40 lines
753 B
Plaintext
40 lines
753 B
Plaintext
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:- object(circle(_Radius, _Color)).
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:- public([
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radius/1,
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color/1,
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area/1,
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perimeter/1,
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print/0]).
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radius(Radius) :-
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parameter(1, Radius).
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color(Color) :-
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parameter(2, Color).
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area(Area) :-
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::radius(Radius),
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Area is 3.1415927*Radius*Radius.
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perimeter(Perimeter) :-
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::radius(Radius),
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Perimeter is 2*3.1415927*Radius.
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print :-
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area(Area), write('area: '), write(Area),
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perimeter(Perimeter), write(', perimeter: '), write(Perimeter),
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color(Color), write(', color: '), write(Color), nl.
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:- end_object.
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% parametric object proxies (with an extra argument to represent identity):
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circle('#1', 1.23, blue).
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circle('#2', 3.71, yellow).
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circle('#3', 0.39, green).
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circle('#4', 5.74, black).
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circle('#5', 8.32, cyan).
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