pylucene 3.5.0-3

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

diff --git a/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/ar/ArabicNormalizer.java b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/ar/ArabicNormalizer.java
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+package org.apache.lucene.analysis.ar;
+
+/**
+ * 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 static org.apache.lucene.analysis.util.StemmerUtil.*;
+
+/**
+ *  Normalizer for Arabic.
+ *  <p>
+ *  Normalization is done in-place for efficiency, operating on a termbuffer.
+ *  <p>
+ *  Normalization is defined as:
+ *  <ul>
+ *  <li> Normalization of hamza with alef seat to a bare alef.
+ *  <li> Normalization of teh marbuta to heh
+ *  <li> Normalization of dotless yeh (alef maksura) to yeh.
+ *  <li> Removal of Arabic diacritics (the harakat)
+ *  <li> Removal of tatweel (stretching character).
+ * </ul>
+ *
+ */
+public class ArabicNormalizer {
+  public static final char ALEF = '\u0627';
+  public static final char ALEF_MADDA = '\u0622';
+  public static final char ALEF_HAMZA_ABOVE = '\u0623';
+  public static final char ALEF_HAMZA_BELOW = '\u0625';
+
+  public static final char YEH = '\u064A';
+  public static final char DOTLESS_YEH = '\u0649';
+
+  public static final char TEH_MARBUTA = '\u0629';
+  public static final char HEH = '\u0647';
+
+  public static final char TATWEEL = '\u0640';
+
+  public static final char FATHATAN = '\u064B';
+  public static final char DAMMATAN = '\u064C';
+  public static final char KASRATAN = '\u064D';
+  public static final char FATHA = '\u064E';
+  public static final char DAMMA = '\u064F';
+  public static final char KASRA = '\u0650';
+  public static final char SHADDA = '\u0651';
+  public static final char SUKUN = '\u0652';
+
+  /**
+   * Normalize an input buffer of Arabic text
+   * 
+   * @param s input buffer
+   * @param len length of input buffer
+   * @return length of input buffer after normalization
+   */
+  public int normalize(char s[], int len) {
+
+    for (int i = 0; i < len; i++) {
+      switch (s[i]) {
+      case ALEF_MADDA:
+      case ALEF_HAMZA_ABOVE:
+      case ALEF_HAMZA_BELOW:
+        s[i] = ALEF;
+        break;
+      case DOTLESS_YEH:
+        s[i] = YEH;
+        break;
+      case TEH_MARBUTA:
+        s[i] = HEH;
+        break;
+      case TATWEEL:
+      case KASRATAN:
+      case DAMMATAN:
+      case FATHATAN:
+      case FATHA:
+      case DAMMA:
+      case KASRA:
+      case SHADDA:
+      case SUKUN:
+        len = delete(s, i, len);
+        i--;
+        break;
+      default:
+        break;
+      }
+    }
+
+    return len;
+  }
+}