Package org.apache.lucene.search.spans

Class 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 Detail

      • matchStart

        protected int matchStart

      • matchEnd

        protected int matchEnd

      • matchWidth

        protected int matchWidth

      • allowedSlop

        private final int allowedSlop

    • Constructor Detail

      • NearSpansOrdered

        public NearSpansOrdered​(int allowedSlop,
                        java.util.List<Spans> subSpans)
                 throws java.io.IOException
        Throws:
        java.io.IOException

    • Method Detail

      • unpositioned

        private boolean unpositioned()

      • nextStartPosition

        public int nextStartPosition()
                      throws java.io.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:
        java.io.IOException

      • stretchToOrder

        private boolean stretchToOrder()
                        throws java.io.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:
        java.io.IOException

      • advancePosition

        private static int advancePosition​(Spans spans,
                                   int position)
                            throws java.io.IOException
        Throws:
        java.io.IOException

      • 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 java.io.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:
        java.io.IOException