Package org.apache.lucene.search

Class IndriScorer

java.lang.Object
org.apache.lucene.search.Scorable
org.apache.lucene.search.Scorer
org.apache.lucene.search.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 Details

    • IndriScorer

      protected IndriScorer(Weight weight, float boost)

  • Method Details

    • 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()