105 lines
3.8 KiB
OCaml
105 lines
3.8 KiB
OCaml
(***********************************************************************)
|
|
(* *)
|
|
(* Objective Caml *)
|
|
(* *)
|
|
(* Damien Doligez, projet Para, 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 GNU Library General Public License, with *)
|
|
(* the special exception on linking described in file ../LICENSE. *)
|
|
(* *)
|
|
(***********************************************************************)
|
|
|
|
(* $Id$ *)
|
|
|
|
(** Pseudo-random number generators (PRNG). *)
|
|
|
|
(** {6 Basic functions} *)
|
|
|
|
val init : int -> unit
|
|
(** Initialize the generator, using the argument as a seed.
|
|
The same seed will always yield the same sequence of numbers. *)
|
|
|
|
val full_init : int array -> unit
|
|
(** Same as {!Random.init} but takes more data as seed. *)
|
|
|
|
val self_init : unit -> unit
|
|
(** Initialize the generator with a more-or-less random seed chosen
|
|
in a system-dependent way. *)
|
|
|
|
val bits : unit -> int
|
|
(** Return 30 random bits in a nonnegative integer.
|
|
@before 3.12.0 used a different algorithm (affects all the following
|
|
functions)
|
|
*)
|
|
|
|
val int : int -> int
|
|
(** [Random.int bound] returns a random integer between 0 (inclusive)
|
|
and [bound] (exclusive). [bound] must be greater than 0 and less
|
|
than 2{^30}. *)
|
|
|
|
val int32 : Int32.t -> Int32.t;;
|
|
(** [Random.int32 bound] returns a random integer between 0 (inclusive)
|
|
and [bound] (exclusive). [bound] must be greater than 0. *)
|
|
|
|
val nativeint : Nativeint.t -> Nativeint.t;;
|
|
(** [Random.nativeint bound] returns a random integer between 0 (inclusive)
|
|
and [bound] (exclusive). [bound] must be greater than 0. *)
|
|
|
|
val int64 : Int64.t -> Int64.t;;
|
|
(** [Random.int64 bound] returns a random integer between 0 (inclusive)
|
|
and [bound] (exclusive). [bound] must be greater than 0. *)
|
|
|
|
val float : float -> float
|
|
(** [Random.float bound] returns a random floating-point number
|
|
between 0 (inclusive) and [bound] (exclusive). If [bound] is
|
|
negative, the result is negative or zero. If [bound] is 0,
|
|
the result is 0. *)
|
|
|
|
val bool : unit -> bool
|
|
(** [Random.bool ()] returns [true] or [false] with probability 0.5 each. *)
|
|
|
|
|
|
(** {6 Advanced functions} *)
|
|
|
|
(** The functions from module [State] manipulate the current state
|
|
of the random generator explicitely.
|
|
This allows using one or several deterministic PRNGs,
|
|
even in a multi-threaded program, without interference from
|
|
other parts of the program.
|
|
*)
|
|
|
|
module State : sig
|
|
type t
|
|
(** The type of PRNG states. *)
|
|
|
|
val make : int array -> t
|
|
(** Create a new state and initialize it with the given seed. *)
|
|
|
|
val make_self_init : unit -> t
|
|
(** Create a new state and initialize it with a system-dependent
|
|
low-entropy seed. *)
|
|
|
|
val copy : t -> t
|
|
(** Return a copy of the given state. *)
|
|
|
|
val bits : t -> int
|
|
val int : t -> int -> int
|
|
val int32 : t -> Int32.t -> Int32.t
|
|
val nativeint : t -> Nativeint.t -> Nativeint.t
|
|
val int64 : t -> Int64.t -> Int64.t
|
|
val float : t -> float -> float
|
|
val bool : t -> bool
|
|
(** These functions are the same as the basic functions, except that they
|
|
use (and update) the given PRNG state instead of the default one.
|
|
*)
|
|
end;;
|
|
|
|
|
|
val get_state : unit -> State.t
|
|
(** Return the current state of the generator used by the basic functions. *)
|
|
|
|
val set_state : State.t -> unit
|
|
(** Set the state of the generator used by the basic functions. *)
|