Generate Random `int`, `float`, and `char` using mirage-crypto-rng

Task

Random Values / Generate Random `int`, `float`, and `char`

Opam Packages Used

  • mirage-crypto-rng Tested with version: 0.11.3 — Used libraries: mirage-crypto-rng.unix
  • cstruct Tested with version: 6.2.0 — Used libraries: cstruct
  • randomconv Tested with version: 0.1.3 — Used libraries: randomconv

Code

Initialize the Mirage_crypto_rng with the an entropy source.

let () =
  Mirage_crypto_rng_unix.initialize
    (module Mirage_crypto_rng.Fortuna)

Random bytes generation function.

let generator n =
  n
  |> Mirage_crypto_rng.generate
  |> Cstruct.to_string

Generate int8, int16, int32 or int64 values.

let int8 () = Randomconv.int8 generator
let int16 () = Randomconv.int16 generator
let int32 () = Randomconv.int32 generator
let int64 () = Randomconv.int64 generator

Generate a random int or float values strictly lower than bound.

let int ?bound () =
  Randomconv.int ?bound generator
let float ?bound () =
  Randomconv.float ?bound generator

Generate char values

let char () = () |> int8 |> Char.chr
let digit () = 48 + int ~bound:10 () |> Char.chr
let majuscule () = 65 + int ~bound:26 () |> Char.chr
let minuscule () = 97 + int ~bound:26 () |> Char.chr
let letter () =
  let n = int ~bound:52 () in
  Char.chr @@ n + if n < 26 then 65 else 71
let alphanum () =
  let n = int ~bound:62 () in
  Char.chr @@ n
  + if n < 10 then 48 else if n < 36 then 55 else 61

Random bytes into byte arrays or big arrays.

let bytes n =
  n
  |> Mirage_crypto_rng.generate
  |> Cstruct.to_bytes
let bigarray n =
  n
  |> Mirage_crypto_rng.generate
  |> Cstruct.to_bigarray

let list n gen = List.init n (fun _ -> gen ())

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