def pow_mod

bend-collections@1.0.0.0 · src/math/natural.bend:293

import Base

293def pow_mod(+b: Nat, +e: Nat, +m: Nat) -> Result<&2, &2, MathError, Nat>:
294  match m:
295    case 0n:
296      Fail{ZeroDivision{}}
297    case 1n+ +mp:
298      Done{pow_mod_go(e, 1n+mp, e, Nat.mod(b, 1n+mp), Nat.mod(1n, 1n+mp))}