1 package org.apache.lucene.analysis.hu;
4 * Licensed to the Apache Software Foundation (ASF) under one or more
5 * contributor license agreements. See the NOTICE file distributed with
6 * this work for additional information regarding copyright ownership.
7 * The ASF licenses this file to You under the Apache License, Version 2.0
8 * (the "License"); you may not use this file except in compliance with
9 * the License. You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
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14 * distributed under the License is distributed on an "AS IS" BASIS,
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16 * See the License for the specific language governing permissions and
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21 * This algorithm is updated based on code located at:
22 * http://members.unine.ch/jacques.savoy/clef/
24 * Full copyright for that code follows:
28 * Copyright (c) 2005, Jacques Savoy
29 * All rights reserved.
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32 * modification, are permitted provided that the following conditions are met:
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40 * this software without specific prior written permission.
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55 import static org.apache.lucene.analysis.util.StemmerUtil.*;
58 * Light Stemmer for Hungarian.
60 * This stemmer implements the "UniNE" algorithm in:
61 * <i>Light Stemming Approaches for the French, Portuguese, German and Hungarian Languages</i>
64 public class HungarianLightStemmer {
65 public int stem(char s[], int len) {
66 for (int i = 0; i < len; i++)
68 case 'á': s[i] = 'a'; break;
70 case 'é': s[i] = 'e'; break;
71 case 'í': s[i] = 'i'; break;
75 case 'ö': s[i] = 'o'; break;
80 case 'ü': s[i] = 'u'; break;
83 len = removeCase(s, len);
84 len = removePossessive(s, len);
85 len = removePlural(s, len);
86 return normalize(s, len);
89 private int removeCase(char s[], int len) {
90 if (len > 6 && endsWith(s, len, "kent"))
94 if (endsWith(s, len, "nak") ||
95 endsWith(s, len, "nek") ||
96 endsWith(s, len, "val") ||
97 endsWith(s, len, "vel") ||
98 endsWith(s, len, "ert") ||
99 endsWith(s, len, "rol") ||
100 endsWith(s, len, "ban") ||
101 endsWith(s, len, "ben") ||
102 endsWith(s, len, "bol") ||
103 endsWith(s, len, "nal") ||
104 endsWith(s, len, "nel") ||
105 endsWith(s, len, "hoz") ||
106 endsWith(s, len, "hez") ||
107 endsWith(s, len, "tol"))
110 if (endsWith(s, len, "al") || endsWith(s, len, "el")) {
111 if (!isVowel(s[len-3]) && s[len-3] == s[len-4])
117 if (endsWith(s, len, "at") ||
118 endsWith(s, len, "et") ||
119 endsWith(s, len, "ot") ||
120 endsWith(s, len, "va") ||
121 endsWith(s, len, "ve") ||
122 endsWith(s, len, "ra") ||
123 endsWith(s, len, "re") ||
124 endsWith(s, len, "ba") ||
125 endsWith(s, len, "be") ||
126 endsWith(s, len, "ul") ||
127 endsWith(s, len, "ig"))
130 if ((endsWith(s, len, "on") || endsWith(s, len, "en")) && !isVowel(s[len-3]))
135 case 'n': return len - 1;
137 case 'e': if (s[len-2] == s[len-3] && !isVowel(s[len-2])) return len - 2;
144 private int removePossessive(char s[], int len) {
146 if (!isVowel(s[len-5]) &&
147 (endsWith(s, len, "atok") ||
148 endsWith(s, len, "otok") ||
149 endsWith(s, len, "etek")))
152 if (endsWith(s, len, "itek") || endsWith(s, len, "itok"))
157 if (!isVowel(s[len-4]) &&
158 (endsWith(s, len, "unk") ||
159 endsWith(s, len, "tok") ||
160 endsWith(s, len, "tek")))
163 if (isVowel(s[len-4]) && endsWith(s, len, "juk"))
166 if (endsWith(s, len, "ink"))
171 if (!isVowel(s[len-3]) &&
172 (endsWith(s, len, "am") ||
173 endsWith(s, len, "em") ||
174 endsWith(s, len, "om") ||
175 endsWith(s, len, "ad") ||
176 endsWith(s, len, "ed") ||
177 endsWith(s, len, "od") ||
178 endsWith(s, len, "uk")))
181 if (isVowel(s[len-3]) &&
182 (endsWith(s, len, "nk") ||
183 endsWith(s, len, "ja") ||
184 endsWith(s, len, "je")))
187 if (endsWith(s, len, "im") ||
188 endsWith(s, len, "id") ||
189 endsWith(s, len, "ik"))
196 case 'e': if (!isVowel(s[len-2])) return len - 1; break;
198 case 'd': if (isVowel(s[len-2])) return len - 1; break;
199 case 'i': return len - 1;
205 @SuppressWarnings("fallthrough")
206 private int removePlural(char s[], int len) {
207 if (len > 3 && s[len-1] == 'k')
211 case 'e': if (len > 4) return len - 2; /* intentional fallthru */
212 default: return len - 1;
217 private int normalize(char s[], int len) {
223 case 'o': return len - 1;
228 private boolean isVowel(char ch) {
235 case 'y': return true;
236 default: return false;