Developer Jürg Billeter, Raffaele Sandrini First appeared 2006; 11 years ago (2006) Stable release 0.36.1 / 3 April 2017; 0 days ago (2017-04-03) Preview release 0.35.90 / 13 March 2017; 21 days ago (2017-03-13) | ||
Vala is an object-oriented programming language with a self-hosting compiler that generates C code and uses the GObject system.
Contents
Vala is syntactically similar to C# and includes several features such as: anonymous functions, signals, properties, generics, assisted memory management, exception handling, type inference, and foreach statements. Its developers Jürg Billeter and Raffaele Sandrini aim to bring these features to the plain C runtime with little overhead and no special runtime support by targeting the GObject object system. Rather than compiling directly to machine code or assembly language, it compiles to a lower level intermediate language. It source-to-source compiles to C, which is then compiled with a C compiler for a given platform, such as GCC.
For memory management, the GObject system provides reference counting. In C, a programmer must manually manage adding and removing references, but in Vala, managing such reference counts is automated if a programmer uses the language's built-in reference types rather than plain pointers.
Using functionality from native code libraries requires writing vapi files, defining the library interfacing. Writing these interface definitions is well-documented for C libraries, especially when based on GObject. However, C++ libraries are not supported. Vapi files are provided for a large portion of the GNOME platform, including GTK+.
Vala was conceived by Jürg Billeter and was implemented by him and Raffaele Sandrini, finishing a self-hosting compiler in May 2006.
Code example
A simple "Hello, World!" Vala program:
A more complex version, showing some of Vala's object-oriented features:
An example using GTK+ to create a GUI "Hello, World!" program (see also GTK+ hello world):
The last example needs an extra parameter to compile on GNOME 3 platforms:
This is the converted C code:
Text editor / IDE support
There are various projects in various states of stability in order to provide syntax highlighting and other text editor/IDE support for Vala:
language-vala-modern package installed)