:- object(point,
instantiates(class),
specializes(object)).
:- info([
version is 1.1,
date is 2000/10/31,
author is 'Paulo Moura',
comment is 'Two dimensional point class.',
source is 'Example adopted from the SICStus Objects documentation.']).
:- public(move/2).
:- mode(move(+integer, +integer), zero_or_one).
:- public(position/2).
:- mode(position(?integer, ?integer), one).
:- private(position_/2).
:- dynamic(position_/2).
:- mode(position_(?integer, ?integer), one).
move(X, Y) :-
::retractall(position_(_, _)),
::assertz(position_(X, Y)).
position(X, Y) :-
::position_(X, Y).
print :-
self(Self),
::position_(X, Y),
writeq(Self), write(' @ '), write((X, Y)), nl.
default_init_option(position-(0, 0)).
default_init_option(Default) :-
^^default_init_option(Default).
process_init_option(position-(X, Y)) :-
process_init_option(Option) :-
^^process_init_option(Option).
instance_base_name(p).
:- end_object.
