ocaml/utils/misc.ml

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(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the Q Public License version 1.0. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Errors *)
exception Fatal_error
let fatal_error msg =
prerr_string ">> Fatal error: "; prerr_endline msg; raise Fatal_error
(* List functions *)
let rec map_end f l1 l2 =
match l1 with
[] -> l2
| hd::tl -> f hd :: map_end f tl l2
let rec for_all2 pred l1 l2 =
match (l1, l2) with
([], []) -> true
| (hd1::tl1, hd2::tl2) -> pred hd1 hd2 && for_all2 pred tl1 tl2
| (_, _) -> false
let rec replicate_list elem n =
if n <= 0 then [] else elem :: replicate_list elem (n-1)
let rec list_remove x = function
[] -> []
| hd :: tl ->
if hd = x then tl else hd :: list_remove x tl
let rec split_last = function
[] -> assert false
| [x] -> ([], x)
| hd :: tl ->
let (lst, last) = split_last tl in
(hd :: lst, last)
(* Options *)
let may f = function
Some x -> f x
| None -> ()
let may_map f = function
Some x -> Some (f x)
| None -> None
(* File functions *)
let find_in_path path name =
if not (Filename.is_implicit name) then
if Sys.file_exists name then name else raise Not_found
else begin
let rec try_dir = function
[] -> raise Not_found
| dir::rem ->
let fullname = Filename.concat dir name in
if Sys.file_exists fullname then fullname else try_dir rem
in try_dir path
end
let remove_file filename =
try
Sys.remove filename
with Sys_error msg ->
()
(* Expand a -I option: if it starts with +, make it relative to the standard
library directory *)
let expand_directory alt s =
if String.length s > 0 && s.[0] = '+'
then Filename.concat alt
(String.sub s 1 (String.length s - 1))
else s
(* Hashtable functions *)
let create_hashtable size init =
let tbl = Hashtbl.create size in
List.iter (fun (key, data) -> Hashtbl.add tbl key data) init;
tbl
(* File copy *)
let copy_file ic oc =
let buff = String.create 0x1000 in
let rec copy () =
let n = input ic buff 0 0x1000 in
if n = 0 then () else (output oc buff 0 n; copy())
in copy()
let copy_file_chunk ic oc len =
let buff = String.create 0x1000 in
let rec copy n =
if n <= 0 then () else begin
let r = input ic buff 0 (min n 0x1000) in
if r = 0 then raise End_of_file else (output oc buff 0 r; copy(n-r))
end
in copy len
(* Integer operations *)
let rec log2 n =
if n <= 1 then 0 else 1 + log2(n asr 1)
let align n a =
if n >= 0 then (n + a - 1) land (-a) else n land (-a)
let no_overflow_add a b = (a lxor b) lor (a lxor (lnot (a+b))) < 0
let no_overflow_sub a b = (a lxor (lnot b)) lor (b lxor (a-b)) < 0