retract/1


Description

retract(Clause)
retract((Head:-Body))

Retracts a dynamic clause from an object.

Template and modes

retract(+clause)

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 is that of a private predicate:
permission_error(modify, private_predicate, Head)
The predicate indicator of Head is that of a protected predicate:
permission_error(modify, protected_predicate, Head)
The predicate indicator of Head is that of a static predicate:
permission_error(modify, static_predicate, Head)
The predicate indicator of Head is not declared:
existence_error(predicate_declaration, Head)

Examples

To retract a matching clause of any dynamic predicate in this:
retract(Clause)
To retract a matching clause of a public or protected dynamic predicate in self:
::retract(Clause)
To retract a matching clause of a public dynamic predicate in an object:
Object::retract(Clause)

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Last updated on: August 6, 2002