Determine columns needed for a fixed-size wide-character string.
elm-wchar is a simple Elm port of wcwidth implemented in C by Markus Kuhn and wcwidth implemented in Python by Jeff Quast.
import WChar
String.length "한" -- => 1
WChar.width '한' -- => Wide (== 2)
String.length "한글" -- => 2
WChar.stringWidth "한글" -- => 4WChar.width and its string version, WChar.stringWidth are defined by IEEE Std
1002.1-2001, a.k.a. POSIX.1-2001, and return the number of columns used
to represent the given wide character and string.
Markus's implementation assumes the wide character given to those functions to be encoded in ISO 10646, which is almost true for JavaScript's characters.
MIT