5345523da3
git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@561 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
130 lines
2.1 KiB
Plaintext
130 lines
2.1 KiB
Plaintext
=================================================================
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Logtalk - Object oriented extension to Prolog
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Release 2.14.1
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Copyright (c) 1998-2002 Paulo Moura. All Rights Reserved.
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=================================================================
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% print the (public and protected) interface of each class:
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| ?- (object, abstract_class, class)::print.
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Object: object
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interface:
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new/1
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delete/1
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instances/1
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metaclass/0
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abstract_class/0
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strict_instance/0
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print/0
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Object: abstract_class
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interface:
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new/1
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delete/1
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instances/1
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metaclass/0
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abstract_class/0
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strict_instance/0
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print/0
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Object: class
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interface:
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new/1
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delete/1
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instances/1
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metaclass/0
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abstract_class/0
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strict_instance/0
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print/0
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yes
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% class is the metaclass of all classes:
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| ?- class::instances(Instances), class::metaclass.
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Instances = [class,abstract_class,object]
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yes
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% create an abstract_class, check it and print its interface:
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| ?- abstract_class::new(ac), ac::abstract_class, ac::print.
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Object: ac
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interface:
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metaclass/0
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abstract_class/0
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strict_instance/0
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print/0
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yes
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% try to create an instance of the abstract class:
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| ?- ac::new(i).
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uncaught exception: error(existence_error(predicate_declaration,new(i)),ac::new(i),user)
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% create a new instantiable class and print its interface:
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| ?- class::new(c), c::print.
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Object: c
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interface:
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new/1
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delete/1
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instances/1
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metaclass/0
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abstract_class/0
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strict_instance/0
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print/0
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yes
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% create an instance of the new class:
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| ?- c::new(i), c::instances(Instances).
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Instances = [i]
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yes
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% because c does not declare any predicates, its instances have no interface:
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| ?- i::current_predicate(Predicate).
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no
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% create an instance of object, root of the inheritance graph, and print its interface:
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| ?- object::new(j), j::print.
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Object: j
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interface:
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strict_instance/0
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print/0
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yes
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% delete the dynamic objects that we created:
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| ?- c::delete(i), class::delete(c), abstract_class::delete(ac), object::delete(j).
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yes
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