Rand.perm: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/src/math/random/rand.bend as Rand
Lines 322-324 of bend-collections-laws-crypto@1.0.0.0/src/math/random/rand.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/random/rand.bend&start_line=322&end_line=324

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

# Go's Perm: a shuffle of 0..n-1
def perm(~S: Data, ~next: S -> W.U64 & S, s: S, +n: Nat) -> List<&2, Nat> & S:
  shuffle(~Nat, ~S, ~next, s, range(n))

Uses (6):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/random/rand.bend&name=range
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/random/rand.bend&name=shuffle
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/u64.bend&name=U64