Performs a single composition step of the
Unicode canonical composition algorithm.
This function includes algorithmic Hangul Jamo composition,
but it is not exactly the inverse of glib.global.unicharDecompose.
No composition can have either of a or b equal to zero.
To be precise, this function composes if and only if
there exists a Primary Composite P which is canonically
equivalent to the sequence <a,b>. See the Unicode
Standard for the definition of Primary Composite.
If a and b do not compose a new character, ch is set to zero.
Performs a single composition step of the Unicode canonical composition algorithm.
This function includes algorithmic Hangul Jamo composition, but it is not exactly the inverse of glib.global.unicharDecompose. No composition can have either of a or b equal to zero. To be precise, this function composes if and only if there exists a Primary Composite P which is canonically equivalent to the sequence <a,b>. See the Unicode Standard for the definition of Primary Composite.
If a and b do not compose a new character, ch is set to zero.
See UAX#15
for details.