-br +filename: learnhack-pt.hh +--- + +Hack é uma linguagem baseada no PHP e roda numa máquina virtual chamada HHVM. +Hack é quase completamente interoperável com códigos PHP existentes e adiciona +alguns recursos úteis de linguagens estaticamente tipadas. + +Somente recursos específicos da linguagem Hack serão abordados aqui. Detalhes +sobre a sintaxe do PHP estão disponíveis no +[artigo PHP](http://learnxinyminutes.com/docs/php/) neste site. + +```php +<?hh + +// A sintaxe do Hack é ativada apenas em arquivos que comecem com <?hh +// Marcadores <?hh não podem ser incluídos em páginas HTML, diferente de <?php. +// Usar o marcador "<?hh //strict" coloca o verificador de tipo no modo estrito. + + +// Indução de tipo de parâmetros escalares +function repeat(string $palavra, int $contagem) +{ + $palavra = trim($palavra); + return str_repeat($palavra . ' ', $contagem); +} + +// Indução de tipo para valores de retorno +function add(...$numeros) : int +{ + return array_sum($numeros); +} + +// Funções que não retornam nada são induzidas com "void" +function truncate(resource $recurso) : void +{ + // ... +} + +// Induções de tipo devem permitir nulos de forma explícita +function identity(?string $stringOuNulo) : ?string +{ + return $stringOuNulo; +} + +// Induções de tipo podem ser especificadas em propriedades de classes +class PropriedadesComTipos +{ + public ?string $nome; + + protected int $id; + + private float $pontuacao = 100.0; + + // O verificador de tipos do Hack reforça que propriedades tipadas devem + // ter um valor padrão ou devem ser definidos no construtor + public function __construct(int $id) + { + $this->id = $id; + } +} + + +// Funções anônimas (lambdas) +$multiplicador = 5; +array_map($y ==> $y * $multiplicador, [1, 2, 3]); + + +// Genéricos +class Caixa<T> +{ + protected T $dados; + + public function __construct(T $dados) { + $this->dados = $dados; + } + + public function pegaDados(): T { + return $this->dados; + } +} + +function abreCaixa(Caixa<int> $caixa) : int +{ + return $caixa->pegaDados(); +} + + +// Formas +// +// Hack adiciona o conceito de formas para definir arrays com uma estrutura +// e tipos de dados garantidos +type Point2D = shape('x' => int, 'y' => int); + +function distancia(Point2D $a, Point2D $b) : float +{ + return sqrt(pow($b['x'] - $a['x'], 2) + pow($b['y'] - $a['y'], 2)); +} + +distancia( + shape('x' => -1, 'y' => 5), + shape('x' => 2, 'y' => 50) +); + + +// Pseudônimos de tipos +// +// Hack adiciona vários recursos para criação de pseudônimos, tornando tipos complexos +// mais fáceis de entender +newtype VectorArray = array<int, Vector<int>>; + +// Um tuple contendo dois inteiros +newtype Point = (int, int); + +function adicionaPontos(Point $p1, Point $p2) : Point +{ + return tuple($p1[0] + $p2[0], $p1[1] + $p2[1]); +} + +adicionaPontos( + tuple(1, 2), + tuple(5, 6) +); + + +// enums em classes +enum TipoDePista : int +{ + Estrada = 0; + Rua = 1; + Alameda = 2; + Avenida = 3; +} + +function getTipoDePista() : TipoDePista +{ + return TipoDePista::Alameda; +} + + +// Especificação de argumentos no construtor (Argument Promotion) +// +// Para evitar que propriedades sejam definidas em mais de um lugar, e +// construtores que só definem propriedades, o Hack adiciona uma sintaxe para +// definir as propriedades e o construtor ao mesmo tempo. +class ArgumentPromotion +{ + public function __construct(public string $nome, + protected int $idade, + private bool $legal) {} +} + +class SemArgumentPromotion +{ + public string $nome; + + protected int $idade; + + private bool $legal; + + public function __construct(string $nome, int $idade, bool $legal) + { + $this->nome = $nome; + $this->idade = $idade; + $this->legal = $legal; + } +} + + +// Multi-tarefas cooperativo +// +// Duas novas palavras-chave ("async" e "await") podem ser usadas para +// trabalhar com multi-tarefas. +// Obs. Isto não envolve threads - apenas permite a transferência de controle +async function printCooperativo(int $inicio, int $fim) : Awaitable<void> +{ + for ($i = $inicio; $i <= $fim; $i++) { + echo "$i "; + + // Permite que outras tarefas façam algo + await RescheduleWaitHandle::create(RescheduleWaitHandle::QUEUE_DEFAULT, 0); + } +} + +// Imprime "1 4 7 2 5 8 3 6 9" +AwaitAllWaitHandle::fromArray([ + printCooperativo(1, 3), + printCooperativo(4, 6), + printCooperativo(7, 9) +])->getWaitHandle()->join(); + + +// Atributos +// +// Atributos são uma forma de definir metadados para funções. +// Hack tem alguns atributos especiais que possuem comportamentos úteis. + +// O atributo especial __Memoize faz com que o resultado da função fique em cache +<<__Memoize>> +function tarefaDemorada() : ?string +{ + return file_get_contents('http://exemplo.com'); +} + +// O corpo da função só é executado uma vez aqui: +tarefaDemorada(); +tarefaDemorada(); + + +// O atributo especial __ConsistentConstruct faz com que o Hack certifique-se +// de que a assinatura do construtor seja a mesma em todas as subclasses +<<__ConsistentConstruct>> +class FooConsistente +{ + public function __construct(int $x, float $y) + { + // ... + } + + public function algumMetodo() + { + // ... + } +} + +class BarConsistente extends FooConsistente +{ + public function __construct(int $x, float $y) + { + // O verificador de tipos do Hack exige que os construtores pai + // sejam chamados + parent::__construct($x, $y); + + // ... + } + + // A anotação __Override é uma anotação opcional que faz com que o + // verificador de tipos do Hack sobrescreva um método em uma classe pai + // ou um trait. Sem __Override, definir este método causará um erro, + // pois ele já foi definido na classe pai (FooConsistente): + <<__Override>> + public function algumMetodo() + { + // ... + } +} + +class SubclasseFooInvalida extends FooConsistente +{ + // Caso o construtor não combine com o construtor da classe pai, o + // verificador de tipos acusará um erro: + // + // "Este objeto é incompatível com o objeto FooConsistente porque algum(ns) + // dos seus métodos são incompatíveis" + // + public function __construct(float $x) + { + // ... + } + + // Usar a anotação __Override em um método que não existe na classe pai + // causará um erro do verificador de tipos: + // "SubclasseFooInvalida::outroMetodo() está marcada para sobrescrever; + // nenhuma definição não-privada foi encontrada ou a classe pai foi + // definida em código não-<?hh" + // + <<__Override>> + public function outroMetodo() + { + // ... + } +} + + +// Traits podem implementar interfaces (não suportado pelo PHP) +interface InterfaceGatinho +{ + public function brinca() : void; +} + +trait TraitGato implements InterfaceGatinho +{ + public function brinca() : void + { + // ... + } +} + +class Samuel +{ + use TraitGato; +} + + +$gato = new Samuel(); +$gato instanceof InterfaceGatinho === true; // True + +``` + +## Mais informações + +Visite a [documentação do Hack](http://docs.hhvm.com/manual/en/hacklangref.php) +para ver explicações detalhadas dos recursos que Hack adiciona ao PHP, ou o [site oficial do Hack](http://hanlang.org/) +para outras informações. + +Visite o [site oficial do HHVM](http://hhvm.com/) para aprender a instalar o HHVM. + +Visite [este artigo](http://docs.hhvm.com/manual/en/hack.unsupported.php) para ver +os recursos do PHP que o Hack não suporta e ver incompatibilidades entre Hack e PHP. diff --git a/pt-br/javascript-pt.html.markdown b/pt-br/javascript-pt.html.markdown new file mode 100644 index 00000000..406042fa --- /dev/null +++ b/pt-br/javascript-pt.html.markdown @@ -0,0 +1,547 @@ +--- +language: javascript +contributors: + - ["Adam Brenecki", "http://adam.brenecki.id.au"] + - ["Ariel Krakowski", "http://www.learneroo.com"] +translators: + - ["Willian Justen", "http://willianjusten.com.br"] +lang: pt-br +--- + +JavaScript foi criada por Brendan Eich, funcionário da Netscape na época, em 1995. Ela +foi originalmente criada para ser uma linguagem de script para websites, +complementando o uso de Java para aplicações web mais complexas, mas a sua +integração com páginas web e seu suporte nativo nos browsers fez com que +ela se tornasse mais comum que Java no frontend web. + +Javascript não é somente limitada a browsers web, existindo o Node.js, +que é um projeto que fornece um interpretador baseado no motor V8 do Google +Chrome e está se tornando cada vez mais famoso. + +Feedback são muito apreciados! Você me encontrar em +[@adambrenecki](https://twitter.com/adambrenecki), ou +[adam@brenecki.id.au](mailto:adam@brenecki.id.au). + +```js +// Comentários são como em C. Comentários de uma linha começam com duas barras, +/* e comentários de múltplas linhas começam com barra-asterisco + e fecham com asterisco-barra */ + +// comandos podem ser terminados com ; +facaAlgo(); + +// ... mas eles não precisam ser, o ponto-e-vírgula é automaticamente +// inserido quando há uma nova linha, exceto alguns casos. +facaAlgo() + +// Como esses casos podem causar resultados inesperados, vamos continuar +// a usar ponto-e-vírgula neste guia. + +/////////////////////////////////// +// 1. Números, Strings e Operadores + +// Javascript tem um tipo de número (que é o 64-bit IEEE 754 double). +// Doubles tem uma mantissa 52-bit, que é suficiente para guardar inteiros +// acima de 9✕10¹⁵ precisamente. +3; // = 3 +1.5; // = 1.5 + +// A aritmética básica funciona como seria de se esperar. +1 + 1; // = 2 +0.1 + 0.2; // = 0.30000000000000004 +8 - 1; // = 7 +10 * 2; // = 20 +35 / 5; // = 7 + +// Inclusive divisão desigual. +5 / 2; // = 2.5 + +// Operadores Bitwise também funcionam; quando você faz uma operação bitwise +// seu float é convertido para um int de até 32 bits. +1 << 2; // = 4 + +// A precedência é aplicada com parênteses. +(1 + 3) * 2; // = 8 + +// Existem três especiais valores não-é-número-real: +Infinity; // resultado de 1/0 +-Infinity; // resultado de -1/0 +NaN; // resultado de 0/0 + +// Existe também o tipo booleano. +true; +false; + +// Strings são criados com ' ou ". +'abc'; +"Olá, mundo"; + +// Negação usa o símbolo ! +!true; // = false +!false; // = true + +// Igualdade é o sinal de === +1 === 1; // = true +2 === 1; // = false + +// Desigualdade é o sinal de !== +1 !== 1; // = false +2 !== 1; // = true + +// Mais comparações +1 < 10; // = true +1 > 10; // = false +2 <= 2; // = true +2 >= 2; // = true + +// Strings são concatenadas com + +"Olá " + "mundo!"; // = "Olá mundo!" + +// e comparadas com < e > +"a" < "b"; // = true + +// A comparação de tipos não é feita com o uso de ==... +"5" == 5; // = true +null == undefined; // = true + +// ...a menos que use === +"5" === 5; // = false +null === undefined; // = false + +// ...isso pode resultar em comportamentos estranhos... +13 + !0; // 14 +"13" + !0; // '13true' + +// Você pode acessar caracteres de uma String usando o `charAt` +"Isto é uma String".charAt(0); // = 'I' + +// ...ou usar `substring` para pegar pedaços maiores. +"Olá mundo".substring(0, 3); // = "Olá" + +// `length` é uma propriedade, portanto não use (). +"Olá".length; // = 3 + +// Existe também o `null` e o `undefined`. +null; // usado para indicar um valor não considerado +undefined; // usado para indicar um valor que não é a atualmente definido + // (entretando `undefined` é considerado de fato um valor + +// false, null, undefined, NaN, 0 and "" são valores falsos; +// qualquer outro valor é verdadeiro +// Note que 0 é falso e "0" é verdadeiro, até mesmo 0 == "0". + +/////////////////////////////////// +// 2. Variáveis, Arrays e Objetos + +// Variáveis são declaradas com a palavra-chave `var`. O Javascript é +// dinâmicamente tipado, portanto você não precisa especificar o tipo. +// Atribuições usam um simples caracter de `=`. +var someVar = 5; + +// se você deixar de colocar a palavra-chave var, você não irá receber um erro... +someOtherVar = 10; + +// ...mas sua variável será criada no escopo global, não no escopo em que você +// definiu ela. + +// Variáveis declaradas sem receberem um valor são definidas como `undefined`. +var someThirdVar; // = undefined + +// Existe um shorthand para operações matemáticas em variáveis: +someVar += 5; // equivalente a someVar = someVar + 5; someVar é 10 agora +someVar *= 10; // agora someVar é 100 + +// e um para adição e subtração de 1 +someVar++; // agora someVar é 101 +someVar--; // volta para 100 + +// Arrays são listas ordenadas de valores, de qualquer tipo. +var myArray = ["Olá", 45, true]; + +// Seus membros podem ser acessados usando a sintaxe de colchetes. +// O indíce de um Array começa pelo 0. +myArray[1]; // = 45 + +// Arrays são mutáveis e de tamanho variável. +myArray.push("World"); +myArray.length; // = 4 + +// Adicionar/modificar em um índice específico +myArray[3] = "Hello"; + +// Objetos de Javascript são equivalentes aos dicionários ou maps de outras +// linguagens: uma coleção não ordenada de pares chave-valor. +var myObj = {chave1: "Olá", chave2: "Mundo"}; + +// Chaves são strings, mas as aspas não são necessárias se elas são +// identificadores válidos no Javascript. Valores podem ser de qualquer tipo. +var myObj = {myKey: "myValue", "my other key": 4}; + +// Atributos de objetos também podem ser acessados com a sintaxe de colchetes. +myObj["my other key"]; // = 4 + +// ... ou usando a sintaxe de ponto, passando a chave que é um identificador +// válido. +myObj.myKey; // = "myValue" + +// Objetos são mutáveis, valores podem ser modificados e novas chaves +// adicionadas. +myObj.myThirdKey = true; + +// Se você tentar acessar um valor que não foi determinado ainda, você irá +// receber `undefined`. +myObj.myFourthKey; // = undefined + +/////////////////////////////////// +// 3. Lógica e Estruturas de Controle + +// A sintaxe para essa seção é quase idêntica a maioria das linguagens. + +// The `if` structure works as you'd expect. +// A estrutura `if` funciona como deveria ser. +var count = 1 +if (count == 3){ + // executa se count é 3 +} else if (count == 4){ + // executa se count é 4 +} else { + // executa se count não é 3 nem 4 +} + +// Como se faz um `while`. +while (true){ + // Um loop infinito! +} + +// Os loops do-while são como os loops de while, exceto quando eles sempre +// executam pelo menos uma vez. +do { + input = getInput(); +} while (!isValid(input)) + +// The `for` loop is the same as C and Java: +// initialisation; continue condition; iteration. + +// O loop `for` é o mesmo de C e Java: +// inicialização, condição para continuar; iteração +for (var i = 0; i < 5; i++){ + // vai rodar cinco vezes +} + +// && é o `e` lógico , || é o `ou` lógico +if (house.size == "big" && house.colour == "blue"){ + house.contains = "bear"; +} +if (cor == "red" || cor == "blue"){ + // cor é vermelha OU azul +} + +// && e || "pequeno circuito", é útil para determinar valores padrões. +var name = otherName || "padrão"; + +// O `switch` checa pela igualdade com `===`. +// Use `break` após cada `case` +grade = 'B'; +switch (grade) { + case 'A': + console.log("Great job"); + break; + case 'B': + console.log("OK job"); + break; + case 'C': + console.log("You can do better"); + break; + default: + console.log("Oy vey"); + break; +} + + +/////////////////////////////////// +// 4. Funções, Escopos e Closures + +// Funções Javascript são declaradas com a palavra-chave `function`. +function myFunction(thing){ + return thing.toUpperCase(); +} +myFunction("foo"); // = "FOO" + +// Repare que o valor a ser retornado deve começar na mesma linha que +// a palavra-chave `return`, senão você sempre irá retornar `undefined` +// visto que o ponto-e-vírgula é inserido automáticamente nas quebras de +// linha. Preste atenção quando usar o estilo Allman. +function myFunction() +{ + return // <- ponto-e-vírgula adicionado automaticamente aqui + { + thisIsAn: 'object literal' + } +} +myFunction(); // = undefined + +// Funções Javascript são objetos de primeira classe, portanto elas podem +// ser atribuídas a nomes de variáveis e serem passadas para outras funções +// como argumentos - por exemplo, quando criamos um manipulador de eventos: +function myFunction(){ + // este código será chamado em 5 segundos +} +setTimeout(myFunction, 5000); +// Nota: `setTimeout` não é parte da linguagem Javascript, mas é provido pelos +// browsers e o Node.js. + +// Objetos de funções não precisam nem serem declarados com nome - você pode +// escrever a definição de uma função anônima diretamente nos argumentos de +// outra função. +setTimeout(function(){ + // este código será chamado em 5 segundos +}, 5000); + +// O Javascript tem escopo de função; as funções tem seu próprio escopo, +// mas outros blocos não. +if (true){ + var i = 5; +} +i; // = 5 - não `undefined` como você esperaria numa linguagem de blogo-escopo + +// Isso levou a padrão comum chamado de IIFE (Imediately Invoked Function +// Expression) ou (Expressão