OCaml library : Random.State

# Module Random.State

    module State: sig .. end

    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 random seed chosen in a system-dependent way. The seed is obtained as described in `Random.self_init`.

    val copy : t -> t

Return a copy of the given state.

    val bits : t -> int

    val int : t -> int -> int

    val full_int : t -> int -> int

    val int_in_range : t -> min:int -> max:int -> int

    val int32 : t -> Int32.t -> Int32.t

    val int32_in_range : t -> min:int32 -> max:int32 -> int32

    val nativeint : t -> Nativeint.t -> Nativeint.t

    val nativeint_in_range : t -> min:nativeint -> max:nativeint -> nativeint

    val int64 : t -> Int64.t -> Int64.t

    val int64_in_range : t -> min:int64 -> max:int64 -> int64

    val float : t -> float -> float

    val bool : t -> bool

    val bits32 : t -> Int32.t

    val bits64 : t -> Int64.t

    val nativebits : t -> Nativeint.t

These functions are the same as the basic functions, except that they use (and update) the given PRNG state instead of the default one.

    val split : t -> t

Draw a fresh PRNG state from the given PRNG state. (The given PRNG state is modified.) The new PRNG is statistically independent from the given PRNG. Data can be drawn from both PRNGs, in any order, without risk of correlation. Both PRNGs can be split later, arbitrarily many times.

- Since 5.0

    val to_binary_string : t -> string

Serializes the PRNG state into an immutable sequence of bytes. See `Random.State.of_binary_string` for deserialization.

The `string` type is intended here for serialization only, the encoding is not human-readable and may not be printable.

Note that the serialization format may differ across OCaml versions.

- Since 5.1

    val of_binary_string : string -> t

Deserializes a byte sequence obtained by calling `Random.State.to_binary_string`. The resulting PRNG state will produce the same random numbers as the state that was passed as input to `Random.State.to_binary_string`.

- Since 5.1
- Raises `Failure` if the input is not in the expected format. Note that the serialization format may differ across OCaml versions. Unlike the functions provided by the `Marshal` module, this function either produces a valid state or fails cleanly with a `Failure` exception. It can be safely used on user-provided, untrusted inputs.