Is

java.lang.Object
- org.projog.core.predicate.AbstractSingleResultPredicate
- - org.projog.core.predicate.builtin.compare.Is

All Implemented Interfaces:

KnowledgeBaseConsumer, PredicateFactory, PreprocessablePredicateFactory
```
public final class Is
extends AbstractSingleResultPredicate
implements PreprocessablePredicateFactory
```
X is Y - evaluate arithmetic expression.
Firstly structure Y is evaluated as an arithmetic expression to give a number. Secondly an attempt is made to match the number to X. The goal succeeds or fails based on the match.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

private static class Is.PreprocessedIs

private static class Is.Unify

Constructor Summary

Constructors
Constructor Description

Is()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected boolean`	`evaluate(Term arg1, Term arg2)`
`PredicateFactory`	`preprocess(Term arg)`

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

Constructor Detail
- Is
```
public Is()
```

Method Detail

evaluate

protected boolean evaluate(Term arg1,
                           Term arg2)

Overrides:: evaluate in class AbstractSingleResultPredicate

preprocess
```
public PredicateFactory preprocess(Term arg)
```
Specified by:

preprocess in interface PreprocessablePredicateFactory