Allegro 5 api
#include <allegro5/allegro.h> int32_t al_ustr_prev_get(const ALLEGRO_USTR *us, int *pos)
Find the beginning of a code point before byte offset *pos, then return it. Note this performs a pre-increment.
On success returns the code point value. If pos was out of bounds (e.g. past the end of the string), return -1. On an error, such as an invalid byte sequence, return -2. As with al_ustr_prev(3alleg5), invalid byte sequences may be skipped while advancing.
al_ustr_get_next(3alleg5)