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|
=================================================================
Logtalk - Object oriented extension to Prolog
Release 2.27.1
Copyright (c) 1998-2006 Paulo Moura. All Rights Reserved.
=================================================================
% start by loading the necessary library support files (if not
% already loaded):
| ?- logtalk_load([library(hierarchies_loader), library(types_loader)]).
...
% now you are ready for loading the example:
| ?- logtalk_load(sicstus(loader)).
...
% try some simple queries:
| ?- sort(rational)::sort([1/8, 2/7, 6/5, 2/9, 1/3], Sorted).
Sorted = [1/8, 2/9, 2/7, 1/3, 6/5]
yes
| ?- sort(colours)::sort([orange, indigo, red, yellow, violet, blue, green], Sorted).
Sorted = [red, orange, yellow, green, blue, indigo, violet]
yes
% using the pseudo-object user implies using the Prolog built-in standard
% order operators:
| ?- sort(user)::sort([3, 1, 4, 2, 9], Sorted).
Sorted = [1, 2, 3, 4, 9]
yes
% some messages testing object parameter passing and using:
| ?- red_circle(3)::color(Color).
Color = red
yes
| ?- red_circle(3)::area(Area).
Area = 28.274334
yes
| ?- red_circle(3)::ancestors(As).
As = [circle(3, red), ellipse(3, 3, red)]
yes
% show the execution context using a method (context/3) that is defined in the
% hierarchy root and specialized (using super calls) in each descendant:
| ?- red_circle(3)::context.
red_circle1
self: red_circle(3)
this: red_circle(3)
sender: user
circle2
self: red_circle(3)
this: circle(3,red)
sender: user
ellipse3
self: red_circle(3)
this: ellipse(3,3,red)
sender: user
yes
% send a conjunction of messages/goals to an object; just some useful syntax
% sugar:
| ?- square(2)::(side(Side), width(Width), height(Height), area(Area)).
Side = 2
Width = 2
Height = 2
Area = 4
yes
% find all messages accepted by an object:
| ?- square(2)::current_predicate(Pred).
Pred = side/1 ;
Pred = width/1 ;
Pred = height/1 ;
Pred = area/1
yes
% find all data on a specific message accepted by an object:
| ?- square(_)::predicate_property(side(_), Prop).
Prop = public ;
Prop = static ;
Prop = declared_in(square(_133)) ;
Prop = defined_in(square(_164))
yes
|
