Re: [Chicken-users] foreign functions, swig

[felix winkelmann]

On 5/20/06, Dan <address@hidden> wrote:
> Hi all,
>
> I'm trying to create bindings for a large library
> (GSL, which is not so popular these days for some
> reason) as painlessly as possible. Ideally, I would
> write no declarations by hand, just some #include's.
>
> I have tried two approaches:
>
> 1) Using SWIG:
> %module gsl
> %{
> #include <gsl/gsl_rng.h>
> }
> %include <gsl/gsl_rng.h>
>
> This works, but swig has some smart type-checking that
> prevents me from passing srfi-4 f64vector's instead of
> (double *). I don't know how to convert between the
> two in Scheme either.
>
> 2) Using Chicken
>
> #>!
> extern void gsl_sort (double *v, size_t s, size_t N);
> <#
>
> This works with f64vector's, but will be verbose. If I
> just place the #include between #>! and <#, it doesn't
> get parsed. So I'd have to write lots of extern's.
>
> A further problems is that if I pass plain vector's
> instead of f64vector's, csi crashes, but I guess I can
> live with that.
>
> Is there an optimal solution?

Well, interfacing to foreign code (especially large libraries) is never
much fun. I recommend using SWIG and writing special typemaps
for converting double*'s to f64vectors. The SWIG manual explains
how this is done - alternatively I can try, if you can wait a few days.


cheers,
felix