Re: [Chicken-users] [newbie] destroying foreign objects

[Jim Ursetto]

On Jan 30, 2010, at 12:22 AM, Marco Maggi wrote:
>  I   am  skimming   through   Chicken's  documentation   to
> understand what it  can do; is there a  way to automatically
> apply a  finalisation function when  a pointer to  a foreign
> object   (C  language   structure)  is   garbage  collected?
> Something like guardians.

You could use set-finalizer! on the pointer object or whatever scheme  
object contains the raw C pointer.  Does that answer your question?   
There should be some examples in the eggs, for example objc.

$ chicken-doc set-finalizer\!
path: (library set-finalizer!)
procedure: (set-finalizer! X PROC)

Registers a procedure of one argument `PROC`, that will be
called as soon as the non-immediate data object `X` is about to
be garbage-collected (with that object as its argument). Note that
the finalizer will '''not''' be called while interrupts are disabled.
This procedure returns `X`.