def prev_index

bend-collections-laws-crypto@1.0.0.0 · src/crypto/argon2/argon2.bend:219

import Base

219def prev_index(+l: Nat, +q: Nat, +j: Nat, first: Bool) -> Nat:
220  match first:
221    case True{}:
222      Nat.add(Nat.mul(l, q), Nat.sub(q, 1n))
223    case False{}:
224      Nat.sub(Nat.add(Nat.mul(l, q), j), 1n)