let remove_first_blanks s =
let len = String.length s in
try
let rec first_no_blank p =
if p < len then
match s.[p] with
' ' | '\t' -> first_no_blank (p+1)
| _ -> p
else
raise Not_found
in
let p = first_no_blank 0 in
String.sub s p (len - p)
with
Not_found -> ""