/*
 * 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.
 */
package org.apache.lucene.analysis.tokenattributes;


import org.apache.lucene.util.Attribute;

The start and end character offset of a Token. 
/**
 * The start and end character offset of a Token. 
 */
public interface OffsetAttribute extends Attribute {
  
Returns this Token's starting offset, the position of the first character
corresponding to this token in the source text.
 Note that the difference between endOffset() and startOffset() 
may not be equal to termText.length(), as the term text may have been altered by a
stemmer or some other filter.
See Also:
setOffset(int, int)/** 
   * Returns this Token's starting offset, the position of the first character
   * corresponding to this token in the source text.
   * <p>
   * Note that the difference between {@link #endOffset()} and <code>startOffset()</code> 
   * may not be equal to termText.length(), as the term text may have been altered by a
   * stemmer or some other filter.
   * @see #setOffset(int, int) 
   */
  public int startOffset();

  
  
Set the starting and ending offset.
Throws:
IllegalArgumentException – If startOffset or endOffset
        are negative, or if startOffset is greater than 
        endOffset
See Also:
startOffset()
endOffset()/** 
   * Set the starting and ending offset.
   * @throws IllegalArgumentException If <code>startOffset</code> or <code>endOffset</code>
   *         are negative, or if <code>startOffset</code> is greater than 
   *         <code>endOffset</code>
   * @see #startOffset()
   * @see #endOffset()
   */
  public void setOffset(int startOffset, int endOffset);
  

  
Returns this Token's ending offset, one greater than the position of the
last character corresponding to this token in the source text. The length
of the token in the source text is (endOffset() - startOffset()). 
See Also:
setOffset(int, int)/** 
   * Returns this Token's ending offset, one greater than the position of the
   * last character corresponding to this token in the source text. The length
   * of the token in the source text is (<code>endOffset()</code> - {@link #startOffset()}). 
   * @see #setOffset(int, int)
   */
  public int endOffset();
}