Piers Cawley <[EMAIL PROTECTED]> wrote: > Leopold Toetsch <[EMAIL PROTECTED]> writes:
>> Piers Cawley <[EMAIL PROTECTED]> wrote: >>> Leopold Toetsch <[EMAIL PROTECTED]> writes: >> >>>> The terms are misleading a bit here. >>>> - a ParrotClass isa delegate PMC >>>> - a ParrotObject isa ParrotClass >>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >>> That definitely seems to be the wrong way 'round. >> >> Why? A ParrotClass is responsible for the method dispatch. The ParrotObject >> inherits that behavior. > But logically, a Class is an Object, and an object is an *instance* of a > class. Sure. The HLL class C<isa> ParrotClass PMC object. The HLL object is the instantiation of it. Please note that C<ParrotObject> is the underlying PMC, which can't be instantiated directly. > ... Surely a class should be responsible for storing and finding > method, but some other thing, call it a Dispatcher object or the metaclass object? > Of course, if you have OO languages that have weird dispatch rules, you > might need to have multiple dispatchers hanging around but (I'd argue) > you're still better attaching them to classes using composition rather > than inheritance. The C<isa> relationship inside PMCs is just a way to define that missing vtable functions are filled in with the parent's function. You an think of that the PMCs (ParrotObject, ParrotClass, delegate, and possibly mmd_default) together build the metaclass object (or dispatcher in your terms). The ParrotObject PMC just holds the necessary information to instantiate the HLL object. leo
