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package org.apache.lucene.analysis.fr;

/*
 * 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 org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.core.LowerCaseFilter;
import org.apache.lucene.analysis.core.StopFilter;
import org.apache.lucene.analysis.miscellaneous.SetKeywordMarkerFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.snowball.SnowballFilter;
import org.apache.lucene.analysis.standard.StandardFilter;
import org.apache.lucene.analysis.standard.StandardTokenizer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;  // for javadoc
import org.apache.lucene.analysis.util.CharArraySet;
import org.apache.lucene.analysis.util.ElisionFilter;
import org.apache.lucene.analysis.util.StopwordAnalyzerBase;
import org.apache.lucene.analysis.util.WordlistLoader;
import org.apache.lucene.util.IOUtils;
import org.apache.lucene.util.Version;

import java.io.IOException;
import java.io.Reader;
import java.util.Arrays;

/**
 * {@link Analyzer} for French language. 
 * 

* Supports an external list of stopwords (words that * will not be indexed at all) and an external list of exclusions (word that will * not be stemmed, but indexed). * A default set of stopwords is used unless an alternative list is specified, but the * exclusion list is empty by default. *

* * *

You must specify the required {@link Version} * compatibility when creating FrenchAnalyzer: *

    *
  • As of 3.6, FrenchLightStemFilter is used for less aggressive stemming. *
  • As of 3.1, Snowball stemming is done with SnowballFilter, * LowerCaseFilter is used prior to StopFilter, and ElisionFilter and * Snowball stopwords are used by default. *
  • As of 2.9, StopFilter preserves position * increments *
* *

NOTE: This class uses the same {@link Version} * dependent settings as {@link StandardAnalyzer}.

