width c returns the column width of c where c is of type Camomile.UChar.t and the value returned is of type int. This module is implemented purely in OCaml and follows the prototype of POSIX's wcwidth. i.e. If c is a printable character, the value is at least 0. If c is null character (L'\0'), the value is 0. Otherwise, -1 is returned.

when encounter an unprintable character, width_exn c raises Failure "unprintable character" instead of returning -1.

width_utext str returns the column width of str where str is of type Camomile.UText.utext and the value returned is of type (int, int) result. When Ok width returnted, width is the width of str. When Error pos returned, pos is the offset of the left most unprintable character in str.