Include Paulo Moura's Logtalk OO LP system

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@53 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

Logtalk/library/proto_hierarchy.lgt

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+
+:- category(proto_hierarchy,
+	implements(proto_hierarchyp)).
+
+
+	:- info([
+		version is 1.0,
+		authors is 'Paulo Moura',
+		date is 2000/7/24,
+		comment is 'Prototype hierarchy predicates.']).
+
+
+	parent(Parent) :-
+		self(Self),
+		extends_object(Self, Parent).
+
+
+	parents(Parents) :-
+		self(Self),
+		findall(Parent, extends_object(Self, Parent), Parents).
+
+
+	ancestor(Ancestor) :-
+		self(Self),
+		ancestor(Self, Ancestor).
+
+
+	ancestor(Self, Ancestor) :-
+		extends_object(Self, Ancestor).
+
+	ancestor(Self, Ancestor) :-
+		extends_object(Self, Parent),
+		ancestor(Parent, Ancestor).
+
+
+	ancestors(Ancestors) :-
+		self(Self),
+		findall(Ancestor, ancestor(Self, Ancestor), Ancestors).
+
+
+	leaf(Leaf) :-
+		self(Self),
+		leaf(Self, Leaf).
+
+
+	leaf(Self, Leaf) :-
+		extends_object(Leaf, Self),
+		\+ extends_object(_, Leaf).
+
+	leaf(Self, Leaf) :-
+		extends_object(Object, Self),
+		leaf(Object, Leaf).
+
+
+	leaves(Leaves) :-
+		self(Self),
+		findall(Leaf, leaf(Self, Leaf), Leaves).
+
+
+	descendant(Descendant) :-
+		self(Self),
+		descendant(Self, Descendant).
+
+
+	descendant(Self, Descendant) :-
+		extends_object(Descendant, Self).
+
+	descendant(Self, Descendant) :-
+		extends_object(Descendant, Self),
+		\+ extends_object(Descendant, Self).
+
+	descendant(Self, Descendant) :-
+		extends_object(Subclass, Self),
+		descendant(Subclass, Descendant).
+
+
+	descendants(Descendants) :-
+		self(Self),
+		findall(Descendant, descendant(Self, Descendant), Descendants).
+
+
+:- end_category.