/*
*
* 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.
*
*/
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Collections;
using Lucene.Net.Analysis;
using Lucene.Net.Analysis.De;
using Lucene.Net.Analysis.Standard;
using Version = Lucene.Net.Util.Version;
namespace Lucene.Net.Analysis.Fr
{
/*
* {@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 2.9, StopFilter preserves position
* increments
*
*
* NOTE: This class uses the same {@link Version}
* dependent settings as {@link StandardAnalyzer}.
*/
public sealed class FrenchAnalyzer : Analyzer
{
/*
* Extended list of typical French stopwords.
* @deprecated use {@link #getDefaultStopSet()} instead
*/
// TODO make this private in 3.1
public readonly 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"
};
/*
* Contains the stopwords used with the {@link StopFilter}.
*/
private readonly ISet stoptable;
/*
* Contains words that should be indexed but not stemmed.
*/
//TODO make this final in 3.0
private ISet excltable = Support.Compatibility.SetFactory.CreateHashSet();
private readonly Version matchVersion;
/*
* Returns an unmodifiable instance of the default stop-words set.
* @return an unmodifiable instance of the default stop-words set.
*/
public static ISet GetDefaultStopSet()
{
return DefaultSetHolder.DEFAULT_STOP_SET;
}
static class DefaultSetHolder
{
internal static ISet DEFAULT_STOP_SET = CharArraySet.UnmodifiableSet(new CharArraySet((IEnumerable)FRENCH_STOP_WORDS, false));
}
/*
* Builds an analyzer with the default stop words ({@link #FRENCH_STOP_WORDS}).
*/
public FrenchAnalyzer(Version matchVersion)
: this(matchVersion, DefaultSetHolder.DEFAULT_STOP_SET)
{
}
/*
* Builds an analyzer with the given stop words
*
* @param matchVersion
* lucene compatibility version
* @param stopwords
* a stopword set
*/
public FrenchAnalyzer(Version matchVersion, ISet 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, ISet stopwords, ISet stemExclutionSet)
{
this.matchVersion = matchVersion;
this.stoptable = CharArraySet.UnmodifiableSet(CharArraySet.Copy(stopwords));
this.excltable = CharArraySet.UnmodifiableSet(CharArraySet.Copy(stemExclutionSet));
}
/*
* Builds an analyzer with the given stop words.
* @deprecated use {@link #FrenchAnalyzer(Version, Set)} instead
*/
public FrenchAnalyzer(Version matchVersion, params string[] stopwords)
: this(matchVersion, StopFilter.MakeStopSet(stopwords))
{
}
/*
* Builds an analyzer with the given stop words.
* @throws IOException
* @deprecated use {@link #FrenchAnalyzer(Version, Set)} instead
*/
public FrenchAnalyzer(Version matchVersion, FileInfo stopwords)
: this(matchVersion, WordlistLoader.GetWordSet(stopwords))
{
}
/*
* Builds an exclusionlist from an array of Strings.
* @deprecated use {@link #FrenchAnalyzer(Version, Set, Set)} instead
*/
public void SetStemExclusionTable(params string[] exclusionlist)
{
excltable = StopFilter.MakeStopSet(exclusionlist);
PreviousTokenStream = null; // force a new stemmer to be created
}
/*
* Builds an exclusionlist from a Map.
* @deprecated use {@link #FrenchAnalyzer(Version, Set, Set)} instead
*/
public void SetStemExclusionTable(IDictionary exclusionlist)
{
excltable = Support.Compatibility.SetFactory.CreateHashSet(exclusionlist.Keys);
PreviousTokenStream = null; // force a new stemmer to be created
}
/*
* Builds an exclusionlist from the words contained in the given file.
* @throws IOException
* @deprecated use {@link #FrenchAnalyzer(Version, Set, Set)} instead
*/
public void SetStemExclusionTable(FileInfo exclusionlist)
{
excltable = WordlistLoader.GetWordSet(exclusionlist);
PreviousTokenStream = null; // force a new stemmer to be created
}
/*
* Creates a {@link TokenStream} which tokenizes all the text in the provided
* {@link Reader}.
*
* @return A {@link TokenStream} built from a {@link StandardTokenizer}
* filtered with {@link StandardFilter}, {@link StopFilter},
* {@link FrenchStemFilter} and {@link LowerCaseFilter}
*/
public override sealed TokenStream TokenStream(String fieldName, TextReader reader)
{
TokenStream result = new StandardTokenizer(matchVersion, reader);
result = new StandardFilter(result);
result = new StopFilter(StopFilter.GetEnablePositionIncrementsVersionDefault(matchVersion),
result, stoptable);
result = new FrenchStemFilter(result, excltable);
// Convert to lowercase after stemming!
result = new LowerCaseFilter(result);
return result;
}
class SavedStreams
{
protected internal Tokenizer source;
protected internal TokenStream result;
};
/*
* Returns a (possibly reused) {@link TokenStream} which tokenizes all the
* text in the provided {@link Reader}.
*
* @return A {@link TokenStream} built from a {@link StandardTokenizer}
* filtered with {@link StandardFilter}, {@link StopFilter},
* {@link FrenchStemFilter} and {@link LowerCaseFilter}
*/
public override TokenStream ReusableTokenStream(String fieldName, TextReader reader)
{
SavedStreams streams = (SavedStreams)PreviousTokenStream;
if (streams == null)
{
streams = new SavedStreams();
streams.source = new StandardTokenizer(matchVersion, reader);
streams.result = new StandardFilter(streams.source);
streams.result = new StopFilter(StopFilter.GetEnablePositionIncrementsVersionDefault(matchVersion),
streams.result, stoptable);
streams.result = new FrenchStemFilter(streams.result, excltable);
// Convert to lowercase after stemming!
streams.result = new LowerCaseFilter(streams.result);
PreviousTokenStream = streams;
}
else
{
streams.source.Reset(reader);
}
return streams.result;
}
}
}