Lucene.Net  3.0.3
Lucene.Net is a port of the Lucene search engine library, written in C# and targeted at .NET runtime users.
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SingleTermEnum.cs
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2  * Licensed to the Apache Software Foundation (ASF) under one or more
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9  * http://www.apache.org/licenses/LICENSE-2.0
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16  */
17 
18 using System;
19 using Lucene.Net.Index;
20 
21 namespace Lucene.Net.Search
22 {
23  /// <summary>
24  /// Subclass of FilteredTermEnum for enumerating a single term.
25  /// <p/>
26  /// This can be used by <see cref="MultiTermQuery"/>s that need only visit one term,
27  /// but want to preserve MultiTermQuery semantics such as
28  /// <see cref="RewriteMethod"/>.
29  /// </summary>
31  {
32  private Term singleTerm;
33  private bool _endEnum = false;
34 
35  /// <summary>
36  /// Creates a new <c>SingleTermEnum</c>.
37  /// <p/>
38  /// After calling the constructor the enumeration is already pointing to the term,
39  /// if it exists.
40  /// </summary>
41  public SingleTermEnum(IndexReader reader, Term singleTerm)
42  {
43  this.singleTerm = singleTerm;
44  SetEnum(reader.Terms(singleTerm));
45  }
46 
47  public override float Difference()
48  {
49  return 1.0F;
50  }
51 
52  public override bool EndEnum()
53  {
54  return _endEnum;
55  }
56 
57  protected internal override bool TermCompare(Term term)
58  {
59  if (term.Equals(singleTerm))
60  {
61  return true;
62  }
63  else
64  {
65  _endEnum = true;
66  return false;
67  }
68  }
69  }
70 }