Leopold Toetsch:
# The property 'constant', 'ro' or whatever can only be some kind of
# communication: the HLL is telling the PMC to be read only. We could
now
# have in each set-like vtable:
#
# if (we_have_props && !is_bool(prop("ro")) // pseudo code
# set_the_value ...
# else
# throw_exception
#
# or we have a different class, that have in the set-like vtable
slots
# just the exception. No penalty for rw classes.
I'm starting to wonder if we shouldn't copy the vtable at construction
time. That way, we can have our read-only set_* behaviors without
requiring a second class:
void init(...) {
SELF->vtable=copy(this_class's_vtable);
if(is_bool(prop("ro")) {
/*
* I see no reason we can't provide one
implementation
* for all read-onlys--after all, it just needs
to throw
* an exception.
*/
SELF->vtable->set_int=&Parrot_pmc_ro_set_int;
SELF->vtable->set_num=&Parrot_pmc_ro_set_num;
SELF->vtable->set_string=&Parrot_pmc_ro_set_string;
SELF->vtable->set_pmc=&Parrot_pmc_ro_set_pmc;
...
}
}
This would also allow for other class-specific vtable customization.
After all, I doubt ro will be the *only* property that's much more
efficiently implemented as a modified vtable...
--Brent Dax <[EMAIL PROTECTED]>
Perl and Parrot hacker
"Yeah, and my underwear is flame-retardant--that doesn't mean I'm gonna
set myself on fire to prove it."
