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diff --git a/haxe.html.markdown b/haxe.html.markdown new file mode 100644 index 00000000..90b2e250 --- /dev/null +++ b/haxe.html.markdown @@ -0,0 +1,472 @@ +--- +language: haxe +filename: LearnHaxe3.hx +contributors: + - ["Justin Donaldson", "https://github.com/jdonaldson/"] +--- + +Haxe is a web-oriented language that provides platform support for C++, C#, +Swf/ActionScript, Javascript, Java, and Neko byte code (also written by the +Haxe author). Note that this guide is for Haxe version 3. Some of the guide +may be applicable to older versions, but it is recommended to use other +references. + +```haxe +/* + Welcome to Learn Haxe 3 in 15 minutes. http://www.haxe.org + This is an executable tutorial. You can compile and run it using the haxe + compiler, while in the same directory as LearnHaxe.hx: + haxe -main LearnHaxe3 -x out + */ + +// Let's start with comments... this is a single line comment + +/* + And this is multiline. Multiline comments are also used to generate + javadoc-style documentation for haxedoc. They will be used if they precede + a class, class function, or class variable. + */ + +/* + A package declaration isn't necessary, but it's useful if you want to + organize your code into modules later on. Also worth mentioning, all + expressions in Haxe must end in a semicolon: + */ +package; // empty package, no namespace. + + +// if you import code from other files, it must be declared before the rest of +// the code. +import haxe.ds.ArraySort; + +// you can import many classes/modules at once with "*" +import haxe.ds.*; + +// you can also import classes in a special way, enabling them to extend the +// functionality of other classes. More on this later. +using StringTools; + +// Haxe files typically define classes, although they can also define other +// types of code... more on that later. + + +class LearnHaxe3{ + /* + If you want certain code to run automatically, you need to put it in + a static main function, and specify the class in the compiler arguments. + In this case, we've specified the "LearnHaxe3" class in the compiler + arguments above. + */ + static function main(){ + /* + Trace is the default method of printing haxe expressions to the + screen. Different targets will have different methods of + accomplishing this. E.g., java, c++, c#, etc. will print to std + out. Javascript will print to console.log, and flash will print to + an embedded TextField. All traces come with a default newline. + Finally, It's possible to prevent traces from showing by using the + "--no-traces" argument on the compiler. + */ + + + trace("Hello World, with trace()!"); + + /* + Trace can handle any type of value or object. It will try to print + a representation of the expression as best it can. You can also + concatenate strings with the "+" operator: + */ + trace( + " Integer: " + 10 + + " Float: " + 3.14 + + " Boolean: " + true + ); + + + /* + Remember what I said about expressions needing semicolons? You + can put more than one expression on a line if you want. + */ + trace('two expressions..'); trace('one line'); + + + ////////////////////////////////////////////////////////////////// + // Types & Variables + ////////////////////////////////////////////////////////////////// + trace("***Types & Variables***"); + + /* + You can save values and references to data structures using the + "var" keyword: + */ + + var an_integer:Int = 1; + trace(an_integer + " is the value for an_integer"); + + + /* + Haxe is statically typed, so "an_integer" is declared to have an + "Int" type, and the rest of the expression assigns the value "1" to + it. It's not necessary to declare the type in many cases. Here, + the haxe compiler is inferring that the type of another_integer + should be "Int". + */ + + var another_integer = 2; + trace(another_integer + " is the value for another_integer"); + + // The $type() method prints the type that the compiler assigns: + $type(another_integer); + + // You can also represent integers with hexadecimal: + var hex_integer = 0xffffff; + + /* + Haxe uses platform precision for Int and Float sizes. It also + uses the platform behavior for overflow. + (Other numeric types and behavior are possible using special + libraries) + */ + + /* + In addition to simple values like Integers, Floats, and Booleans, + Haxe provides standard library implementations for common data + structures like strings, arrays, lists, and maps: + */ + + var a_string = "some" + 'string'; // strings can have double or single quotes + trace(a_string + " is the value for a_string"); + + var x = 1; + var an_interpolated_string = 'the value of x is $x'; + + /* + Strings are immutable, instance methods will return a copy of + parts or all of the string. + (See also the StringBuf class). + */ + var