Include Paulo Moura's Logtalk OO LP system

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Logtalk/examples/instmethods/NOTES

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+=================================================================
+Logtalk - Object oriented extension to Prolog
+Release 2.8.4
+
+Copyright (c) 1998-2001 Paulo Moura.  All Rights Reserved.
+=================================================================
+
+To load all objects in this example consult the instmethods.loader utility
+file (note that the *.loader files are Prolog files).
+
+This folder contains an example of instance defined methods. When using 
+classes and instances, methods must be declared in a class but the method 
+definitions may be stored in the instances, either overriding or specializing 
+the class definitions.

Logtalk/examples/instmethods/SCRIPT

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+=================================================================
+Logtalk - Object oriented extension to Prolog
+Release 2.8.4
+
+Copyright (c) 1998-2001 Paulo Moura.  All Rights Reserved.
+=================================================================
+
+
+% instance1 definition for method "method" is found in its class:
+
+| ?- instance1::method.
+
+This is the default definition for the method, stored in class root.
+
+yes
+
+
+% instance2 overrides definition of method "method"
+
+| ?- instance2::method.
+
+This is an overriding definition stored in the instance2 instance itself.
+
+yes
+
+
+% instance3 specializes definition of method "method"
+
+| ?- instance3::method.
+
+This is a specializing definition stored in the instance3 instance itself.
+It makes a super call to execute the default definition:
+
+This is the default definition for the method, stored in class root.
+
+yes

Logtalk/examples/instmethods/instance1.lgt

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+
+:- object(instance1,
+	instantiates(root)).
+
+
+:- end_object.

Logtalk/examples/instmethods/instance2.lgt

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+
+:- object(instance2,
+	instantiates(root)).
+
+
+	method :-
+		this(This),
+		write('This is an overriding definition stored in the '),
+		writeq(This),
+		write(' instance itself.'), nl.
+
+
+:- end_object.

Logtalk/examples/instmethods/instance3.lgt

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+
+:- object(instance3,
+	instantiates(root)).
+
+
+	method :-
+		this(This),
+		write('This is a specializing definition stored in the '),
+		writeq(This),
+		write(' instance itself.'), nl,
+		write('It makes a super call to execute the default definition:'), nl, nl,
+		^^method.
+
+
+:- end_object.

Logtalk/examples/instmethods/instmethods.loader

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+
+:- initialization(
+	logtalk_load([
+		root,
+		instance1,
+		instance2,
+		instance3])).

Logtalk/examples/instmethods/root.lgt

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+
+:- object(root,
+	instantiates(root)).
+
+
+	:- public(method/0).
+
+
+	method :-
+		this(This),
+		write('This is the default definition for the method, stored in class '),
+		writeq(This), write('.'), nl.
+
+
+:- end_object.