Chacha8.rekey: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/src/math/random/chacha8.bend as Chacha8
Lines 45-51 of bend-collections-laws-crypto@1.0.0.0/src/math/random/chacha8.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/random/chacha8.bend&start_line=45&end_line=51

import Base
import bend-collections-laws-crypto@1.0.0.0/src/math/u64.bend as W
import bend-collections-laws-crypto@1.0.0.0/src/math/random/chacha8/block.bend as B

# the key of the next iteration: the last four words of the last group
def rekey(l: List<&2, W.U64>) -> B.Key:
  match l:
    case [W.U64{k0, k1}, W.U64{k2, k3}, W.U64{k4, k5}, W.U64{k6, k7}]:
      B.K{k0, k1, k2, k3, k4, k5, k6, k7}
    case _:
      B.K{0, 0, 0, 0, 0, 0, 0, 0}

Uses (3):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/random/chacha8/block.bend&name=Key
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/u64.bend&name=U64