content: package org.apache.lucene.analysis.tokenattributes;
  
  /**
   * 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 org.apache.lucene.analysis.TokenStream;
  import org.apache.lucene.util.AttributeImpl;
  
  /**
   *This attribute can be used to mark a token as a keyword. Keyword aware
   * {@link TokenStream}s can decide to modify a token based on the return value
   * of {@link #isKeyword()} if the token is modified. Stemming filters for
   * instance can use this attribute to conditionally skip a term if
   * {@link #isKeyword()} returns <code>true</code>.
   */
  public final class KeywordAttributeImpl extends AttributeImpl implements
      KeywordAttribute {
    private boolean keyword;
  
    @Override
    public void clear() {
      keyword = false;
    }
  
    @Override
    public void copyTo(AttributeImpl target) {
      KeywordAttribute attr = (KeywordAttribute) target;
      attr.setKeyword(keyword);
    }
  
    @Override
    public int hashCode() {
      return keyword ? 31 : 37;
    }
  
    @Override
    public boolean equals(Object obj) {
      if (this == obj)
        return true;
      if (getClass() != obj.getClass())
        return false;
      final KeywordAttributeImpl other = (KeywordAttributeImpl) obj;
      return keyword == other.keyword;
    }
  
    /**
     * Returns <code>true</code> iff the current token is a keyword, otherwise
     * <code>false</code>/
     * 
     * @return <code>true</code> iff the current token is a keyword, otherwise
     *         <code>false</code>/
     */
    public boolean isKeyword() {
      return keyword;
    }
  
    /**
     * Marks the current token as keyword iff set to <code>true</code>.
     * 
     * @param isKeyword
     *          <code>true</code> iff the current token is a keyword, otherwise
     *          <code>false</code>.
     */
    public void setKeyword(boolean isKeyword) {
      keyword = isKeyword;
    }
  
  }
  