| // lucene version compatibility level: 4.8.1 |
| using Lucene.Net.Analysis.Cn.Smart.Hhmm; |
| using Lucene.Net.Analysis.TokenAttributes; |
| using System; |
| using System.Collections.Generic; |
| |
| namespace Lucene.Net.Analysis.Cn.Smart |
| { |
| /* |
| * 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 breaks sentences into words. |
| /// <para/> |
| /// @lucene.experimental |
| /// </summary> |
| [Obsolete("Use HMMChineseTokenizer instead.")] |
| public sealed class WordTokenFilter : TokenFilter |
| { |
| private WordSegmenter wordSegmenter; |
| |
| private IEnumerator<SegToken> tokenIter; |
| |
| private IList<SegToken> tokenBuffer; |
| |
| private readonly ICharTermAttribute termAtt; |
| private readonly IOffsetAttribute offsetAtt; |
| private readonly ITypeAttribute typeAtt; |
| |
| private int tokStart; // only used if the length changed before this filter |
| private int tokEnd; // only used if the length changed before this filter |
| private bool hasIllegalOffsets; // only if the length changed before this filter |
| |
| /// <summary> |
| /// Construct a new <see cref="WordTokenFilter"/>. |
| /// </summary> |
| /// <param name="input"><see cref="TokenStream"/> of sentences.</param> |
| public WordTokenFilter(TokenStream input) |
| : base(input) |
| { |
| this.wordSegmenter = new WordSegmenter(); |
| this.termAtt = AddAttribute<ICharTermAttribute>(); |
| this.offsetAtt = AddAttribute<IOffsetAttribute>(); |
| this.typeAtt = AddAttribute<ITypeAttribute>(); |
| } |
| |
| public override bool IncrementToken() |
| { |
| if (tokenIter == null || !tokenIter.MoveNext()) |
| { |
| // there are no remaining tokens from the current sentence... are there more sentences? |
| if (m_input.IncrementToken()) |
| { |
| tokStart = offsetAtt.StartOffset; |
| tokEnd = offsetAtt.EndOffset; |
| // if length by start + end offsets doesn't match the term text then assume |
| // this is a synonym and don't adjust the offsets. |
| hasIllegalOffsets = (tokStart + termAtt.Length) != tokEnd; |
| // a new sentence is available: process it. |
| tokenBuffer = wordSegmenter.SegmentSentence(termAtt.ToString(), offsetAtt.StartOffset); |
| tokenIter = tokenBuffer.GetEnumerator(); |
| /* |
| * it should not be possible to have a sentence with 0 words, check just in case. |
| * returning EOS isn't the best either, but its the behavior of the original code. |
| */ |
| if (!tokenIter.MoveNext()) |
| { |
| return false; |
| } |
| } |
| else |
| { |
| return false; // no more sentences, end of stream! |
| } |
| } |
| |
| // WordTokenFilter must clear attributes, as it is creating new tokens. |
| ClearAttributes(); |
| // There are remaining tokens from the current sentence, return the next one. |
| SegToken nextWord = tokenIter.Current; |
| |
| termAtt.CopyBuffer(nextWord.CharArray, 0, nextWord.CharArray.Length); |
| if (hasIllegalOffsets) |
| { |
| offsetAtt.SetOffset(tokStart, tokEnd); |
| } |
| else |
| { |
| offsetAtt.SetOffset(nextWord.StartOffset, nextWord.EndOffset); |
| } |
| typeAtt.Type = "word"; |
| return true; |
| } |
| |
| public override void Reset() |
| { |
| base.Reset(); |
| tokenIter = null; |
| } |
| } |
| } |