1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
(******************************************************************************
* Core *
* *
* Copyright (C) 2008- Jane Street Holding, LLC *
* Contact: opensource@janestreet.com *
* WWW: http://www.janestreet.com/ocaml *
* *
* *
* This library is free software; you can redistribute it and/or *
* modify it under the terms of the GNU Lesser General Public *
* License as published by the Free Software Foundation; either *
* version 2 of the License, or (at your option) any later version. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with this library; if not, write to the Free Software *
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *
* *
******************************************************************************)
(* factored out due to a circular dependency between core_array and core_list *)
let swap t i j =
let tmp = t.(i) in
t.(i) <- t.(j);
t.(j) <- tmp
(** randomly permute an array. *)
let permute ?random_state t =
let state =
match random_state with
| None -> Random.get_state ()
| Some state -> state
in
for i = Array.length t downto 2 do
swap t (i - 1) (Random.State.int state i)
done;
if random_state = None then Random.set_state state
|
