content: 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;
    }
  }
  