content: package org.apache.lucene.analysis.id;
  
  /**
   * 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.tokenattributes.CharTermAttribute;
  import org.apache.lucene.analysis.tokenattributes.KeywordAttribute;
  
  /**
   * A {@link TokenFilter} that applies {@link IndonesianStemmer} to stem Indonesian words.
   */
  public final class IndonesianStemFilter extends TokenFilter {
    private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
    private final KeywordAttribute keywordAtt = addAttribute(KeywordAttribute.class);
    private final IndonesianStemmer stemmer = new IndonesianStemmer();
    private final boolean stemDerivational;
  
    /**
     * Calls {@link #IndonesianStemFilter(TokenStream, boolean) IndonesianStemFilter(input, true)}
     */
    public IndonesianStemFilter(TokenStream input) {
      this(input, true);
    }
    
    /**
     * Create a new IndonesianStemFilter.
     * <p>
     * If <code>stemDerivational</code> is false, 
     * only inflectional suffixes (particles and possessive pronouns) are stemmed.
     */
    public IndonesianStemFilter(TokenStream input, boolean stemDerivational) {
      super(input);
      this.stemDerivational = stemDerivational;
    }
  
    @Override
    public boolean incrementToken() throws IOException {
      if (input.incrementToken()) {
        if(!keywordAtt.isKeyword()) {
          final int newlen = 
            stemmer.stem(termAtt.buffer(), termAtt.length(), stemDerivational);
          termAtt.setLength(newlen);
        }
        return true;
      } else {
        return false;
      }
    }
  }
  