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   SPDX-FileCopyrightText: 1998-2026 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.
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   Unless required by applicable law or agreed to in writing, software
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.. _faq_compatibility:

Compatibility
=============

* :ref:`faq_compatibility_requirements`
* :ref:`faq_compatibility_constraints`
* :ref:`faq_compatibility_modules`

.. _faq_compatibility_requirements:

What are the backend Prolog compiler requirements to run Logtalk?
-----------------------------------------------------------------

See the `backend Prolog compiler requirements guide <https://logtalk.org/backend_requirements.html>`_.

.. _faq_compatibility_constraints:

Can I use constraint-based packages with Logtalk?
-------------------------------------------------

Usually, yes. Some constraint-based packages may define operators
which clash with the ones defined by Logtalk. In these cases,
compatibility with Logtalk depends on the constraint-based packages
providing an alternative for accessing the functionality provided by
those operators. When the constraint solver is encapsulated using a
Prolog module, a possible workaround is to use either explicit module
qualification or encapsulate the call using the :ref:`control_external_call_1`
control construct (thus bypassing the Logtalk compiler).

.. _faq_compatibility_modules:

Can I use Logtalk objects and Prolog modules at the same time?
--------------------------------------------------------------

Yes. In order to call a module predicate from within an object (or category)
you may use an :ref:`directives_use_module_2` directive or use explicit
module qualification (possibly wrapping the call using the Logtalk
control construct :ref:`control_external_call_1` that allows bypassing of
the Logtalk compiler when compiling a predicate call). Logtalk also allows
modules to be compiled as objects (see the :ref:`migration_migration`
for details).
