package org.apache.lucene.analysis.hi;
/**
* 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 static org.apache.lucene.analysis.util.StemmerUtil.*;
/**
* Normalizer for Hindi.
* <p>
* Normalizes text to remove some differences in spelling variations.
* <p>
* Implements the Hindi-language specific algorithm specified in:
* <i>Word normalization in Indian languages</i>
* Prasad Pingali and Vasudeva Varma.
* http://web2py.iiit.ac.in/publications/default/download/inproceedings.pdf.3fe5b38c-02ee-41ce-9a8f-3e745670be32.pdf
* <p>
* with the following additions from <i>Hindi CLIR in Thirty Days</i>
* Leah S. Larkey, Margaret E. Connell, and Nasreen AbdulJaleel.
* http://maroo.cs.umass.edu/pub/web/getpdf.php?id=454:
* <ul>
* <li>Internal Zero-width joiner and Zero-width non-joiners are removed
* <li>In addition to chandrabindu, NA+halant is normalized to anusvara
* </ul>
*
*/
public class HindiNormalizer {
/**
* Normalize an input buffer of Hindi text
*
* @param s input buffer
* @param len length of input buffer
* @return length of input buffer after normalization
*/
public int normalize(char s[], int len) {
for (int i = 0; i < len; i++) {
switch (s[i]) {
// dead n -> bindu
case '\u0928':
if (i + 1 < len && s[i + 1] == '\u094D') {
s[i] = '\u0902';
len = delete(s, i + 1, len);
}
break;
// candrabindu -> bindu
case '\u0901':
s[i] = '\u0902';
break;
// nukta deletions
case '\u093C':
len = delete(s, i, len);
i--;
break;
case '\u0929':
s[i] = '\u0928';
break;
case '\u0931':
s[i] = '\u0930';
break;
case '\u0934':
s[i] = '\u0933';
break;
case '\u0958':
s[i] = '\u0915';
break;
case '\u0959':
s[i] = '\u0916';
break;
case '\u095A':
s[i] = '\u0917';
break;
case '\u095B':
s[i] = '\u091C';
break;
case '\u095C':
s[i] = '\u0921';
break;
case '\u095D':
s[i] = '\u0922';
break;
case '\u095E':
s[i] = '\u092B';
break;
case '\u095F':
s[i] = '\u092F';
break;
// zwj/zwnj -> delete
case '\u200D':
case '\u200C':
len = delete(s, i, len);
i--;
break;
// virama -> delete
case '\u094D':
len = delete(s, i, len);
i--;
break;
// chandra/short -> replace
case '\u0945':
case '\u0946':
s[i] = '\u0947';
break;
case '\u0949':
case '\u094A':
s[i] = '\u094B';
break;
case '\u090D':
case '\u090E':
s[i] = '\u090F';
break;
case '\u0911':
case '\u0912':
s[i] = '\u0913';
break;
case '\u0972':
s[i] = '\u0905';
break;
// long -> short ind. vowels
case '\u0906':
s[i] = '\u0905';
break;
case '\u0908':
s[i] = '\u0907';
break;
case '\u090A':
s[i] = '\u0909';
break;
case '\u0960':
s[i] = '\u090B';
break;
case '\u0961':
s[i] = '\u090C';
break;
case '\u0910':
s[i] = '\u090F';
break;
case '\u0914':
s[i] = '\u0913';
break;
// long -> short dep. vowels
case '\u0940':
s[i] = '\u093F';
break;
case '\u0942':
s[i] = '\u0941';
break;
case '\u0944':
s[i] = '\u0943';
break;
case '\u0963':
s[i] = '\u0962';
break;
case '\u0948':
s[i] = '\u0947';
break;
case '\u094C':
s[i] = '\u094B';
break;
default:
break;
}
}
return len;
}
}