org.projog.core.predicate.builtin.db

Class Erase

java.lang.Object

org.projog.core.predicate.AbstractSingleResultPredicate

org.projog.core.predicate.builtin.db.Erase

All Implemented Interfaces:

KnowledgeBaseConsumer, PredicateFactory

public final class Erase
extends AbstractSingleResultPredicate

erase(X) - removes a record from the recorded database.

Removes from the recorded database the term associated with the reference specified by X. The goal succeeds even if there is no term associated with the specified reference.

Constructor Summary

Constructors

Constructor and Description
Erase()

Method Summary

Modifier and Type	Method and Description
protected boolean	evaluate(Term arg)
protected void	init() This method is called by AbstractSingleResultPredicate.setKnowledgeBase(KnowledgeBase).

Methods inherited from class org.projog.core.predicate.AbstractSingleResultPredicate

evaluate, evaluate, evaluate, evaluate, evaluate, getArithmeticOperators, getFileHandles, getKnowledgeBase, getOperands, getPredicate, getPredicates, getProjogListeners, getSpyPoints, getTermFormatter, isRetryable, setKnowledgeBase

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.projog.core.predicate.PredicateFactory

isAlwaysCutOnBacktrack

Constructor Detail

Erase

public Erase()

Method Detail

init

protected void init()

Description copied from class: AbstractSingleResultPredicate

This method is called by AbstractSingleResultPredicate.setKnowledgeBase(KnowledgeBase).

Can be overridden by subclasses to perform initialisation before any calls to AbstractSingleResultPredicate.evaluate(Term...) are made. As AbstractSingleResultPredicate.setKnowledgeBase(KnowledgeBase) will have already been called before this method is invoked, overridden versions will be able to access the KnowledgeBase using AbstractSingleResultPredicate.getKnowledgeBase().

Overrides:

init in class AbstractSingleResultPredicate

evaluate

protected boolean evaluate(Term arg)

Overrides:

evaluate in class AbstractSingleResultPredicate