beagled/Lucene.Net/Search/Weight.cs

   1 /*
   2  * Copyright 2004 The Apache Software Foundation
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 using System;
  17 using IndexReader = Lucene.Net.Index.IndexReader;
  18 namespace Lucene.Net.Search
  19 {
  20
  21         /// <summary>Expert: Calculate query weights and build query scorers.
  22         ///
  23         /// <p>A Weight is constructed by a query, given a Searcher ({@link
  24         /// Query#CreateWeight(Searcher)}).  The {@link #SumOfSquaredWeights()} method
  25         /// is then called on the top-level query to compute the query normalization
  26         /// factor (@link Similarity#queryNorm(float)}).  This factor is then passed to
  27         /// {@link #Normalize(float)}.  At this point the weighting is complete and a
  28         /// scorer may be constructed by calling {@link #Scorer(IndexReader)}.
  29         /// </summary>
  30         public interface Weight
  31         {
  32         /// <summary>The query that this concerns. </summary>
  33         Query Query
  34         {
  35             get;
  36
  37         }
  38         /// <summary>The weight for this query. </summary>
  39         float Value
  40         {
  41             get;
  42
  43         }
  44
  45                 /// <summary>The sum of squared weights of contained query clauses. </summary>
  46                 float SumOfSquaredWeights();
  47
  48                 /// <summary>Assigns the query normalization factor to this. </summary>
  49                 void  Normalize(float norm);
  50
  51                 /// <summary>Constructs a scorer for this. </summary>
  52                 Scorer Scorer(IndexReader reader);
  53
  54                 /// <summary>An explanation of the score computation for the named document. </summary>
  55                 Explanation Explain(IndexReader reader, int doc);
  56         }
  57 }