de Função Invocada Imediatamente), que previne +// que variáveis temporárias vazem para o escopo global. +(function(){ + var temporary = 5; + // Nós podemos acessar o escopo global definindo o "objeto global", que + // no browser vai ser sempre `window`. O objeto global pode ter um nome + // diferente para ambiente não-browser como o Node.js. + window.permanent = 10; +})(); +temporary; // levanta um erro de referência inexiste +permanent; // = 10 + +// Uma das principais características do Javascript é a closure. Que é +// uma função definida dentro de outra função, a função interna pode acessar +// todas as variáveis da função externa, mesmo depois da função de fora +// finalizar sua execução. +function sayHelloInFiveSeconds(name){ + var prompt = "Hello, " + name + "!"; + + // Funções internas são colocadas no escopo local por padrão, assim como + // se fossem declaradas com `var`. + function inner(){ + alert(prompt); + } + setTimeout(inner, 5000); + // `setTimeout` é assíncrono, portanto a função `sayHelloInFiveSeconds` + // vai sair imediatamente, e o `setTimeout` irá chamar a interna depois. + // Entretanto. como a interna é fechada dentro de "sayHelloInFiveSeconds", + // a interna permanece podendo acessar a variável `prompt` quando depois + // de chamada. +} +sayHelloInFiveSeconds("Adam"); // Vai abrir um popup com "Hello, Adam!" em 5s + +/////////////////////////////////// +// 5. Mais sobre Objetos; Construtores e Prototypes + +// Objetos podem conter funções. +var myObj = { + myFunc: function(){ + return "Olá mundo!"; + } +}; +myObj.myFunc(); // = "Olá mundo!" + +// Quando uma função ligada a um objeto é chamada, ela pode acessar o objeto +// da qual foi ligada usando a palavra-chave `this`. +myObj = { + myString: "Olá mundo!", + myFunc: function(){ + return this.myString; + } +}; +myObj.myFunc(); // = "Olá mundo!" + +// O `this` só funciona para dentro do escopo do objeto, portanto, se chamarmos +// um método do objeto fora de seu escopo, este não irá funcionar. +var myFunc = myObj.myFunc; +myFunc(); // = undefined + +// Inversamente, uma função pode ser atribuída a um objeto e ganhar a acesso +// através do `this`, até mesmo se ela não for chamada quando foi definida. +var myOtherFunc = function(){ + return this.myString.toUpperCase(); +} +myObj.myOtherFunc = myOtherFunc; +myObj.myOtherFunc(); // = "OLÁ MUNDO!" + +// Nós podemos também especificar um contexto onde a função irá executar, +// usando o `call` ou `apply`. + +var anotherFunc = function(s){ + return this.myString + s; +} +anotherFunc.call(myObj, " E Olá Lua!"); // = "Olá mundo! E Olá Lua!" + +// A função `apply` é praticamente a mesma coisa, mas ela pega um array +// como lista de argumentos. + +anotherFunc.apply(myObj, [" E Olá Sol!"]); // = "Olá mundo! E Olá Sol!" + +// Isto é util quando trabalhamos com uma função que aceita uma sequência de +// argumentos e você quer passar um array. + +Math.min(42, 6, 27); // = 6 +Math.min([42, 6, 27]); // = NaN (uh-oh!) +Math.min.apply(Math, [42, 6, 27]); // = 6 + +// Mas, o `call` e `apply` são somente temporários. Quando você quiser que +// permaneça sempre no escopo, use `bind`. + +var boundFunc = anotherFunc.bind(myObj); +boundFunc(" E Olá Saturno!"); // = "Olá mundo! E Olá Saturno!" + +// `bind` também pode ser usado para parcialmente aplicar (curry) uma função. + +var product = function(a, b){ return a * b; } +var doubler = product.bind(this, 2); +doubler(8); // = 16 + +// Quando você invoca uma função com a palavra-chave `new`, um novo objeto +// é criado, e fica disponível para a função pela palavra-chave `this`. +// Funções são desenhadas para serem invocadas como se invocam os construtores. + +var MyConstructor = function(){ + this.myNumber = 5; +} +myNewObj = new MyConstructor(); // = {myNumber: 5} +myNewObj.myNumber; // = 5 + +// Todo objeto JavaScript possui um `prototype`. Quando você tenta acessar +// uma propriedade de um objeto que não existe no objeto atual, o interpretador +// vai olhar imediatamente para o seu prototype. + +// Algumas implementações em JS deixam você acessar o objeto prototype com a +// propriedade mágica `__proto__`. Enquanto isso é util para explicar +// prototypes, não é parte de um padrão; nós vamos falar de algumas formas de +// usar prototypes depois. + +var myObj = { + myString: "Olá Mundo!" +}; +var myPrototype = { + meaningOfLife: 42, + myFunc: function(){ + return this.myString.toLowerCase() + } +}; + +myObj.__proto__ = myPrototype; +myObj.meaningOfLife; // = 42 + +// This works for functions, too. +// Isto funciona para funções, também. +myObj.myFunc(); // = "olá mundo!" + +// É claro, se sua propriedade não está em seu prototype, +// o prototype do prototype será procurado e por aí vai. +myPrototype.__proto__ = { + myBoolean: true +}; +myObj.myBoolean; // = true + +// Não há cópia envolvida aqui; cada objeto guarda uma referência do +// prototype. Isso significa que podemos alterar o prototype e nossas mudanças +// serão refletidas em qualquer lugar. +myPrototype.meaningOfLife = 43; +myObj.meaningOfLife; // = 43 + + +// Nós mencionamos que o `__proto__` não é uma forma padrão, e não há uma +// forma padrão de mudar o prototype de um objeto já existente. Entretanto, +// existem duas formas de se criar um objeto com um dado prototype. + +// A primeira forma é `Object.create`, que é uma adição recente do JS, +// e ainda não está disponível em todas as implementações. +var myObj = Object.create(myPrototype); +myObj.meaningOfLife; // = 43 + +// A segunda forma, que funciona em qualquer lugar, é feita com construtores. +// Construtores tem uma propriedade chamada prototype. Este *não* é o prototype +// do construtor em si; ao invés disso, ele é o prototype dos novos objetos +// criados pelo construtor. +MyConstructor.prototype = { + myNumber: 5, + getMyNumber: function(){ + return this.myNumber; + } +}; +var myNewObj2 = new MyConstructor(); +myNewObj2.getMyNumber(); // = 5 +myNewObj2.myNumber = 6 +myNewObj2.getMyNumber(); // = 6 + +// Tipos originais da linguagem como strings e números também possuem +// construtores equivalentes. +var myNumber = 12; +var myNumberObj = new Number(12); +myNumber == myNumberObj; // = true + +// Exceto, que eles não são totalmente equivalentes. +typeof myNumber; // = 'number' +typeof myNumberObj; // = 'object' +myNumber === myNumberObj; // = false +if (0){ + // O código não vai executar, porque 0 é um valor falso. +} + +// Entretanto, esses objetos encapsulados e as funções originais compartilham +// um mesmo prototype, portanto você pode adicionar funcionalidades a uma string, +// por exemplo. +String.prototype.firstCharacter = function(){ + return this.charAt(0); +} +"abc".firstCharacter(); // = "a" + +// Esse fato é usado para criar os chamados `polyfills`, que implementam +// uma nova característica do Javascript em uma versão mais velha, para que +// assim funcionem em ambientes mais velhos como browsers ultrapassados. + +// Havíamos mencionado que `Object.create` não estava ainda disponível em +// todos as implementações, mas nós podemos usá-lo com esse polyfill: +if (Object.create === undefined){ // don't overwrite it if it exists + Object.create = function(proto){ + // faz um construtor temporário com o prototype certo + var Constructor = function(){}; + Constructor.prototype = proto; + // então utiliza o new para criar um objeto prototype apropriado + return new Constructor(); + } +} +``` + +## Leitura Adicional + +O [Mozilla Developer +Network](https://developer.mozilla.org/en-US/docs/Web/JavaScript) dispõe de uma +excelente documentação sobre Javascript e seu uso nos browsers. E mais, +é uma wiki, portanto conforme você vai aprendendo, mais você pode ir ajudando +os outros compartilhando do seu conhecimento. + +[Uma re-introdução do JavaScript pela MDN] +(https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript) +cobre muito dos conceitos abordados aqui em mais detalhes. Este guia fala +somente sobre a linguagem JavaScript em si; se você quiser aprender mais +sobre e como usar o JavaScript em páginas na web, comece aprendendo sobre +[Document Object +Model](https://developer.mozilla.org/en-US/docs/Using_the_W3C_DOM_Level_1_Core) + +[Aprenda Javascript por Exemplos e com Desafios](http://www.learneroo.com/modules/64/nodes/350) é uma +variação desse guia com desafios. + +[JavaScript Garden](http://bonsaiden.github.io/JavaScript-Garden/) é um guia +profundo de todas as partes do JavaScript. + +[JavaScript: The Definitive Guide](http://www.amazon.com/gp/product/0596805527/) é o guia clássico +/ livro de referência. + +Parte desse artigo foi adaptado do tutorial de Python do Louie Dinh que está +nesse site e do [Tutorial de JS](https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript) +da Mozilla Developer Network. diff --git a/pt-br/swift-pt.html.markdown b/pt-br/swift-pt.html.markdown index 72a57e4a..e840b8cf 100644 --- a/pt-br/swift-pt.html.markdown +++ b/pt-br/swift-pt.html.markdown @@ -221,7 +221,7 @@ println("Gas price: \(price)") // Número variável de argumentos func setup(numbers: Int...) { - // its an array + // é um array let number = numbers[0] let argCount = numbers.count } diff --git a/pt-pt/scala-pt.html.markdown b/pt-pt/scala-pt.html.markdown new file mode 100644 index 00000000..a4c1c02b --- /dev/null +++ b/pt-pt/scala-pt.html.markdown @@ -0,0 +1,651 @@ +--- +language: Scala +filename: learnscala-pt.scala +contributors: + - ["George Petrov", "http://github.com/petrovg"] + - ["Dominic Bou-Samra", "http://dbousamra.github.com"] + - ["Geoff Liu", "http://geoffliu.me"] + - ["Ha-Duong Nguyen", "http://reference-error.org"] +translators: + - ["João Costa", "http://joaocosta.eu"] +lang: pt-pt +--- + +Scala - a linguagem escalável + +```scala + +/* + Prepare tudo: + + 1) Faça Download do Scala - http://www.scala-lang.org/downloads + 2) Faça unzip/untar para onde preferir e coloque o subdirectório `bin` na + variável de ambiente `PATH` + 3) Inicie a REPL de Scala correndo o comando `scala`. Deve aparecer: + + scala> + + Isto é chamado de REPL (Read-Eval-Print Loop / Lê-Avalia-Imprime Repete). + Pode escrever qualquer expressão de Scala e o resultado será imprimido. + Vamos mostrar ficheiros de Scala mais à frente neste tutorial mas, para já, + vamos começar com os básicos. + +*/ + + +///////////////////////////////////////////////// +// 1. Basicos +///////////////////////////////////////////////// + +// Uma linha de comentários é marcada com duas barras + +/* + Comentários de multiplas linhas, como se pode ver neste exemplo, são assim. +*/ + +// Imprimir, forçando uma nova linha no final +println("Hello world!") +println(10) + +// Imprimir, sem forçar uma nova linha no final +print("Hello world") + +// Valores são declarados com var ou val. +// As declarações val são imutáveis, enquanto que vars são mutáveis. +// A immutabilidade é uma propriedade geralmente vantajosa. +val x = 10 // x é agora 10 +x = 20 // erro: reatribuição de um val +var y = 10 +y = 20 // y é agora 12 + +/* + Scala é uma linguagem estaticamente tipada, no entanto, nas declarações acima + não especificamos um tipo. Isto é devido a uma funcionalidade chamada + inferência de tipos. Na maior parte dos casos, o compilador de scala consegue + inferir qual o tipo de uma variável, pelo que não o temos de o declarar sempre. + Podemos declarar o tipo de uma variável da seguinte forma: +*/ +val z: Int = 10 +val a: Double = 1.0 + +// Note a conversão automática de Int para Double: o resultado é 10.0, não 10 +val b: Double = 10 + +// Valores booleanos +true +false + +// Operações booleanas +!true // false +!false // true +true == false // false +10 > 5 // true + +// A matemática funciona da maneira habitual +1 + 1 // 2 +2 - 1 // 1 +5 * 3 // 15 +6 / 2 // 3 +6 / 4 // 1 +6.0 / 4 // 1.5 + + +// Avaliar expressões na REPL dá o tipo e valor do resultado + +1 + 7 + +/* A linha acima resulta em: + + scala> 1 + 7 + res29: Int = 8 + + Isto significa que o resultado de avaliar 1 + 7 é um objecto do tipo Int com + o valor 8. + + Note que "res29" é um nome de uma variavel gerado sequencialmente para + armazenar os resultados das expressões que escreveu, por isso o resultado + pode ser ligeiramente diferente. +*/ + +"Strings em scala são rodeadas por aspas" +'a' // Um caracter de Scala +// 'Strings entre plicas não existem' <= Isto causa um erro + +// Strings tem os métodos de Java habituais definidos +"olá mundo".length +"olá mundo".substring(2, 6) +"olá mundo".replace("á", "é") + +// Para além disso, também possuem métodos de Scala. +// Ver: scala.collection.immutable.StringOps +"olá mundo".take(5) +"olá mundo".drop(5) + +// Interpolação de Strings: repare no prefixo "s" +val n = 45 +s"Temos $n maçãs" // => "Temos 45 maçãs" + +// Expressões dentro de Strings interpoladas também são possíveis +val a = Array(11, 9, 6) +s"A minha segunda filha tem ${a(0) - a(2)} anos." // => "A minha segunda filha tem 5 anos." +s"Temos o dobro de ${n / 2.0} em maçãs." // => "Temos o dobro de 22.5 em maçãs." +s"Potência de 2: ${math.pow(2, 2)}" // => "Potência de 2: 4" + +// Strings interpoladas são formatadas com o prefixo "f" +f"Potência de 5: ${math.pow(5, 2)}%1.0f" // "Potência de 5: 25" +f"Raíz quadrada 122: ${math.sqrt(122)}%1.4f" // "Raíz quadrada de 122: 11.0454" + +// Strings prefixadas com "raw" ignoram caracteres especiais +raw"Nova linha: \n. Retorno: \r." // => "Nova Linha: \n. Retorno: \r." + +// Alguns caracteres tem de ser "escapados", e.g. uma aspa dentro de uma string: +"Esperaram fora do \"Rose and Crown\"" // => "Esperaram fora do "Rose and Crown"" + +// Strings rodeadas por três aspas podem-se estender por varias linhas e conter aspas +val html = """<form id="daform"> + <p>Carrega aqui, Zé</p> + <input type="submit"> + </form>""" + + +///////////////////////////////////////////////// +// 2. Funções +///////////////////////////////////////////////// + +// Funções são definidas como: +// +// def nomeDaFuncao(args...): TipoDeRetorno = { corpo... } +// +// Se vem de linugagens mais tradicionais, repare na omissão da palavra +// return keyword. Em Scala, a ultima expressão de um bloco é o seu +// valor de retorno +def somaQuadrados(x: Int, y: Int): Int = { + val x2 = x * x + val y2 = y * y + x2 + y2 +} + +// As { } podem ser omitidas se o corpo da função for apenas uma expressão: +def somaQuadradosCurto(x: Int, y: Int): Int = x * x + y * y + +// A sintaxe para chamar funções deve ser familiar: +somaQuadrados(3, 4) // => 25 + +// Na maior parte dos casos (sendo funções recursivas a principal excepção), o +// tipo de retorno da função pode ser omitido, sendo que a inferencia de tipos +// é aplicada aos valores de retorno +def quadrado(x: Int) = x * x // O compilador infere o tipo de retorno Int + +// Funções podem ter parâmetros por omissão: +def somaComOmissão(x: Int, y: Int = 5) = x + y +somaComOmissão(1, 2) // => 3 +somaComOmissão(1) // => 6 + + +// Funções anónimas são definidas da seguinte forma: +(x: Int) => x * x + +// Ao contrário de defs, o tipo de input de funções anónimas pode ser omitido +// se o contexto o tornar óbvio. Note que o tipo "Int => Int" representa uma +// funão que recebe Int e retorna Int. +val quadrado: Int => Int = x => x * x + +// Funcões anónimas são chamadas como funções normais: +quadrado(10) // => 100 + +// Se cada argumento de uma função anónima for usado apenas uma vez, existe +// uma forma ainda mais curta de os definir. Estas funções anónumas são +// extremamente comuns, como será visto na secção sobre estruturas de dados. +val somaUm: Int => Int = _ + 1 +val somaEstranha: (Int, Int) => Int = (_ * 2 + _ * 3) + +somaUm(5) // => 6 +somaEstranha(2, 4) // => 16 + + +// O código return existe em Scala, mas apenas retorna do def mais interior +// que o rodeia. +// AVISO: Usar return em Scala deve ser evitado, pois facilmente leva a erros. +// Não tem qualquer efeito em funções anónimas, por exemplo: +def foo(x: Int): Int = { + val funcAnon: Int => Int = { z => + if (z > 5) + return z // Esta linha faz com que z seja o retorno de foo! + else + z + 2 // Esta linha define o retorno de funcAnon + } + funcAnon(x) // Esta linha define o valor de retorno de foo +} + + +///////////////////////////////////////////////// +// 3. Controlo de fluxo +///////////////////////////////////////////////// + +1 to 5 +val r = 1 to 5 +r.foreach(println) + +r foreach println +// NB: Scala é bastante brando no que toca a pontos e parentisis - estude as +// regras separadamente. Isto permite escrever APIs e DSLs bastante legiveis + +(5 to 1 by -1) foreach (println) + +// Ciclos while +var i = 0 +while (i < 10) { println("i " + i); i += 1 } + +while (i < 10) { println("i " + i); i += 1 } // Sim, outra vez. O que aconteceu? Porquê? + +i // Mostra o valor de i. Note que o while é um ciclo no sentido clássico - + // executa sequencialmente enquanto muda uma variável. Ciclos while são + // rápidos, por vezes até mais que ciclos de Java, mas combinadores e + // compreensões (usados anteriormente) são mais fáceis de entender e + // paralelizar + +// Um ciclo do while +i = 0 +do { + println("i ainda é menor que 10") + i += 1 +} while (i < 10) + +// A forma idiomática em Scala de definir acções recorrentes é através de +// recursão em cauda. +// Funções recursivas necessitam de um tipo de retorno definido explicitamente. +// Neste caso, é Unit. +def mostraNumerosEntre(a: Int, b: Int): Unit = { + print(a) + if (a < b) + mostraNumerosEntre(a + 1, b) +} +mostraNumerosEntre(1, 14) + + +// Condicionais + +val x = 10 + +if (x == 1) println("yeah") +if (x == 10) println("yeah") +if (x == 11) println("yeah") +if (x == 11) println ("yeah") else println("nay") + +println(if (x == 10) "yeah" else "nope") +val text = if (x == 10) "yeah" else "nope" + + +///////////////////////////////////////////////// +// 4. Estruturas de dados +///////////////////////////////////////////////// + +val a = Array(1, 2, 3, 5, 8, 13) +a(0) +a(3) +a(21) // Lança uma excepção + +val m = Map("fork" -> "tenedor", "spoon" -> "cuchara", "knife" -> "cuchillo") +m("fork") +m("spoon") +m("bottle") // Lança uma excepção + +val safeM = m.withDefaultValue("no lo se") +safeM("bottle") + +val s = Set(1, 3, 7) +s(0) +s(1) + +/* Veja a documentação de mapas de scala em - + * http://www.scala-lang.org/api/current/index.html#scala.collection.immutable.Map + * e verifique que a consegue aceder + */ + + +// Tuplos + +(1, 2) + +(4, 3, 2) + +(1, 2, "três") + +(a, 2, "três") + +// Porquê ter isto? +val divideInts = (x: Int, y: Int) => (x / y, x % y) + +divideInts(10, 3) // A função divideInts returna o resultado e o resto + +// Para aceder aos elementos de um tuplo, pode-se usar _._n, onde n é o indice +// (começado em 1) do elemento +val d = divideInts(10, 3) + +d._1 + +d._2 + + +///////////////////////////////////////////////// +// 5. Programação Orientada a Objectos +///////////////////////////////////////////////// + +/* + Aparte: Até agora tudo o que fizemos neste tutorial foram expressões simples + (valores, funções, etc). Estas expressões são suficientes para executar no + interpretador da linha de comandos para testes rápidos, mas não podem existir + isoladas num ficheiro de Scala. Por exemplo, não é possivel correr um + ficheiro scala que apenas contenha "val x = 5". Em vez disso, as únicas + construções de topo permitidas são: + + - object + - class + - case class + - trait + + Vamos agora explicar o que são: +*/ + +// Classes são semelhantes a classes noutras linguagens. Os argumentos do +// construtor são declarados após o nome da classe, sendo a inicialização feita +// no corpo da classe. +class Cão(rc: String) { + // Código de construção + var raça: String = rc + + // Define um método chamado "ladra", que retorna uma String + def ladra = "Woof, woof!" + + // Valores e métodos são assumidos como públicos, mas é possivel usar + // os códigos "protected" and "private". + private def dormir(horas: Int) = + println(s"Vou dormir por $horas horas") + + // Métodos abstractos são métodos sem corpo. Se descomentarmos a próxima + // linha, a classe Cão é declarada como abstracta + // abstract class Cão(...) { ... } + // def persegue(oQue: String): String +} + +val oMeuCão = new Cão("greyhound") +println(oMeuCão.raça) // => "greyhound" +println(oMeuCão.ladra) // => "Woof, woof!" + + +// O termo "object" cria um tipo e uma instancia singleton desse tipo. É comum +// que classes de Scala possuam um "objecto companheiro", onde o comportamento +// por instância é capturado nas classes, equanto que o comportamento +// relacionado com todas as instancias dessa classe ficam no objecto. +// A diferença é semelhante a métodos de classes e métodos estáticos noutras +// linguagens. Note que objectos e classes podem ter o mesmo nome. +object Cão { + def raçasConhecidas = List("pitbull", "shepherd", "retriever") + def criarCão(raça: String) = new Cão(raça) +} + + +// Case classes são classes com funcionalidades extra incluidas. Uma questão +// comum de iniciantes de scala é quando devem usar classes e quando devem usar +// case classes. A linha é difusa mas, em geral, classes tendem a concentrar-se +// em encapsulamento, polimorfismo e comportamento. Os valores nestas classes +// tendem a ser privados, sendo apenas exposotos métodos. O propósito principal +// das case classes é armazenarem dados imutáveis. Geralmente possuem poucos +// métods, sendo que estes raramente possuem efeitos secundários. +case class Pessoa(nome: String, telefone: String) + +// Cria uma nova instancia. De notar que case classes não precisam de "new" +val jorge = Pessoa("Jorge", "1234") +val cátia = Pessoa("Cátia", "4567") + +// Case classes trazem algumas vantagens de borla, como acessores: +jorge.telefone // => "1234" + +// Igualdade por campo (não é preciso fazer override do .equals) +Pessoa("Jorge", "1234") == Pessoa("Cátia", "1236") // => false + +// Cópia simples +// outroJorge == Person("jorge", "9876") +val outroJorge = jorge.copy(telefone = "9876") + +// Entre outras. Case classes também suportam correspondência de padrões de +// borla, como pode ser visto de seguida. + + +// Traits em breve! + + +///////////////////////////////////////////////// +// 6. Correspondência de Padrões +///////////////////////////////////////////////// + +// A correspondência de padrões é uma funcionalidade poderosa e bastante +// utilizada em Scala. Eis como fazer correspondência de padrões numa case class: +// Nota: Ao contrário de outras linguagens, cases em scala não necessitam de +// breaks, a computação termina no primeiro sucesso. + +def reconhecePessoa(pessoa: Pessoa): String = pessoa match { + // Agora, especifique os padrões: + case Pessoa("Jorge", tel) => "Encontramos o Jorge! O seu número é " + tel + case Pessoa("Cátia", tel) => "Encontramos a Cátia! O seu número é " + tel + case Pessoa(nome, tel) => "Econtramos alguém : " + nome + ", telefone : " + tel +} + +val email = "(.*)@(.*)".r // Define uma regex para o próximo exemplo. + +// A correspondência de padrões pode parecer familiar aos switches em linguagens +// derivadas de C, mas é muto mais poderoso. Em Scala, é possível fazer +// correspondências com muito mais: +def correspondeTudo(obj: Any): String = obj match { + // Pode-se corresponder valores: + case "Olá mundo" => "Recebi uma string Olá mundo." + + // Corresponder por tipo: + case x: Double => "Recebi um Double: " + x + + // Corresponder tendo em conta condições especificas: + case x: Int if x > 10000 => "Recebi um número bem grande!" + + // Fazer correspondências com case classes (visto anteriormente): + case Pessoa(nome, tel) => s"Recebi o contacto para $nome!" + + // Fazer correspondência com expressões regulares: + case email(nome, dominio) => s"Recebi o endereço de email $nome@$dominio" + + // Corresponder tuplos: + case (a: Int, b: Double, c: String) => s"Recebi o tuplo: $a, $b, $c" + + // Corresponder estruturas de dados: + case List(1, b, c) => s"Recebi uma lista de 3 elementos começada em 1: 1, $b, $c" + + // Combinar padrões: + case List(List((1, 2, "YAY"))) => "Recebi uma lista de lista de triplo" +} + +// Na realidade, é possível fazer correspondência com qualquer objecto que +// defina o método "unapply". Esta funcionalidade é tão poderosa que permite +// definir funções sob a forma de padrões: +val funcPaddrao: Pessoa => String = { + case Pessoa("Jorge", tel) => s"Número do Jorge: $tel" + case Pessoa(nome, tel) => s"Número de alguém: $tel" +} + + +///////////////////////////////////////////////// +// 7. Programação Funcional +///////////////////////////////////////////////// + +// Scala permite que funções e métodos retornem, ou recebam como parámetros, +// outras funções ou métodos + +val soma10: Int => Int = _ + 10 // Função que recebe um Int e retorna um Int +List(1, 2, 3) map soma10 // List(11, 12, 13) - soma10 é aplicado a cada elemento + +// Funções anónimas também podem ser usadas +List(1, 2, 3) map (x => x + 10) + +// Sendo que o símbolo _ também pode ser usado se a função anónima só receber +// um argumento. Este fica com o valor da variável +List(1, 2, 3) map (_ + 10) + +// Se tanto o bloco como a função apenas receberem um argumento, o próprio +// _ pode ser omitido +List("Dom", "Bob", "Natalia") foreach println + + +// Combinadores + +s.map(quadrado) + +val sQuadrado = s.map(quadrado) + +sQuadrado.filter(_ < 10) + +sQuadrado.reduce (_+_) + +// O método filter recebe um predicado (uma função de A => Boolean) e escolhe +// todos os elementos que satisfazem o predicado +List(1, 2, 3) filter (_ > 2) // List(3) +case class Pessoa(nome: String, idade: Int) +List( + Pessoa(nome = "Dom", idade = 23), + Pessoa(nome = "Bob", idade = 30) +).filter(_.idade > 25) // List(Pessoa("Bob", 30)) + + +// O método foreach recebe uma função de A => Unit, executando essa função em +// cada elemento da colecção +val aListOfNumbers = List(1, 2, 3, 4, 10, 20, 100) +aListOfNumbers foreach (x => println(x)) +aListOfNumbers foreach println + +// Compreensões For + +for { n <- s } yield quadrado(n) + +val nQuadrado2 = for { n <- s } yield quadrado(n) + +for { n <- nQuadrado2 if n < 10 } yield n + +for { n <- s; nQuadrado = n * n if nQuadrado < 10} yield nQuadrado + +/* Nota: isto não são ciclos for: A semântica de um ciclo é 'repetir', enquanto + que uma compreensão define a relação entre dois conjuntos de dados. */ + + +///////////////////////////////////////////////// +// 8. Implicitos +///////////////////////////////////////////////// + +/* AVISO IMPORTANTE: Implicitos são um conjunto de funcionalidades muito + * poderosas em Scala, que podem ser fácilmente abusadas. Iniciantes devem + * resistir a tentação de usá-los até que compreendam não só como funcionam, + * mas também as melhores práticas. Apenas incluimos esta secção no tutorial + * devido a estes serem tão comuns em bibliotecas de Scala que muitas delas + * se tornam impossíveis de usar sem conhecer implicitos. Este capítulo serve + * para compreender como trabalhar com implicitos, não como declará-los. +*/ + +// Qualquer valor (vals, funções, objectos, etc) pode ser declarado como +// implicito usando a palavra "implicit". Vamos usar a classe Cão da secção 5 +// nestes exemplos + +implicit val oMeuIntImplicito = 100 +implicit def aMinhaFunçãoImplicita(raça: String) = new Cão("Golden " + raça) + +// Por si só, a palavra implicit não altera o comportamento de um valor, sendo +// que estes podem ser usados da forma habitual. +oMeuIntImplicito + 2 // => 102 +aMinhaFunçãoImplicita("Pitbull").raça // => "Golden Pitbull" + +// A diferença é que estes valores podem ser utilizados quando outro pedaço de +// código "necessite" de uma valor implicito. Um exemplo são argumentos +// implicitos de funções: +def enviaCumprimentos(aQuem: String)(implicit quantos: Int) = + s"Olá $aQuem, $quantos cumprimentos para ti e para os teus!" + +// Se dermos um valor a "quantos", a função comporta-se normalmente +enviaCumprimentos("João")(1000) // => "Olá João, 1000 cumprimentos para ti e para os teus!" + +// Mas, se omitirmos o parâmetro implicito, um valor implicito do mesmo tipo é +// usado, neste caso, "oMeuInteiroImplicito" +enviaCumprimentos("Joana") // => "Olá Joana, 100 cumprimentos para ti e para os teus!" + +// Parâmentros implicitos de funções permitem-nos simular classes de tipos de +// outras linguagens funcionais. Isto é tão comum que tem a sua própria notação. +// As seguintes linhas representam a mesma coisa +// def foo[T](implicit c: C[T]) = ... +// def foo[T : C] = ... + + +// Outra situação em que o compilador prouca um implicito é se encontrar uma +// expressão +// obj.método(...) +// mas "obj" não possuir um método chamado "método". Neste cso, se houver uma +// conversão implicita A => B, onde A é o tipo de obj, e B possui um método +// chamado "método", a conversão é aplicada. Ou seja, tendo +// aMinhaFunçãoImplicita definida, podemos dizer +"Retriever".raça // => "Golden Retriever" +"Sheperd".ladra // => "Woof, woof!" + +// Neste caso, a String é primeiro convertida para Cão usando a nossa funão, +// sendo depois chamado o método apropriado. Esta é uma funcionalidade +// incrivelmente poderosa, sendo que deve ser usada com cautela. Na verdade, +// ao definir a função implicita, o compilador deve lançar um aviso a insisitir +// que só deve definir a função se souber o que está a fazer. + + +///////////////////////////////////////////////// +// 9. Misc +///////////////////////////////////////////////// + +// Importar coisas +import scala.collection.immutable.List + +// Importar todos os "sub pacotes" +import scala.collection.immutable._ + +// Importar multiplas classes numa linha +import scala.collection.immutable.{List, Map} + +// Renomear uma classe importada usando '=>' +import scala.collection.immutable.{List => ImmutableList} + +// Importar todas as classes excepto algumas. Set e Map são excluidos: +import scala.collection.immutable.{Map => _, Set => _, _} + +// O ponto de entrada de um programa em Scala é definido por un ficheiro .scala +// com um método main: +object Aplicação { + def main(args: Array[String]): Unit = { + // código aqui. + } +} + +// Ficheiros podem conter várias classes o objectos. Compilar com scalac + + + + +// Input e output + +// Ler um ficheiro linha a linha +import scala.io.Source +for(linha <- Source.fromFile("ficheiro.txt").getLines()) + println(linha) + +// Escrever um ficheiro usando o PrintWriter de Java +val writer = new PrintWriter("ficheiro.txt") +writer.write("Escrevendo linha por linha" + util.Properties.lineSeparator) +writer.write("Outra linha aqui" + util.Properties.lineSeparator) +writer.close() + +``` + +## Mais recursos + +* [Scala for the impatient](http://horstmann.com/scala/) +* [Twitter Scala school](http://twitter.github.io/scala_school/) +* [The scala documentation](http://docs.scala-lang.org/) +* [Try Scala in your browser](http://scalatutorials.com/tour/) +* Join the [Scala user group](https://groups.google.com/forum/#!forum/scala-user) diff --git a/purescript.html.markdown b/purescript.html.markdown index 6bff7545..a006cdff 100644 --- a/purescript.html.markdown +++ b/purescript.html.markdown @@ -70,12 +70,12 @@ true && (9 >= 19 || 1 < 2) -- true -- Safe access return Maybe a head [1,2,3] -- Just (1) -tail [3,2,1] -- Just ([2,1]) +tail [3,2,1] -- Just ([2,1]) init [1,2,3] -- Just ([1,2]) last [3,2,1] -- Just (1) -- Random access - indexing [3,4,5,6,7] !! 2 -- Just (5) --- Range +-- Range 1..5 -- [1,2,3,4,5] length [2,2,2] -- 3 drop 3 [5,4,3,2,1] -- [2,1] @@ -129,10 +129,10 @@ first :: [Number] -> Number first (x:_) = x first [3,4,5] -- 3 second :: [Number] -> Number -second (_:y:_) = y +second (_:y:_) = y second [3,4,5] -- 4 sumTwo :: [Number] -> [Number] -sumTwo (x:y:rest) = (x+y) : rest +sumTwo (x:y:rest) = (x+y) : rest sumTwo [2,3,4,5,6] -- [5,4,5,6] -- sumTwo doesn't handle when the array is empty or just have one @@ -161,7 +161,7 @@ ecoTitle {title: "The Quantum Thief"} -- Object does not have property author -- Lambda expressions (\x -> x*x) 3 -- 9 -(\x y -> x*x + y*y) 4 5 -- 41 +(\x y -> x*x + y*y) 4 5 -- 41 sqr = \x -> x*x -- Currying @@ -187,7 +187,7 @@ foldr (+) 0 (1..10) -- 55 sum (1..10) -- 55 product (1..10) -- 3628800 --- Testing with predicate +-- Testing with predicate any even [1,2,3] -- true all even [1,2,3] -- false diff --git a/python.html.markdown b/python.html.markdown index 352f7349..6cfb5dca 100644 --- a/python.html.markdown +++ b/python.html.markdown @@ -198,7 +198,7 @@ li[::-1] # => [3, 4, 2, 1] # Remove arbitrary elements from a list with "del" del li[2] # li is now [1, 2, 3] -r + # You can add lists li + other_li # => [1, 2, 3, 4, 5, 6] # Note: values for li and for other_li are not modified. @@ -473,9 +473,12 @@ add_10(3) # => 13 # There are also anonymous functions (lambda x: x > 2)(3) # => True +(lambda x, y: x ** 2 + y ** 2)(2, 1) # => 5 # There are built-in higher order functions 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] # We can use list comprehensions for nice maps and filters diff --git a/python3.html.markdown b/python3.html.markdown index b3acb122..cd1a83cc 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -4,6 +4,7 @@ contributors: - ["Louie Dinh", "http://pythonpracticeprojects.com"] - ["Steven Basart", "http://github.com/xksteven"] - ["Andre Polykanine", "https://github.com/Oire"] + - ["Zachary Ferguson", "http://github.com/zfergus2"] filename: learnpython3.py --- @@ -36,7 +37,7 @@ Note: This article applies to Python 3 specifically. Check out [here](http://lea 8 - 1 # => 7 10 * 2 # => 20 -# Except division which returns floats by default +# Except division which returns floats, real numbers, by default 35 / 5 # => 7.0 # Result of integer division truncated down both for positive and negative. @@ -51,13 +52,13 @@ Note: This article applies to Python 3 specifically. Check out [here](http://lea # Modulo operation 7 % 3 # => 1 -# Exponentiation (x to the yth power) +# Exponentiation (x**y, x to the yth power) 2**4 # => 16 # Enforce precedence with parentheses (1 + 3) * 2 # => 8 -# Boolean values are primitives +# Boolean values are primitives (Note: the capitalization) True False @@ -95,6 +96,16 @@ False or True #=> True 1 < 2 < 3 # => True 2 < 3 < 2 # => False +# (is vs. ==) is checks if two variable refer to the same object, but == checks +# if the objects pointed to have the same values. +a = [1, 2, 3, 4] # Point a at a new list, [1, 2, 3, 4] +b = a # Point b at what a is pointing to +b is a # => True, a and b refer to the same object +b == a # => True, a's and b's objects are equal +b = [1, 2, 3, 4] # Point a at a new list, [1, 2, 3, 4] +b is a # => False, a and b do not refer to the same object +b == a # => True, a's and b's objects are equal + # Strings are created with " or ' "This is a string." 