a_sub_string = a_string.substr(0,4); + trace(a_sub_string + " is the value for a_sub_string"); + + /* + Arrays are zero-indexed, dynamic, and mutable. Missing values are + defined as null. + */ + var a = new Array<String>(); // an array that contains Strings + a[0] = 'foo'; + trace(a.length + " is the value for a.length"); + a[9] = 'bar'; + trace(a.length + " is the value for a.length (after modification)"); + trace(a[3] + " is the value for a[3]"); //null + + /* + Arrays are *generic*, so you can indicate which values they contain + with a type parameter: + */ + var a2 = new Array<Int>(); // an array of Ints + var a3 = new Array<Array<String>>(); // an Array of Arrays (of Strings). + + /* + Maps are simple key/value data structures. The key and the value + can be of any type. + */ + var m = new Map<String, Int>(); // The keys are strings, the values are Ints. + m.set('foo', 4); + // You can also use array notation; + m['bar'] = 5; + trace(m.exists('bar') + " is the value for m.exists('bar')"); + trace(m.get('bar') + " is the value for m.get('bar')"); + trace(m['bar'] + " is the value for m['bar']"); + + var m2 = ['foo' => 4, 'baz' => 6]; // Alternative map syntax + trace(m2 + " is the value for m2"); + + /* + Remember, you can use type inference. The Haxe compiler will + decide the type of the variable the first time you pass an + argument that sets a type parameter. + */ + var m3 = new Map(); + m3.set(6, 'baz'); // m3 is now a Map<Int,String> + trace(m3 + " is the value for m3"); + + /* + Haxe has many more common datastructures in the haxe.ds module, such as + List, Stack, and BalancedTree + */ + + + ////////////////////////////////////////////////////////////////// + // Operators + ////////////////////////////////////////////////////////////////// + + trace("***OPERATORS***"); + + // basic arithmetic + trace((4 + 3) + " is the value for (4 + 3)"); + trace((5 - 1) + " is the value for (5 - 1)"); + trace((2 * 4) + " is the value for (2 * 4)"); + trace((8 / 4) + " is the value for (8 / 3) (division always produces Floats)"); + trace((12 % 4) + " is the value for (12 % 4)"); + + + //basic comparison + trace((3 == 2) + " is the value for 3 == 2"); + trace((3 != 2) + " is the value for 3 != 2"); + trace((3 > 2) + " is the value for 3 > 2"); + trace((3 < 2) + " is the value for 3 < 2"); + trace((3 >= 2) + " is the value for 3 >= 2"); + trace((3 <= 2) + " is the value for 3 <= 2"); + + //bitwise operators + /* + ~ Unary bitwise complement + << Signed left shift + >> Signed right shift + >>> Unsigned right shift + & Bitwise AND + ^ Bitwise exclusive OR + | Bitwise inclusive OR + */ + + //increments + var i = 0; + trace("Increments and decrements"); + trace(i++); //i = 1. Post-Incrementation + trace(++i); //i = 2. Pre-Incrementation + trace(i--); //i = 1. Post-Decrementation + trace(--i); //i = 0. Pre-Decrementation + + ////////////////////////////////////////////////////////////////// + // Control Structures + ////////////////////////////////////////////////////////////////// + trace("***CONTROL STRUCTURES***"); + + // if statements + var j = 10; + if (j == 10){ + trace("this is printed"); + } else if (j > 10){ + trace("not greater than 10, so not printed"); + } else { + trace("also not printed."); + } + + trace("Looping and Iteration"); + + // while loop + var k = 0; + while(k < 100){ + // trace(counter); // will print out numbers 0-99 + k++; + } + + // do-while loop + var l = 0; + do{ + trace("do statement always runs at least once"); + } while (i > 0); + + // for loop + /* + There is no c-style for loop in Haxe, because they are prone + to error, and not necessary. Instead, Haxe has a much simpler + and safer version that uses Iterators (more on those later). + */ + var m = [1,2,3]; + for (val in m){ + trace(val + " is the value for val in the m array"); + } + + // Note that you can iterate on an index using a range + // (more on ranges later as well) + var n = ['foo', 'bar', 'baz']; + for (val in 0...n.length){ + trace(val + " is the value for val (an index for m)"); + } + + + trace("Array Comprehensions"); + + // Array comprehensions give you the ability to iterate over arrays + // while also creating filters and modifications. + var filtered_n = [for (val in n) if (val != "foo") val]; + trace(filtered_n + " is the value for filtered_n"); + + var modified_n = [for (val in n) val += '!']; + trace(modified_n + " is the value for modified_n"); + + var filtered_and_modified_n = [for (val in n) if (val != "foo") val += "!"]; + trace(filtered_and_modified_n + " is the value for filtered_and_modified_n"); + + ////////////////////////////////////////////////////////////////// + // Switch Statements (Value Type) + ////////////////////////////////////////////////////////////////// + trace("***SWITCH STATEMENTS (VALUE TYPES)***"); + + /* + Switch