60 lines
989 B
Plaintext
60 lines
989 B
Plaintext
|
|
||
|
|
:- object(brick_stack,
|
||
|
|
instantiates(constrained_relation)).
|
||
|
|
|
||
|
|
|
||
|
|
:- info([
|
||
|
|
version is 1.0,
|
||
|
|
date is 1998/3/23,
|
||
|
|
authors is 'Paulo Moura',
|
||
|
|
comment is 'Stack of bricks as a constrained binary relation.']).
|
||
|
|
|
||
|
|
|
||
|
|
descriptor_([top, bottom]).
|
||
|
|
|
||
|
|
|
||
|
|
domain_(top, brick).
|
||
|
|
domain_(bottom, brick).
|
||
|
|
|
||
|
|
|
||
|
|
key_([top, bottom]).
|
||
|
|
|
||
|
|
|
||
|
|
cardinality_(top, 0, 1).
|
||
|
|
cardinality_(bottom, 0, 1).
|
||
|
|
|
||
|
|
|
||
|
|
delete_option_(top, cascade).
|
||
|
|
delete_option_(bottom, restrict).
|
||
|
|
|
||
|
|
|
||
|
|
add_tuple([A, B]) :-
|
||
|
|
B::position(Xb, Yb),
|
||
|
|
Ya2 is Yb + 1,
|
||
|
|
{A::move(Xb, Ya2)},
|
||
|
|
^^add_tuple([A, B]).
|
||
|
|
|
||
|
|
|
||
|
|
activ_points_(top, before, []).
|
||
|
|
activ_points_(top, after, [move(_, _)]).
|
||
|
|
|
||
|
|
activ_points_(bottom, before, []).
|
||
|
|
activ_points_(bottom, after, [move(_, _)]).
|
||
|
|
|
||
|
|
|
||
|
|
propagate(after, move(X, Y), Top, top, [Top, Bottom]) :-
|
||
|
|
!,
|
||
|
|
Y2 is Y - 1,
|
||
|
|
(Bottom::position(X, Y2) ->
|
||
|
|
true
|
||
|
|
;
|
||
|
|
::remove_tuple([Top, Bottom])).
|
||
|
|
|
||
|
|
propagate(after, move(X, Y), Bottom, bottom, [Top, Bottom]) :-
|
||
|
|
!,
|
||
|
|
Y2 is Y + 1,
|
||
|
|
{Top::move(X, Y2)}.
|
||
|
|
|
||
|
|
|
||
|
|
:- end_object.
|