content: package org.apache.lucene.analysis.fr;
  
  /**
   * 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.
   */
  
  import java.io.IOException;
  
  import org.apache.lucene.analysis.TokenFilter;
  import org.apache.lucene.analysis.TokenStream;
  import org.apache.lucene.analysis.KeywordMarkerFilter;
  import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
  import org.apache.lucene.analysis.tokenattributes.KeywordAttribute;
  
  /**
   * A {@link TokenFilter} that applies {@link FrenchLightStemmer} to stem French
   * words.
   * <p>
   * To prevent terms from being stemmed use an instance of
   * {@link KeywordMarkerFilter} or a custom {@link TokenFilter} that sets
   * the {@link KeywordAttribute} before this {@link TokenStream}.
   * </p>
   */
  public final class FrenchLightStemFilter extends TokenFilter {
    private final FrenchLightStemmer stemmer = new FrenchLightStemmer();
    private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
    private final KeywordAttribute keywordAttr = addAttribute(KeywordAttribute.class);
  
    public FrenchLightStemFilter(TokenStream input) {
      super(input);
    }
    
    @Override
    public boolean incrementToken() throws IOException {
      if (input.incrementToken()) {
        if (!keywordAttr.isKeyword()) {
          final int newlen = stemmer.stem(termAtt.buffer(), termAtt.length());
          termAtt.setLength(newlen);
        }
        return true;
      } else {
        return false;
      }
    }
  }
  