..
   This file is part of Logtalk <https://logtalk.org/>  
   Copyright 1998-2021 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.


.. index:: pair: ununinstantiation_error/1; Built-in method
.. _methods_uninstantiation_error_1:

``uninstantiation_error/1``
===========================

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

::

   uninstantiation_error(Culprit)

Throws an uninstantiation error. Used when an argument or one of its
sub-arguments is bound but a variable is required. For example, trying
to open a file with a stream argument bound.

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 calls:


::

   ...,
   context(Context),
   throw(error(uninstantiation_error(Culprit), Context)).

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

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

::

   uninstantiation_error(@nonvar) - error

Errors
------

| When called:
|     ``uninstantiation_error(Culprit)``

Examples
--------

::

   ...,
   var(Handler),
   uninstantiation_error(my_stream).

.. seealso::

   :ref:`methods_catch_3`,
   :ref:`methods_throw_1`,
   :ref:`methods_context_1`,
   :ref:`methods_instantiation_error_0`,
   :ref:`methods_type_error_2`,
   :ref:`methods_domain_error_2`,
   :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`
