Package org.apache.lucene.queries.spans

Class NearSpansOrdered

java.lang.Object

org.apache.lucene.search.DocIdSetIterator

org.apache.lucene.queries.spans.Spans

org.apache.lucene.queries.spans.NearSpansOrdered

public class NearSpansOrdered
extends Spans

A Spans that is formed from the ordered subspans of a SpanNearQuery where the subspans do not overlap and have a maximum slop between them.

The formed spans only contains minimum slop matches.
The matching slop is computed from the distance(s) between the non overlapping matching Spans.
Successive matches are always formed from the successive Spans of the SpanNearQuery.

The formed spans may contain overlaps when the slop is at least 1. For example, when querying using

t1 t2 t3

with slop at least 1, the fragment:

t1 t2 t1 t3 t2 t3

matches twice:

t1 t2 .. t3      

      t1 .. t2 t3

Expert: Only public for subclassing. Most implementations should not need this class

Field Summary

Fields

Modifier and Type	Field	Description
protected int	matchEnd
protected int	matchStart
protected int	matchWidth

Fields inherited from class org.apache.lucene.queries.spans.Spans

NO_MORE_POSITIONS

Fields inherited from class org.apache.lucene.search.DocIdSetIterator

NO_MORE_DOCS

Constructor Summary

Constructors

Constructor	Description
NearSpansOrdered(int allowedSlop, List<Spans> subSpans)

Method Summary

Modifier and Type	Method	Description
int	advance(int target)
TwoPhaseIterator	asTwoPhaseIterator()	Return a TwoPhaseIterator view of this ConjunctionSpans.
void	collect(SpanCollector collector)	Collect postings data from the leaves of the current Spans.
long	cost()
int	docID()
int	endPosition()	Returns the end position for the current start position, or -1 when Spans.nextStartPosition() was not yet called on the current doc.
Spans[]	getSubSpans()
int	nextDoc()
int	nextStartPosition()	Returns the next start position for the current doc.
float	positionsCost()	Return an estimation of the cost of using the positions of this Spans for any single document, but only after Spans.asTwoPhaseIterator() returned null.
int	startPosition()	Returns the start position in the current doc, or -1 when Spans.nextStartPosition() was not yet called on the current doc.
int	width()	Return the width of the match, which is typically used to sloppy freq.

Methods inherited from class org.apache.lucene.queries.spans.Spans

doCurrentSpans, doStartCurrentDoc, toString

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

all, empty, range, slowAdvance

Methods inherited from class java.lang.Object

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

Field Detail

matchStart

protected int matchStart

matchEnd

protected int matchEnd

matchWidth

protected int matchWidth

Constructor Detail

NearSpansOrdered

public NearSpansOrdered(int allowedSlop,
                        List<Spans> subSpans)
                 throws IOException

Throws:

IOException

Method Detail

nextStartPosition

public int nextStartPosition()
                      throws IOException

Description copied from class: Spans

Returns the next start position for the current doc. There is always at least one start/end position per doc. After the last start/end position at the current doc this returns Spans.NO_MORE_POSITIONS.

Specified by:

nextStartPosition in class Spans

Throws:

IOException

startPosition

public int startPosition()

Description copied from class: Spans

Returns the start position in the current doc, or -1 when Spans.nextStartPosition() was not yet called on the current doc. After the last start/end position at the current doc this returns Spans.NO_MORE_POSITIONS.

Specified by:

startPosition in class Spans

endPosition

public int endPosition()

Description copied from class: Spans

Returns the end position for the current start position, or -1 when Spans.nextStartPosition() was not yet called on the current doc. After the last start/end position at the current doc this returns Spans.NO_MORE_POSITIONS.

Specified by:

endPosition in class Spans

width

public int width()

Description copied from class: Spans

Return the width of the match, which is typically used to sloppy freq. It is only legal to call this method when the iterator is on a valid doc ID and positioned. The return value must be positive, and lower values means that the match is better.

Specified by:

width in class Spans

collect

public void collect(SpanCollector collector)
             throws IOException

Description copied from class: Spans

Collect postings data from the leaves of the current Spans.

This method should only be called after Spans.nextStartPosition(), and before Spans.NO_MORE_POSITIONS has been reached.

Specified by:

collect in class Spans

Parameters:

collector - a SpanCollector

Throws:

IOException

docID

public int docID()

Specified by:

docID in class DocIdSetIterator

cost

public long cost()

Specified by:

cost in class DocIdSetIterator

nextDoc

public int nextDoc()
            throws IOException

Specified by:

nextDoc in class DocIdSetIterator

Throws:

IOException

advance

public int advance(int target)
            throws IOException

Specified by:

advance in class DocIdSetIterator

Throws:

IOException

asTwoPhaseIterator

public TwoPhaseIterator asTwoPhaseIterator()

Return a TwoPhaseIterator view of this ConjunctionSpans.

Overrides:

asTwoPhaseIterator in class Spans

See Also:

Scorer.twoPhaseIterator()

positionsCost

public float positionsCost()

Description copied from class: Spans

Return an estimation of the cost of using the positions of this Spans for any single document, but only after Spans.asTwoPhaseIterator() returned null. Otherwise this method should not be called. The returned value is independent of the current document.

Specified by:

positionsCost in class Spans

getSubSpans

public Spans[] getSubSpans()