IsCompositionExcluded

Short summary

This function check if a recomposed codepoint is excluded from the canonical recomposition, used for NFC normalization.

Attention: The list of codepoints is given by the UCD CompositionExclusions.txt from the Unicode std 15.1.0 (August 2024)

• Return type: BOOL

Parameters

Name	Type	Comment	Kind
codePoint	UnicodeCodePoint	codepoint to be checked	input

Code

Declaration

FUNCTION INTERNAL IsCompositionExcluded : BOOL
VAR_INPUT
	(* codepoint to be checked *)
	codePoint :UnicodeCodePoint;
END_VAR

Implementation

IsCompositionExcluded := FALSE;
CASE codePoint OF
// ================================================
// (1) Script Specifics
//
// This list of characters cannot be derived from the UnicodeData.txt file.
//
// Included are the following subcategories:
//
// - Many precomposed characters using a nukta diacritic in the Devanagari,
//   Bangla/Bengali, Gurmukhi, or Odia/Oriya scripts.
// - Tibetan letters and subjoined letters with decompositions including 
//   U+0FB7 TIBETAN SUBJOINED LETTER HA or U+0FB5 TIBETAN SUBJOINED LETTER SSA.
// - Two two-part Tibetan vowel signs involving top and bottom pieces.
// - A large collection of compatibility precomposed characters for Hebrew
//   involving dagesh and/or other combining marks.
//
// This list is unlikely to grow.
//
// ================================================

16#0958,    //  DEVANAGARI LETTER QA
16#0959,    //  DEVANAGARI LETTER KHHA
16#095A,    //  DEVANAGARI LETTER GHHA
16#095B,    //  DEVANAGARI LETTER ZA
16#095C,    //  DEVANAGARI LETTER DDDHA
16#095D,    //  DEVANAGARI LETTER RHA
16#095E,    //  DEVANAGARI LETTER FA
16#095F,    //  DEVANAGARI LETTER YYA
16#09DC,    //  BENGALI LETTER RRA
16#09DD,    //  BENGALI LETTER RHA
16#09DF,    //  BENGALI LETTER YYA
16#0A33,    //  GURMUKHI LETTER LLA
16#0A36,    //  GURMUKHI LETTER SHA
16#0A59,    //  GURMUKHI LETTER KHHA
16#0A5A,    //  GURMUKHI LETTER GHHA
16#0A5B,    //  GURMUKHI LETTER ZA
16#0A5E,    //  GURMUKHI LETTER FA
16#0B5C,    //  ORIYA LETTER RRA
16#0B5D,    //  ORIYA LETTER RHA
16#0F43,    //  TIBETAN LETTER GHA
16#0F4D,    //  TIBETAN LETTER DDHA
16#0F52,    //  TIBETAN LETTER DHA
16#0F57,    //  TIBETAN LETTER BHA
16#0F5C,    //  TIBETAN LETTER DZHA
16#0F69,    //  TIBETAN LETTER KSSA
16#0F76,    //  TIBETAN VOWEL SIGN VOCALIC R
16#0F78,    //  TIBETAN VOWEL SIGN VOCALIC L
16#0F93,    //  TIBETAN SUBJOINED LETTER GHA
16#0F9D,    //  TIBETAN SUBJOINED LETTER DDHA
16#0FA2,    //  TIBETAN SUBJOINED LETTER DHA
16#0FA7,    //  TIBETAN SUBJOINED LETTER BHA
16#0FAC,    //  TIBETAN SUBJOINED LETTER DZHA
16#0FB9,    //  TIBETAN SUBJOINED LETTER KSSA
16#FB1D,    //  HEBREW LETTER YOD WITH HIRIQ
16#FB1F,    //  HEBREW LIGATURE YIDDISH YOD YOD PATAH
16#FB2A,    //  HEBREW LETTER SHIN WITH SHIN DOT
16#FB2B,    //  HEBREW LETTER SHIN WITH SIN DOT
16#FB2C,    //  HEBREW LETTER SHIN WITH DAGESH AND SHIN DOT
16#FB2D,    //  HEBREW LETTER SHIN WITH DAGESH AND SIN DOT
16#FB2E,    //  HEBREW LETTER ALEF WITH PATAH
16#FB2F,    //  HEBREW LETTER ALEF WITH QAMATS
16#FB30,    //  HEBREW LETTER ALEF WITH MAPIQ
16#FB31,    //  HEBREW LETTER BET WITH DAGESH
16#FB32,    //  HEBREW LETTER GIMEL WITH DAGESH
16#FB33,    //  HEBREW LETTER DALET WITH DAGESH
16#FB34,    //  HEBREW LETTER HE WITH MAPIQ
16#FB35,    //  HEBREW LETTER VAV WITH DAGESH
16#FB36,    //  HEBREW LETTER ZAYIN WITH DAGESH
16#FB38,    //  HEBREW LETTER TET WITH DAGESH
16#FB39,    //  HEBREW LETTER YOD WITH DAGESH
16#FB3A,    //  HEBREW LETTER FINAL KAF WITH DAGESH
16#FB3B,    //  HEBREW LETTER KAF WITH DAGESH
16#FB3C,    //  HEBREW LETTER LAMED WITH DAGESH
16#FB3E,    //  HEBREW LETTER MEM WITH DAGESH
16#FB40,    //  HEBREW LETTER NUN WITH DAGESH
16#FB41,    //  HEBREW LETTER SAMEKH WITH DAGESH
16#FB43,    //  HEBREW LETTER FINAL PE WITH DAGESH
16#FB44,    //  HEBREW LETTER PE WITH DAGESH
16#FB46,    //  HEBREW LETTER TSADI WITH DAGESH
16#FB47,    //  HEBREW LETTER QOF WITH DAGESH
16#FB48,    //  HEBREW LETTER RESH WITH DAGESH
16#FB49,    //  HEBREW LETTER SHIN WITH DAGESH
16#FB4A,    //  HEBREW LETTER TAV WITH DAGESH
16#FB4B,    //  HEBREW LETTER VAV WITH HOLAM
16#FB4C,    //  HEBREW LETTER BET WITH RAFE
16#FB4D,    //  HEBREW LETTER KAF WITH RAFE
16#FB4E:    //  HEBREW LETTER PE WITH RAFE
	IsCompositionExcluded := TRUE;	

