SPN_API SpnFunction *spn_func_new_closure(SpnFunction *prototype)
{
SpnFunction *func = spn_object_new(&spn_class_func);
/* only a Sparkling function can be used as the prototype
* of a closure, native ones can't. A top-level program
* cannot be used to form a closure either.
*/
assert(prototype->native == 0);
assert(prototype->topprg == 0);
assert(prototype->is_closure == 0);
func->native = 0;
func->topprg = 0;
func->is_closure = 1;
func->nwords = 0; /* unused */
/* func->symtab is always a weak pointer for closures,
* because the prototype is never a top-level program,
* and only function objects that represent a top-level
* program have a strong symbol table pointer.
*/
func->name = prototype->name; /* weak pointer */
func->env = prototype->env; /* weak pointer */
func->readsymtab = 0; /* unused */
func->symtab = prototype->symtab; /* weak pointer */
func->upvalues = spn_array_new();
func->repr = prototype->repr;
return func;
}
SpnFunction *spn_func_new_topprg(const char *name, spn_uword *bc, size_t nwords)
{
SpnFunction *func = spn_object_new(&spn_class_func);
func->native = 0;
func->topprg = 1;
func->is_closure = 0;
func->nwords = nwords;
func->name = name;
func->env = func; /* top program's environment is itself */
func->readsymtab = 0;
func->symtab = spn_array_new();
func->upvalues = NULL; /* unused */
func->repr.bc = bc; /* strong pointer */
return func;
}
/* convenience value constructor */
SpnValue spn_makearray(void)
{
return makeobject(spn_array_new());
}
