1 files changed, 263 insertions, 0 deletions
diff --git a/vala.html.markdown b/vala.html.markdown
new file mode 100755
index 00000000..036e873d
--- /dev/null
+++ b/vala.html.markdown
@@ -0,0 +1,263 @@
+---
+language: vala
+contributors:
+    - ["Milo Gilad", "https://github.com/Myl0g"]
+filename: LearnVala.vala
+---
+
+In GNOME's own words, "Vala is a programming language that aims to bring modern programming language features to GNOME developers without imposing any additional runtime requirements and without using a different ABI compared to applications and libraries written in C."
+
+Vala has aspects of Java and C#, so it'll be natural to those who know either or.
+
+[Read more here.](https://wiki.gnome.org/Projects/Vala)
+
+```vala
+
+// Single line comment
+
+/* Multiline
+Comment */
+
+/**
+* Documentation comment
+*/
+
+/* Data Types */
+
+// Vala supports the data types supported by most other programming languages.
+
+char character = 'a'
+unichar unicode_character = 'u' // 32-bit unicode character
+
+int i = 2; // ints can also have guaranteed sizes (e.g. int64, uint64)
+uint j = -6; // Won't compile; unsigned ints can only be positive
+
+long k;
+
+short l;
+ushort m;
+
+string text = "Hello,"; // Note that the == operator will check string content
+
+string verbatim = """This is a verbatim (a.k.a. raw) string. Special characters
+(e.g. \n) are not interpreted. They may also be multiple lines long.""";
+
+// String Templates allow for easy string formatting
+string string_template = @"$text world"; // "$text" evaluates to "Hello"
+
+int test = 5;
+int test2 = 10;
+string template2 = @"$(test * test2) is a number."; // Expression evaluation
+
+string template_slice = string_template[7:12]; // => "world"
+
+// Most data types have methods for parsing.
+
+bool parse_bool = bool.parse("false"); // => false
+int parse_int = int.parse("-52");
+string parse_string = parse_int.to_string();
+
+/* Basic I/O */
+
+stdout.printf(parse_string); // Prints to console
+string input = stdin.read_line(); // Gets input from console
+
+stderr.printf("Error message"); // Error printing
+
+/* Arrays */
+
+int[] int_array = new int[10]; // Array of ints with 10 slots
+int better_int_array[10]; // Shorter way of making int array with 10 slots
+int_array.length; // => 10;
+
+int[] int_array2 = {5, 10, 15, 20}; // Can be created on-the-fly
+
+int[] array_slice = int_array2[1:3]; // Slice (copy of data)
+unowned int[] array_slice_ref = int_array2[1:3]; // Reference to data
+
+// Multi-dimensional Arrays (defined with a number of commas in the brackets)
+
+int[,] multi_array = new int[6,4]; // 6 is the number of arrays, 4 is their size
+int[,] multi_array2 = {{7, 4, 6, 4},
+                       {3, 2, 4, 6},
+                       {5, 9, 5, 1}};
+multi_array2[2,3] = 12; // 2 is the array, 3 is the index in the array
+int first_d = multi_array2.length[0] // => 3
+int second_d = multi_array2.length[1] // => 4
+
+// Stacked arrays (e.g. int[][]) where array lengths vary are not supported.
+
+// Multi-dimensional arrays cannot be sliced, nor can they be converted to one-
+// dimensional.
