---

This file is part of Logtalk https://logtalk.org/ SPDX-FileCopyrightText: 1998-2023 Paulo Moura <pmoura@logtalk.org> SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

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.