org.projog.core.predicate.builtin.compound

Class Disjunction

java.lang.Object

org.projog.core.predicate.AbstractPredicateFactory

org.projog.core.predicate.builtin.compound.Disjunction

All Implemented Interfaces:

KnowledgeBaseConsumer, PredicateFactory, PreprocessablePredicateFactory

public final class Disjunction
extends AbstractPredicateFactory
implements PreprocessablePredicateFactory

X;Y - disjunction.

X;Y specifies a disjunction of goals. X;Y succeeds if either X succeeds or Y succeeds. If X fails then an attempt is made to satisfy Y. If Y fails the entire disjunction fails.

Note: The behaviour of this predicate changes when its first argument is of the form ->/2, i.e. the "if/then" predicate. When a ->/2 predicate is the first argument of a ;/2 predicate then the resulting behaviour is a "if/then/else" statement of the form ((if->then);else).

See Also:

IfThen

Constructor Summary

Constructors

Constructor and Description
Disjunction()

Method Summary

Modifier and Type	Method and Description
protected Predicate	getPredicate(Term firstArg, Term secondArg)
PredicateFactory	preprocess(Term term)

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

getArithmeticOperators, getFileHandles, getKnowledgeBase, getOperands, getPredicate, getPredicate, getPredicate, getPredicate, 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

getPredicate, isAlwaysCutOnBacktrack, isRetryable

Constructor Detail

Disjunction

public Disjunction()

Method Detail

preprocess

public PredicateFactory preprocess(Term term)

Specified by:

preprocess in interface PreprocessablePredicateFactory

getPredicate

protected Predicate getPredicate(Term firstArg,
                                 Term secondArg)

Overrides:

getPredicate in class AbstractPredicateFactory