module BatRandom:sig
..end
Pseudo-random number generators (PRNG).
This module extends Stdlib's Random module, go there for documentation on the rest of the functions and types.
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.
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 230.
val int32 : Stdlib.Int32.t -> Stdlib.Int32.t
Random.int32 bound
returns a random integer between 0 (inclusive)
and bound
(exclusive). bound
must be greater than 0.
val nativeint : Stdlib.Nativeint.t -> Stdlib.Nativeint.t
Random.nativeint bound
returns a random integer between 0 (inclusive)
and bound
(exclusive). bound
must be greater than 0.
val int64 : Stdlib.Int64.t -> Stdlib.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.
val char : unit -> char
Return a random Latin-1 character.
val full_range_int : unit -> int
full_range_int ()
returns the maximum entropy possible in a
single int: 31 bits on 32-bit platforms and 63 bits on 64-bit
platforms. Intentionally gives different results on different
platforms, so is not portable.
val enum_bits : unit -> int BatEnum.t
val enum_int : int -> int BatEnum.t
val enum_bool : unit -> bool BatEnum.t
val enum_float : float -> float BatEnum.t
val enum_int32 : Stdlib.Int32.t -> Stdlib.Int32.t BatEnum.t
val enum_int64 : Stdlib.Int64.t -> Stdlib.Int64.t BatEnum.t
val enum_nativeint : Stdlib.Nativeint.t -> Stdlib.Nativeint.t BatEnum.t
val enum_char : unit -> char BatEnum.t
val choice : 'a BatEnum.t -> 'a
choice e
returns a randomly-chosen element of e
.
This function only works on finite enumerations with less than 230 elements.
val multi_choice : int -> 'a BatEnum.t -> 'a BatEnum.t
multi_choice n e
returns an enumeration of n
randomly-chosen elements of e
.
val shuffle : 'a BatEnum.t -> 'a array
shuffle e
returns a new array, containing the
same set of elements as e
, but in a random order.
Shuffling is implemented using the Fisher-Yates
algorithm and works in O(n), where n is the number
of elements of e
.
This function only works on finite enumerations with less than 230 elements.
module State:sig
..end
Manipulate the current state of the random generator.
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.
module Incubator:sig
..end