:- object(circle(Radius, Color),
extends(ellipse(Radius, Radius, Color))).
:- info([
author is 'Paulo Moura',
version is 1.0,
date is 2000/4/22,
comment is 'Parametric object for representing geometric circles.',
parnames is ['Radius', 'Color'],
source is 'Example adopted from the SICStus Objects documentation.']).
:- public(r/1).
:- mode(r(?number), zero_or_one).
:- info(r/1, [
comment is 'Circle radius.',
argnames is ['Radius']]).
r(Radius) :-
parameter(1, Radius).
color(Color) :-
parameter(2, Color).
rx(Radius) :-
::r(Radius).
ry(Radius) :-
context :-
write(circle2), nl,
self(Self), write('self: '), writeq(Self), nl,
this(This), write('this: '), writeq(This), nl,
sender(Sender), write('sender: '), writeq(Sender), nl, nl,
^^context.
:- end_object.
