package org.apache.lucene.analysis;
/**
* 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.
*/
import java.io.Reader;
import org.apache.lucene.util.AttributeSource;
/**
* LowerCaseTokenizer performs the function of LetterTokenizer
* and LowerCaseFilter together. It divides text at non-letters and converts
* them to lower case. While it is functionally equivalent to the combination
* of LetterTokenizer and LowerCaseFilter, there is a performance advantage
* to doing the two tasks at once, hence this (redundant) implementation.
* <P>
* 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.
*/
public final class LowerCaseTokenizer extends LetterTokenizer {
/** Construct a new LowerCaseTokenizer. */
public LowerCaseTokenizer(Reader in) {
super(in);
}
/** Construct a new LowerCaseTokenizer using a given {@link AttributeSource}. */
public LowerCaseTokenizer(AttributeSource source, Reader in) {
super(source, in);
}
/** Construct a new LowerCaseTokenizer using a given {@link org.apache.lucene.util.AttributeSource.AttributeFactory}. */
public LowerCaseTokenizer(AttributeFactory factory, Reader in) {
super(factory, in);
}
/** Converts char to lower case
* {@link Character#toLowerCase(char)}.*/
@Override
protected char normalize(char c) {
return Character.toLowerCase(c);
}
}