beagled/Lucene.Net/Search/ScoreDocComparator.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 namespace Lucene.Net.Search
  18 {
  19
  20
  21         /// <summary> Expert: Compares two ScoreDoc objects for sorting.
  22         ///
  23         /// <p>Created: Feb 3, 2004 9:00:16 AM
  24         ///
  25         /// </summary>
  26         /// <author>   Tim Jones (Nacimiento Software)
  27         /// </author>
  28         /// <since>   lucene 1.4
  29         /// </since>
  30         /// <version>  $Id: ScoreDocComparator.cs,v 1.1 2005/01/17 19:54:30 joeshaw Exp $
  31         /// </version>
  32         public struct ScoreDocComparator_Fields
  33     {
  34                 /// <summary>Special comparator for sorting hits according to computed relevance (document score). </summary>
  35                 public readonly static ScoreDocComparator RELEVANCE;
  36                 /// <summary>Special comparator for sorting hits according to index order (document number). </summary>
  37                 public readonly static ScoreDocComparator INDEXORDER;
  38                 static ScoreDocComparator_Fields()
  39                 {
  40                         RELEVANCE = new AnonymousClassScoreDocComparator();
  41                         INDEXORDER = new AnonymousClassScoreDocComparator1();
  42                 }
  43         }
  44         public class AnonymousClassScoreDocComparator : ScoreDocComparator
  45         {
  46                 public virtual int Compare(ScoreDoc i, ScoreDoc j)
  47                 {
  48                         if (i.score > j.score)
  49                                 return - 1;
  50                         if (i.score < j.score)
  51                                 return 1;
  52                         return 0;
  53                 }
  54                 public virtual System.IComparable SortValue(ScoreDoc i)
  55                 {
  56                         return (float) i.score;
  57                 }
  58                 public virtual int SortType()
  59                 {
  60                         return SortField.SCORE;
  61                 }
  62         }
  63         public class AnonymousClassScoreDocComparator1 : ScoreDocComparator
  64         {
  65                 public virtual int Compare(ScoreDoc i, ScoreDoc j)
  66                 {
  67                         if (i.doc < j.doc)
  68                                 return - 1;
  69                         if (i.doc > j.doc)
  70                                 return 1;
  71                         return 0;
  72                 }
  73                 public virtual System.IComparable SortValue(ScoreDoc i)
  74                 {
  75                         return (System.Int32) i.doc;
  76                 }
  77                 public virtual int SortType()
  78                 {
  79                         return SortField.DOC;
  80                 }
  81         }
  82         public interface ScoreDocComparator
  83         {
  84
  85
  86                 /// <summary> Compares two ScoreDoc objects and returns a result indicating their
  87                 /// sort order.
  88                 /// </summary>
  89                 /// <param name="i">First ScoreDoc
  90                 /// </param>
  91                 /// <param name="j">Second ScoreDoc
  92                 /// </param>
  93                 /// <returns> <code>-1</code> if <code>i</code> should come before <code>j</code><br><code>1</code> if <code>i</code> should come after <code>j</code><br><code>0</code> if they are equal
  94                 /// </returns>
  95                 /// <seealso cref="java.util.Comparator">
  96                 /// </seealso>
  97                 int Compare(ScoreDoc i, ScoreDoc j);
  98
  99
 100                 /// <summary> Returns the value used to sort the given document.  The
 101                 /// object returned must implement the java.io.Serializable
 102                 /// interface.  This is used by multisearchers to determine how to collate results from their searchers.
 103                 /// </summary>
 104                 /// <seealso cref="FieldDoc">
 105                 /// </seealso>
 106                 /// <param name="i">Document
 107                 /// </param>
 108                 /// <returns> Serializable object
 109                 /// </returns>
 110                 System.IComparable SortValue(ScoreDoc i);
 111
 112
 113                 /// <summary> Returns the type of sort.  Should return <code>SortField.SCORE</code>, <code>SortField.DOC</code>, <code>SortField.STRING</code>, <code>SortField.INTEGER</code>,
 114                 /// <code>SortField.FLOAT</code> or <code>SortField.CUSTOM</code>.  It is not valid to return <code>SortField.AUTO</code>.
 115                 /// This is used by multisearchers to determine how to collate results from their searchers.
 116                 /// </summary>
 117                 /// <returns> One of the constants in SortField.
 118                 /// </returns>
 119                 /// <seealso cref="SortField">
 120                 /// </seealso>
 121                 int SortType();
 122         }
 123 }