| using Lucene.Net.Analysis.Ja.TokenAttributes; |
| using Lucene.Net.Analysis.TokenAttributes; |
| |
| namespace Lucene.Net.Analysis.Ja |
| { |
| /* |
| * 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> |
| /// Replaces term text with the <see cref="IBaseFormAttribute"/>. |
| /// <para/> |
| /// This acts as a lemmatizer for verbs and adjectives. |
| /// To prevent terms from being stemmed use an instance of |
| /// <see cref="Miscellaneous.SetKeywordMarkerFilter"/> or a custom <see cref="TokenFilter"/> that sets |
| /// the <see cref="IKeywordAttribute"/> before this <see cref="TokenStream"/>. |
| /// </summary> |
| public sealed class JapaneseBaseFormFilter : TokenFilter |
| { |
| private readonly ICharTermAttribute termAtt; |
| private readonly IBaseFormAttribute basicFormAtt; |
| private readonly IKeywordAttribute keywordAtt; |
| |
| public JapaneseBaseFormFilter(TokenStream input) |
| : base(input) |
| { |
| this.termAtt = AddAttribute<ICharTermAttribute>(); |
| this.basicFormAtt = AddAttribute<IBaseFormAttribute>(); |
| this.keywordAtt = AddAttribute<IKeywordAttribute>(); |
| } |
| |
| public override bool IncrementToken() |
| { |
| if (m_input.IncrementToken()) |
| { |
| if (!keywordAtt.IsKeyword) |
| { |
| string baseForm = basicFormAtt.GetBaseForm(); |
| if (baseForm != null) |
| { |
| termAtt.SetEmpty().Append(baseForm); |
| } |
| } |
| return true; |
| } |
| else |
| { |
| return false; |
| } |
| } |
| } |
| } |