--- /dev/null
+package org.apache.lucene.analysis.hu;
+
+/**
+ * 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.
+ */
+
+/*
+ * This algorithm is updated based on code located at:
+ * http://members.unine.ch/jacques.savoy/clef/
+ *
+ * Full copyright for that code follows:
+ */
+
+/*
+ * Copyright (c) 2005, Jacques Savoy
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer. Redistributions in binary
+ * form must reproduce the above copyright notice, this list of conditions and
+ * the following disclaimer in the documentation and/or other materials
+ * provided with the distribution. Neither the name of the author nor the names
+ * of its contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+import static org.apache.lucene.analysis.util.StemmerUtil.*;
+
+/**
+ * Light Stemmer for Hungarian.
+ * <p>
+ * This stemmer implements the "UniNE" algorithm in:
+ * <i>Light Stemming Approaches for the French, Portuguese, German and Hungarian Languages</i>
+ * Jacques Savoy
+ */
+public class HungarianLightStemmer {
+ public int stem(char s[], int len) {
+ for (int i = 0; i < len; i++)
+ switch(s[i]) {
+ case 'á': s[i] = 'a'; break;
+ case 'ë':
+ case 'é': s[i] = 'e'; break;
+ case 'í': s[i] = 'i'; break;
+ case 'ó':
+ case 'ő':
+ case 'õ':
+ case 'ö': s[i] = 'o'; break;
+ case 'ú':
+ case 'ű':
+ case 'ũ':
+ case 'û':
+ case 'ü': s[i] = 'u'; break;
+ }
+
+ len = removeCase(s, len);
+ len = removePossessive(s, len);
+ len = removePlural(s, len);
+ return normalize(s, len);
+ }
+
+ private int removeCase(char s[], int len) {
+ if (len > 6 && endsWith(s, len, "kent"))
+ return len - 4;
+
+ if (len > 5) {
+ if (endsWith(s, len, "nak") ||
+ endsWith(s, len, "nek") ||
+ endsWith(s, len, "val") ||
+ endsWith(s, len, "vel") ||
+ endsWith(s, len, "ert") ||
+ endsWith(s, len, "rol") ||
+ endsWith(s, len, "ban") ||
+ endsWith(s, len, "ben") ||
+ endsWith(s, len, "bol") ||
+ endsWith(s, len, "nal") ||
+ endsWith(s, len, "nel") ||
+ endsWith(s, len, "hoz") ||
+ endsWith(s, len, "hez") ||
+ endsWith(s, len, "tol"))
+ return len - 3;
+
+ if (endsWith(s, len, "al") || endsWith(s, len, "el")) {
+ if (!isVowel(s[len-3]) && s[len-3] == s[len-4])
+ return len - 3;
+ }
+ }
+
+ if (len > 4) {
+ if (endsWith(s, len, "at") ||
+ endsWith(s, len, "et") ||
+ endsWith(s, len, "ot") ||
+ endsWith(s, len, "va") ||
+ endsWith(s, len, "ve") ||
+ endsWith(s, len, "ra") ||
+ endsWith(s, len, "re") ||
+ endsWith(s, len, "ba") ||
+ endsWith(s, len, "be") ||
+ endsWith(s, len, "ul") ||
+ endsWith(s, len, "ig"))
+ return len - 2;
+
+ if ((endsWith(s, len, "on") || endsWith(s, len, "en")) && !isVowel(s[len-3]))
+ return len - 2;
+
+ switch(s[len-1]) {
+ case 't':
+ case 'n': return len - 1;
+ case 'a':
+ case 'e': if (s[len-2] == s[len-3] && !isVowel(s[len-2])) return len - 2;
+ }
+ }
+
+ return len;
+ }
+
+ private int removePossessive(char s[], int len) {
+ if (len > 6) {
+ if (!isVowel(s[len-5]) &&
+ (endsWith(s, len, "atok") ||
+ endsWith(s, len, "otok") ||
+ endsWith(s, len, "etek")))
+ return len - 4;
+
+ if (endsWith(s, len, "itek") || endsWith(s, len, "itok"))
+ return len - 4;
+ }
+
+ if (len > 5) {
+ if (!isVowel(s[len-4]) &&
+ (endsWith(s, len, "unk") ||
+ endsWith(s, len, "tok") ||
+ endsWith(s, len, "tek")))
+ return len - 3;
+
+ if (isVowel(s[len-4]) && endsWith(s, len, "juk"))
+ return len - 3;
+
+ if (endsWith(s, len, "ink"))
+ return len - 3;
+ }
+
+ if (len > 4) {
+ if (!isVowel(s[len-3]) &&
+ (endsWith(s, len, "am") ||
+ endsWith(s, len, "em") ||
+ endsWith(s, len, "om") ||
+ endsWith(s, len, "ad") ||
+ endsWith(s, len, "ed") ||
+ endsWith(s, len, "od") ||
+ endsWith(s, len, "uk")))
+ return len - 2;
+
+ if (isVowel(s[len-3]) &&
+ (endsWith(s, len, "nk") ||
+ endsWith(s, len, "ja") ||
+ endsWith(s, len, "je")))
+ return len - 2;
+
+ if (endsWith(s, len, "im") ||
+ endsWith(s, len, "id") ||
+ endsWith(s, len, "ik"))
+ return len - 2;
+ }
+
+ if (len > 3)
+ switch(s[len-1]) {
+ case 'a':
+ case 'e': if (!isVowel(s[len-2])) return len - 1; break;
+ case 'm':
+ case 'd': if (isVowel(s[len-2])) return len - 1; break;
+ case 'i': return len - 1;
+ }
+
+ return len;
+ }
+
+ @SuppressWarnings("fallthrough")
+ private int removePlural(char s[], int len) {
+ if (len > 3 && s[len-1] == 'k')
+ switch(s[len-2]) {
+ case 'a':
+ case 'o':
+ case 'e': if (len > 4) return len - 2; /* intentional fallthru */
+ default: return len - 1;
+ }
+ return len;
+ }
+
+ private int normalize(char s[], int len) {
+ if (len > 3)
+ switch(s[len-1]) {
+ case 'a':
+ case 'e':
+ case 'i':
+ case 'o': return len - 1;
+ }
+ return len;
+ }
+
+ private boolean isVowel(char ch) {
+ switch(ch) {
+ case 'a':
+ case 'e':
+ case 'i':
+ case 'o':
+ case 'u':
+ case 'y': return true;
+ default: return false;
+ }
+ }
+}
fnp / pylucene.git / blobdiff