Logtalk 2.26.2 files.

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1487 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

Logtalk/examples/lo/travellers/sorting.lgt

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+
+:- object(quick(_Order)).
+
+	:- info([
+		author is 'Paulo Moura',
+		version is 1.0,
+		date is 2000/4/22,
+		parnames is ['Order'],
+		comment is '.',
+		source is 'Example adopted from the Francis G. McCabe L&O documentation.']).
+
+	:- public(sort/2).
+	:- mode(sort(+list, -list), one).
+
+	sort([], []).
+	sort([X| L], S):-
+		split(L, X, L1, L2),
+		sort(L1, S1),
+		sort(L2, S2),
+		app(S1, [X| S2], S).
+
+	split([], _, [], []).
+	split([D| L], X, [D| L1], L2):-
+		parameter(1, Order),
+		Order::less(D, X),
+		!,
+		split(L, X, L1, L2).
+	split([D| L], X, L1, [D| L2]):-
+		split(L, X, L1, L2).
+
+	app([], L, L).
+	app([H| T], L, [H| T2]) :-
+		app(T, L, T2).
+
+:- end_object.
+
+
+
+:- object(descend).
+
+	:- info([
+		author is 'Paulo Moura',
+		version is 1.0,
+		date is 2000/4/22,
+		comment is '.',
+		source is 'Example adopted from the Francis G. McCabe L&O documentation.']).
+
+	:- public(less/2).
+
+	less(X, Y):-
+		X >= Y.
+
+:- end_object.
+
+
+:- object(natural).
+
+	:- info([
+		author is 'Paulo Moura',
+		version is 1.0,
+		date is 2000/4/22,
+		comment is '.',
+		source is 'Example adopted from the Francis G. McCabe L&O documentation.']).
+
+	:- public(less/2).
+
+	less(X, Y):-
+		X < Y.
+
+:- end_object.
+
+
+:- object(geographic(_OX, _OY)).
+
+	:- info([
+		author is 'Paulo Moura',
+		version is 1.0,
+		date is 2000/4/22,
+		parnames is ['OX', 'OY'],
+		comment is '.',
+		source is 'Example adopted from the Francis G. McCabe L&O documentation.']).
+
+	:- public(less/2).
+
+	less(Town1, Town2):-
+		angle(Town1, Angle1),
+		angle(Town2, Angle2),
+		Angle1 < Angle2.
+
+    angle(Town, Angle) :-
+		Town::at(X, Y),
+		parameter(1, OX),
+		parameter(2, OY),
+    	angle(X, Y, OX, OY, Angle).
+
+    angle(X, Y, OX, OY, Angle) :-
+		X > OX,
+		Y >= OY,
+		Angle is atan((Y-OY)/(X-OX)).
+
+    angle(X, Y, OX, OY, Angle) :-
+		X > OX,
+		Y < OY,
+		pi(Pi),
+		Angle is Pi + Pi - atan((OY-Y)/(X-OX)).
+
+    angle(X, Y, OX, OY, Angle) :-
+		X < OX,
+		Y >= OY,
+		pi(Pi),
+		Angle is Pi - atan((Y-OY)/(OX-X)).
+
+    angle(X, Y, OX, OY, Angle) :-
+		X < OX,
+		Y < OY,
+		pi(Pi),
+		Angle is Pi + atan((OY-Y)/(OX-X)).
+
+    angle(OX, Y, OX, OY, Angle) :- 
+		Y > OY,
+    	pi(Pi),
+    	Angle is Pi / 2.
+
+    angle(OX, Y, OX, OY, Angle) :-
+		Y =< OY,
+    	pi(Pi),
+    	Angle is 1.5 * Pi.
+
+	pi(Pi) :-
+		Pi is 4.0*atan(1.0).
+
+:- end_object.
+
+
+:- object(metric(_Town)).
+
+	:- info([
+		author is 'Paulo Moura',
+		version is 1.0,
+		date is 2000/4/22,
+		comment is '.',
+		parnames is ['Town'],
+		source is 'Example adopted from the Francis G. McCabe L&O documentation.']).
+
+	:- public(less/2).
+
+	less((Town1, _), (Town2, _)):-
+		parameter(1, Town),
+		Town::crow_flies(Town1, Distance1),
+		Town::crow_flies(Town2, Distance2),
+		Distance1 < Distance2.		
+
+:- end_object.