Package org.apache.lucene.search

Class IndriScorer

  • Direct Known Subclasses:
    IndriDisjunctionScorer
    public abstract class IndriScorer
extends Scorer
    The Indri parent scorer that stores the boost so that IndriScorers can use the boost outside of the term.

    • Constructor Detail

      • IndriScorer

        protected IndriScorer​(Weight weight,
                      float boost)

    • Method Detail

      • iterator

        public abstract DocIdSetIterator iterator()
        Description copied from class: Scorer
        Return a DocIdSetIterator over matching documents.

        The returned iterator will either be positioned on -1 if no documents have been scored yet, DocIdSetIterator.NO_MORE_DOCS if all documents have been scored already, or the last document id that has been scored otherwise.

        The returned iterator is a view: calling this method several times will return iterators that have the same state.

        Specified by:
        iterator in class Scorer

      • getMaxScore

        public abstract float getMaxScore​(int upTo)
                           throws IOException
        Description copied from class: Scorer
        Return the maximum score that documents between the last target that this iterator was shallow-advanced to included and upTo included.
        Specified by:
        getMaxScore in class Scorer
        Throws:
        IOException

      • score

        public abstract float score()
                     throws IOException
        Description copied from class: Scorable
        Returns the score of the current document matching the query.
        Specified by:
        score in class Scorable
        Throws:
        IOException

      • smoothingScore

        public abstract float smoothingScore​(int docId)
                              throws IOException
        Description copied from class: Scorable
        Returns the smoothing score of the current document matching the query. This score is used when the query/term does not appear in the document, and behaves like an idf. The smoothing score is particularly important when the Scorer returns a product of probabilities so that the document score does not go to zero when one probability is zero. This can return 0 or a smoothing score.

        Smoothing scores are described in many papers, including: Metzler, D. and Croft, W. B. , "Combining the Language Model and Inference Network Approaches to Retrieval," Information Processing and Management Special Issue on Bayesian Networks and Information Retrieval, 40(5), pp.735-750.

        Overrides:
        smoothingScore in class Scorable
        Throws:
        IOException

      • docID

        public abstract int docID()
        Description copied from class: Scorable
        Returns the doc ID that is currently being scored.
        Specified by:
        docID in class Scorable

      • getBoost

        public float getBoost()