beagled/Lucene.Net/Analysis/TokenStream.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
  17 using System;
  18
  19 namespace Lucene.Net.Analysis
  20 {
  21
  22         /// <summary>A TokenStream enumerates the sequence of tokens, either from
  23         /// fields of a document or from query text.
  24         /// <p>
  25         /// This is an abstract class.  Concrete subclasses are:
  26         /// <ul>
  27         /// <li>{@link Tokenizer}, a TokenStream
  28         /// whose input is a Reader; and
  29         /// <li>{@link TokenFilter}, a TokenStream
  30         /// whose input is another TokenStream.
  31         /// </ul>
  32         /// </summary>
  33
  34         public abstract class TokenStream
  35         {
  36                 /// <summary>Returns the next token in the stream, or null at EOS. </summary>
  37                 public abstract Token Next();
  38
  39                 /// <summary>Releases resources associated with this stream. </summary>
  40                 public virtual void  Close()
  41                 {
  42                 }
  43         }
  44 }