LetterTokenizer.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
 * 
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * See the License for the specific language governing permissions and
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using AttributeSource = Lucene.Net.Util.AttributeSource;

namespace Lucene.Net.Analysis
{
    
    /// <summary>A LetterTokenizer is a tokenizer that divides text at non-letters.  That's
    /// to say, it defines tokens as maximal strings of adjacent letters, as defined
    /// by java.lang.Character.isLetter() predicate.
    /// Note: this does a decent job for most European languages, but does a terrible
    /// job for some Asian languages, where words are not separated by spaces. 
    /// </summary>
    
    public class LetterTokenizer:CharTokenizer
    {
        /// <summary>Construct a new LetterTokenizer. </summary>
        public LetterTokenizer(System.IO.TextReader @in):base(@in)
        {
        }
        
        /// <summary>Construct a new LetterTokenizer using a given <see cref="AttributeSource" />. </summary>
        public LetterTokenizer(AttributeSource source, System.IO.TextReader @in)
            : base(source, @in)
        {
        }
        
        /// <summary>Construct a new LetterTokenizer using a given <see cref="Lucene.Net.Util.AttributeSource.AttributeFactory" />. </summary>
        public LetterTokenizer(AttributeFactory factory, System.IO.TextReader @in)
            : base(factory, @in)
        {
        }
        
        /// <summary>Collects only characters which satisfy
        /// <see cref="char.IsLetter(char)" />.
        /// </summary>
        protected internal override bool IsTokenChar(char c)
        {
            return System.Char.IsLetter(c);
        }
    }
}