Re: [Vala] Define constant at compile time

[Jan Hudec <bulb ucw cz>]

On Tue, Nov 16, 2010 at 12:28:23 -0800, Anatol Pomozov wrote:
> But what if you want to change the real constant value at the
> compile-time? A classical example is DEBUG vs OPTIMIZED mode. During
> development I want to log of information to stdout, like this:
>
> if (DEBUG) {
>   stdout.printf("User ID is: $user");
> }
>
> and I don't want to have this code in the release version. To make it
> happen one can use something like
>
> bool DEBUG=false;
>
> and compile the vala program with -DDEBUG (or its equivalent
> -DDEBUG=true). This compiler flag changes the default value of the
> const.
>
> Type-safety means that vala compile knows that DEBUG is boolean and
> complains if someone tries to use number/string here (-DDEBUG=foo) or
> tries to set value for unexisting constant.

You know, vala DOES support THAT. Simply

    #if DEBUG
    stdout.printf("USer ID is: $user");
    #endif

and than:

    valac -DDEBUG ...

It is a flag -- either it's there or not.

-- 
                                                 Jan 'Bulb' Hudec <bulb ucw cz>