src/Lucene.Net/Analysis/TokenAttributes/PositionIncrementAttribute.cs

using Lucene.Net.Util;
using System;

namespace Lucene.Net.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.
     */

    /// <summary>
    /// Determines the position of this token
    /// relative to the previous <see cref="Token"/> in a <see cref="TokenStream"/>, used in phrase
    /// searching.
    ///
    /// <para/>The default value is one.
    ///
    /// <para/>Some common uses for this are:
    /// 
    /// <list type="bullet">
    /// <item><description>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.</description></item>
    ///
    /// <item><description>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.</description></item>
    /// </list>
    /// </summary>
    /// <seealso cref="Lucene.Net.Index.DocsAndPositionsEnum"/>
    public interface IPositionIncrementAttribute : IAttribute
    {
        /// <summary>
        /// Gets or Sets the position increment (the distance from the prior term). The default value is one.
        /// </summary>
        /// <exception cref="ArgumentException"> if value is set to a negative value. </exception>
        int PositionIncrement { set; get; }
    }
}