# Module Array_permute.Random

    module Random: Core_random

Pseudo-random number generators (PRNG).

###### Basic functions

Note that all of these "basic" functions mutate a global random state.

    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 230.

    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.

###### Advanced functions

    module State: sig .. end

The functions from module `State` manipulate the current state of the random generator explicitely.

    val get_state : unit -> [ `Consider_using_Random_State_default ]

OCaml's `Random.get_state` makes a copy of the default state, which is almost certainly not what you want. `State.default`, which is the actual default state, is probably what you want.

    val set_state : State.t -> unit

Set the state of the generator used by the basic functions.