X-Git-Url: https://git.mdrn.pl/pylucene.git/blobdiff_plain/a2e61f0c04805cfcb8706176758d1283c7e3a55c..aaeed5504b982cf3545252ab528713250aa33eed:/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/fr/ElisionFilter.java diff --git a/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/fr/ElisionFilter.java b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/fr/ElisionFilter.java new file mode 100644 index 0000000..ef558e4 --- /dev/null +++ b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/fr/ElisionFilter.java @@ -0,0 +1,146 @@ +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 java.io.IOException; +import java.util.Set; +import java.util.Arrays; +import org.apache.lucene.analysis.standard.StandardTokenizer; // for javadocs +import org.apache.lucene.analysis.CharArraySet; +import org.apache.lucene.analysis.TokenStream; +import org.apache.lucene.analysis.TokenFilter; +import org.apache.lucene.analysis.tokenattributes.CharTermAttribute; +import org.apache.lucene.util.Version; + +/** + * Removes elisions from a {@link TokenStream}. For example, "l'avion" (the plane) will be + * tokenized as "avion" (plane). + * + * @see Elision in Wikipedia + */ +public final class ElisionFilter extends TokenFilter { + private CharArraySet articles = CharArraySet.EMPTY_SET; + private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class); + private static final CharArraySet DEFAULT_ARTICLES = CharArraySet.unmodifiableSet( + new CharArraySet(Version.LUCENE_CURRENT, Arrays.asList( + "l", "m", "t", "qu", "n", "s", "j"), true)); + + private static char[] apostrophes = {'\'', '\u2019'}; + + /** + * Set the stopword articles + * @param matchVersion the lucene backwards compatibility version + * @param articles a set of articles + * @deprecated use {@link #ElisionFilter(Version, TokenStream, Set)} instead + */ + @Deprecated + public void setArticles(Version matchVersion, Set articles) { + this.articles = CharArraySet.unmodifiableSet( + CharArraySet.copy(matchVersion, articles)); + } + + /** + * Set the stopword articles + * @param articles a set of articles + * @deprecated use {@link #setArticles(Version, Set)} instead + */ + @Deprecated + public void setArticles(Set articles) { + setArticles(Version.LUCENE_CURRENT, articles); + } + /** + * Constructs an elision filter with standard stop words + */ + public ElisionFilter(Version matchVersion, TokenStream input) { + this(matchVersion, input, DEFAULT_ARTICLES); + } + + /** + * Constructs an elision filter with standard stop words + * @deprecated use {@link #ElisionFilter(Version, TokenStream)} instead + */ + @Deprecated + public ElisionFilter(TokenStream input) { + this(Version.LUCENE_30, input); + } + + /** + * Constructs an elision filter with a Set of stop words + * @deprecated use {@link #ElisionFilter(Version, TokenStream, Set)} instead + */ + @Deprecated + public ElisionFilter(TokenStream input, Set articles) { + this(Version.LUCENE_30, input, articles); + } + + /** + * Constructs an elision filter with a Set of stop words + * @param matchVersion the lucene backwards compatibility version + * @param input the source {@link TokenStream} + * @param articles a set of stopword articles + */ + public ElisionFilter(Version matchVersion, TokenStream input, Set articles) { + super(input); + this.articles = CharArraySet.unmodifiableSet( + new CharArraySet(matchVersion, articles, true)); + } + + /** + * Constructs an elision filter with an array of stop words + * @deprecated use {@link #ElisionFilter(Version, TokenStream, Set)} instead + */ + @Deprecated + public ElisionFilter(TokenStream input, String[] articles) { + this(Version.LUCENE_CURRENT, input, + new CharArraySet(Version.LUCENE_CURRENT, + Arrays.asList(articles), true)); + } + + /** + * Increments the {@link TokenStream} with a {@link CharTermAttribute} without elisioned start + */ + @Override + public final boolean incrementToken() throws IOException { + if (input.incrementToken()) { + char[] termBuffer = termAtt.buffer(); + int termLength = termAtt.length(); + + int minPoz = Integer.MAX_VALUE; + for (int i = 0; i < apostrophes.length; i++) { + char apos = apostrophes[i]; + // The equivalent of String.indexOf(ch) + for (int poz = 0; poz < termLength ; poz++) { + if (termBuffer[poz] == apos) { + minPoz = Math.min(poz, minPoz); + break; + } + } + } + + // An apostrophe has been found. If the prefix is an article strip it off. + if (minPoz != Integer.MAX_VALUE + && articles.contains(termAtt.buffer(), 0, minPoz)) { + termAtt.copyBuffer(termAtt.buffer(), minPoz + 1, termAtt.length() - (minPoz + 1)); + } + + return true; + } else { + return false; + } + } +}