# from Rutger Vos
# on Sunday 31 July 2005 04:36 pm:
> #---------------------------------------------------------
void set_parent(SV* obj, SV* parent) {
/* this ought to work, no? */
// work: yes...
// good idea: ?
Node* apparent = (Node*)SvIV(SvRV(parent));
printf("name: %s\n", apparent->name);
((Node*)SvIV(SvRV(obj)))->parent = apparent;
}
SV* get_parent(SV* obj) {
Node* self = (Node*)SvIV(SvRV(obj));
printf("parent name: %s\n", self->parent->name);
SV* obj_ref = newSViv(0);
// duplicate large portions of code from new() without the benefit
// of knowing what class the parent is in...
return(obj_ref);
}
> #---------------------------------------------------------
The problem with your set_parent is that you have thrown away the perl
object to get the pointer value and only stored that integer. If you
for some reason need $parent to come from a different class,
get_parent() will never be privy to that info. If that's okay, I guess
you could rewrite most of your new() inside of get_parent() so that you
can return a blessed ref.
If you keep the whole object (SV* parent) inside your struct (can you do
that? I dunno (refcount issues?)), then your C code will always have to
unpack it (but I guess a macro or function could help relieve the
tedium there.) If you don't, then you will always have to recreate it
when your C code needs to return a blessed ref and this could get messy
if you don't know the parent's class (which I guess could be part of
your struct if you want to go that route.)
--Eric
--
Peer's Law: The solution to the problem changes the problem.
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