statements in Haxe are very powerful. In addition to working + on basic values like strings and ints, they can also work on the + generalized algebraic data types in enums (more on enums later). + Here's some basic value examples for now: + */ + var my_dog_name = 'fido'; + var favorite_thing = ''; + switch(my_dog_name){ + case "fido" : favorite_thing = 'bone'; + case "rex" : favorite_thing = 'shoe'; + case "spot" : favorite_thing = 'tennis ball'; + case _ : favorite_thing = 'some unknown treat'; + } + // The "_" case above is a "wildcard" value + // that will match anything. + + trace("My dog's name is" + my_dog_name + + ", and his favorite thing is a: " + + favorite_thing); + + ////////////////////////////////////////////////////////////////// + // Expression Statements + ////////////////////////////////////////////////////////////////// + trace("***EXPRESSION STATEMENTS***"); + + /* + Haxe control statements are very powerful because every statement + is also an expression, consider: + */ + + // if statements + var k = if (true){ + 10; + } else { + 20; + } + + trace("K equals ", k); // outputs 10 + + var other_favorite_thing = switch(my_dog_name) { + case "fido" : 'teddy'; + case "rex" : 'stick'; + case "spot" : 'football'; + case _ : 'some unknown treat'; + } + + trace("My dog's name is" + my_dog_name + + ", and his other favorite thing is a: " + + other_favorite_thing); + + ////////////////////////////////////////////////////////////////// + // Converting Value Types + ////////////////////////////////////////////////////////////////// + + // You can convert strings to ints fairly easily. + + // string to integer + Std.parseInt("0"); // returns 0 + Std.parseFloat("0.4"); // returns 0.4; + + // integer to string + Std.string(0); // returns "0"; + // concatenation with strings will auto-convert to string. + 0 + ""; // returns "0"; + true + ""; // returns "true"; + // See documentation for parsing in Std for more details. + + ////////////////////////////////////////////////////////////////// + // Basic Object Oriented Programming + ////////////////////////////////////////////////////////////////// + trace("***BASIC OBJECT ORIENTED PROGRAMMING***"); + + + // create an instance of FooClass. The classes for this are at the + // end of the file. + var instance = new FooClass(3); + + // read the public variable normally + trace(instance.public_any + " is the value for instance.public_any"); + + // we can read this variable + trace(instance.public_read + " is the value for instance.public_read"); + // but not write it + // instance.public_write = 4; // this will throw an error if uncommented: + // trace(instance.public_write); // as will this. + + trace(instance + " is the value for instance"); // calls the toString method + trace(instance.toString() + " is the value for instance.toString()"); // same thing + + + // instance has the "FooClass" type, while acceptBaseFoo has the + // BaseFooClass type. However, since FooClass extends BaseFooClass, + // it is accepted. + BaseFooClass.acceptBaseFoo(instance); + } + +} + +/* + This is the "child class" of the main LearnHaxe3 Class + */ +class FooClass extends BaseFooClass implements BaseFooInterface{ + public var public_any:Int; // public variables are accessible anywhere + public var public_read (default,null): Int; // use this style to only enable public read + public var public_write (null, default): Int; // or public write + public var property (get, set): Int; // use this style to enable getters/setters + + // private variables are not available outside the class. + // see @:allow for ways around this. + var _private:Int; // variables are private if they are not marked public + + // a public constructor + public function new(arg:Int){ + super(); // call the constructor of the parent object, since we extended BaseFooClass + + this.public_any= 0; + this._private = arg; + + } + + // getter for _private + function get_property() : Int { + return _private; + } + + // setter for _private + function set_property(val:Int) : Int { + _private = val; + return val; + } + + // special function that is called whenever an instance is cast to a string. + public function toString(){ + return _private + " with toString() method!"; + } + + // this class needs to have this function defined, since it implements + // the BaseFooInterface interface. + public function baseFunction(x: Int) : String{ + // convert the int to string automatically + return x + " was passed into baseFunction!"; + } +} + +/* + A simple class to extend +*/ +class BaseFooClass { + var base_variable:Int; + public function new(){ + base_variable = 4; + } + public static function acceptBaseFoo(b:BaseFooClass){ + } +} + +/* + A simple interface to implement +*/ +interface BaseFooInterface{ + public function baseFunction(x:Int):String; +} + +``` + |