ocaml/stdlib/char.ml

63 lines
2.2 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 int_of_char: 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
let char_of_int = chr
external is_printable: char -> bool = "is_printable"
external string_create: int -> string = "create_string"
external string_unsafe_get : string -> int -> char = "%string_unsafe_get"
external string_unsafe_set : string -> int -> char -> unit
= "%string_unsafe_set"
let escaped = function
'\'' -> "\\'"
| '\\' -> "\\\\"
| '\n' -> "\\n"
| '\t' -> "\\t"
| c -> if is_printable c then begin
let s = string_create 1 in
string_unsafe_set s 0 c;
s
end 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
let lowercase c =
if (c >= 'A' && c <= 'Z')
|| (c >= '\192' && c <= '\214')
|| (c >= '\216' && c <= '\222')
then unsafe_chr(code c + 32)
else c
let uppercase c =
if (c >= 'a' && c <= 'z')
|| (c >= '\224' && c <= '\246')
|| (c >= '\248' && c <= '\254')
then unsafe_chr(code c - 32)
else c