Lucene.Net/Analysis/Analyzer.cs

   1 using System;
   2 using System.IO;
   3
   4 namespace Lucene.Net.Analysis
   5 {
   6         /* ====================================================================
   7          * The Apache Software License, Version 1.1
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  29          *    if and wherever such third-party acknowledgments normally appear.
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  31          * 4. The names "Apache" and "Apache Software Foundation" and
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  58          */
  59
  60         /// <summary>
  61         /// An Analyzer builds TokenStreams, which analyze text.  It thus represents a
  62         ///  policy for extracting index terms from text.
  63         ///  <p>
  64         ///  Typical implementations first build a Tokenizer, which breaks the stream of
  65         ///  characters from the TextReader into raw Tokens.  One or more TokenFilters may
  66         ///  then be applied to the output of the Tokenizer.
  67         ///  </p>
  68         ///  <p>
  69         ///  WARNING: You must override one of the methods defined by this class in your
  70         ///  subclass or the Analyzer will enter an infinite loop.
  71         ///  </p>
  72         /// </summary>
  73         public abstract class Analyzer
  74         {
  75                 /// <summary>
  76                 /// Creates a TokenStream which tokenizes all the text in the provided
  77                 /// TextReader.  Default implementation forwards to TokenStream(TextReader) for
  78                 /// compatibility with older version.  Override to allow Analyzer to choose
  79                 /// strategy based on document and/or field.  Must be able to handle null
  80                 /// field name for backward compatibility.
  81                 /// </summary>
  82                 /// <param name="fieldName"></param>
  83                 /// <param name="reader"></param>
  84                 /// <returns></returns>
  85                 public virtual TokenStream TokenStream(String fieldName, TextReader reader)
  86                 {
  87                         // implemented for backward compatibility
  88                         return TokenStream(reader);
  89                 }
  90
  91                 /// <summary>
  92                 /// Creates a TokenStream which tokenizes all the text in the provided
  93                 /// TextReader. Provided for backward compatibility only.
  94                 /// <see cref="TokenStream(String, TextReader)"/>
  95                 /// </summary>
  96                 /// <param name="reader"></param>
  97                 /// <returns></returns>
  98                 /// <remarks>deprecated, use TokenStream(String, TextReader) instead.</remarks>
  99                 public virtual TokenStream TokenStream(TextReader reader)
 100                 {
 101                         return TokenStream(null, reader);
 102                 }
 103         }
 104 }