'This is also a string.' @@ -145,6 +156,10 @@ bool({}) #=> False # Python has a print function print("I'm Python. Nice to meet you!") +# By default the print function also prints out a newline at the end. +# Use the optional argument end to change the end character. +print("Hello, World", end="!") # => Hello, World! + # No need to declare variables before assigning to them. # Convention is to use lower_case_with_underscores some_var = 5 @@ -191,6 +206,9 @@ li[::-1] # => [3, 4, 2, 1] # Use any combination of these to make advanced slices # li[start:end:step] +# Make a one layer deep copy using slices +li2 = li[:] # => li2 = [1, 2, 4, 3] but (li2 is li) will result in false. + # Remove arbitrary elements from a list with "del" del li[2] # li is now [1, 2, 3] @@ -213,6 +231,12 @@ tup = (1, 2, 3) tup[0] # => 1 tup[0] = 3 # Raises a 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'> + # You can do most of the list operations on tuples too len(tup) # => 3 tup + (4, 5, 6) # => (1, 2, 3, 4, 5, 6) @@ -232,6 +256,12 @@ empty_dict = {} # Here is a prefilled dictionary filled_dict = {"one": 1, "two": 2, "three": 3} +# Note keys for dictionaries have to be immutable types. This is to ensure that +# the key can be converted to a constant hash value for quick look-ups. +# Immutable types include ints, floats, strings, tuples. +invalid_dict = {[1,2,3]: "123"} # => Raises a TypeError: unhashable type: 'list' +valid_dict = {(1,2,3):[1,2,3]} # Values can be of any type, however. + # Look up values with [] filled_dict["one"] # => 1 @@ -278,6 +308,10 @@ empty_set = set() # Initialize a set with a bunch of values. Yeah, it looks a bit like a dict. Sorry. some_set = {1, 1, 2, 2, 3, 4} # some_set is now {1, 2, 3, 4} +# Similar to keys of a dictionary, elements of a set have to be immutable. +invalid_set = {[1], 1} # => Raises a TypeError: unhashable type: 'list' +valid_set = {(1,), 1} + # Can set new variables to a set filled_set = some_set @@ -299,6 +333,7 @@ filled_set | other_set # => {1, 2, 3, 4, 5, 6} 10 in filled_set # => False + #################################################### ## 3. Control Flow and Iterables #################################################### @@ -352,6 +387,18 @@ for i in range(4, 8): print(i) """ +"range(lower, upper, step)" returns an iterable of numbers +from the lower number to the upper number, while incrementing +by step. If step is not indicated, the default value is 1. +prints: + 4 + 6 + 8 +""" +for i in range(4, 8, 2): + print(i) +""" + While loops go until a condition is no longer met. prints: 0 @@ -376,7 +423,7 @@ else: # Optional clause to the try/except block. Must follow all except blocks print("All good!") # Runs only if the code in try raises no exceptions finally: # Execute under all circumstances print("We can clean up resources here") - + # Instead of try/finally to cleanup resources you can use a with statement with open("myfile.txt") as f: for line in f: @@ -464,6 +511,15 @@ 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) +# Returning multiple values (with tuple assignments) +def swap(x, y): + return y, x # Return multiple values as a tuple without the parenthesis. + # (Note: parenthesis have been excluded but can be included) + +x = 1 +y = 2 +x, y = swap(x, y) # => x = 2, y = 1 +# (x, y) = swap(x,y) # Again parenthesis have been excluded but can be included. # Function Scope x = 5 @@ -494,10 +550,13 @@ add_10(3) # => 13 # There are also anonymous functions (lambda x: x > 2)(3) # => True +(lambda x, y: x ** 2 + y ** 2)(2, 1) # => 5 # TODO - Fix for iterables # There are built-in higher order functions 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] # We can use list comprehensions for nice maps and filters diff --git a/r.html.markdown b/r.html.markdown index d3d725d3..93751df5 100644 --- a/r.html.markdown +++ b/r.html.markdown @@ -36,8 +36,8 @@ head(rivers) # peek at the data set length(rivers) # how many rivers were measured? # 141 summary(rivers) # what are some summary statistics? -# Min. 1st Qu. Median Mean 3rd Qu. Max. -# 135.0 310.0 425.0 591.2 680.0 3710.0 +# Min. 1st Qu. Median Mean 3rd Qu. Max. +# 135.0 310.0 425.0 591.2 680.0 3710.0 # make a stem-and-leaf plot (a histogram-like data visualization) stem(rivers) @@ -54,14 +54,14 @@ stem(rivers) # 14 | 56 # 16 | 7 # 18 | 9 -# 20 | +# 20 | # 22 | 25 # 24 | 3 -# 26 | -# 28 | -# 30 | -# 32 | -# 34 | +# 26 | +# 28 | +# 30 | +# 32 | +# 34 | # 36 | 1 stem(log(rivers)) # Notice that the data are neither normal nor log-normal! @@ -70,7 +70,7 @@ stem(log(rivers)) # Notice that the data are neither normal nor log-normal! # The decimal point is 1 digit(s) to the left of the | # # 48 | 1 -# 50 | +# 50 | # 52 | 15578 # 54 | 44571222466689 # 56 | 023334677000124455789 @@ -85,7 +85,7 @@ stem(log(rivers)) # Notice that the data are neither normal nor log-normal! # 74 | 84 # 76 | 56 # 78 | 4 -# 80 | +# 80 | # 82 | 2 # make a histogram: @@ -108,7 +108,7 @@ sort(discoveries) # [76] 4 4 4 4 5 5 5 5 5 5 5 6 6 6 6 6 6 7 7 7 7 8 9 10 12 stem(discoveries, scale=2) -# +# # The decimal point is at the | # # 0 | 000000000 @@ -122,14 +122,14 @@ stem(discoveries, scale=2) # 8 | 0 # 9 | 0 # 10 | 0 -# 11 | +# 11 | # 12 | 0 max(discoveries) # 12 summary(discoveries) -# Min. 1st Qu. Median Mean 3rd Qu. Max. -# 0.0 2.0 3.0 3.1 4.0 12.0 +# Min. 1st Qu. Median Mean 3rd Qu. Max. +# 0.0 2.0 3.0 3.1 4.0 12.0 # Roll a die a few times round(runif(7, min=.5, max=6.5)) @@ -262,7 +262,7 @@ class(NULL) # NULL parakeet = c("beak", "feathers", "wings", "eyes") parakeet # => -# [1] "beak" "feathers" "wings" "eyes" +# [1] "beak" "feathers" "wings" "eyes" parakeet <- NULL parakeet # => @@ -279,7 +279,7 @@ as.numeric("Bilbo") # => # [1] NA # Warning message: -# NAs introduced by coercion +# NAs introduced by coercion # Also note: those were just the basic data types # There are many more data types, such as for dates, time series, etc. @@ -419,10 +419,10 @@ mat %*% t(mat) mat2 <- cbind(1:4, c("dog", "cat", "bird", "dog")) mat2 # => -# [,1] [,2] -# [1,] "1" "dog" -# [2,] "2" "cat" -# [3,] "3" "bird" +# [,1] [,2] +# [1,] "1" "dog" +# [2,] "2" "cat" +# [3,] "3" "bird" # [4,] "4" "dog" class(mat2) # matrix # Again, note what happened! diff --git a/racket.html.markdown b/racket.html.markdown index e345db8b..0fe3f030 100644 --- a/racket.html.markdown +++ b/racket.html.markdown @@ -285,7 +285,7 @@ m ; => '#hash((b . 2) (a . 1) (c . 3)) <-- no `d' (= 3 3.0) ; => #t (= 2 1) ; => #f -;; `eq?' returns #t if 2 arguments refer to the same object (in memory), +;; `eq?' returns #t if 2 arguments refer to the same object (in memory), ;; #f otherwise. ;; In other words, it's a simple pointer comparison. (eq? '() '()) ; => #t, since there exists only one empty list in memory @@ -320,7 +320,7 @@ m ; => '#hash((b . 2) (a . 1) (c . 3)) <-- no `d' (eqv? (string-append "foo" "bar") (string-append "foo" "bar")) ; => #f ;; `equal?' supports the comparison of the following datatypes: -;; strings, byte strings, pairs, mutable pairs, vectors, boxes, +;; strings, byte strings, pairs, mutable pairs, vectors, boxes, ;; hash tables, and inspectable structures. ;; for other datatypes, `equal?' and `eqv?' return the same result. (equal? 3 3.0) ; => #f diff --git a/red.html.markdown b/red.html.markdown index f33060c4..05da3c3f 100644 --- a/red.html.markdown +++ b/red.html.markdown @@ -8,31 +8,31 @@ contributors: --- -Red was created out of the need to get work done, and the tool the author wanted to use, the language of REBOL, had a couple of drawbacks. +Red was created out of the need to get work done, and the tool the author wanted to use, the language of REBOL, had a couple of drawbacks. It was not Open Sourced at that time and it is an interpreted language, what means that it is on average slow compared to a compiled language. Red, together with its C-level dialect Red/System, provides a language that covers the entire programming space you ever need to program something in. -Red is a language heavily based on the language of REBOL. Where Red itself reproduces the flexibility of the REBOL language, the underlying language Red will be built upon, -Red/System, covers the more basic needs of programming like C can, being closer to the metal. +Red is a language heavily based on the language of REBOL. Where Red itself reproduces the flexibility of the REBOL language, the underlying language Red will be built upon, +Red/System, covers the more basic needs of programming like C can, being closer to the metal. -Red will be the world's first Full Stack Programming Language. This means that it will be an effective tool to do (almost) any programming task on every level -from the metal to the meta without the aid of other stack tools. -Furthermore Red will be able to cross-compile Red source code without using any GCC like toolchain +Red will be the world's first Full Stack Programming Language. This means that it will be an effective tool to do (almost) any programming task on every level +from the metal to the meta without the aid of other stack tools. +Furthermore Red will be able to cross-compile Red source code without using any GCC like toolchain from any platform to any other platform. And it will do this all from a binary executable that is supposed to stay under 1 MB. Ready to learn your first Red? ``` -All text before the header will be treated as comment, as long as you avoid using the -word "red" starting with a capital "R" in this pre-header text. This is a temporary -shortcoming of the used lexer but most of the time you start your script or program -with the header itself. -The header of a red script is the capitalized word "red" followed by a +All text before the header will be treated as comment, as long as you avoid using the +word "red" starting with a capital "R" in this pre-header text. This is a temporary +shortcoming of the used lexer but most of the time you start your script or program +with the header itself. +The header of a red script is the capitalized word "red" followed by a whitespace character followed by a block of square brackets []. -The block of brackets can be filled with useful information about this script or +The block of brackets can be filled with useful information about this script or program: the author's name, the filename, the version, the license, a summary of what the program does or any other files it needs. -The red/System header is just like the red header, only saying "red/System" and +The red/System header is just like the red header, only saying "red/System" and not "red". Red [] @@ -49,21 +49,21 @@ comment { ; Your program's entry point is the first executable code that is found ; no need to restrict this to a 'main' function. -; Valid variable names start with a letter and can contain numbers, -; variables containing only capital A thru F and numbers and ending with 'h' are -; forbidden, because that is how hexadecimal numbers are expressed in Red and +; Valid variable names start with a letter and can contain numbers, +; variables containing only capital A thru F and numbers and ending with 'h' are +; forbidden, because that is how hexadecimal numbers are expressed in Red and ; Red/System. ; assign a value to a variable using a colon ":" my-name: "Red" -reason-for-using-the-colon: {Assigning values using the colon makes - the equality sign "=" exclusively usable for comparisons purposes, - exactly what "=" was intended for in the first place! +reason-for-using-the-colon: {Assigning values using the colon makes + the equality sign "=" exclusively usable for comparisons purposes, + exactly what "=" was intended for in the first place! Remember this y = x + 1 and x = 1 => y = 2 stuff from school? } is-this-name-valid?: true -; print output using print, or prin for printing without a newline or linefeed at the +; print output using print, or prin for printing without a newline or linefeed at the ; end of the printed text. prin " My name is " print my-name @@ -77,20 +77,20 @@ My name is Red ; ; Datatypes ; -; If you know Rebol, you probably have noticed it has lots of datatypes. Red -; does not have yet all those types, but as Red want to be close to Rebol it +; If you know Rebol, you probably have noticed it has lots of datatypes. Red +; does not have yet all those types, but as Red want to be close to Rebol it ; will have a lot of datatypes. -; You can recognize types by the exclamation sign at the end. But beware -; names ending with an exclamation sign are allowed. -; Some of the available types are integer! string! block! - -; Declaring variables before using them? -; Red knows by itself what variable is best to use for the data you want to use it -; for. -; A variable declaration is not always necessary. +; You can recognize types by the exclamation sign at the end. But beware +; names ending with an exclamation sign are allowed. +; Some of the available types are integer! string! block! + +; Declaring variables before using them? +; Red knows by itself what variable is best to use for the data you want to use it +; for. +; A variable declaration is not always necessary. ; It is considered good coding practise to declare your variables, ; but it is not forced upon you by Red. -; You can declare a variable and specify its type. a variable's type determines its +; You can declare a variable and specify its type. a variable's type determines its ; size in bytes. ; Variables of integer! type are usually 4 bytes or 32 bits @@ -101,7 +101,7 @@ my-integer: 0 type? my-integer integer! -; A variable can be initialized using another variable that gets initialized +; A variable can be initialized using another variable that gets initialized ; at the same time. i2: 1 + i1: 1 @@ -111,9 +111,9 @@ i2 - i1 ; result 1 i2 * i1 ; result 2 i1 / i2 ; result 0 (0.5, but truncated towards 0) -; Comparison operators are probably familiar, and unlike in other languages you +; Comparison operators are probably familiar, and unlike in other languages you ; only need a single '=' sign for comparison. -; There is a boolean like type in Red. It has values true and false, but also the +; There is a boolean like type in Red. It has values true and false, but also the ; values on/off or yes/no can be used 3 = 2 ; result false @@ -125,15 +125,15 @@ i1 / i2 ; result 0 (0.5, but truncated towards 0) ; ; Control Structures -; +; ; if -; Evaluate a block of code if a given condition is true. IF does not return any value, +; Evaluate a block of code if a given condition is true. IF does not return any value, ; so cannot be used in an expression. if a < 0 [print "a is negative"] ; either -; Evaluate a block of code if a given condition is true, else evaluate an alternative -; block of code. If the last expressions in both blocks have the same type, EITHER can +; Evaluate a block of code if a given condition is true, else evaluate an alternative +; block of code. If the last expressions in both blocks have the same type, EITHER can ; be used inside an expression. either a < 0 [ either a = 0 [ @@ -147,7 +147,7 @@ either a < 0 [ print ["a is " msg lf] -; There is an alternative way to write this +; There is an alternative way to write this ; (Which is allowed because all code paths return a value of the same type): msg: either a < 0 [ @@ -162,7 +162,7 @@ msg: either a < 0 [ print ["a is " msg lf] ; until -; Loop over a block of code until the condition at end of block, is met. +; Loop over a block of code until the condition at end of block, is met. ; UNTIL does not return any value, so it cannot be used in an expression. c: 5 until [ @@ -172,11 +172,11 @@ until [ ] ; will output: ooooo -; Note that the loop