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Re: Inheriting from foreign objects
From: |
Thien-Thi Nguyen |
Subject: |
Re: Inheriting from foreign objects |
Date: |
Tue, 23 Apr 2002 13:43:56 -0700 |
From: Neil Jerram <address@hidden>
Date: 10 Apr 2002 20:47:13 +0100
Andreas> Is there a way I can cleanly derive from C-created classes?
I'd say you're in virgin territory here, and that any advice you can
give on such problems, and on defining a C API for GOOPS, would be
very useful.
it looks like foreign bit is set when superclass list is empty. perhaps
a good guideline would be to use at least `(list <object>)' for `supers'
for normal operation. btw, it doesn't look like user-supplied ctor/dtor
are suppressed based on foreign bit in any case.
[cc guile-user in order to ask survey question: which goops-related C
functions do people use now? the answer to this helps shape definition
of the C interface to goops -- thanks!]
thi
_______________________________
SCM
scm_make_class (SCM meta, char *s_name, SCM supers, size_t size,
void * (*constructor) (SCM initargs),
size_t (*destructor) (void *))
{
SCM name, class;
name = scm_str2symbol (s_name);
if (SCM_NULLP (supers))
supers = scm_list_1 (scm_class_foreign_object);
class = scm_basic_basic_make_class (meta, name, supers, SCM_EOL);
scm_sys_inherit_magic_x (class, supers);
if (destructor != 0)
{
SCM_SET_SLOT (class, scm_si_destructor, (SCM) destructor);
SCM_SET_CLASS_DESTRUCTOR (class, scm_free_foreign_object);
}
else if (size > 0)
{
SCM_SET_CLASS_DESTRUCTOR (class, scm_struct_free_light);
SCM_SET_CLASS_INSTANCE_SIZE (class, size);
}
SCM_SET_SLOT (class, scm_si_layout, scm_str2symbol (""));
SCM_SET_SLOT (class, scm_si_constructor, (SCM) constructor);
return class;
}