LengthFilter.cs

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/* 
 * 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.
 */

using Lucene.Net.Analysis.Tokenattributes;

namespace Lucene.Net.Analysis
{
    
    public sealed class LengthFilter:TokenFilter
    {
        
        internal int min;
        internal int max;
        
        private readonly ITermAttribute termAtt;
        
        public LengthFilter(TokenStream in_Renamed, int min, int max)
            : base(in_Renamed)
        {
            this.min = min;
            this.max = max;
            termAtt = AddAttribute<ITermAttribute>();
        }
        
        public override bool IncrementToken()
        {
            // return the first non-stop word found
            while (input.IncrementToken())
            {
                var len = termAtt.TermLength();
                if (len >= min && len <= max)
                {
                    return true;
                }
                // note: else we ignore it but should we index each part of it?
            }
            // reached EOS -- return false
            return false;
        }
    }
}