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-rwxr-xr-xvala.html.markdown37
1 files changed, 19 insertions, 18 deletions
diff --git a/vala.html.markdown b/vala.html.markdown
index 4072f3b3..a0fbc5c1 100755
--- a/vala.html.markdown
+++ b/vala.html.markdown
@@ -7,7 +7,7 @@ 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.
+Vala has aspects of Java and C#, so it'll be natural to those who know either.
[Read more here.](https://wiki.gnome.org/Projects/Vala)
@@ -24,8 +24,6 @@ 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
@@ -40,10 +38,10 @@ 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.""";
+(e.g. \n and "") 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"
+string string_template = @"$text world"; // "$text" evaluates to "Hello,"
int test = 5;
int test2 = 10;
@@ -54,8 +52,8 @@ 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();
+int parse_int = int.parse("-52"); // => -52
+string parse_string = parse_int.to_string(); // => "-52"
/* Basic I/O */
@@ -67,7 +65,7 @@ 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 better_int_array[10]; // Above expression, shortened
int_array.length; // => 10;
int[] int_array2 = {5, 10, 15, 20}; // Can be created on-the-fly
@@ -80,7 +78,7 @@ unowned int[] array_slice_ref = int_array2[1:3]; // Reference to data
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}};
+ {5, 9, 5, 1}}; // new int[3,4]
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
@@ -97,12 +95,12 @@ 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"
+stdout.printf((string) chars); // Casts the array to a string and prints it
/* Control Flow */
-var a = 1;
-var b = 2;
+int a = 1;
+int b = 2;
int[] foreach_demo = {2, 4, 6, 8};
while (b > a) { // While loop; checks if expression is true before executing
@@ -147,7 +145,7 @@ 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:
+// Dynamically casted objects must be 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
@@ -158,8 +156,6 @@ 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;
}
@@ -173,12 +169,17 @@ void some_method(int number) { } // Won't compile
void some_better_method(string text, int number = 0) { }
+some_better_method("text");
+some_better_method("text", 12);
+
// 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)
}
@@ -200,7 +201,7 @@ void final_delegate_demo() {
call_delegate(delegate_match); // Passes matching method as argument
}
-// Lambdas/Anonymous Methods are defined with "=>"
+// Lambdas (a.k.a. Anonymous Methods) are defined with "=>"
(a) => { stdout.printf("%d\n", a); } // Prints "a"
@@ -235,13 +236,13 @@ enum HouseSize { // An example of an enum
BIG
}
-
/* 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
+ protected bool is_digital = true; // protected (this class and subclasses)
+ internal bool sent = false; // internal (classes in same package)
public void send(string message_sender) { // public method
sender = message_sender;