will always be evaluated at least once, even if the condition is +; Note that the loop will always be evaluated at least once, even if the condition is ; not met from the beginning. ; while -; While a given condition is met, evaluate a block of code. +; While a given condition is met, evaluate a block of code. ; WHILE does not return any value, so it cannot be used in an expression. c: 5 while [c > 0][ @@ -206,7 +206,7 @@ print twice b ; will output 6. ## Further Reading -The main source for information about Red is the [Red language homepage](http://www.red-lang.org). +The main source for information about Red is the [Red language homepage](http://www.red-lang.org). The source can be found on [github](https://github.com/red/red). @@ -218,4 +218,4 @@ Browse or ask questions on [Stack Overflow](stackoverflow.com/questions/tagged/r Maybe you want to try Red right away? That is possible on the [try Rebol and Red site](http://tryrebol.esperconsultancy.nl). -You can also learn Red by learning some [Rebol](http://www.rebol.com/docs.html). +You can also learn Red by learning some [Rebol](http://www.rebol.com/docs.html). diff --git a/ru-ru/javascript-ru.html.markdown b/ru-ru/javascript-ru.html.markdown index 79844565..8655ae4a 100644 --- a/ru-ru/javascript-ru.html.markdown +++ b/ru-ru/javascript-ru.html.markdown @@ -470,9 +470,6 @@ myNumber === myNumberObj; // = false if (0) { // Этот код не выполнится, потому что 0 - это ложь. } -if (Number(0)) { - // Этот код *выполнится*, потому что Number(0) истинно. -} // Впрочем, объекты-обёртки и встроенные типы имеют общие прототипы, // поэтому вы можете расширить функционал строк, например: diff --git a/ru-ru/ruby-ru.html.markdown b/ru-ru/ruby-ru.html.markdown index 318e0e09..69b5fb46 100644 --- a/ru-ru/ruby-ru.html.markdown +++ b/ru-ru/ruby-ru.html.markdown @@ -158,6 +158,7 @@ array << 6 #=> [1, 2, 3, 4, 5, 6] hash = {'color' => 'green', 'number' => 5} hash.keys #=> ['color', 'number'] +hash.values #=> ['green', 5] # Значение в хэше легко может быть найдено по ключу: hash['color'] #=> 'green' diff --git a/ruby-ecosystem.html.markdown b/ruby-ecosystem.html.markdown index d8a02d36..1fbcc752 100644 --- a/ruby-ecosystem.html.markdown +++ b/ruby-ecosystem.html.markdown @@ -42,7 +42,7 @@ 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. + 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/). diff --git a/ruby.html.markdown b/ruby.html.markdown index 7bd28d86..fe142365 100644 --- a/ruby.html.markdown +++ b/ruby.html.markdown @@ -106,8 +106,14 @@ placeholder = 'use string interpolation' 'hello ' + 3 #=> TypeError: can't convert Fixnum into String 'hello ' + 3.to_s #=> "hello 3" -# print to the output +# 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 +print "I'm printing!" +#=> I'm printing! => nill # Variables x = 25 #=> 25 @@ -168,6 +174,10 @@ array[-1] #=> 5 # 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 array[1..3] #=> [2, 3, 4] @@ -265,6 +275,19 @@ 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 +# to it as defined in your block, and returns an entirely new array. +array = [1,2,3,4,5] +doubled = array.map do |element| + element * 2 +end +puts doubled +#=> [2,4,6,8,10] +puts array +#=> [1,2,3,4,5] + grade = 'B' case grade diff --git a/rust.html.markdown b/rust.html.markdown index 4fbd6144..b2854b0c 100644 --- a/rust.html.markdown +++ b/rust.html.markdown @@ -6,20 +6,20 @@ filename: learnrust.rs --- Rust is a programming language developed by Mozilla Research. -Rust combines low-level control over performance with high-level convenience and -safety guarantees. +Rust combines low-level control over performance with high-level convenience and +safety guarantees. -It achieves these goals without requiring a garbage collector or runtime, making +It achieves these goals without requiring a garbage collector or runtime, making it possible to use Rust libraries as a "drop-in replacement" for C. -Rust’s first release, 0.1, occurred in January 2012, and for 3 years development +Rust’s first release, 0.1, occurred in January 2012, and for 3 years development moved so quickly that until recently the use of stable releases was discouraged -and instead the general advise was to use nightly builds. +and instead the general advice was to use nightly builds. -On May 15th 2015, Rust 1.0 was released with a complete guarantee of backward +On May 15th 2015, Rust 1.0 was released with a complete guarantee of backward compatibility. Improvements to compile times and other aspects of the compiler are currently available in the nightly builds. Rust has adopted a train-based release -model with regular releases every six weeks. Rust 1.1 beta was made available at +model with regular releases every six weeks. Rust 1.1 beta was made available at the same time of the release of Rust 1.0. Although Rust is a relatively low-level language, Rust has some functional diff --git a/scala.html.markdown b/scala.html.markdown index c482752d..7f545196 100644 --- a/scala.html.markdown +++ b/scala.html.markdown @@ -6,7 +6,6 @@ contributors: - ["Dominic Bou-Samra", "http://dbousamra.github.com"] - ["Geoff Liu", "http://geoffliu.me"] - ["Ha-Duong Nguyen", "http://reference-error.org"] -filename: learn.scala --- Scala - the scalable language @@ -43,9 +42,13 @@ Scala - the scalable language // Printing, and forcing a new line on the next print println("Hello world!") println(10) +// Hello world! +// 10 // Printing, without forcing a new line on next print print("Hello world") +print(10) +// Hello world!10 // Declaring values is done using either var or val. // val declarations are immutable, whereas vars are mutable. Immutability is @@ -240,10 +243,11 @@ i // Show the value of i. Note that while is a loop in the classical sense - // comprehensions above is easier to understand and parallelize // A do while loop +i = 0 do { - println("x is still less than 10") - x += 1 -} while (x < 10) + println("i is still less than 10") + i += 1 +} while (i < 10) // Tail recursion is an idiomatic way of doing recurring things in Scala. // Recursive functions need an explicit return type, the compiler can't infer it. @@ -562,8 +566,8 @@ sendGreetings("Jane") // => "Hello Jane, 100 blessings to you and yours!" // Implicit function parameters enable us to simulate type classes in other // functional languages. It is so often used that it gets its own shorthand. The // following two lines mean the same thing: -def foo[T](implicit c: C[T]) = ... -def foo[T : C] = ... +// def foo[T](implicit c: C[T]) = ... +// def foo[T : C] = ... // Another situation in which the compiler looks for an implicit is if you have diff --git a/self.html.markdown b/self.html.markdown index 69524a84..9290a0c9 100644 --- a/self.html.markdown +++ b/self.html.markdown @@ -5,13 +5,13 @@ contributors: filename: learnself.self --- -Self is a fast prototype based OO language which runs in its own JIT vm. Most development is done through interacting with live objects through a visual development environment called *morphic* with integrated browsers and debugger. +Self is a fast prototype based OO language which runs in its own JIT vm. Most development is done through interacting with live objects through a visual development environment called *morphic* with integrated browsers and debugger. Everything in Self is an object. All computation is done by sending messages to objects. Objects in Self can be understood as sets of key-value slots. # Constructing objects -The inbuild Self parser can construct objects, including method objects. +The inbuild Self parser can construct objects, including method objects. ``` "This is a comment" @@ -38,18 +38,18 @@ The inbuild Self parser can construct objects, including method objects. x <- 20. |) -"An object which understands the method 'doubleX' which +"An object which understands the method 'doubleX' which doubles the value of x and then returns the object" (| x <- 20. doubleX = (x: x * 2. self) |) -"An object which understands all the messages -that 'traits point' understands". The parser -looks up 'traits point' by sending the messages -'traits' then 'point' to a known object called -the 'lobby'. It looks up the 'true' object by +"An object which understands all the messages +that 'traits point' understands". The parser +looks up 'traits point' by sending the messages +'traits' then 'point' to a known object called +the 'lobby'. It looks up the 'true' object by also sending the message 'true' to the lobby." (| parent* = traits point. x = 7. @@ -63,19 +63,19 @@ also sending the message 'true' to the lobby." Messages can either be unary, binary or keyword. Precedence is in that order. Unlike Smalltalk, the precedence of binary messages must be specified, and all keywords after the first must start with a capital letter. Messages are separeated from their destination by whitespace. ``` -"unary message, sends 'printLine' to the object '23' +"unary message, sends 'printLine' to the object '23' which prints the string '23' to stdout and returns the receiving object (ie 23)" 23 printLine "sends the message '+' with '7' to '23', then the message '*' with '8' to the result" -(23 + 7) * 8 +(23 + 7) * 8 "sends 'power:' to '2' with '8' returns 256" -2 power: 8 +2 power: 8 -"sends 'keyOf:IfAbsent:' to 'hello' with arguments 'e' and '-1'. +"sends 'keyOf:IfAbsent:' to 'hello' with arguments 'e' and '-1'. Returns 1, the index of 'e' in 'hello'." -'hello' keyOf: 'e' IfAbsent: -1 +'hello' keyOf: 'e' IfAbsent: -1 ``` # Blocks @@ -90,13 +90,13 @@ Examples of the use of a block: ``` "returns 'HELLO'" -'hello' copyMutable mapBy: [|:c| c capitalize] +'hello' copyMutable mapBy: [|:c| c capitalize] "returns 'Nah'" -'hello' size > 5 ifTrue: ['Yay'] False: ['Nah'] +'hello' size > 5 ifTrue: ['Yay'] False: ['Nah'] "returns 'HaLLO'" -'hello' copyMutable mapBy: [|:c| +'hello' copyMutable mapBy: [|:c| c = 'e' ifTrue: [c capitalize] False: ['a']] ``` @@ -105,7 +105,7 @@ Multiple expressions are separated by a period. ^ returns immediately. ``` "returns An 'E'! How icky!" -'hello' copyMutable mapBy: [|:c. tmp <- ''| +'hello' copyMutable mapBy: [|:c. tmp <- ''| tmp: c capitalize. tmp = 'E' ifTrue: [^ 'An \'E\'! How icky!']. c capitalize @@ -119,7 +119,7 @@ Blocks are performed by sending them the message 'value' and inherit (delegate t x: 15. "Repeatedly sends 'value' to the first block while the result of sending 'value' to the second block is the 'true' object" - [x > 0] whileTrue: [x: x - 1]. + [x > 0] whileTrue: [x: x - 1]. x ] value ``` @@ -130,12 +130,12 @@ Methods are like blocks but they are not within a context but instead are stored ``` "Here is an object with one assignable slot 'x' and a method 'reduceXTo: y'. -Sending the message 'reduceXTo: 10' to this object will put +Sending the message 'reduceXTo: 10' to this object will put the object '10' in the 'x' slot and return the original object" -(| +(| x <- 50. reduceXTo: y = ( - [x > y] whileTrue: [x: x - 1]. + [x > y] whileTrue: [x: x - 1]. self) |) . diff --git a/smalltalk.html.markdown b/smalltalk.html.markdown new file mode 100644 index 00000000..3b388505 --- /dev/null +++ b/smalltalk.html.markdown @@ -0,0 +1,955 @@ +--- +language: smalltalk +contributors: + - ["Jigyasa Grover", "https://github.com/jig08"] +--- + +- Smalltalk is an object-oriented, dynamically typed, reflective programming language. +- 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: +- 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` + +##Variable scope: +- Global: defined in Dictionary 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 + +`"Comments are enclosed in quotes"` + +`"Period (.) is the statement seperator"` + +## Transcript: +``` +Transcript clear. "clear to transcript window" +Transcript show: 'Hello World'. "output string in transcript window" +Transcript nextPutAll: 'Hello World'. "output string in transcript window" +Transcript nextPut: $A. "output character in transcript window" +Transcript space. "output space character in transcript window" +Transcript tab. "output tab character in transcript window" +Transcript cr. "carriage return / linefeed" +'Hello' printOn: Transcript. "append print string into the window" +'Hello' storeOn: Transcript. "append store string into the window" +Transcript endEntry. "flush the output buffer" +``` + +##Assignment: +``` +| x y | +x _ 4. "assignment (Squeak) <-" +x := 5. "assignment" +x := y := z := 6. "compound assignment" +x := (y := 6) + 1. +x := Object new. "bind to allocated instance of a class" +x := 123 class. "discover the object class" +x := Integer superclass. "discover the superclass of a class" +x := Object allInstances. "get an array of all instances of a class" +x := Integer allSuperclasses. "get all superclasses of a class" +x := 1.2 hash. "hash value for object" +y := x copy. "copy object" +y := x shallowCopy. "copy object (not overridden)" +y := x deepCopy. "copy object and instance vars" +y := x veryDeepCopy. "complete tree copy using a dictionary" +``` + +##Constants: +``` +| b | +b := true. "true constant" +b := false. "false constant" +x := nil. "nil object constant" +x := 1. "integer constants" +x := 3.14. "float constants" +x := 2e-2. "fractional constants" +x := 16r0F. "hex constant". +x := -1. "negative constants" +x := 'Hello'. "string constant" +x := 'I''m here'. "single quote escape" +x := $A. "character constant" +x := $ . "character constant (space)" +x := #aSymbol. "symbol constants" +x := #(3 2 1). "array constants" +x := #('abc' 2 $a). "mixing of types allowed" + +``` + +## Booleans: +``` +| b x y | +x := 1. y := 2. +b := (x = y). "equals" +b := (x ~= y). "not equals" +b := (x == y). "identical" +b := (x ~~ y). "not identical" +b := (x > y). "greater than" +b := (x < y). "less than" +b := (x >= y). "greater than or equal" +b := (x <= y). "less than or equal" +b := b not. "boolean not" +b := (x < 5) & (y > 1). "boolean and" +b := (x < 5) | (y > 1). "boolean or" +b := (x < 5) and: [y > 1]. "boolean and (short-circuit)" +b := (x < 5) or: [y > 1]. "boolean or (short-circuit)" +b := (x < 5) eqv: (y > 1). "test if both true or both false" +b := (x < 5) xor: (y > 1). "test if one true and other false" +b := 5 between: 3 and: 12. "between (inclusive)" +b := 123 isKindOf: Number. "test if object is class or subclass of" +b := 123 isMemberOf: SmallInteger. "test if object is type of class" +b := 123 respondsTo: sqrt. "test if object responds to message" +b := x isNil. "test if object is nil" +b := x isZero. "test if number is zero" +b := x positive. "test if number is positive" +b := x strictlyPositive. "test if number is greater than zero" +b := x negative. "test if number is negative" +b := x even. "test if number is even" +b := x odd. "test if number is odd" +b := x isLiteral. "test if literal constant" +b := x isInteger. "test if object is integer" +b := x isFloat. "test if object is float" +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: +``` +| x | +x := 6 + 3. "addition" +x := 6 - 3. "subtraction" +x := 6 * 3. "multiplication" +x := 1 + 2 * 3. "evaluation always left to right (1 + 2) * 3" +x := 5 / 3. "division with fractional result" +x := 5.0 / 3.0. "division with float result" +x := 5.0 // 3.0. "integer divide" +x := 5.0 \\ 3.0. "integer remainder" +x := -5. "unary minus" +x := 5 sign. "numeric sign (1, -1 or 0)" +x := 5 negated. "negate receiver" +x := 1.2 integerPart. "integer part of number (1.0)" +x := 1.2 fractionPart. "fractional part of number (0.2)" +x := 5 reciprocal. "reciprocal function" +x := 6 * 3.1. "auto convert to float" +x := 5 squared. "square function" +x := 25 sqrt. "square root" +x := 5 raisedTo: 2. "power function" +x := 5 raisedToInteger: 2. "power function with integer" +x := 5 exp. "exponential" +x := -5 abs. "absolute value" +x := 3.99 rounded. "round" +x := 3.99 truncated. "truncate" +x := 3.99 roundTo: 1. "round to specified decimal places" +x := 3.99 truncateTo: 1. "truncate to specified decimal places" +x := 3.99 floor. "truncate" +x := 3.99 ceiling. "round up" +x := 5 factorial. "factorial" +x := -5 quo: 3. "integer divide rounded toward zero" +x := -5 rem: 3. "integer remainder rounded toward zero" +x := 28 gcd: 12. "greatest common denominator" +x := 28 lcm: 12. "least common multiple" +x := 100 ln. "natural logarithm" +x := 100 log. "base 10 logarithm" +x := 100 log: 10. "logarithm with specified base" +x := 100 floorLog: 10. "floor of the log" +x := 180 degreesToRadians. "convert degrees to radians" +x := 3.14 radiansToDegrees. "convert radians to degrees" +x := 0.7 sin. "sine" +x := 0.7 cos. "cosine" +x := 0.7 tan. "tangent" +x := 0.7 arcSin. "arcsine" +x := 0.7 arcCos. "arccosine" +x := 0.7 arcTan. "arctangent" +x := 10 max: 20. "get maximum of two numbers" +x := 10 min: 20. "get minimum of two numbers" +x := Float pi. "pi" +x := Float e. "exp constant" +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: +``` +| b x | +x := 16rFF bitAnd: 16r0F. "and bits" +x := 16rF0 bitOr: 16r0F. "or bits" +x := 16rFF bitXor: 16r0F. "xor bits" +x := 16rFF bitInvert. "invert bits" +x := 16r0F bitShift: 4. "left shift" +x := 16rF0 bitShift: -4. "right shift" +"x := 16r80 bitAt: 7." "bit at position (0|1) [!Squeak]" +x := 16r80 highbit. "position of highest bit set" +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: +``` +| x | +x := 3.99 asInteger. "convert number to integer (truncates in Squeak)" +x := 3.99 asFraction. "convert number to fraction" +x := 3 asFloat. "convert number to float" +x := 65 asCharacter. "convert integer to character" +x := $A asciiValue. "convert character to integer" +x := 3.99 printString. "convert object to string via printOn:" +x := 3.99 storeString. "convert object to string via storeOn:" +x := 15 radix: 16. "convert to string in given base" +x := 15 printStringBase: 16. +x := 15 storeStringBase: 16. + +``` + +## Blocks: +- blocks are objects and may be assigned to a variable +- value is last expression evaluated unless explicit return +- blocks may be nested +- specification [ arguments | | localvars | expressions ] +- Squeak does not currently support localvars in blocks +- max of three arguments allowed +- `^`expression terminates block & method (exits all nested blocks) +- blocks intended for long term storage should not contain `^` + +``` +| x y z | +x := [ y := 1. z := 2. ]. x value. "simple block usage" +x := [ :argOne :argTwo | argOne, ' and ' , argTwo.]