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= The Vala Programming Language

Vala is a programming language mainly targeted at GNOME developers.

Its syntax is inspired by C# (and thus, indirectly, by Java). But
unlike C# and Java, Vala does not attempt to provide memory safety:
Vala is compiled to C, and the C code is compiled with GCC using
typical compiler flags. Basic operations like integer arithmetic
are directly mapped to C constructs. As a results, the
recommendations in  xref:programming-languages/C.adoc#chap-Defensive_Coding-C[Defensive Coding in C] apply.

In particular, the following Vala language constructs can result in
undefined behavior at run time:

* Integer arithmetic, as described in xref:programming-languages/C.adoc#sect-Defensive_Coding-C-Arithmetic[Recommendations for Integer Arithmetic].

* Pointer arithmetic, string subscripting and the
`substring` method on strings (the
`string` class in the
`glib-2.0` package) are not range-checked. It
is the responsibility of the calling code to ensure that the
arguments being passed are valid. This applies even to cases
(like `substring`) where the implementation
would have range information to check the validity of indexes.
See xref:programming-languages/C.adoc#sect-Defensive_Coding-C-Pointers[Recommendations for Pointers and Array Handling]

* Similarly, Vala only performs garbage collection (through
reference counting) for `GObject` values. For
plain C pointers (such as strings), the programmer has to ensure
that storage is deallocated once it is no longer needed (to
avoid memory leaks), and that storage is not being deallocated
while it is still being used (see xref:programming-languages/C.adoc#sect-Defensive_Coding-C-Use-After-Free[Use-after-free errors]).