pylucene 3.5.0-3

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

diff --git a/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/br/BrazilianStemFilter.java b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/br/BrazilianStemFilter.java
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+++ b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/br/BrazilianStemFilter.java
@@ -0,0 +1,89 @@
+package org.apache.lucene.analysis.br;
+
+/**
+ * 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 org.apache.lucene.analysis.KeywordMarkerFilter; // for javadoc
+import org.apache.lucene.analysis.TokenFilter;
+import org.apache.lucene.analysis.TokenStream;
+import org.apache.lucene.analysis.tokenattributes.KeywordAttribute;
+import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
+
+/**
+ * A {@link TokenFilter} that applies {@link BrazilianStemmer}.
+ * <p>
+ * To prevent terms from being stemmed use an instance of
+ * {@link KeywordMarkerFilter} or a custom {@link TokenFilter} that sets
+ * the {@link KeywordAttribute} before this {@link TokenStream}.
+ * </p>
+ * @see KeywordMarkerFilter
+ * 
+ */
+public final class BrazilianStemFilter extends TokenFilter {
+
+  /**
+   * {@link BrazilianStemmer} in use by this filter.
+   */
+  private BrazilianStemmer stemmer = new BrazilianStemmer();
+  private Set<?> exclusions = null;
+  private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
+  private final KeywordAttribute keywordAttr = addAttribute(KeywordAttribute.class);
+
+  /**
+   * Creates a new BrazilianStemFilter 
+   * 
+   * @param in the source {@link TokenStream} 
+   */
+  public BrazilianStemFilter(TokenStream in) {
+    super(in);
+  }
+  
+  /**
+   * Creates a new BrazilianStemFilter 
+   * 
+   * @param in the source {@link TokenStream} 
+   * @param exclusiontable a set of terms that should be prevented from being stemmed.
+   * @deprecated use {@link KeywordAttribute} with {@link KeywordMarkerFilter} instead.
+   */
+  @Deprecated
+  public BrazilianStemFilter(TokenStream in, Set<?> exclusiontable) {
+    this(in);
+    this.exclusions = exclusiontable;
+  }
+
+  @Override
+  public boolean incrementToken() throws IOException {
+    if (input.incrementToken()) {
+      final String term = termAtt.toString();
+      // Check the exclusion table.
+      if (!keywordAttr.isKeyword() && (exclusions == null || !exclusions.contains(term))) {
+        final String s = stemmer.stem(term);
+        // If not stemmed, don't waste the time adjusting the token.
+        if ((s != null) && !s.equals(term))
+          termAtt.setEmpty().append(s);
+      }
+      return true;
+    } else {
+      return false;
+    }
+  }
+}
+
+