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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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       http://www.apache.org/licenses/LICENSE-2.0

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.. rst-class:: align-right

**built-in method**

.. index:: pair: domain_error/2; Built-in method
.. _methods_domain_error_2:

``domain_error/2``
==================

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

::

   domain_error(Domain, Culprit)

Throws a domain error. Used when an argument is of the correct type but
outside the valid domain. For example, trying to use an atom as an operator
specifier that is not a valid specifier. This built-in method is declared
private and thus cannot be used as a message to an object. Calling this
predicate is equivalent to the following sequence of goals:

::

   ...,
   context(Context),
   throw(error(domain_error(Domain,Culprit), Context)).

This allows the user to generate errors in the same format used by the
runtime.

Possible values for ``Domain`` include:

- ``character_code_list``
- ``close_option``
- ``flag_option``
- ``flag_value``
- ``compiler_flag``
- ``flag``
- ``prolog_flag``
- ``io_mode``
- ``non_empty_list``
- ``not_less_than_zero``
- ``operator_priority``
- ``operator_specifier``
- ``read_option``
- ``source_sink``
- ``stream``
- ``stream_option``
- ``stream_or_alias``
- ``stream_position``
- ``stream_property``
- ``write_option``
- ``character_code_list``
- ``text_encoding``
- ``directive``
- ``object_directive``
- ``protocol_directive``
- ``category_directive``
- ``object_relation``
- ``protocol_relation``
- ``category_relation``
- ``object_property``
- ``protocol_property``
- ``category_property``
- ``predicate_property``
- ``meta_argument_specifier``
- ``meta_directive_template``
- ``closure``
- ``allocation``
- ``redefinition``
- ``message_sending_goal``
- ``class``
- ``prototype``
- ``scope``
- ``boolean``

The value of ``Culprit`` is the argument or one of its sub-terms that caused
the error.

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

::

   domain_error(+atom, @nonvar) - error

Errors
------

| When called:
|     ``domain_error(Domain, Culprit)``

Examples
--------

::

   ...,
   atom(Color),
   \+ color(Color),
   domain_error(color, Color).

.. seealso::

   :ref:`methods_catch_3`,
   :ref:`methods_throw_1`,
   :ref:`methods_context_1`,
   :ref:`methods_instantiation_error_0`,
   :ref:`methods_uninstantiation_error_1`,
   :ref:`methods_type_error_2`,
   :ref:`methods_consistency_error_3`,
   :ref:`methods_existence_error_2`,
   :ref:`methods_permission_error_3`,
   :ref:`methods_representation_error_1`,
   :ref:`methods_evaluation_error_1`,
   :ref:`methods_resource_error_1`,
   :ref:`methods_syntax_error_1`,
   :ref:`methods_system_error_0`
