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Vala is an object-oriented programming language with a self-hosting compiler that generates C code and uses the GObject system (that "can be seen as an alternative to C-derived languages such as C++ and Objective-C"). 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.〔(【引用サイトリンク】title=Vala: high-level programming with less fat )〕 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 higher 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 (see also GTK+ hello world) void main () A more complex version, showing some of Vala's object-oriented features: class Sample : Object } An example using GTK+ to create a GUI "Hello, World!" program: using Gtk; int main (string[] args) The last example needs an extra parameter to compile on GNOME3 platforms: valac --pkg gtk+-3.0 hellogtk.vala This is the converted C code: / * hellogtk.c generated by valac 0.28.0, the Vala compiler * generated from hellogtk.vala, do not modify */ #include #include #include #include #include #define _g_object_unref0(var) ((var == NULL) ? NULL : (var = (g_object_unref (var), NULL))) gint _vala_main (gchar * * args, int args_length1); static void _gtk_main_quit_gtk_widget_destroy (GtkWidget * _sender, gpointer self); static void _gtk_main_quit_gtk_widget_destroy (GtkWidget * _sender, gpointer self) gint _vala_main (gchar * * args, int args_length1) int main (int argc, char * * argv) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Vala (programming language)」の詳細全文を読む スポンサード リンク
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