pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / analyzers / common / src / java / org / apache / lucene / analysis / snowball / SnowballAnalyzer.java

diff --git a/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/snowball/SnowballAnalyzer.java b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/snowball/SnowballAnalyzer.java
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+++ b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/snowball/SnowballAnalyzer.java
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+package org.apache.lucene.analysis.snowball;
+
+/**
+ * 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.*;
+import org.apache.lucene.analysis.en.EnglishPossessiveFilter;
+import org.apache.lucene.analysis.standard.*;
+import org.apache.lucene.analysis.tr.TurkishLowerCaseFilter;
+import org.apache.lucene.util.Version;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.util.Set;
+
+/** Filters {@link StandardTokenizer} with {@link StandardFilter}, {@link
+ * LowerCaseFilter}, {@link StopFilter} and {@link SnowballFilter}.
+ *
+ * Available stemmers are listed in org.tartarus.snowball.ext.  The name of a
+ * stemmer is the part of the class name before "Stemmer", e.g., the stemmer in
+ * {@link org.tartarus.snowball.ext.EnglishStemmer} is named "English".
+ *
+ * <p><b>NOTE</b>: This class uses the same {@link Version}
+ * dependent settings as {@link StandardAnalyzer}, with the following addition:
+ * <ul>
+ *   <li> As of 3.1, uses {@link TurkishLowerCaseFilter} for Turkish language.
+ * </ul>
+ * </p>
+ * @deprecated Use the language-specific analyzer in contrib/analyzers instead. 
+ * This analyzer will be removed in Lucene 5.0
+ */
+@Deprecated
+public final class SnowballAnalyzer extends Analyzer {
+  private String name;
+  private Set<?> stopSet;
+  private final Version matchVersion;
+
+  /** Builds the named analyzer with no stop words. */
+  public SnowballAnalyzer(Version matchVersion, String name) {
+    this.name = name;
+    this.matchVersion = matchVersion;
+  }
+
+  /** 
+   * Builds the named analyzer with the given stop words.
+   * @deprecated Use {@link #SnowballAnalyzer(Version, String, Set)} instead.  
+   */
+  @Deprecated
+  public SnowballAnalyzer(Version matchVersion, String name, String[] stopWords) {
+    this(matchVersion, name);
+    stopSet = StopFilter.makeStopSet(matchVersion, stopWords);
+  }
+  
+  /** Builds the named analyzer with the given stop words. */
+  public SnowballAnalyzer(Version matchVersion, String name, Set<?> stopWords) {
+    this(matchVersion, name);
+    stopSet = CharArraySet.unmodifiableSet(CharArraySet.copy(matchVersion,
+        stopWords));
+  }
+
+  /** Constructs a {@link StandardTokenizer} filtered by a {@link
+      StandardFilter}, a {@link LowerCaseFilter}, a {@link StopFilter},
+      and a {@link SnowballFilter} */
+  @Override
+  public TokenStream tokenStream(String fieldName, Reader reader) {
+    TokenStream result = new StandardTokenizer(matchVersion, reader);
+    result = new StandardFilter(matchVersion, result);
+    // remove the possessive 's for english stemmers
+    if (matchVersion.onOrAfter(Version.LUCENE_31) && 
+        (name.equals("English") || name.equals("Porter") || name.equals("Lovins")))
+      result = new EnglishPossessiveFilter(result);
+    // Use a special lowercase filter for turkish, the stemmer expects it.
+    if (matchVersion.onOrAfter(Version.LUCENE_31) && name.equals("Turkish"))
+      result = new TurkishLowerCaseFilter(result);
+    else
+      result = new LowerCaseFilter(matchVersion, result);
+    if (stopSet != null)
+      result = new StopFilter(matchVersion,
+                              result, stopSet);
+    result = new SnowballFilter(result, name);
+    return result;
+  }
+  
+  private class SavedStreams {
+    Tokenizer source;
+    TokenStream result;
+  }
+  
+  /** Returns a (possibly reused) {@link StandardTokenizer} filtered by a 
+   * {@link StandardFilter}, a {@link LowerCaseFilter}, 
+   * a {@link StopFilter}, and a {@link SnowballFilter} */
+  @Override
+  public TokenStream reusableTokenStream(String fieldName, Reader reader)
+      throws IOException {
+    SavedStreams streams = (SavedStreams) getPreviousTokenStream();
+    if (streams == null) {
+      streams = new SavedStreams();
+      streams.source = new StandardTokenizer(matchVersion, reader);
+      streams.result = new StandardFilter(matchVersion, streams.source);
+      // Use a special lowercase filter for turkish, the stemmer expects it.
+      if (matchVersion.onOrAfter(Version.LUCENE_31) && name.equals("Turkish"))
+        streams.result = new TurkishLowerCaseFilter(streams.result);
+      else
+        streams.result = new LowerCaseFilter(matchVersion, streams.result);
+      if (stopSet != null)
+        streams.result = new StopFilter(matchVersion,
+                                        streams.result, stopSet);
+      streams.result = new SnowballFilter(streams.result, name);
+      setPreviousTokenStream(streams);
+    } else {
+      streams.source.reset(reader);
+    }
+    return streams.result;
+  }
+}