retractall
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BAP Online Manuals : Library Reference : Library by Name : retractall
Previous: retract
Next: rmdir
Previous: retract
Next: rmdir
6.2.113. retractall
discards information from the database.
SYNOPSIS
retractall(Term)
SYNTAX
retractall(Term) (i)
ARGUMENTS
void(Term) (i) Term to be removed from database entries
DESCRIPTION
This is a standard PROLOG built-in. It succeeds once and remove all database entries
that match Term on the way. Different from standard prolog you may use this with an
uninstantiated variable to remove all entries.
Its definition is:
PREDICATE retractall(void). retractall(Term):- retract(Term),fail. retractall(_).
EXAMPLE
asserta(hello), asserta(world), database(X), write(X),nl, fail ; retractall(X).
ERRORS
No runtime errors.
LAYERS
prolog-process, client-server, object
RELATED PREDICATES
asserta , assertz , retract , clause , database , listing
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