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Copyright 1998-2021 Paulo Moura <pmoura@logtalk.org>  
SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License");
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Design pattern:
	Iterator

Description:
	"Provide a way to access the elements of an aggregate object
	sequentially without exposing its underlying representation."

This pattern can be used with both classes and prototypes.

A straightforward implementation of this design pattern is to define an
iterator predicate that enumerates elements using backtracking. This
predicate can then be called from meta-predicates such as the de facto
standard `forall/2` predicate.
