Module org.apache.lucene.queries
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.ConjunctionSpans
org.apache.lucene.queries.spans.NearSpansOrdered
public class NearSpansOrdered extends ConjunctionSpans
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 Details

    • matchStart

      protected int matchStart

    • matchEnd

      protected int matchEnd

    • matchWidth

      protected int matchWidth

    • allowedSlop

      private final int allowedSlop

  • Constructor Details

  • Method Details

    • twoPhaseCurrentDocMatches

      boolean twoPhaseCurrentDocMatches() throws IOException
      Specified by:
      twoPhaseCurrentDocMatches in class ConjunctionSpans
      Throws:
      IOException

    • unpositioned

      private boolean unpositioned()

    • 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

    • stretchToOrder

      private boolean stretchToOrder() throws IOException
      Order the subSpans within the same document by using nextStartPosition on all subSpans after the first as little as necessary. Return true when the subSpans could be ordered in this way, otherwise at least one is exhausted in the current doc.
      Throws:
      IOException

    • advancePosition

      private static int advancePosition(Spans spans, int position) throws IOException
      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