IfThen

java.lang.Object
- org.projog.core.predicate.AbstractPredicateFactory
- - org.projog.core.predicate.builtin.compound.IfThen

All Implemented Interfaces:

KnowledgeBaseConsumer, PredicateFactory, PreprocessablePredicateFactory
```
public final class IfThen
extends AbstractPredicateFactory
implements PreprocessablePredicateFactory
```
X->Y - if X succeeds then Y is evaluated.
Note: The behaviour of this predicate changes when it is specified as the first argument of a structure of the form ;/2, i.e. the "disjunction" 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:

Disjunction

Nested Class Summary

Nested Classes
Modifier and Type Class Description

private static class IfThen.OptimisedIfThen

Constructor Summary

Constructors
Constructor Description

IfThen()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected Predicate`	`getPredicate(Term conditionTerm, Term thenTerm)`
`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
- IfThen
```
public IfThen()
```

Method Detail

getPredicate

protected Predicate getPredicate(Term conditionTerm,
                                 Term thenTerm)

Overrides:: getPredicate in class AbstractPredicateFactory

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

preprocess in interface PreprocessablePredicateFactory