org.apache.lucene.search
Class ReqExclScorer

java.lang.Object
  org.apache.lucene.search.DocIdSetIterator
      org.apache.lucene.search.Scorer
          org.apache.lucene.search.ReqExclScorer

public class ReqExclScorer
extends Scorer

A Scorer for queries with a required subscorer and an excluding (prohibited) subscorer.
This Scorer implements DocIdSetIterator.skipTo(int), and it uses the skipTo() on the given scorers.

Constructor Summary

ReqExclScorer(Scorer reqScorer, Scorer exclScorer)
Construct a ReqExclScorer.

Method Summary

int	doc() Returns the current document number.
Explanation	explain(int doc) Returns an explanation of the score for a document.
boolean	next() Moves to the next docId in the set.
float	score() Returns the score of the current document matching the query.
boolean	skipTo(int target) Skips to the first match beyond the current whose document number is greater than or equal to a given target.

Methods inherited from class org.apache.lucene.search.Scorer

getSimilarity, score, score

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReqExclScorer

public ReqExclScorer(Scorer reqScorer,
                     Scorer exclScorer)

Construct a ReqExclScorer.

Parameters:

reqScorer - The scorer that must match, except where

exclScorer - indicates exclusion.

Method Detail

next

public boolean next()
             throws IOException

Description copied from class: DocIdSetIterator

Moves to the next docId in the set. Returns true, iff there is such a docId.

Specified by:

next in class DocIdSetIterator

Throws:

IOException

doc

public int doc()

Description copied from class: DocIdSetIterator

Returns the current document number.

This is invalid until DocIdSetIterator.next() is called for the first time.

Specified by:

doc in class DocIdSetIterator

score

public float score()
            throws IOException

Returns the score of the current document matching the query. Initially invalid, until next() is called the first time.

Specified by:

score in class Scorer

Returns:

The score of the required scorer.

Throws:

IOException

skipTo

public boolean skipTo(int target)
               throws IOException

Skips to the first match beyond the current whose document number is greater than or equal to a given target.
When this method is used the explain(int) method should not be used.

Specified by:

skipTo in class DocIdSetIterator

Parameters:

target - The target document number.

Returns:

true iff there is such a match.

Throws:

IOException

explain

public Explanation explain(int doc)
                    throws IOException

Description copied from class: Scorer

Returns an explanation of the score for a document.
When this method is used, the DocIdSetIterator.next(), DocIdSetIterator.skipTo(int) and Scorer.score(HitCollector) methods should not be used.

Specified by:

explain in class Scorer

Parameters:

doc - The document number for the explanation.

Throws:

IOException