- let n = String.length str in
- if n = width then str
- else if n > width then String.sub str 0 width
- else (* if n < width then *) str ^ String.make (width-n) ' '
+ if width <= 0 then ""
+ else (
+ let n = String.length str in
+ if n = width then str
+ else if n > width then String.sub str 0 width
+ else (* if n < width then *) str ^ String.make (width-n) ' '
+ )