/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
using System;
using System.IO;
using Lucene.Net.Analysis;
namespace Lucene.Net.Analysis.Ru
{
///
/// A RussianLetterTokenizer is a tokenizer that extends LetterTokenizer by additionally looking up letters
/// in a given "russian charset". The problem with LeterTokenizer is that it uses Character.isLetter() method,
/// which doesn't know how to detect letters in encodings like CP1252 and KOI8
/// (well-known problems with 0xD7 and 0xF7 chars)
///
public class RussianLetterTokenizer : CharTokenizer
{
///
/// Construct a new LetterTokenizer.
///
private char[] charset;
public RussianLetterTokenizer(TextReader _in, char[] charset) : base(_in)
{
this.charset = charset;
}
///
/// Collects only characters which satisfy Char.IsLetter(char).
///
///
///
protected override bool IsTokenChar(char c)
{
if (Char.IsLetter(c))
return true;
for (int i = 0; i < charset.Length; i++)
{
if (c == charset[i])
return true;
}
return false;
}
}
}