Type-safe, printf-style formatting for PureScript.
> format (width 6) 123
" 123"
> format (signed <> width 6) 123
" +123"
> format (zeroFill <> width 6) (-123)
"-00123"
> format (width 8 <> precision 3) pi
" 3.142"
> format (width 8 <> precision 3) 10.0
" 10.000"
> format (width 8) "foo"
" foo"