+
+int[] add_to_array = {};
+add_to_array += 12; // Arrays can be dynamically added to
+
+add_to_array.resize(20); // Array now has 20 slots
+
+uint8[] chars = "test message".data;
+chars.move(5, 0, 7);
+print ((string) chars); // Casts the array to a string and prints "message"
+
+/* Control Flow */
+
+var a = 1;
+var b = 2;
+int[] foreach_demo = {2, 4, 6, 8};
+
+while (b > a) { // While loop; checks if expression is true before executing
+  b--;
+}
+
+do {
+  b--;
+}
+while (b > a); // Do While loop; executes the code in "do" before while (b > a)
+
+for (a = 0; a < 10; a++) { stdout.printf("%d\n", a); } // for loop
+
+foreach (int foreach_demo_var in foreach_demo) {
+  stdout.printf("%d\n", foreach_demo_var);
+} // foreach works on any iterable collection
+
+if (a == 0) {
+  break;
+} else if (a > 1) {
+  stdout.printf("%d\n", a);
+} else {
+  break;
+} // if-then-else
+
+switch (a) {
+  case 1:
+    stdout.printf("A is 1\n");
+    break;
+  case 5:
+  case 10:
+    stdout.printf("A is 5 or 10\n");
+    break;
+  default:
+    stdout.printf("???\n")
+    break;
+} // switch statement
+
+/* Type Casting and Inference */
+
+int cast_to_float = 10;
+float casted_float = (float) cast_to_float; // static casting; no runtime checks
+
+// For runtime checks, use dynamic casting.
+// Dynamically casted objects must meet the following:
+// - Object's class is the same class as the desired type
+// - Object's class is a subclass of the desired type
+// - Desired class is an interface implemented by the object's class
+
+float dyna_casted_float = cast_to_float as float // Won't compile
+
+var inferred_string = "hello"; // Type inference
+
+/* Methods (a.k.a. functions) */
+
+// Vala methods are C functions, and are bound by the same rules.
+
+int method_demo(string arg1, Object arg2) { // Returns int and takes args
+    return 1;
+}
+
+// Vala methods cannot be overloaded.
+
+void some_method(string text) { }
+void some_method(int number) { }  // Won't compile
+
+// To achieve similar functionality, use default argument values.
+
+void some_better_method(string text, int number = 0) { }
+
+// varargs (variable-length argument lists) are also supported.
+
+void method_with_varargs(int arg1, ...) {
+    var varargs_list = va_list(); // gets the varargs list
+    string arg_string = varargs_list.arg(); // gets arguments, one after another
+    int int_vararg = varargs_list.arg();
+    stdout.printf("%s, %d\n", arg_string, int_vararg)
+}
+
+string? ok_to_be_null(int? test_int) { } // "?" denotes possible null value
+
+// Delegates
+
+delegate void DelegateDemo(char char_a);
+
+void delegate_match(char char_a) { // Matches the delegate's signature
+  stdout.printf("%d\n");
+}
+
+void call_delegate(DelegateDemo d, char char_b) { // Takes a delegate arg
+  d(char_b) // calls delegate
+}
+
+void final_delegate_demo() {
+  call_delegate(delegate_match); // Passes matching method as argument
+}
+
+// Lambdas/Anonymous Methods are defined with "=>"
+
+(a) => { stdout.printf("%d\n", a); } // Prints "a"
+
+/* Namespaces */
+
+namespace NamespaceDemo {
+  // Allows you to organize variable names
+  int namespace_int = 12;
+}
+namespace_int += 5; // Won't compile
+
+using NamespaceDemo;
+namespace_int += 5; // Valid
+
+/* Structs */
+
+struct Closet {
+  public uint shirts; // Default access modifier is private
+  public uint jackets;
+}
+
+Closet struct_init_1 = Closet(); // or Closet struct_init_1 = {};
+Closet struct_init_2 = {15, 3};
+var struct_init_3 = Closet() { // Type inference also works
+  shirts = 15;
+  jackets = 3;
+}
+
+/* Classes and Object-Oriented Programming */
+
+class Message : GLib.Object { // Class Message extends GLib's Object
+  private string sender; // a private field
+  public string text {get; set;} // a public property
+  internal bool sent = false; // internal (classes in same package) field
+
+  public void send(string message_sender) { // public method
+    sender = message_sender;
+    sent = true;
+  }
+
+  public Message() { // Constructor
+    // ...
+  }
+
+}
+
+interface InterfaceDemo { // Can be used as a mixin
+  // ...
+}
+
+
+enum HouseSize {
+  SMALL,
+  MODERATE,
+  BIG
+}
+
+```
+
+* Read about building GUIs with GTK+ and Vala [here](http://archive.is/7C7bw).