:- object(abstract_class,
instantiates(class),
specializes(object)).
:- info([
author is 'Paulo Moura',
version is 1.0,
date is 2000/4/22,
comment is 'Default metaclass for all abstract classes.']).
:- public(metaclass/0).
:- mode(metaclass, zero_or_one).
:- public(abstract_class/0).
:- mode(abstract_class, zero_or_one).
abstract_class :-
self(Self),
Self \= abstract_class.
metaclass :-
once((
instantiates_class(Class, Self),
Class::current_predicate(abstract_class/0))).
strict_instance :-
fail.
:- end_object.
