Lucene.Net  3.0.3
Lucene.Net is a .NET port of the Java Lucene Indexing Library
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PhrasePositions.cs
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17 
18 using System;
19 
20 using Lucene.Net.Index;
21 
22 namespace Lucene.Net.Search
23 {
24 
26  sealed class PhrasePositions
27  {
28  internal int doc; // current doc
29  internal int position; // position in doc
30  internal int count; // remaining pos in this doc
31  internal int offset; // position in phrase
32  internal TermPositions tp; // stream of positions
33  internal PhrasePositions next; // used to make lists
34  internal bool repeats; // there's other pp for same term (e.g. query="1st word 2nd word"~1)
35 
36  internal PhrasePositions(TermPositions t, int o)
37  {
38  tp = t;
39  offset = o;
40  }
41 
42  internal bool Next()
43  {
44  // increments to next doc
45  if (!tp.Next())
46  {
47  tp.Close(); // close stream
48  doc = System.Int32.MaxValue; // sentinel value
49  return false;
50  }
51  doc = tp.Doc;
52  position = 0;
53  return true;
54  }
55 
56  internal bool SkipTo(int target)
57  {
58  if (!tp.SkipTo(target))
59  {
60  tp.Close(); // close stream
61  doc = System.Int32.MaxValue; // sentinel value
62  return false;
63  }
64  doc = tp.Doc;
65  position = 0;
66  return true;
67  }
68 
69 
70  internal void FirstPosition()
71  {
72  count = tp.Freq; // read first pos
73  NextPosition();
74  }
75 
81  internal bool NextPosition()
82  {
83  if (count-- > 0)
84  {
85  // read subsequent pos's
86  position = tp.NextPosition() - offset;
87  return true;
88  }
89  else
90  return false;
91  }
92  }
93 }