Package org.projog.core.predicate.builtin.compare

Class PredSort

java.lang.Object

org.projog.core.predicate.AbstractSingleResultPredicate

org.projog.core.predicate.builtin.compare.PredSort

All Implemented Interfaces:

KnowledgeBaseConsumer, PredicateFactory, PreprocessablePredicateFactory

public final class PredSort
extends AbstractSingleResultPredicate
implements PreprocessablePredicateFactory

predsort(X,Y,Z) - sorts a list using the specified predicate.

Sorts the list represented by Y using the predicate represented by X - and attempts to unify the result with Z. The predicate represented by X must indicate whether the second argument is equal, less than or greater than the third argument - by unifying the first argument with an atom which has the value =, < or >.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	PredSort.PredSortComparator
private static class	PredSort.PreprocessedPredSort

Field Summary

Fields

Modifier and Type	Field	Description
private static int	FIRST_ARG_ARITY	The arity of the predicate represented by the first argument.

Constructor Summary

Constructors

Constructor	Description
PredSort()

Method Summary

Modifier and Type	Method	Description
protected boolean	evaluate(Term predicateName, Term input, Term sorted)
private static boolean	evaluatePredSort(PredicateFactory pf, Term predicateName, Term input, Term sorted)
PredicateFactory	preprocess(Term term)

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

getPredicate, isAlwaysCutOnBacktrack, isRetryable

Field Detail

FIRST_ARG_ARITY

private static final int FIRST_ARG_ARITY

The arity of the predicate represented by the first argument.

See Also:

Constant Field Values

Constructor Detail

PredSort

public PredSort()

Method Detail

evaluate

protected boolean evaluate(Term predicateName,
                           Term input,
                           Term sorted)

Overrides:

evaluate in class AbstractSingleResultPredicate

evaluatePredSort

private static boolean evaluatePredSort(PredicateFactory pf,
                                        Term predicateName,
                                        Term input,
                                        Term sorted)

preprocess

public PredicateFactory preprocess(Term term)

Specified by:

preprocess in interface PreprocessablePredicateFactory