.. This file is part of Logtalk https://logtalk.org/ SPDX-FileCopyrightText: 1998-2024 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

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.. rst-class:: align-right

directive

.. index:: pair: encoding/1; Directive .. _directives_encoding_1:

encoding/1

Description

::

encoding(Encoding)

Declares the source file text encoding. Requires a :term:`backend Prolog compiler` supporting the chosen encoding. When used, this directive must be the first term in the source file in the first line. This directive is also supported in files included in a main file or in a dynamically created entity using :ref:directives_include_1 directives.

The encoding used in a source file (and, in the case of a Unicode encoding, any BOM present) will be used for the intermediate Prolog file generated by the compiler. Logtalk uses the encoding names specified by `IANA http://www.iana.org/assignments/character-sets/character-sets.xhtml_. In those cases where a preferred MIME name alias is specified, the alias is used instead. Examples includes 'US-ASCII'`, 'ISO-8859-1', 'ISO-8859-2', 'ISO-8859-15', 'UCS-2', 'UCS-2LE', 'UCS-2BE', 'UTF-8', 'UTF-16', 'UTF-16LE', 'UTF-16BE', 'UTF-32', 'UTF-32LE', 'UTF-32BE', 'Shift_JIS', and 'EUC-JP'. When writing portable code that cannot be expressed using ASCII, 'UTF-8' is the most commonly supported Unicode encoding.

The backend Prolog compiler adapter files define a table that translates between the Logtalk and Prolog specific atoms that represent each supported encoding. The :ref:`encoding_directive <flag_encoding_directive>` read-only flag can be used to find if a backend supports this directive and how.

Template and modes

::

encoding(+atom)

Examples

::

:- encoding('UTF-8').