8.2 Canonical combining class
Every Unicode character or code point has a canonical combining class
assigned to it.
What is the meaning of the canonical combining class? Essentially, it
indicates the priority with which a combining character is attached to its
base character. The characters for which the canonical combining class is 0
are the base characters, and the characters for which it is greater than 0 are
the combining characters. Combining characters are rendered
near/attached/around their base character, and combining characters with small
combining classes are attached "first" or "closer" to the base character.
The canonical combining class of a character is a number in the range
0..255. The possible values are described in the Unicode Character Database
http://www.unicode.org/Public/UNIDATA/UCD.html. The list here is
not definitive; more values can be added in future versions.
— Constant: int
UC_CCC_NR
The canonical combining class value for “Not Reordered” characters.
The value is 0.
— Constant: int
UC_CCC_OV
The canonical combining class value for “Overlay” characters.
— Constant: int
UC_CCC_NK
The canonical combining class value for “Nukta” characters.
— Constant: int
UC_CCC_KV
The canonical combining class value for “Kana Voicing” characters.
— Constant: int
UC_CCC_VR
The canonical combining class value for “Virama” characters.
— Constant: int
UC_CCC_ATBL
The canonical combining class value for “Attached Below Left” characters.
— Constant: int
UC_CCC_ATB
The canonical combining class value for “Attached Below” characters.
— Constant: int
UC_CCC_ATAR
The canonical combining class value for “Attached Above Right” characters.
— Constant: int
UC_CCC_BL
The canonical combining class value for “Below Left” characters.
— Constant: int
UC_CCC_B
The canonical combining class value for “Below” characters.
— Constant: int
UC_CCC_BR
The canonical combining class value for “Below Right” characters.
— Constant: int
UC_CCC_L
The canonical combining class value for “Left” characters.
— Constant: int
UC_CCC_R
The canonical combining class value for “Right” characters.
— Constant: int
UC_CCC_AL
The canonical combining class value for “Above Left” characters.
— Constant: int
UC_CCC_A
The canonical combining class value for “Above” characters.
— Constant: int
UC_CCC_AR
The canonical combining class value for “Above Right” characters.
— Constant: int
UC_CCC_DB
The canonical combining class value for “Double Below” characters.
— Constant: int
UC_CCC_DA
The canonical combining class value for “Double Above” characters.
— Constant: int
UC_CCC_IS
The canonical combining class value for “Iota Subscript” characters.
The following function looks up the canonical combining class of a character.
— Function: int
uc_combining_class (
ucs4_t uc)
Returns the canonical combining class of a Unicode character.