. "set up block with argument passing" +Transcript show: (x value: 'First' value: 'Second'); cr. "use block with argument passing" +"x := [ | z | z := 1.]. *** localvars not available in squeak blocks" +``` + +## 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) +- accessing (get/set methods) +- testing (boolean tests - is) +- comparing (boolean tests with parameter +- displaying (gui related methods) +- printing (methods for printing) +- updating (receive notification of changes) +- private (methods private to class) +- instance-creation (class methods for creating instance) +``` +| x | +x := 2 sqrt. "unary message" +x := 2 raisedTo: 10. "keyword message" +x := 194 * 9. "binary message" +Transcript show: (194 * 9) printString; cr. "combination (chaining)" +x := 2 perform: #sqrt. "indirect method invocation" +Transcript "Cascading - send multiple messages to receiver" + show: 'hello '; + show: 'world'; + cr. +x := 3 + 2; * 100. "result=300. Sends message to same receiver (3)" +``` + +##Conditional Statements: +``` +| x | +x > 10 ifTrue: [Transcript show: 'ifTrue'; cr]. "if then" +x > 10 ifFalse: [Transcript show: 'ifFalse'; cr]. "if else" +x > 10 "if then else" + ifTrue: [Transcript show: 'ifTrue'; cr] + ifFalse: [Transcript show: 'ifFalse'; cr]. +x > 10 "if else then" + ifFalse: [Transcript show: 'ifFalse'; cr] + ifTrue: [Transcript show: 'ifTrue'; cr]. +Transcript + show: + (x > 10 + ifTrue: ['ifTrue'] + ifFalse: ['ifFalse']); + cr. +Transcript "nested if then else" + show: + (x > 10 + ifTrue: [x > 5 + ifTrue: ['A'] + ifFalse: ['B']] + ifFalse: ['C']); + cr. +switch := Dictionary new. "switch functionality" +switch at: $A put: [Transcript show: 'Case A'; cr]. +switch at: $B put: [Transcript show: 'Case B'; cr]. +switch at: $C put: [Transcript show: 'Case C'; cr]. +result := (switch at: $B) value. +``` + +## Iteration statements: +``` +| x y | +x := 4. y := 1. +[x > 0] whileTrue: [x := x - 1. y := y * 2]. "while true loop" +[x >= 4] whileFalse: [x := x + 1. y := y * 2]. "while false loop" +x timesRepeat: [y := y * 2]. "times repear loop (i := 1 to x)" +1 to: x do: [:a | y := y * 2]. "for loop" +1 to: x by: 2 do: [:a | y := y / 2]. "for loop with specified increment" +#(5 4 3) do: [:a | x := x + a]. "iterate over array elements" +``` + +## Character: +``` +| x y | +x := $A. "character assignment" +y := x isLowercase. "test if lower case" +y := x isUppercase. "test if upper case" +y := x isLetter. "test if letter" +y := x isDigit. "test if digit" +y := x isAlphaNumeric. "test if alphanumeric" +y := x isSeparator. "test if seperator char" +y := x isVowel. "test if vowel" +y := x digitValue. "convert to numeric digit value" +y := x asLowercase. "convert to lower case" +y := x asUppercase. "convert to upper case" +y := x asciiValue. "convert to numeric ascii value" +y := x asString. "convert to string" +b := $A <= $B. "comparison" +y := $A max: $B. + +``` + +## Symbol: +``` +| b x y | +x := #Hello. "symbol assignment" +y := 'String', 'Concatenation'. "symbol concatenation (result is string)" +b := x isEmpty. "test if symbol is empty" +y := x size. "string size" +y := x at: 2. "char at location" +y := x copyFrom: 2 to: 4. "substring" +y := x indexOf: $e ifAbsent: [0]. "first position of character within string" +x do: [:a | Transcript show: a printString; cr]. "iterate over the string" +b := x conform: [:a | (a >= $a) & (a <= $z)]. "test if all elements meet condition" +y := x select: [:a | a > $a]. "return all elements that meet condition" +y := x asString. "convert symbol to string" +y := x asText. "convert symbol to text" +y := x asArray. "convert symbol to array" +y := x asOrderedCollection. "convert symbol to ordered collection" +y := x asSortedCollection. "convert symbol to sorted collection" +y := x asBag. "convert symbol to bag collection" +y := x asSet. "convert symbol to set collection" +``` + +## String: +``` +| b x y | +x := 'This is a string'. "string assignment" +x := 'String', 'Concatenation'. "string concatenation" +b := x isEmpty. "test if string is empty" +y := x size. "string size" +y := x at: 2. "char at location" +y := x copyFrom: 2 to: 4. "substring" +y := x indexOf: $a ifAbsent: [0]. "first position of character within string" +x := String new: 4. "allocate string object" +x "set string elements" + at: 1 put: $a; + at: 2 put: $b; + at: 3 put: $c; + at: 4 put: $e. +x := String with: $a with: $b with: $c with: $d. "set up to 4 elements at a time" +x do: [:a | Transcript show: a printString; cr]. "iterate over the string" +b := x conform: [:a | (a >= $a) & (a <= $z)]. "test if all elements meet condition" +y := x select: [:a | a > $a]. "return all elements that meet condition" +y := x asSymbol. "convert string to symbol" +y := x asArray. "convert string to array" +x := 'ABCD' asByteArray. "convert string to byte array" +y := x asOrderedCollection. "convert string to ordered collection" +y := x asSortedCollection. "convert string to sorted collection" +y := x asBag. "convert string to bag collection" +y := x asSet. "convert string to set collection" +y := x shuffled. "randomly shuffle string" +``` + +## Array: Fixed length collection +- ByteArray: Array limited to byte elements (0-255) +- WordArray: Array limited to word elements (0-2^32) + +``` +| b x y sum max | +x := #(4 3 2 1). "constant array" +x := Array with: 5 with: 4 with: 3 with: 2. "create array with up to 4 elements" +x := Array new: 4. "allocate an array with specified size" +x "set array elements" + at: 1 put: 5; + at: 2 put: 4; + at: 3 put: 3; + at: 4 put: 2. +b := x isEmpty. "test if array is empty" +y := x size. "array size" +y := x at: 4. "get array element at index" +b := x includes: 3. "test if element is in array" +y := x copyFrom: 2 to: 4. "subarray" +y := x indexOf: 3 ifAbsent: [0]. "first position of element within array" +y := x occurrencesOf: 3. "number of times object in collection" +x do: [:a | Transcript show: a printString; cr]. "iterate over the array" +b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition" +y := x select: [:a | a > 2]. "return collection of elements that pass test" +y := x reject: [:a | a < 2]. "return collection of elements that fail test" +y := x collect: [:a | a + a]. "transform each element for new collection" +y := x detect: [:a | a > 3] ifNone: []. "find position of first element that passes test" +sum := 0. x do: [:a | sum := sum + a]. sum. "sum array elements" +sum := 0. 1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum array elements" +sum := x inject: 0 into: [:a :c | a + c]. "sum array elements" +max := x inject: 0 into: [:a :c | (a > c) "find max element in array" + ifTrue: [a] + ifFalse: [c]]. +y := x shuffled. "randomly shuffle collection" +y := x asArray. "convert to array" +"y := x asByteArray." "note: this instruction not available on Squeak" +y := x asWordArray. "convert to word array" +y := x asOrderedCollection. "convert to ordered collection" +y := x asSortedCollection. "convert to sorted collection" +y := x asBag. "convert to bag collection" +y := x asSet. "convert to set collection" +``` + +##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" +x := OrderedCollection new. "allocate collection" +x add: 3; add: 2; add: 1; add: 4; yourself. "add element to collection" +y := x addFirst: 5. "add element at beginning of collection" +y := x removeFirst. "remove first element in collection" +y := x addLast: 6. "add element at end of collection" +y := x removeLast. "remove last element in collection" +y := x addAll: #(7 8 9). "add multiple elements to collection" +y := x removeAll: #(7 8 9). "remove multiple elements from collection" +x at: 2 put: 3. "set element at index" +y := x remove: 5 ifAbsent: []. "remove element from collection" +b := x isEmpty. "test if empty" +y := x size. "number of elements" +y := x at: 2. "retrieve element at index" +y := x first. "retrieve first element in collection" +y := x last. "retrieve last element in collection" +b := x includes: 5. "test if element is in collection" +y := x copyFrom: 2 to: 3. "subcollection" +y := x indexOf: 3 ifAbsent: [0]. "first position of element within collection" +y := x occurrencesOf: 3. "number of times object in collection" +x do: [:a | Transcript show: a printString; cr]. "iterate over the collection" +b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition" +y := x select: [:a | a > 2]. "return collection of elements that pass test" +y := x reject: [:a | a < 2]. "return collection of elements that fail test" +y := x collect: [:a | a + a]. "transform each element for new collection" +y := x detect: [:a | a > 3] ifNone: []. "find position of first element that passes test" +sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements" +sum := 0. 1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum elements" +sum := x inject: 0 into: [:a :c | a + c]. "sum elements" +max := x inject: 0 into: [:a :c | (a > c) "find max element in collection" + ifTrue: [a] + ifFalse: [c]]. +y := x shuffled. "randomly shuffle collection" +y := x asArray. "convert to array" +y := x asOrderedCollection. "convert to ordered collection" +y := x asSortedCollection. "convert to sorted collection" +y := x asBag. "convert to bag collection" +y := x asSet. "convert to set collection" +``` + +## 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" +x := SortedCollection new. "allocate collection" +x := SortedCollection sortBlock: [:a :c | a > c]. "set sort criteria" +x add: 3; add: 2; add: 1; add: 4; yourself. "add element to collection" +y := x addFirst: 5. "add element at beginning of collection" +y := x removeFirst. "remove first element in collection" +y := x addLast: 6. "add element at end of collection" +y := x removeLast. "remove last element in collection" +y := x addAll: #(7 8 9). "add multiple elements to collection" +y := x removeAll: #(7 8 9). "remove multiple elements from collection" +y := x remove: 5 ifAbsent: []. "remove element from collection" +b := x isEmpty. "test if empty" +y := x size. "number of elements" +y := x at: 2. "retrieve element at index" +y := x first. "retrieve first element in collection" +y := x last. "retrieve last element in collection" +b := x includes: 4. "test if element is in collection" +y := x copyFrom: 2 to: 3. "subcollection" +y := x indexOf: 3 ifAbsent: [0]. "first position of element within collection" +y := x occurrencesOf: 3. "number of times object in collection" +x do: [:a | Transcript show: a printString; cr]. "iterate over the collection" +b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition" +y := x select: [:a | a > 2]. "return collection of elements that pass test" +y := x reject: [:a | a < 2]. "return collection of elements that fail test" +y := x collect: [:a | a + a]. "transform each element for new collection" +y := x detect: [:a | a > 3] ifNone: []. "find position of first element that passes test" +sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements" +sum := 0. 1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum elements" +sum := x inject: 0 into: [:a :c | a + c]. "sum elements" +max := x inject: 0 into: [:a :c | (a > c) "find max element in collection" + ifTrue: [a] + ifFalse: [c]]. +y := x asArray. "convert to array" +y := x asOrderedCollection. "convert to ordered collection" +y := x asSortedCollection. "convert to sorted collection" +y := x asBag. "convert to bag collection" +y := x asSet. "convert to set collection" +``` + +## 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" +x := Bag new. "allocate collection" +x add: 4; add: 3; add: 1; add: 2; yourself. "add element to collection" +x add: 3 withOccurrences: 2. "add multiple copies to collection" +y := x addAll: #(7 8 9). "add multiple elements to collection" +y := x removeAll: #(7 8 9). "remove multiple elements from collection" +y := x remove: 4 ifAbsent: []. "remove element from collection" +b := x isEmpty. "test if empty" +y := x size. "number of elements" +b := x includes: 3. "test if element is in collection" +y := x occurrencesOf: 3. "number of times object in collection" +x do: [:a | Transcript show: a printString; cr]. "iterate over the collection" +b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition" +y := x select: [:a | a > 2]. "return collection of elements that pass test" +y := x reject: [:a | a < 2]. "return collection of elements that fail test" +y := x collect: [:a | a + a]. "transform each element for new collection" +y := x detect: [:a | a > 3] ifNone: []. "find position of first element that passes test" +sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements" +sum := x inject: 0 into: [:a :c | a + c]. "sum elements" +max := x inject: 0 into: [:a :c | (a > c) "find max element in collection" + ifTrue: [a] + ifFalse: [c]]. +y := x asOrderedCollection. "convert to ordered collection" +y := x asSortedCollection. "convert to sorted collection" +y := x asBag. "convert to bag collection" +y := x asSet. "convert to set collection" +``` + +## 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" +x := Set new. "allocate collection" +x add: 4; add: 3; add: 1; add: 2; yourself. "add element to collection" +y := x addAll: #(7 8 9). "add multiple elements to collection" +y := x removeAll: #(7 8 9). "remove multiple elements from collection" +y := x remove: 4 ifAbsent: []. "remove element from collection" +b := x isEmpty. "test if empty" +y := x size. "number of elements" +x includes: 4. "test if element is in collection" +x do: [:a | Transcript show: a printString; cr]. "iterate over the collection" +b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition" +y := x select: [:a | a > 2]. "return collection of elements that pass test" +y := x reject: [:a | a < 2]. "return collection of elements that fail test" +y := x collect: [:a | a + a]. "transform each element for new collection" +y := x detect: [:a | a > 3] ifNone: []. "find position of first element that passes test" +sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements" +sum := x inject: 0 into: [:a :c | a + c]. "sum elements" +max := x inject: 0 into: [:a :c | (a > c) "find max element in collection" + ifTrue: [a] + ifFalse: [c]]. +y := x asArray. "convert to array" +y := x asOrderedCollection. "convert to ordered collection" +y := x asSortedCollection. "convert to sorted collection" +y := x asBag. "convert to bag collection" +y := x asSet. "convert to set collection" +``` + +## Interval: +``` +| b x y sum max | +x := Interval from: 5 to: 10. "create interval object" +x := 5 to: 10. +x := Interval from: 5 to: 10 by: 2. "create interval object with specified increment" +x := 5 to: 10 by: 2. +b := x isEmpty. "test if empty" +y := x size. "number of elements" +x includes: 9. "test if element is in collection" +x do: [:k | Transcript show: k printString; cr]. "iterate over interval" +b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition" +y := x select: [:a | a > 7]. "return collection of elements that pass test" +y := x reject: [:a | a < 2]. "return collection of elements that fail test" +y := x collect: [:a | a + a]. "transform each element for new collection" +y := x detect: [:a | a > 3] ifNone: []. "find position of first element that passes test" +sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements" +sum := 0. 