initializes the iterator, starting at startptr and crossing length bytes.
mbi_avail (iter)
- returns true if there are more multibyte chracters available before
+ returns true if there are more multibyte characters available before
the end of string is reached. In this case, mbi_cur (iter) is
- initialized to the next multibyte chracter.
+ initialized to the next multibyte character.
mbi_advance (iter)
advances the iterator by one multibyte character.