Fixed.digit_on: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/spec/math/fixed.bend as Fixed
Lines 229-240 of bend-collections-laws-math@1.0.0.0/spec/math/fixed.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/spec/math/fixed.bend&start_line=229&end_line=240

import Base
import bend-collections-laws-math@1.0.0.0/spec/lib/common.bend as C

# the value of exactly k base-256 digits, least significant first; None
# for another length or a digit of 256 or more
def digit_on(r: Maybe<&2, Nat>, ok: Bool, +x: Nat) -> Maybe<&2, Nat>:
  match r:
    case Some{+v}:
      match ok:
        case True{}:
          Some{Nat.add(x, C.shift(8n, v))}
        case False{}:
          None{}
    case None{}:
      None{}

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/spec/lib/common.bend&name=shift