Re: [Chicken-users] Use of define-foreign-record

[felix winkelmann]

On Tue, 14 Dec 2004 17:59:24 -0600, Ariel Rios <address@hidden> wrote:
> Hello,
> 
> Which is the way of adding C struct definitions?
> 
> Let's say I have defined the following:
> 
> //something.h
> 
> struct _something
> {
>   _foo foo;
> 
>   char *title;
>   int  index;
> 
>  };
> 
> Then on my scm file what do I put?
> 
> (define-foreing-record ...)
> 

You can do something along these lines:

#>
typedef void *_foo; /* just defined, so the example works. */

 struct _something
 {
   _foo foo;
 
   char *title;
   int  index;
 
  };
<#

#>!
/* define-foreign-record does not define any allocator: */

static struct _something *make_something(char *name, int index)
{
  struct _something *s = (struct _something *)malloc(sizeof(struct _something));

  s->title = strdup(name);
  s->index = index;
  return s;
}

static void free_something(struct _something *s)
{
  free(s->title);
  free(s);
}
<#

(define-foreign-record _something
  (c-string title)
  (int index) )

(define s1 (make_something "abc" 123))
(print (_something-title s1))
(print (_something-index s1))
(free_something s1)


cheers,
felix