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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 folder contains an example of using the message printing mechanism to provide software localization in several natural languages. Each language localization is defined in its own category. Typically, only the category for the selected language would be loaded, possibly with the help of conditional compilation directives. But we load them all in this example. The selected language can be represented in several ways. Here we use a single object parameter. Another alternative would be to use any mechanism for setting the default language (e.g., a simple global fact). The main point is that an application core logic should be decoupled from the natural language used when interacting with the user. Customizing the application for another natural language should ideally be as simple as defining a set of entities holding the message text translations and loading these localization files at application startup. The solution used in this example support loading more than one localization at the same time but this is usually not required. In the simple case where a single localization would be loaded at any given time, the code can be simplified by removing the country code parametrization from the core logic.