.. 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

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.. rst-class:: align-right

built-in method

.. index:: pair: retractall/1; Built-in method .. _methods_retractall_1:

retractall/1

Description

::

retractall(Head)

Retracts all clauses with a matching head for an object dynamic predicate.

When the predicate indicator for Head is declared in a :ref:directives_uses_2 or :ref:directives_use_module_2 directive, the clauses are retracted in the referenced object or module. When the backend Prolog compiler supports a module system, the predicate argument can also be module qualified.

This method may be used to retract clauses for predicates that are not declared dynamic for dynamic objects provided that the predicates are declared in :term:this.

Modes and number of proofs

::

retractall(@callable) - one

Errors

| Head is a variable: | instantiation_error | Head is neither a variable nor a callable term: | type_error(callable, Head) | The predicate indicator of Head, Name/Arity, is that of a private predicate: | permission_error(modify, private_predicate, Name/Arity) | The predicate indicator of Head, Name/Arity, is that of a protected predicate: | permission_error(modify, protected_predicate, Name/Arity) | The predicate indicator of Head, Name/Arity, is that of a static predicate: | permission_error(modify, static_predicate, Name/Arity) | The predicate indicator of Head, Name/Arity, is not declared: | existence_error(predicate_declaration, Name/Arity)

Examples

| To retract all clauses with a matching head of a dynamic predicate in :term:this: | retractall(Head) | To retract all clauses with a matching head of a public or protected dynamic predicate in :term:self: | ::retractall(Head) | To retract all clauses with a matching head of a public dynamic predicate in an explicit object: | Object::retractall(Head)

.. seealso::

:ref:methods_abolish_1, :ref:methods_asserta_1, :ref:methods_assertz_1, :ref:methods_clause_2, :ref:methods_retract_1, :ref:directives_dynamic_0, :ref:directives_dynamic_1, :ref:directives_uses_2, :ref:directives_use_module_2