lib/mlton/basic/random.sig

   1 (* Copyright (C) 2009 Matthew Fluet.
   2  * Copyright (C) 1999-2006 Henry Cejtin, Matthew Fluet, Suresh
   3  *    Jagannathan, and Stephen Weeks.
   4  *
   5  * MLton is released under a BSD-style license.
   6  * See the file MLton-LICENSE for details.
   7  *)
   8
   9 signature RANDOM =
  10    sig
  11       val alphaNumString: int -> string
  12       val charFrom: string -> char
  13       val bool: unit -> bool
  14       val list: 'a list -> 'a option
  15       (* natLessThan n returns a random number uniform in [0, n). *)
  16       val natLessThan: int -> int
  17       val nRandom: {list: 'a list, length: int, n: int} -> 'a list
  18       (* 0.0 <= real() <= 1.0 *)
  19       val real: unit -> real
  20       val seed: unit -> Word.t option
  21       val srand: Word.t -> unit
  22       val useed: unit -> Word.t option
  23       val word: unit -> Word.t
  24       (* word w returns a random number uniform in [0, w). *)
  25       val wordLessThan: Word.t -> Word.t
  26    end