pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / analysis / LowerCaseFilter.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/analysis/LowerCaseFilter.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/analysis/LowerCaseFilter.java
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+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/analysis/LowerCaseFilter.java
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+package org.apache.lucene.analysis;
+
+/**
+ * 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 org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
+import org.apache.lucene.util.CharacterUtils;
+import org.apache.lucene.util.Version;
+
+/**
+ * Normalizes token text to lower case.
+ * <a name="version"/>
+ * <p>You must specify the required {@link Version}
+ * compatibility when creating LowerCaseFilter:
+ * <ul>
+ *   <li> As of 3.1, supplementary characters are properly lowercased.
+ * </ul>
+ */
+public final class LowerCaseFilter extends TokenFilter {
+  private final CharacterUtils charUtils;
+  private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
+  
+  /**
+   * Create a new LowerCaseFilter, that normalizes token text to lower case.
+   * 
+   * @param matchVersion See <a href="#version">above</a>
+   * @param in TokenStream to filter
+   */
+  public LowerCaseFilter(Version matchVersion, TokenStream in) {
+    super(in);
+    charUtils = CharacterUtils.getInstance(matchVersion);
+  }
+  
+  /**
+   * @deprecated Use {@link #LowerCaseFilter(Version, TokenStream)} instead.
+   */
+  @Deprecated
+  public LowerCaseFilter(TokenStream in) {
+    this(Version.LUCENE_30, in);
+  }
+
+  @Override
+  public final boolean incrementToken() throws IOException {
+    if (input.incrementToken()) {
+      final char[] buffer = termAtt.buffer();
+      final int length = termAtt.length();
+      for (int i = 0; i < length;) {
+       i += Character.toChars(
+               Character.toLowerCase(
+                   charUtils.codePointAt(buffer, i)), buffer, i);
+      }
+      return true;
+    } else
+      return false;
+  }
+}