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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.

To load this example and for sample queries, please see the SCRIPT.txt file.

This example requires using ECLiPSe as the backend Prolog compiler. It illustrates using a ECLiPSe structure notation, which provides a solution for using structures with field names rather than positional arguments. This is accomplished by using a single parameter, instantiated to a structure, and by defining a set of predicates for accessing the individual parameters by a key (instead of using the Logtalk built-in parameter/2 method that indexes individual parameters by position). The access predicates are goal-expanded to the corresponding ECLiPSe structure built-in predicates.