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Syntax Guide ​

Original Source: Vala Syntax Guide

The syntax of Vala is similar to C#, modified to better fit the GObject type system. Vala supports modern language features as the following:

  • OOP (classes, abstract classes, mixin interfaces, type polymorphism)
  • Namespaces
  • Delegates
  • Properties
  • Signals
  • Property change notifications
  • Foreach
  • Lambda expressions / Closures
  • Type inference for local variables
  • Generics
  • Non-null types
  • Assisted memory management (automatic reference counting)
  • Deterministic destructors (suitable for RAII)
  • Exception handling (checked exceptions)
  • Asynchronous methods (coroutines)
  • Preconditions and postconditions (contract programming)
  • Run-time type information
  • Named constructors
  • Verbatim strings and string templates
  • Array and string slicing
  • Conditional compilation
  • Dynamic and static D-Bus support
  • C# like syntax
  • C ABI compatibility
  • Experimental:
    • Chained relational expressions
    • Regular expression literals
    • Main blocks

Keywords ​

  • Selection: if, else, switch, case, default
  • Iteration: do, while, for, foreach, in
  • Jumping: break, continue, return
  • Exception Handling: try, catch, finally, throw
  • Synchronization: lock, unlock
  • Type Declaration: class, interface, struct, enum, delegate, errordomain
  • Type Modifiers: const, weak, unowned, dynamic
  • Modifiers: abstract, virtual, override, signal, extern, static, async, inline, new, sealed, partial
  • Access Modifiers: public, private, protected, internal
  • Method Parameters: out, ref
  • Method Contract Keywords: throws, requires, ensures
  • Namespaces: namespace, using
  • Operator Keywords: as, is, in, new, delete, sizeof, typeof
  • Access Keywords: this, base
  • Literal Keywords: null, true, false
  • Property Context: get, set, construct, default, value
  • Construction Blocks: construct, static construct, class construct
  • Other: void, var, yield, global, owned, with

Operators ​

  • Arithmetic: +, -, *, /, %
  • Bitwise: ~, &, |, ^, <<, >>
  • Relational: <, >, <=, >=
  • Equality: ==, !=
  • Logic: !, &&, ||
  • Assignment: =, +=, -=, *= , /=, %=, &=, |=, ^=, <<=, >>=
  • Increment, Decrement: ++, --
  • Pointer: &, *, ->, delete
  • Conditional: ?:
  • Null-Coalescing: ??
  • String Concatenation: +
  • Method Invocation: ()
  • Member Access: .
  • Index: []
  • Slice: [:]
  • Lambda: =>
  • Casting: (Type), (!), as
  • Type Checking: is
  • Ownership Transfer: (owned)
  • Namespace Alias Qualifier: :: (currently only with global)
  • Other: new, sizeof, typeof, in