discards information from the database.
retractall(Term)
retractall(Term) (i)
void(Term) (i) Term to be removed from database entries
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(_).
asserta(hello), asserta(world), database(X), write(X),nl, fail ; retractall(X).
No runtime errors.
prolog-process, client-server, object
asserta , assertz , retract , clause , database , listing