| using Lucene.Net.Analysis.Ja.TokenAttributes; |
| using Lucene.Net.Analysis.Ja.Util; |
| using Lucene.Net.Analysis.TokenAttributes; |
| using System.Text; |
| |
| 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> |
| /// A <see cref="TokenFilter"/> that replaces the term |
| /// attribute with the reading of a token in either katakana or romaji form. |
| /// The default reading form is katakana. |
| /// </summary> |
| public sealed class JapaneseReadingFormFilter : TokenFilter |
| { |
| private readonly ICharTermAttribute termAttr; |
| private readonly IReadingAttribute readingAttr; |
| |
| private readonly StringBuilder buffer = new StringBuilder(); // LUCENENET: marked readonly |
| private readonly bool useRomaji; // LUCENENET: marked readonly |
| |
| public JapaneseReadingFormFilter(TokenStream input, bool useRomaji) |
| : base(input) |
| { |
| this.useRomaji = useRomaji; |
| this.termAttr = AddAttribute<ICharTermAttribute>(); |
| this.readingAttr = AddAttribute<IReadingAttribute>(); |
| } |
| |
| public JapaneseReadingFormFilter(TokenStream input) |
| : this(input, false) |
| { |
| } |
| |
| public override bool IncrementToken() |
| { |
| if (m_input.IncrementToken()) |
| { |
| string reading = readingAttr.GetReading(); |
| |
| if (useRomaji) |
| { |
| if (reading == null) |
| { |
| // if its an OOV term, just try the term text |
| buffer.Length = 0; |
| ToStringUtil.GetRomanization(buffer, termAttr.ToString()); |
| termAttr.SetEmpty().Append(buffer); |
| } |
| else |
| { |
| buffer.Length = 0; |
| ToStringUtil.GetRomanization(buffer, reading); |
| termAttr.SetEmpty().Append(buffer); |
| } |
| } |
| else |
| { |
| // just replace the term text with the reading, if it exists |
| if (reading != null) |
| { |
| termAttr.SetEmpty().Append(reading); |
| } |
| } |
| return true; |
| } |
| else |
| { |
| return false; |
| } |
| } |
| } |
| } |