// ================================================
// (2) Post Composition Version precomposed characters
//
// These characters cannot be derived solely from the UnicodeData.txt file
// in this version of Unicode.
//
// Note that characters added to the standard after the
// Composition Version and which have canonical decomposition mappings
// are not automatically added to this list of Post Composition
// Version precomposed characters.
// ================================================

16#2ADC ,   //  FORKING
16#1D15E,   //  MUSICAL SYMBOL HALF NOTE
16#1D15F,   //  MUSICAL SYMBOL QUARTER NOTE
16#1D160,   //  MUSICAL SYMBOL EIGHTH NOTE
16#1D161,   //  MUSICAL SYMBOL SIXTEENTH NOTE
16#1D162,   //  MUSICAL SYMBOL THIRTY-SECOND NOTE
16#1D163,   //  MUSICAL SYMBOL SIXTY-FOURTH NOTE
16#1D164,   //  MUSICAL SYMBOL ONE HUNDRED TWENTY-EIGHTH NOTE
16#1D1BB,   //  MUSICAL SYMBOL MINIMA
16#1D1BC,   //  MUSICAL SYMBOL MINIMA BLACK
16#1D1BD,   //  MUSICAL SYMBOL SEMIMINIMA WHITE
16#1D1BE,   //  MUSICAL SYMBOL SEMIMINIMA BLACK
16#1D1BF,   //  MUSICAL SYMBOL FUSA WHITE
16#1D1C0:   //  MUSICAL SYMBOL FUSA BLACK	
	IsCompositionExcluded := TRUE;
ELSE
	IsCompositionExcluded := FALSE;
END_CASE