1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum elements" +sum := x inject: 0 into: [:a :c | a + c]. "sum elements" +max := x inject: 0 into: [:a :c | (a > c) "find max element in collection" + ifTrue: [a] + ifFalse: [c]]. +y := x asArray. "convert to array" +y := x asOrderedCollection. "convert to ordered collection" +y := x asSortedCollection. "convert to sorted collection" +y := x asBag. "convert to bag collection" +y := x asSet. "convert to set collection" +``` + +##Associations: +``` +| x y | +x := #myVar->'hello'. +y := x key. +y := x value. +``` + +## Dictionary: +## IdentityDictionary: uses identity test (== rather than =) +``` +| b x y | +x := Dictionary new. "allocate collection" +x add: #a->4; add: #b->3; add: #c->1; add: #d->2; yourself. "add element to collection" +x at: #e put: 3. "set element at index" +b := x isEmpty. "test if empty" +y := x size. "number of elements" +y := x at: #a ifAbsent: []. "retrieve element at index" +y := x keyAtValue: 3 ifAbsent: []. "retrieve key for given value with error block" +y := x removeKey: #e ifAbsent: []. "remove element from collection" +b := x includes: 3. "test if element is in values collection" +b := x includesKey: #a. "test if element is in keys collection" +y := x occurrencesOf: 3. "number of times object in collection" +y := x keys. "set of keys" +y := x values. "bag of values" +x do: [:a | Transcript show: a printString; cr]. "iterate over the values collection" +x keysDo: [:a | Transcript show: a printString; cr]. "iterate over the keys collection" +x associationsDo: [:a | Transcript show: a printString; cr]."iterate over the associations" +x keysAndValuesDo: [:aKey :aValue | Transcript "iterate over keys and values" + show: aKey printString; space; + show: aValue printString; cr]. +b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition" +y := x select: [:a | a > 2]. "return collection of elements that pass test" +y := x reject: [:a | a < 2]. "return collection of elements that fail test" +y := x collect: [:a | a + a]. "transform each element for new collection" +y := x detect: [:a | a > 3] ifNone: []. "find position of first element that passes test" +sum := 0. x do: [:a | sum := sum + a]. sum. "sum elements" +sum := x inject: 0 into: [:a :c | a + c]. "sum elements" +max := x inject: 0 into: [:a :c | (a > c) "find max element in collection" + ifTrue: [a] + ifFalse: [c]]. +y := x asArray. "convert to array" +y := x asOrderedCollection. "convert to ordered collection" +y := x asSortedCollection. "convert to sorted collection" +y := x asBag. "convert to bag collection" +y := x asSet. "convert to set collection" + +Smalltalk at: #CMRGlobal put: 'CMR entry'. "put global in Smalltalk Dictionary" +x := Smalltalk at: #CMRGlobal. "read global from Smalltalk Dictionary" +Transcript show: (CMRGlobal printString). "entries are directly accessible by name" +Smalltalk keys do: [ :k | "print out all classes" + ((Smalltalk at: k) isKindOf: Class) + ifFalse: [Transcript show: k printString; cr]]. +Smalltalk at: #CMRDictionary put: (Dictionary new). "set up user defined dictionary" +CMRDictionary at: #MyVar1 put: 'hello1'. "put entry in dictionary" +CMRDictionary add: #MyVar2->'hello2'. "add entry to dictionary use key->value combo" +CMRDictionary size. "dictionary size" +CMRDictionary keys do: [ :k | "print out keys in dictionary" + Transcript show: k printString; cr]. +CMRDictionary values do: [ :k | "print out values in dictionary" + Transcript show: k printString; cr]. +CMRDictionary keysAndValuesDo: [:aKey :aValue | "print out keys and values" + Transcript + show: aKey printString; + space; + show: aValue printString; + cr]. +CMRDictionary associationsDo: [:aKeyValue | "another iterator for printing key values" + Transcript show: aKeyValue printString; cr]. +Smalltalk removeKey: #CMRGlobal ifAbsent: []. "remove entry from Smalltalk dictionary" +Smalltalk removeKey: #CMRDictionary ifAbsent: []. "remove user dictionary from Smalltalk dictionary" +``` + +## Internal Stream: +``` +| b x ios | +ios := ReadStream on: 'Hello read stream'. +ios := ReadStream on: 'Hello read stream' from: 1 to: 5. +[(x := ios nextLine) notNil] + whileTrue: [Transcript show: x; cr]. +ios position: 3. +ios position. +x := ios next. +x := ios peek. +x := ios contents. +b := ios atEnd. + +ios := ReadWriteStream on: 'Hello read stream'. +ios := ReadWriteStream on: 'Hello read stream' from: 1 to: 5. +ios := ReadWriteStream with: 'Hello read stream'. +ios := ReadWriteStream with: 'Hello read stream' from: 1 to: 10. +ios position: 0. +[(x := ios nextLine) notNil] + whileTrue: [Transcript show: x; cr]. +ios position: 6. +ios position. +ios nextPutAll: 'Chris'. +x := ios next. +x := ios peek. +x := ios contents. +b := ios atEnd. +``` + +## FileStream: +``` +| b x ios | +ios := FileStream newFileNamed: 'ios.txt'. +ios nextPut: $H; cr. +ios nextPutAll: 'Hello File'; cr. +'Hello File' printOn: ios. +'Hello File' storeOn: ios. +ios close. + +ios := FileStream oldFileNamed: 'ios.txt'. +[(x := ios nextLine) notNil] + whileTrue: [Transcript show: x; cr]. +ios position: 3. +x := ios position. +x := ios next. +x := ios peek. +b := ios atEnd. +ios close. +``` + +## Date: +``` +| x y | +x := Date today. "create date for today" +x := Date dateAndTimeNow. "create date from current time/date" +x := Date readFromString: '01/02/1999'. "create date from formatted string" +x := Date newDay: 12 month: #July year: 1999 "create date from parts" +x := Date fromDays: 36000. "create date from elapsed days since 1/1/1901" +y := Date dayOfWeek: #Monday. "day of week as int (1-7)" +y := Date indexOfMonth: #January. "month of year as int (1-12)" +y := Date daysInMonth: 2 forYear: 1996. "day of month as int (1-31)" +y := Date daysInYear: 1996. "days in year (365|366)" +y := Date nameOfDay: 1 "weekday name (#Monday,...)" +y := Date nameOfMonth: 1. "month name (#January,...)" +y := Date leapYear: 1996. "1 if leap year; 0 if not leap year" +y := x weekday. "day of week (#Monday,...)" +y := x previous: #Monday. "date for previous day of week" +y := x dayOfMonth. "day of month (1-31)" +y := x day. "day of year (1-366)" +y := x firstDayOfMonth. "day of year for first day of month" +y := x monthName. "month of year (#January,...)" +y := x monthIndex. "month of year (1-12)" +y := x daysInMonth. "days in month (1-31)" +y := x year. "year (19xx)" +y := x daysInYear. "days in year (365|366)" +y := x daysLeftInYear. "days left in year (364|365)" +y := x asSeconds. "seconds elapsed since 1/1/1901" +y := x addDays: 10. "add days to date object" +y := x subtractDays: 10. "subtract days to date object" +y := x subtractDate: (Date today). "subtract date (result in days)" +y := x printFormat: #(2 1 3 $/ 1 1). "print formatted date" +b := (x <= Date today). "comparison" +``` + +## Time: +``` +| x y | +x := Time now. "create time from current time" +x := Time dateAndTimeNow. "create time from current time/date" +x := Time readFromString: '3:47:26 pm'. "create time from formatted string" +x := Time fromSeconds: (60 * 60 * 4). "create time from elapsed time from midnight" +y := Time millisecondClockValue. "milliseconds since midnight" +y := Time totalSeconds. "total seconds since 1/1/1901" +y := x seconds. "seconds past minute (0-59)" +y := x minutes. "minutes past hour (0-59)" +y := x hours. "hours past midnight (0-23)" +y := x addTime: (Time now). "add time to time object" +y := x subtractTime: (Time now). "subtract time to time object" +y := x asSeconds. "convert time to seconds" +x := Time millisecondsToRun: [ "timing facility" + 1 to: 1000 do: [:index | y := 3.14 * index]]. +b := (x <= Time now). "comparison" +``` + +## Point: +``` +| x y | +x := 200@100. "obtain a new point" +y := x x. "x coordinate" +y := x y. "y coordinate" +x := 200@100 negated. "negates x and y" +x := (-200@-100) abs. "absolute value of x and y" +x := (200.5@100.5) rounded. "round x and y" +x := (200.5@100.5) truncated. "truncate x and y" +x := 200@100 + 100. "add scale to both x and y" +x := 200@100 - 100. "subtract scale from both x and y" +x := 200@100 * 2. "multiply x and y by scale" +x := 200@100 / 2. "divide x and y by scale" +x := 200@100 // 2. "divide x and y by scale" +x := 200@100 \\ 3. "remainder of x and y by scale" +x := 200@100 + 50@25. "add points" +x := 200@100 - 50@25. "subtract points" +x := 200@100 * 3@4. "multiply points" +x := 200@100 // 3@4. "divide points" +x := 200@100 max: 50@200. "max x and y" +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 fromUser. +``` + +## Pen: +``` +| myPen | +Display restoreAfter: [ + Display fillWhite. + +myPen := Pen new. "get graphic pen" +myPen squareNib: 1. +myPen color: (Color blue). "set pen color" +myPen home. "position pen at center of display" +myPen up. "makes nib unable to draw" +myPen down. "enable the nib to draw" +myPen north. "points direction towards top" +myPen turn: -180. "add specified degrees to direction" +myPen direction. "get current angle of pen" +myPen go: 50. "move pen specified number of pixels" +myPen location. "get the pen position" +myPen goto: 200@200. "move to specified point" +myPen place: 250@250. "move to specified point without drawing" +myPen print: 'Hello World' withFont: (TextStyle default fontAt: 1). +Display extent. "get display width@height" +Display width. "get display width" +Display height. "get display height" + +]. +``` + +## Dynamic Message Calling/Compiling: +``` +| receiver message result argument keyword1 keyword2 argument1 argument2 | +"unary message" +receiver := 5. +message := 'factorial' asSymbol. +result := receiver perform: message. +result := Compiler evaluate: ((receiver storeString), ' ', message). +result := (Message new setSelector: message arguments: #()) sentTo: receiver. + +"binary message" +receiver := 1. +message := '+' asSymbol. +argument := 2. +result := receiver perform: message withArguments: (Array with: argument). +result := Compiler evaluate: ((receiver storeString), ' ', message, ' ', (argument storeString)). +result := (Message new setSelector: message arguments: (Array with: argument)) sentTo: receiver. + +"keyword messages" +receiver := 12. +keyword1 := 'between:' asSymbol. +keyword2 := 'and:' asSymbol. +argument1 := 10. +argument2 := 20. +result := receiver + perform: (keyword1, keyword2) asSymbol + withArguments: (Array with: argument1 with: argument2). +result := Compiler evaluate: + ((receiver storeString), ' ', keyword1, (argument1 storeString) , ' ', keyword2, (argument2 storeString)). +result := (Message + new + setSelector: (keyword1, keyword2) asSymbol + arguments: (Array with: argument1 with: argument2)) + sentTo: receiver. +``` + +## Class/Meta-class: +``` +| b x | +x := String name. "class name" +x := String category. "organization category" +x := String comment. "class comment" +x := String kindOfSubclass. "subclass type - subclass: variableSubclass, etc" +x := String definition. "class definition" +x := String instVarNames. "immediate instance variable names" +x := String allInstVarNames. "accumulated instance variable names" +x := String classVarNames. "immediate class variable names" +x := String allClassVarNames. "accumulated class variable names" +x := String sharedPools. "immediate dictionaries used as shared pools" +x := String allSharedPools. "accumulated dictionaries used as shared pools" +x := String selectors. "message selectors for class" +x := String sourceCodeAt: #size. "source code for specified method" +x := String allInstances. "collection of all instances of class" +x := String superclass. "immediate superclass" +x := String allSuperclasses. "accumulated superclasses" +x := String withAllSuperclasses. "receiver class and accumulated superclasses" +x := String subclasses. "immediate subclasses" +x := String allSubclasses. "accumulated subclasses" +x := String withAllSubclasses. "receiver class and accumulated subclasses" +b := String instSize. "number of named instance variables" +b := String isFixed. "true if no indexed instance variables" +b := String isVariable. "true if has indexed instance variables" +b := String isPointers. "true if index instance vars contain objects" +b := String isBits. "true if index instance vars contain bytes/words" +b := String isBytes. "true if index instance vars contain bytes" +b := String isWords. true if index instance vars contain words" +Object withAllSubclasses size. "get total number of class entries" +``` + +## Debuging: +``` +| a b x | +x yourself. "returns receiver" +String browse. "browse specified class" +x inspect. "open object inspector window" +x confirm: 'Is this correct?'. +x halt. "breakpoint to open debugger window" +x halt: 'Halt message'. +x notify: 'Notify text'. +x error: 'Error string'. "open up error window with title" +x doesNotUnderstand: #cmrMessage. "flag message is not handled" +x shouldNotImplement. "flag message should not be implemented" +x subclassResponsibility. "flag message as abstract" +x errorImproperStore. "flag an improper store into indexable object" +x errorNonIntegerIndex. "flag only integers should be used as index" +x errorSubscriptBounds. "flag subscript out of bounds" +x primitiveFailed. "system primitive failed" + +a := 'A1'. b := 'B2'. a become: b. "switch two objects" +Transcript show: a, b; cr. +``` + +## Misc +``` +| x | +"Smalltalk condenseChanges." "compress the change file" +x := FillInTheBlank request: 'Prompt Me'. "prompt user for input" +Utilities openCommandKeyHelp +``` + + + + +## Ready For More? + +### Free Online + +* [GNU Smalltalk User's Guide](https://www.gnu.org/software/smalltalk/manual/html_node/Tutorial.html) +* [smalltalk dot org](http://www.smalltalk.org/smalltalk/learning.html) +* [Computer Programming using GNU Smalltalk](http://www.canol.info/books/computer_programming_using_gnu_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) +* [BYTE: A Special issue on Smalltalk](https://archive.org/details/byte-magazine-1981-08) +* [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/) diff --git a/swift.html.markdown b/swift.html.markdown index 509c9d2f..f451288d 100644 --- a/swift.html.markdown +++ b/swift.html.markdown @@ -3,8 +3,9 @@ language: swift contributors: - ["Grant Timmerman", "http://github.com/grant"] - ["Christopher Bess", "http://github.com/cbess"] - - ["Joey Huang", "http://github.com/kamidox"] + - ["Joey Huang", "http://github.com/kamidox"] - ["Anthony Nguyen", "http://github.com/anthonyn60"] + - ["Clayton Walker", "https://github.com/cwalk"] filename: learnswift.swift --- @@ -12,7 +13,7 @@ Swift is a programming language for iOS and OS X development created by Apple. D 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/RoadMapiOS/index.html), which has a complete tutorial on Swift. +See also Apple's [getting started guide](https://developer.apple.com/library/prerelease/ios/referencelibrary/GettingStarted/DevelopiOSAppsSwift/), which has a complete tutorial on Swift. ```swift // import a module @@ -57,8 +58,9 @@ let piText = "Pi = \(π), Pi 2 = \(π * 2)" // String interpolation print("Build value: \(buildValue)") // Build value: 7 /* - Optionals are a Swift language feature that allows you to store a `Some` or - `None` value. + Optionals are a Swift language feature that either contains a value, + or contains nil (no value) to indicate that a value is missing. + A question mark (?) after the type marks the value as optional. Because Swift requires every property to have a value, even nil must be explicitly stored as an Optional value. @@ -74,11 +76,17 @@ if someOptionalString != nil { if someOptionalString!.hasPrefix("opt") { print("has the prefix") } - + let empty = someOptionalString?.isEmpty } someOptionalString = nil +/* + Trying to use ! to access a non-existent optional value triggers a runtime + error. Always make sure that an optional contains a non-nil value before + using ! to force-unwrap its value. +*/ + // implicitly unwrapped optional var unwrappedString: String! = "Value is expected." // same as above, but ! is a postfix operator (more syntax candy) @@ -93,13 +101,13 @@ if let someOptionalStringConstant = someOptionalString { // Swift has support for storing a value of any type. // AnyObject == id -// Unlike Objective-C `id`, AnyObject works with any value (Class, Int, struct, etc) +// Unlike Objective-C `id`, AnyObject works with any value (Class, Int, struct, etc.) var anyObjectVar: AnyObject = 7 anyObjectVar = "Changed value to a string, not good practice, but possible." /* Comment here - + /* Nested comments are also supported */ @@ -295,10 +303,10 @@ print(numbers) // [3, 6, 18] // MARK: Structures // -// Structures and classes have very similar capabilites +// Structures and classes have very similar capabilities struct NamesTable { let names = [String]() - + // Custom subscript subscript(index: Int) -> String { return names[index] @@ -329,7 +337,7 @@ public class Shape { internal class Rect: Shape { var sideLength: Int = 1 - + // Custom getter and setter property private var perimeter: Int { get { @@ -340,11 +348,11 @@ internal class Rect: Shape { sideLength = newValue / 4 } } - + // Lazily load a property // subShape remains nil (uninitialized) until getter called lazy var subShape = Rect(sideLength: 4) - + // If you don't need a custom getter and setter, // but still want to run code before and after getting or setting // a property, you can use `willSet` and `didSet` @@ -354,19 +362,19 @@ internal class Rect: Shape { print(someIdentifier) } } - + init(sideLength: Int) { self.sideLength = sideLength // always super.init last when init custom properties super.init() } - + func shrink() { if sideLength > 0 { --sideLength } } - + override func getArea() -> Int { return sideLength * sideLength } @@ -398,13 +406,13 @@ class Circle: Shape { override func getArea() -> Int { return 3 * radius * radius } - + // Place a question mark postfix after `init` is an optional init // which can return nil init?