/*
* 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;
/** 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.
*
* @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 #setPositionIncrement(int)
*/
public int getPositionIncrement();
}