All functions that take char parameters accept unichar as well. Functions with more than one parameter, when called with at least one unichar parameter, results in implicit conversion of any non-unichar parameters to unichar.
To guarantee the integrity of surrogate pairs when enable surrogate processing is set to 1 (the default), the string functions do not allow surrogate pairs to be split. Positions fall at the beginning of a surrogate pair.
Several functions round out the unichar support. Included are the functions to_unichar() and uscalar(), which are analogous to char() and ascii(). The functions uhighsurr() and ulowsurr() allow the explicit handling of surrogate pairs in user code.
There are restrictions when using unitext with functions. For information, see the restriction description under the “Usage” section for each function in the Reference Manual: Blocks.