diku-dk / cpprandom Goto Github PK

For example, this program will not terminate:

import "lib/github.com/diku-dk/cpprandom/random"

module rng = minstd_rand
module dist = uniform_int_distribution u32 rng

let main (seed: i32) =
  let r = rng.rng_from_seed [seed]
  in dist.rand (rng.min,rng.max+1) r

The problem is this loop where it tries to ensure that the distribution is not unbalanced. If the range is too great, then secure_max becomes 0, and the loop becomes infinite.

uniform_int_distribution i64 minstd_rand generates numbers outside the range when the range is between negative numbers.

import "lib/github.com/diku-dk/cpprandom/random"
module dist = uniform_int_distribution i64 minstd_rand
let snd (_,b) = b
let main = snd <| dist.rand (-20,-10) (minstd_rand.rng_from_seed [1234])

This program returns 4294967281i64, for example

Both book and comment say join_rngs but in code I see only join_rng defined.