.. 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

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.

.. rst-class:: align-right

built-in method

.. index:: pair: permission_error/3; Built-in method .. _methods_permission_error_3:

permission_error/3

Description

permission_error(Operation, Permission, Culprit)

Throws an permission error. Used when an operation is not allowed. For example, sending a message for a predicate that is not within the scope of the sender. 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(permission_error(Operation,Permission,Culprit), Context)).

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

Possible values for Operation include:

access
create
modify
open
input
output
reposition
repeat Possible values for Permission include:
predicate_declaration
protected_predicate
private_predicate
static_predicate
database
object
static_object
static_protocol
static_category
entity_relation
operator
flag
engine
binary_stream
text_stream
source_sink
stream
past_end_of_stream The value of Culprit is the argument or one of its sub-terms that caused the error.

Modes and number of proofs

permission_error(@nonvar, @nonvar, @nonvar) - error

Errors

| When called: | permission_error(Operation, Permission, Culprit)

Examples

..., \+ writable(File), permission_error(modify, file, File).

.. 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_domain_error_2, :ref:methods_existence_error_2, :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