beagled/Lucene.Net/Analysis/Analyzer.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.Analysis
  18 {
  19
  20         /// <summary>An Analyzer builds TokenStreams, which analyze text.  It thus represents a
  21         /// policy for extracting index terms from text.
  22         /// <p>
  23         /// Typical implementations first build a Tokenizer, which breaks the stream of
  24         /// characters from the Reader into raw Tokens.  One or more TokenFilters may
  25         /// then be applied to the output of the Tokenizer.
  26         /// </p>
  27         /// <p>
  28         /// WARNING: You must override one of the methods defined by this class in your
  29         /// subclass or the Analyzer will enter an infinite loop.
  30         /// </p>
  31         /// </summary>
  32         public abstract class Analyzer
  33         {
  34                 /// <summary>Creates a TokenStream which tokenizes all the text in the provided
  35                 /// Reader.  Default implementation forwards to tokenStream(Reader) for
  36                 /// compatibility with older version.  Override to allow Analyzer to choose
  37                 /// strategy based on document and/or Field.  Must be able to handle null
  38                 /// Field name for backward compatibility.
  39                 /// </summary>
  40                 public virtual TokenStream TokenStream(System.String fieldName, System.IO.TextReader reader)
  41                 {
  42                         // implemented for backward compatibility
  43                         return TokenStream(reader);
  44                 }
  45
  46                 /// <summary>Creates a TokenStream which tokenizes all the text in the provided
  47                 /// Reader.  Provided for backward compatibility only.
  48                 /// </summary>
  49                 /// <deprecated> use TokenStream(String, Reader) instead.
  50                 /// </deprecated>
  51                 /// <seealso cref="Reader)">
  52                 /// </seealso>
  53                 public virtual TokenStream TokenStream(System.IO.TextReader reader)
  54                 {
  55                         return TokenStream(null, reader);
  56                 }
  57         }
  58 }