Rand.uint64n: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/src/math/random/rand.bend as Rand
Lines 166-168 of bend-collections-laws-math@1.0.0.0/src/math/random/rand.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/src/math/random/rand.bend&start_line=166&end_line=168

import Base
import bend-collections-laws-math@1.0.0.0/src/math/u64.bend as W

# uniform in [0, n) for n > 0 (Go's Uint64N)
def uint64n(~S: Data, ~next: S -> W.U64 & S, s: S, +n: W.U64) -> W.U64 & S:
  uint64n_pick(~S, ~next, s, n, is_pow2(n))

Uses (4):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/random/rand.bend&name=is_pow2
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/random/rand.bend&name=uint64n_pick
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/u64.bend&name=U64