New smob interface

[Klaus Schilling <Klaus.Schilling@home.ivm.de>]

Mikael Djurfeldt writes:
 > 
 > This is how the naive user does it:
 > 
 > typedef struct my_type_t {
 >   int a;
 >   int b;
 > } my_type_t;
 > 
 > #define MY_TYPE_A(x) (((my_type_t *) SCM_SMOB_DATA (x))->a)
 > #define MY_TYPE_B(x) (((my_type_t *) SCM_SMOB_DATA (x))->b)
 > 
 > long my_type = scm_make_smob_type ("my-type", sizeof (my_type_t));
 > 
 > SCM
 > scm_make_my_type (int a, int b)
 > {
 >   SCM z = scm_make_smob (my_type);
 >   MY_TYPE_A (z) = a;
 >   MY_TYPE_B (z) = b;
 >   return z;
 > }
 > 
 > Just as before, the advanced user can write his own versions of the
 > mark, free, print, and, equalp functions:
 > 
 > scm_set_smob_mark (my_type, my_mark);
 > scm_set_smob_free (my_type, my_free);
 > etc.
 > 


Would the following work for a wrapper for the ncurses library:

long WINDOW_type = scm_make_smob_type ("WINDOW_type", sizeof (WINDOW));
#define SCM2WINDOW (x) ((WINDOW *)SCM_SMOB_DATA)

scm_size_t WINDOW_free (SCM object)
{
  WINDOW *w;
  w = SCM2WINDOW (object);
  gh_defer_ints ();
  delwin (w);
  gh_allow_ints ();
  return sizeof (WINDOW);
}


scm_set_smob_free (WINDOW_type, &WINDOW_free);

SCM WINDOW2SCM (WINDOW *w)
{
 SCM z;
 SCM_NEWSMOB (z, WINDOW_type, w);
 return z;
}





Or does the fact that windows may contain pointers to other windows which
are subject to guile's memory administration make it impossible to use
scm_make_smob?