Nth

java.lang.Object
- org.projog.core.predicate.AbstractPredicateFactory
- - org.projog.core.predicate.builtin.list.Nth

All Implemented Interfaces:

KnowledgeBaseConsumer, PredicateFactory
```
public final class Nth
extends AbstractPredicateFactory
```
nth0(X,Y,Z) / nth1(X,Y,Z) - examines an element of a list.
Indexing starts at 0 when using nth0. Indexing starts at 1 when using nth1.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

private class Nth.Retryable

Field Summary

Fields
Modifier and Type Field Description

private int startingIdx

Constructor Summary

Constructors
Modifier Constructor Description

private Nth(int startingIdx)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`private boolean`	`evaluate(int index, Term list, Term element)`
`protected Predicate`	`getPredicate(Term index, Term list, Term element)`
`static Nth`	`nth0()`
`static Nth`	`nth1()`

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
isAlwaysCutOnBacktrack

Field Detail
- startingIdx
```
private final int startingIdx
```

Constructor Detail
- Nth
```
private Nth(int startingIdx)
```

Method Detail

nth0
```
public static Nth nth0()
```

nth1
```
public static Nth nth1()
```

getPredicate

protected Predicate getPredicate(Term index,
                                 Term list,
                                 Term element)

Overrides:: getPredicate in class AbstractPredicateFactory

evaluate

private boolean evaluate(int index,
                         Term list,
                         Term element)