ocaml/stdlib/char.ml

40 lines
1.5 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Character operations *)
external code: char -> int = "%identity"
external unsafe_chr: int -> char = "%identity"
let chr n =
if n < 0 or n > 255 then invalid_arg "Char.chr" else unsafe_chr n
external is_printable: char -> bool = "is_printable"
let escaped = function
'\'' -> "\\'"
| '\\' -> "\\\\"
| '\n' -> "\\n"
| '\t' -> "\\t"
| c -> if is_printable c then
String.make 1 c
else begin
let n = code c in
let s = String.create 4 in
String.unsafe_set s 0 '\\';
String.unsafe_set s 1 (unsafe_chr (48 + n / 100));
String.unsafe_set s 2 (unsafe_chr (48 + (n / 10) mod 10));
String.unsafe_set s 3 (unsafe_chr (48 + n mod 10));
s
end