..
   This file is part of Logtalk <https://logtalk.org/>
   SPDX-FileCopyrightText: 1998-2025 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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       http://www.apache.org/licenses/LICENSE-2.0

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.. rst-class:: align-right

**built-in predicate**

.. index:: pair: current_protocol/1; Built-in predicate
.. _predicates_current_protocol_1:

``current_protocol/1``
======================

Description
-----------

::

   current_protocol(Protocol)

Enumerates, by backtracking, all currently defined protocols. All
protocols are found, either static, dynamic, or built-in.

Modes and number of proofs
--------------------------

::

   current_protocol(?protocol_identifier) - zero_or_more

Errors
------

| ``Protocol`` is neither a variable nor a valid protocol identifier:
|     ``type_error(protocol_identifier, Protocol)``

Examples
--------

::

   % enumerate the defined protocols:
   | ?- current_protocol(Protocol).

   Protocol = expanding ;
   Protocol = monitoring ;
   Protocol = forwarding ;
   ...

.. seealso::

   :ref:`predicates_abolish_protocol_1`,
   :ref:`predicates_create_protocol_3`,
   :ref:`predicates_protocol_property_2`,
   :ref:`predicates_conforms_to_protocol_2_3`,
   :ref:`predicates_extends_protocol_2_3`,
   :ref:`predicates_implements_protocol_2_3`