*/ public final class FrenchAnalyzer extends StopwordAnalyzerBase { /** * Extended list of typical French stopwords. * @deprecated (3.1) remove in Lucene 5.0 (index bw compat) */ @Deprecated private final static String[] FRENCH_STOP_WORDS = { "a", "afin", "ai", "ainsi", "après", "attendu", "au", "aujourd", "auquel", "aussi", "autre", "autres", "aux", "auxquelles", "auxquels", "avait", "avant", "avec", "avoir", "c", "car", "ce", "ceci", "cela", "celle", "celles", "celui", "cependant", "certain", "certaine", "certaines", "certains", "ces", "cet", "cette", "ceux", "chez", "ci", "combien", "comme", "comment", "concernant", "contre", "d", "dans", "de", "debout", "dedans", "dehors", "delà", "depuis", "derrière", "des", "désormais", "desquelles", "desquels", "dessous", "dessus", "devant", "devers", "devra", "divers", "diverse", "diverses", "doit", "donc", "dont", "du", "duquel", "durant", "dès", "elle", "elles", "en", "entre", "environ", "est", "et", "etc", "etre", "eu", "eux", "excepté", "hormis", "hors", "hélas", "hui", "il", "ils", "j", "je", "jusqu", "jusque", "l", "la", "laquelle", "le", "lequel", "les", "lesquelles", "lesquels", "leur", "leurs", "lorsque", "lui", "là", "ma", "mais", "malgré", "me", "merci", "mes", "mien", "mienne", "miennes", "miens", "moi", "moins", "mon", "moyennant", "même", "mêmes", "n", "ne", "ni", "non", "nos", "notre", "nous", "néanmoins", "nôtre", "nôtres", "on", "ont", "ou", "outre", "où", "par", "parmi", "partant", "pas", "passé", "pendant", "plein", "plus", "plusieurs", "pour", "pourquoi", "proche", "près", "puisque", "qu", "quand", "que", "quel", "quelle", "quelles", "quels", "qui", "quoi", "quoique", "revoici", "revoilà", "s", "sa", "sans", "sauf", "se", "selon", "seront", "ses", "si", "sien", "sienne", "siennes", "siens", "sinon", "soi", "soit", "son", "sont", "sous", "suivant", "sur", "ta", "te", "tes", "tien", "tienne", "tiennes", "tiens", "toi", "ton", "tous", "tout", "toute", "toutes", "tu", "un", "une", "va", "vers", "voici", "voilà", "vos", "votre", "vous", "vu", "vôtre", "vôtres", "y", "à", "ça", "ès", "été", "être", "ô" }; /** File containing default French stopwords. */ public final static String DEFAULT_STOPWORD_FILE = "french_stop.txt"; /** Default set of articles for ElisionFilter */ public static final CharArraySet DEFAULT_ARTICLES = CharArraySet.unmodifiableSet( new CharArraySet(Version.LUCENE_CURRENT, Arrays.asList( "l", "m", "t", "qu", "n", "s", "j", "d", "c", "jusqu", "quoiqu", "lorsqu", "puisqu"), true)); /** * Contains words that should be indexed but not stemmed. */ private final CharArraySet excltable; /** * Returns an unmodifiable instance of the default stop-words set. * @return an unmodifiable instance of the default stop-words set. */ public static CharArraySet getDefaultStopSet(){ return DefaultSetHolder.DEFAULT_STOP_SET; } private static class DefaultSetHolder { /** @deprecated (3.1) remove this in Lucene 5.0, index bw compat */ @Deprecated static final CharArraySet DEFAULT_STOP_SET_30 = CharArraySet .unmodifiableSet(new CharArraySet(Version.LUCENE_CURRENT, Arrays.asList(FRENCH_STOP_WORDS), false)); static final CharArraySet DEFAULT_STOP_SET; static { try { DEFAULT_STOP_SET = WordlistLoader.getSnowballWordSet(IOUtils.getDecodingReader(SnowballFilter.class, DEFAULT_STOPWORD_FILE, IOUtils.CHARSET_UTF_8), Version.LUCENE_CURRENT); } catch (IOException ex) { // default set should always be present as it is part of the // distribution (JAR) throw new RuntimeException("Unable to load default stopword set"); } } } /** * Builds an analyzer with the default stop words ({@link #getDefaultStopSet}). */ public FrenchAnalyzer(Version matchVersion) { this(matchVersion, matchVersion.onOrAfter(Version.LUCENE_31) ? DefaultSetHolder.DEFAULT_STOP_SET : DefaultSetHolder.DEFAULT_STOP_SET_30); } /** * Builds an analyzer with the given stop words * * @param matchVersion * lucene compatibility version * @param stopwords * a stopword set */ public FrenchAnalyzer(Version matchVersion, CharArraySet stopwords){ this(matchVersion, stopwords, CharArraySet.EMPTY_SET); } /** * Builds an analyzer with the given stop words * * @param matchVersion * lucene compatibility version * @param stopwords * a stopword set * @param stemExclutionSet * a stemming exclusion set */ public FrenchAnalyzer(Version matchVersion, CharArraySet stopwords, CharArraySet stemExclutionSet) { super(matchVersion, stopwords); this.excltable = CharArraySet.unmodifiableSet(CharArraySet .copy(matchVersion, stemExclutionSet)); } /** * Creates * {@link org.apache.lucene.analysis.Analyzer.TokenStreamComponents} * used to tokenize all the text in the provided {@link Reader}. * * @return {@link org.apache.lucene.analysis.Analyzer.TokenStreamComponents} * built from a {@link StandardTokenizer} filtered with * {@link StandardFilter}, {@link ElisionFilter}, * {@link LowerCaseFilter}, {@link StopFilter}, * {@link SetKeywordMarkerFilter} if a stem exclusion set is * provided, and {@link FrenchLightStemFilter} */ @Override protected TokenStreamComponents createComponents(String fieldName, Reader reader) { if (matchVersion.onOrAfter(Version.LUCENE_31)) { final Tokenizer source = new StandardTokenizer(matchVersion, reader); TokenStream result = new StandardFilter(matchVersion, source); result = new ElisionFilter(result, DEFAULT_ARTICLES); result = new LowerCaseFilter(matchVersion, result); result = new StopFilter(matchVersion, result, stopwords); if(!excltable.isEmpty()) result = new SetKeywordMarkerFilter(result, excltable); if (matchVersion.onOrAfter(Version.LUCENE_36)) { result = new FrenchLightStemFilter(result); } else { result = new SnowballFilter(result, new org.tartarus.snowball.ext.FrenchStemmer()); } return new TokenStreamComponents(source, result); } else { final Tokenizer source = new StandardTokenizer(matchVersion, reader); TokenStream result = new StandardFilter(matchVersion, source); result = new StopFilter(matchVersion, result, stopwords); if(!excltable.isEmpty()) result = new SetKeywordMarkerFilter(result, excltable); result = new FrenchStemFilter(result); // Convert to lowercase after stemming! return new TokenStreamComponents(source, new LowerCaseFilter(matchVersion, result)); } } }




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