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


import org.apache.lucene.util.Attribute;

Determines the position of this token
relative to the previous Token in a TokenStream, used in phrase
searching.
The default value is one.
Some common uses for this are:

Set it to zero to put multiple terms in the same position.  This is
useful if, e.g., a word has multiple stems.  Searches for phrases
including either stem will match.  In this case, all but the first stem's
increment should be set to zero: the increment of the first instance
should be one.  Repeating a token with an increment of zero can also be
used to boost the scores of matches on that token.
Set it to values greater than one to inhibit exact phrase matches.
If, for example, one does not want phrases to match across removed stop
words, then one could build a stop word filter that removes stop words and
also sets the increment to the number of stop words removed before each
non-stop word.  Then exact phrase queries will only match when the terms
occur with no intervening stop words.

See Also:
PostingsEnum/** Determines the position of this token
 * relative to the previous Token in a TokenStream, used in phrase
 * searching.
 *
 * <p>The default value is one.
 *
 * <p>Some common uses for this are:<ul>
 *
 * <li>Set it to zero to put multiple terms in the same position.  This is
 * useful if, e.g., a word has multiple stems.  Searches for phrases
 * including either stem will match.  In this case, all but the first stem's
 * increment should be set to zero: the increment of the first instance
 * should be one.  Repeating a token with an increment of zero can also be
 * used to boost the scores of matches on that token.
 *
 * <li>Set it to values greater than one to inhibit exact phrase matches.
 * If, for example, one does not want phrases to match across removed stop
 * words, then one could build a stop word filter that removes stop words and
 * also sets the increment to the number of stop words removed before each
 * non-stop word.  Then exact phrase queries will only match when the terms
 * occur with no intervening stop words.
 *
 * </ul>
 * 
 * @see org.apache.lucene.index.PostingsEnum
 */
public interface PositionIncrementAttribute extends Attribute {
  
Set the position increment. The default value is one.
Params:
positionIncrement – the distance from the prior term
Throws:
IllegalArgumentException – if positionIncrement 
        is negative.
See Also:
getPositionIncrement()/** Set the position increment. The default value is one.
   *
   * @param positionIncrement the distance from the prior term
   * @throws IllegalArgumentException if <code>positionIncrement</code> 
   *         is negative.
   * @see #getPositionIncrement()
   */
  public void setPositionIncrement(int positionIncrement);

  
Returns the position increment of this Token.
See Also:
setPositionIncrement(int)/** Returns the position increment of this Token.
   * @see #setPositionIncrement(int)
   */
  public int getPositionIncrement();
}