Module Splittable_random

A splittable pseudo-random number generator (SPRNG) functions like a PRNG in that it can be used as a stream of random values; it can also be "split" to produce a second, independent stream of random values.

This module implements a splittable pseudo-random number generator that sacrifices cryptographic-quality randomness in favor of performance.

The primary difference between Splittable_random and Random is the State.split operation for generating new pseudo-random states. While it is easy to simulate State.split using Random, the result has undesirable statistical properties; the new state does not behave independently of the original. It is better to switch to Splittable_random if you need an operation like State.split, as this module has been implemented with the statistical properties of splitting in mind. For most other purposes, Random is likely a better choice, as its implementation passes all Diehard tests, while Splittable_random fails some Diehard tests.

module State : sig ... end
val bool : State.t -> Base.bool

Produces a random, fair boolean.

val int : State.t -> lo:Base.int -> hi:Base.int -> Base.int

Produce a random number uniformly distributed in the given inclusive range. (In the case of float, hi may or may not be attainable, depending on rounding.)

val int32 : State.t -> lo:Base.int32 -> hi:Base.int32 -> Base.int32
val int63 : State.t -> lo:Base.Int63.t -> hi:Base.Int63.t -> Base.Int63.t
val int64 : State.t -> lo:Base.int64 -> hi:Base.int64 -> Base.int64
val nativeint : State.t -> lo:Base.nativeint -> hi:Base.nativeint -> Base.nativeint
val float : State.t -> lo:Base.float -> hi:Base.float -> Base.float
val unit_float : State.t -> Base.float

unit_float state = float state ~lo:0. ~hi:1., but slightly more efficient (and right endpoint is exclusive).

module Log_uniform : sig ... end