(radius: Int) { self.radius = radius super.init() - + if radius <= 0 { return nil } @@ -458,7 +466,7 @@ enum Furniture { case Desk(height: Int) // Associate with String and Int case Chair(String, Int) - + func description() -> String { switch self { case .Desk(let height): @@ -497,7 +505,7 @@ protocol ShapeGenerator { class MyShape: Rect { var delegate: TransformShape? - + func grow() { sideLength += 2 @@ -532,7 +540,7 @@ extension Int { var customProperty: String { return "This is \(self)" } - + func multiplyBy(num: Int) -> Int { return num * self } @@ -574,4 +582,18 @@ print(mySquare.sideLength) // 4 // change side length using custom !!! operator, increases size by 3 !!!mySquare print(mySquare.sideLength) // 12 + +// Operators can also be generics +infix operator <-> {} +func <-><T: Equatable> (inout a: T, inout b: T) { + let c = a + a = b + b = c +} + +var foo: Float = 10 +var bar: Float = 20 + +foo <-> bar +print("foo is \(foo), bar is \(bar)") // "foo is 20.0, bar is 10.0" ``` diff --git a/tcl.html.markdown b/tcl.html.markdown index af2911c9..b90bd690 100644 --- a/tcl.html.markdown +++ b/tcl.html.markdown @@ -14,7 +14,7 @@ programming language. It can also be used as a portable C library, even in cases where no scripting capability is needed, as it provides data structures such as dynamic strings, lists, and hash tables. The C library also provides portable functionality for loading dynamic libraries, string formatting and -code conversion, filesystem operations, network operations, and more. +code conversion, filesystem operations, network operations, and more. Various features of Tcl stand out: * Convenient cross-platform networking API @@ -58,14 +58,14 @@ lighter that that of Lisp, just gets out of the way. #! /bin/env tclsh ################################################################################ -## 1. Guidelines +## 1. Guidelines ################################################################################ # Tcl is not Bash or C! This needs to be said because standard shell quoting # habits almost work in Tcl and it is common for people to pick up Tcl and try # to get by with syntax they know from another language. It works at first, # but soon leads to frustration with more complex scripts. - + # Braces are just a quoting mechanism, not a code block constructor or a list # constructor. Tcl doesn't have either of those things. Braces are used, # though, to escape special characters in procedure bodies and in strings that @@ -73,7 +73,7 @@ lighter that that of Lisp, just gets out of the way. ################################################################################ -## 2. Syntax +## 2. Syntax ################################################################################ # Every line is a command. The first word is the name of the command, and @@ -83,13 +83,13 @@ lighter that that of Lisp, just gets out of the way. # are used, they are not a string constructor, but just another escaping # character. -set greeting1 Sal +set greeting1 Sal set greeting2 ut set greeting3 ations #semicolon also delimits commands -set greeting1 Sal; set greeting2 ut; set greeting3 ations +set greeting1 Sal; set greeting2 ut; set greeting3 ations # Dollar sign introduces variable substitution @@ -126,11 +126,11 @@ puts lots\nof\n\n\n\n\n\nnewlines set somevar { This is a literal $ sign, and this \} escaped brace remains uninterpreted -} +} # In a word enclosed in double quotes, whitespace characters lose their special -# meaning +# meaning set name Neo set greeting "Hello, $name" @@ -178,7 +178,7 @@ set greeting "Hello $people::person1::name" ################################################################################ -## 3. A Few Notes +## 3. A Few Notes ################################################################################ # All other functionality is implemented via commands. From this point on, @@ -193,8 +193,8 @@ set greeting "Hello $people::person1::name" namespace delete :: -# Because of name resolution behaviour, it's safer to use the "variable" command to -# declare or to assign a value to a namespace. If a variable called "name" already +# Because of name resolution behaviour, it's safer to use the "variable" command to +# declare or to assign a value to a namespace. If a variable called "name" already # exists in the global namespace, using "set" here will assign a value to the global variable # instead of creating a new variable in the local namespace. namespace eval people { @@ -210,7 +210,7 @@ set people::person1::name Neo ################################################################################ -## 4. Commands +## 4. Commands ################################################################################ # Math can be done with the "expr" command. @@ -295,7 +295,7 @@ while {$i < 10} { # A list is a specially-formatted string. In the simple case, whitespace is sufficient to delimit values -set amounts 10\ 33\ 18 +set amounts 10\ 33\ 18 set amount [lindex $amounts 1] @@ -339,7 +339,7 @@ eval {set name Neo} eval [list set greeting "Hello, $name"] -# Therefore, when using "eval", use [list] to build up a desired command +# Therefore, when using "eval", use [list] to build up a desired command set command {set name} lappend command {Archibald Sorbisol} eval $command @@ -355,8 +355,8 @@ eval $command ;# There is an error here, because there are too many arguments \ # This mistake can easily occur with the "subst" command. set replacement {Archibald Sorbisol} set command {set name $replacement} -set command [subst $command] -eval $command ;# The same error as before: to many arguments to "set" in \ +set command [subst $command] +eval $command ;# The same error as before: too many arguments to "set" in \ {set name Archibald Sorbisol} @@ -364,12 +364,12 @@ eval $command ;# The same error as before: to many arguments to "set" in \ # command. set replacement [list {Archibald Sorbisol}] set command {set name $replacement} -set command [subst $command] +set command [subst $command] eval $command # It is extremely common to see the "list" command being used to properly -# format values that are substituted into Tcl script templates. There are +# format values that are substituted into Tcl script templates. There are # several examples of this, below. @@ -422,12 +422,12 @@ proc while {condition script} { # The "coroutine" command creates a separate call stack, along with a command # to enter that call stack. The "yield" command suspends execution in that -# stack. +# stack. proc countdown {} { #send something back to the initial "coroutine" command yield - set count 3 + set count 3 while {$count > 1} { yield [incr count -1] } @@ -435,12 +435,12 @@ proc countdown {} { } coroutine countdown1 countdown coroutine countdown2 countdown -puts [countdown 1] ;# -> 2 -puts [countdown 2] ;# -> 2 -puts [countdown 1] ;# -> 1 -puts [countdown 1] ;# -> 0 +puts [countdown 1] ;# -> 2 +puts [countdown 2] ;# -> 2 +puts [countdown 1] ;# -> 1 +puts [countdown 1] ;# -> 0 puts [coundown 1] ;# -> invalid command name "countdown1" -puts [countdown 2] ;# -> 1 +puts [countdown 2] ;# -> 1 ``` diff --git a/tr-tr/csharp-tr.html.markdown b/tr-tr/csharp-tr.html.markdown index a68026a5..91c7c269 100644 --- a/tr-tr/csharp-tr.html.markdown +++ b/tr-tr/csharp-tr.html.markdown @@ -234,7 +234,8 @@ on a new line! ""Wow!"", the masses cried"; // Üçlü operatörler // Basit bir if/else ifadesi şöyle yazılabilir // <koşul> ? <true> : <false> - string isTrue = (true) ? "True" : "False"; + int toCompare = 17; + string isTrue = toCompare == 17 ? "True" : "False"; // While döngüsü int fooWhile = 0; diff --git a/tr-tr/swift-tr.html.markdown b/tr-tr/swift-tr.html.markdown index 90f3fcd5..c13f5ecf 100644 --- a/tr-tr/swift-tr.html.markdown +++ b/tr-tr/swift-tr.html.markdown @@ -7,13 +7,10 @@ lang: tr-tr --- Swift iOS ve OSX platformlarında geliştirme yapmak için Apple tarafından oluşturulan yeni bir programlama dilidir. Objective - C ile beraber kullanılabilecek ve de hatalı kodlara karşı daha esnek bir yapı sunacak bir şekilde tasarlanmıştır. Swift 2014 yılında Apple'ın geliştirici konferansı WWDC de tanıtıldı. Xcode 6+'a dahil edilen LLVM derleyici ile geliştirildi. - -The official [Swift Programming Language](https://itunes.apple.com/us/book/swift-programming-language/id881256329) book from Apple is now available via iBooks. + Apple'ın resmi [Swift Programlama Dili](https://itunes.apple.com/us/book/swift-programming-language/id881256329) kitabı iBooks'ta yerini aldı. -See also Apple's [getting started guide](https://developer.apple.com/library/prerelease/ios/referencelibrary/GettingStarted/RoadMapiOS/index.html), which has a complete tutorial on Swift. - Ayrıca Swift ile gelen tüm özellikleri görmek için Apple'ın [başlangıç kılavuzu](https://developer.apple.com/library/prerelease/ios/referencelibrary/GettingStarted/RoadMapiOS/index.html)na bakmanızda yarar var. @@ -244,7 +241,7 @@ print("Benzin fiyatı: \(fiyat)") // Çeşitli Argümanlar func ayarla(sayilar: Int...) { - // its an array + // bu bir dizidir let sayi = sayilar[0] let argumanSAyisi = sayilar.count } diff --git a/visualbasic.html.markdown b/visualbasic.html.markdown index 00d61843..bdfdcc10 100644 --- a/visualbasic.html.markdown +++ b/visualbasic.html.markdown @@ -17,7 +17,7 @@ Module Module1 ' This navigation system is explained however as we go deeper into this ' tutorial, you'll understand what it all means. Console.Title = ("Learn X in Y Minutes") - Console.WriteLine("NAVIGATION") 'Display + Console.WriteLine("NAVIGATION") 'Display Console.WriteLine("") Console.ForegroundColor = ConsoleColor.Green Console.WriteLine("1. Hello World Output") @@ -39,13 +39,13 @@ Module Module1 Case "2" 'Hello Input Console.Clear() HelloWorldInput() - Case "3" 'Calculating Whole Numbers + Case "3" 'Calculating Whole Numbers Console.Clear() CalculatingWholeNumbers() - Case "4" 'Calculting Decimal Numbers + Case "4" 'Calculting Decimal Numbers Console.Clear() CalculatingDecimalNumbers() - Case "5" 'Working Calcculator + Case "5" 'Working Calcculator Console.Clear() WorkingCalculator() Case "6" 'Using Do While Loops @@ -74,7 +74,7 @@ Module Module1 'One - I'm using numbers to help with the above navigation when I come back 'later to build it. - 'We use private subs to seperate different sections of the program. + 'We use private subs to seperate different sections of the program. Private Sub HelloWorldOutput() 'Title of Console Application Console.Title = "Hello World Ouput | Learn X in Y Minutes" @@ -172,7 +172,7 @@ Module Module1 'program more than once. Console.Title = "UsingDoWhileLoops | Learn X in Y Minutes" Dim answer As String 'We use the variable "String" as the answer is text - Do 'We start the program with + Do 'We start the program with Console.Write("First number: ") Dim a As Double = Console.ReadLine Console.Write("Second number: ") @@ -192,7 +192,7 @@ Module Module1 Console.WriteLine(" = " + f.ToString.PadLeft(3)) Console.ReadLine() 'Ask the question, does the user wish to continue? Unfortunately it - 'is case sensitive. + 'is case sensitive. Console.Write("Would you like to continue? (yes / no)") 'The program grabs the variable and prints and starts again. answer = Console.ReadLine @@ -208,8 +208,8 @@ Module Module1 Console.Title = "Using For Loops | Learn X in Y Minutes" 'Declare Variable and what number it should count down in Step -1, - 'Step -2, Step -3 ect. - For i As Integer = 10 To 0 Step -1 + 'Step -2, Step -3 ect. + For i As Integer = 10 To 0 Step -1 Console.WriteLine(i.ToString) 'Print the value of the counter Next i 'Calculate new value Console.WriteLine("Start") 'Lets start the program baby!! @@ -236,7 +236,7 @@ Module Module1 'Nine Private Sub IfElseStatement() Console.Title = "If / Else Statement | Learn X in Y Minutes" - 'Sometimes its important to consider more than two alternatives. + 'Sometimes it is important to consider more than two alternatives. 'Sometimes there are a good few others. 'When this is the case, more than one if statement would be required. 'An if statement is great for vending machines. Where the user enters a code. @@ -274,8 +274,8 @@ End Module ## References -I learnt Visual Basic in the console application. It allowed me to understand the principles of computer programming to go on to learn other programming languages easily. +I learnt Visual Basic in the console application. It allowed me to understand the principles of computer programming to go on to learn other programming languages easily. -I created a more indepth <a href="http://www.vbbootcamp.co.uk/" Title="Visual Basic Tutorial">Visual Basic tutorial</a> for those who would like to learn more. +I created a more indepth <a href="http://www.vbbootcamp.co.uk/" Title="Visual Basic Tutorial">Visual Basic tutorial</a> for those who would like to learn more. -The entire syntax is valid. Copy the and paste in to the Visual Basic compiler and run (F5) the program. +The entire syntax is valid. Copy the and paste in to the Visual Basic compiler and run (F5) the program. diff --git a/xml.html.markdown b/xml.html.markdown index 059ea132..d407512d 100644 --- a/xml.html.markdown +++ b/xml.html.markdown @@ -38,10 +38,10 @@ Unlike HTML, XML does not specify how to display or to format data, just carry i <!-- Above is a typical XML file. It starts with a declaration, informing some metadata (optional). - + XML uses a tree structure. Above, the root node is 'bookstore', which has - three child nodes, all 'books'. Those nodes has more child nodes, and so on... - + three child nodes, all 'books'. Those nodes has more child nodes, and so on... + Nodes are created using open/close tags, and childs are just nodes between the open and close tags.--> @@ -54,8 +54,8 @@ Unlike HTML, XML does not specify how to display or to format data, just carry i 2 - Elements -> That's pure data. That's what the parser will retrieve from the XML file. Elements appear between the open and close tags. --> - - + + <!-- Below, an element with two attributes --> <file type="gif" id="4293">computer.gif</file> @@ -68,14 +68,14 @@ A XML document is well-formated if it is syntactically correct. However, it is possible to inject more constraints in the document, using document definitions, such as DTD and XML Schema. -A XML document which follows a document definition is called valid, -regarding that document. +A XML document which follows a document definition is called valid, +regarding that document. With this tool, you can check the XML data outside the application logic. ```xml -<!-- Below, you can see an simplified version of bookstore document, +<!-- Below, you can see an simplified version of bookstore document, with the addition of DTD definition.--> <?xml version="1.0" encoding="UTF-8"?> diff --git a/zh-cn/csharp-cn.html.markdown b/zh-cn/csharp-cn.html.markdown index a3cda5b3..971c1be9 100644 --- a/zh-cn/csharp-cn.html.markdown +++ b/zh-cn/csharp-cn.html.markdown @@ -232,7 +232,8 @@ on a new line! ""Wow!"", the masses cried"; // 三元表达式 // 简单的 if/else 语句可以写成： // <条件> ? <真> : <假> - string isTrue = (true) ? "True" : "False"; + int toCompare = 17; + string isTrue = toCompare == 17 ? "True" : "False"; // While 循环 int fooWhile = 0; diff --git a/zh-cn/javascript-cn.html.markdown b/zh-cn/javascript-cn.html.markdown index dfeb2012..bdef0099 100644 --- a/zh-cn/javascript-cn.html.markdown +++ b/zh-cn/javascript-cn.html.markdown @@ -447,9 +447,6 @@ myNumber === myNumberObj; // = false if (0){ // 这段代码不会执行，因为0代表假 } -if (Number(0)){ - // 这段代码*会*执行，因为Number(0)代表真 -} // 不过，包装类型和内置类型共享一个原型， // 所以你实际可以给内置类型也增加一些功能，例如对string： |