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package org.apache.lucene.analysis.ar;


import static org.apache.lucene.analysis.util.StemmerUtil.*;

Normalizer for Arabic.

Normalization is done in-place for efficiency, operating on a termbuffer.

Normalization is defined as:

  • Normalization of hamza with alef seat to a bare alef.
  • Normalization of teh marbuta to heh
  • Normalization of dotless yeh (alef maksura) to yeh.
  • Removal of Arabic diacritics (the harakat)
  • Removal of tatweel (stretching character).
/** * 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
Params:
  • s – input buffer
  • len – length of input buffer
Returns:length of input buffer after normalization
/** * 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; } }