+++ /dev/null
-package org.apache.lucene.analysis.fi;
-
-/**
- * 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 Finnish.
- * <p>
- * This stemmer implements the algorithm described in:
- * <i>Report on CLEF-2003 Monolingual Tracks</i>
- * Jacques Savoy
- */
-public class FinnishLightStemmer {
-
- public int stem(char s[], int len) {
- if (len < 4)
- return len;
-
- for (int i = 0; i < len; i++)
- switch(s[i]) {
- case 'ä':
- case 'å': s[i] = 'a'; break;
- case 'ö': s[i] = 'o'; break;
- }
-
- len = step1(s, len);
- len = step2(s, len);
- len = step3(s, len);
- len = norm1(s, len);
- len = norm2(s, len);
- return len;
- }
-
- private int step1(char s[], int len) {
- if (len > 8) {
- if (endsWith(s, len, "kin"))
- return step1(s, len-3);
- if (endsWith(s, len, "ko"))
- return step1(s, len-2);
- }
-
- if (len > 11) {
- if (endsWith(s, len, "dellinen"))
- return len-8;
- if (endsWith(s, len, "dellisuus"))
- return len-9;
- }
- return len;
- }
-
- private int step2(char s[], int len) {
- if (len > 5) {
- if (endsWith(s, len, "lla")
- || endsWith(s, len, "tse")
- || endsWith(s, len, "sti"))
- return len-3;
-
- if (endsWith(s, len, "ni"))
- return len-2;
-
- if (endsWith(s, len, "aa"))
- return len-1; // aa -> a
- }
-
- return len;
- }
-
- private int step3(char s[], int len) {
- if (len > 8) {
- if (endsWith(s, len, "nnen")) {
- s[len-4] = 's';
- return len-3;
- }
-
- if (endsWith(s, len, "ntena")) {
- s[len-5] = 's';
- return len-4;
- }
-
- if (endsWith(s, len, "tten"))
- return len-4;
-
- if (endsWith(s, len, "eiden"))
- return len-5;
- }
-
- if (len > 6) {
- if (endsWith(s, len, "neen")
- || endsWith(s, len, "niin")
- || endsWith(s, len, "seen")
- || endsWith(s, len, "teen")
- || endsWith(s, len, "inen"))
- return len-4;
-
- if (s[len-3] == 'h' && isVowel(s[len-2]) && s[len-1] == 'n')
- return len-3;
-
- if (endsWith(s, len, "den")) {
- s[len-3] = 's';
- return len-2;
- }
-
- if (endsWith(s, len, "ksen")) {
- s[len-4] = 's';
- return len-3;
- }
-
- if (endsWith(s, len, "ssa")
- || endsWith(s, len, "sta")
- || endsWith(s, len, "lla")
- || endsWith(s, len, "lta")
- || endsWith(s, len, "tta")
- || endsWith(s, len, "ksi")
- || endsWith(s, len, "lle"))
- return len-3;
- }
-
- if (len > 5) {
- if (endsWith(s, len, "na")
- || endsWith(s, len, "ne"))
- return len-2;
-
- if (endsWith(s, len, "nei"))
- return len-3;
- }
-
- if (len > 4) {
- if (endsWith(s, len, "ja")
- || endsWith(s, len, "ta"))
- return len-2;
-
- if (s[len-1] == 'a')
- return len-1;
-
- if (s[len-1] == 'n' && isVowel(s[len-2]))
- return len-2;
-
- if (s[len-1] == 'n')
- return len-1;
- }
-
- return len;
- }
-
- private int norm1(char s[], int len) {
- if (len > 5 && endsWith(s, len, "hde")) {
- s[len-3] = 'k';
- s[len-2] = 's';
- s[len-1] = 'i';
- }
-
- if (len > 4) {
- if (endsWith(s, len, "ei") || endsWith(s, len, "at"))
- return len-2;
- }
-
- if (len > 3)
- switch(s[len-1]) {
- case 't':
- case 's':
- case 'j':
- case 'e':
- case 'a':
- case 'i': return len-1;
- }
-
- return len;
- }
-
- private int norm2(char s[], int len) {
- if (len > 8) {
- if (s[len-1] == 'e'
- || s[len-1] == 'o'
- || s[len-1] == 'u')
- len--;
- }
-
- if (len > 4) {
- if (s[len-1] == 'i')
- len--;
-
- if (len > 4) {
- char ch = s[0];
- for (int i = 1; i < len; i++) {
- if (s[i] == ch &&
- (ch == 'k' || ch == 'p' || ch == 't'))
- len = delete(s, i--, len);
- else
- ch = s[i];
- }
- }
- }
-
- 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