:- object(class,
instantiates(class),
specializes(abstract_class)).
:- info([
author is 'Paulo Moura',
version is 1.0,
date is 2000/4/22,
comment is 'Instantiation root and default metaclass for all classes.']).
:- public(new/1).
:- mode(new(+object), zero_or_one).
:- public(delete/1).
:- mode(delete(+object), zero_or_one).
:- public(instances/1).
:- mode(instances(-list), one).
new(Object) :-
self(Self),
create_object(Object, [instantiates(Self)], [], []).
delete(Object) :-
instantiates_class(Object, Self),
\+ instantiates_class(_, Object),
\+ specializes_class(_, Object),
abolish_object(Object).
instances(Instances) :-
findall(Instance, instantiates_class(Instance, Self), Instances).
abstract_class :-
fail.
:- end_object.
