Re: [Vala] Creating a binding for a non-glib library and using delegate to map a function pointer

[Luca Dionisi <luca dionisi gmail com>]

On Sat, Mar 12, 2011 at 12:38 PM, Abderrahim Kitouni
<a kitouni gmail com> wrote:
> في ج، 11-03-2011 عند 16:25 +0100 ، كتب Luca Dionisi:
> > Perhaps I got the point where I was wrong.
> >
> > On Fri, Mar 11, 2011 at 12:42 PM, Luca Dionisi <luca dionisi gmail com> wrote:
> > > First pass, I prepared a direct mapping vapi.
> > >  libfoo.vapi    [http://pastebin.com/rZb6JqAZ]
> > >  [IMPORTANT note: if I don't miss something, I have
> > >  [to create a delegate, named FunctionDelegate, in the vapi
> > >  [file in order to map the function pointer argument.
> >
> > Another way to do that is to define the delegate in another vala
> > source file and include it in the compilation where libfoo.vapi is
> > used.
> I think it would be better to just create a new header that you
> reference in the vapi, it would be easier to distribute with your
> wrapping library.

I'll try to do that.

> Another important point: you shouldn't use has_target=false if the
> library you are binding has user_data arguments, so your
> FunctionDelegate should be defined as
>
> public delegate void* FunctionDelegate ();
>
> And generally, you should try to avoid using void* if possible. For
> example, if it makes sense for your library, you can use a generic
> delegate.

I don't get how this would map a prototype like:
void foobar(void *(*f)(void *), void *user_data);

To be explicit in real world, I want to make a binding for GNU Pth. In
their header there is:

extern pth_t          pth_spawn(pth_attr_t, void *(*)(void *), void *);