org.projog.core.predicate.builtin.compare

Class Equal

java.lang.Object

org.projog.core.predicate.AbstractSingleResultPredicate

org.projog.core.predicate.builtin.compare.Equal

All Implemented Interfaces:

KnowledgeBaseConsumer, PredicateFactory

public final class Equal
extends AbstractSingleResultPredicate

X=Y - an equality test.

If X can be matched with Y the goal succeeds else the goal fails. A X=Y goal will consider an uninstantiated variable to be equal to anything. A X=Y goal will always succeed if either argument is uninstantiated.

Constructor Summary

Constructors

Constructor and Description
Equal()

Method Summary

Modifier and Type	Method and Description
protected boolean	evaluate(Term arg1, Term arg2)

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

evaluate, evaluate, evaluate, evaluate, evaluate, getArithmeticOperators, getFileHandles, getKnowledgeBase, getOperands, getPredicate, getPredicates, getProjogListeners, getSpyPoints, getTermFormatter, init, 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

Equal

public Equal()

Method Detail

evaluate

protected boolean evaluate(Term arg1,
                           Term arg2)

Overrides:

evaluate in class AbstractSingleResultPredicate