| using Lucene.Net.Analysis.TokenAttributes; |
| |
| namespace Lucene.Net.Analysis.Tr |
| { |
| /* |
| * 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. |
| */ |
| |
| /// <summary> |
| /// Strips all characters after an apostrophe (including the apostrophe itself). |
| /// <para> |
| /// In Turkish, apostrophe is used to separate suffixes from proper names |
| /// (continent, sea, river, lake, mountain, upland, proper names related to |
| /// religion and mythology). This filter intended to be used before stem filters. |
| /// For more information, see <a href="http://www.ipcsit.com/vol57/015-ICNI2012-M021.pdf"> |
| /// Role of Apostrophes in Turkish Information Retrieval</a> |
| /// </para> |
| /// </summary> |
| public sealed class ApostropheFilter : TokenFilter |
| { |
| private readonly ICharTermAttribute termAtt; |
| |
| public ApostropheFilter(TokenStream @in) |
| : base(@in) |
| { |
| termAtt = AddAttribute<ICharTermAttribute>(); |
| } |
| |
| public override sealed bool IncrementToken() |
| { |
| if (!m_input.IncrementToken()) |
| { |
| return false; |
| } |
| |
| char[] buffer = termAtt.Buffer; |
| int length = termAtt.Length; |
| |
| for (int i = 0; i < length; i++) |
| { |
| if (buffer[i] == '\'' || buffer[i] == '\u2019') |
| { |
| termAtt.Length = i; |
| return true; |
| } |
| } |
| return true; |
| } |
| } |
| } |