def dec.step

bend-kit-netip@0.1.0.0 · netip.bend:40

import Base

40# A non-digit wraps past 9 in (c - 48), so it fails the digit test.
41def dec.step(+d: U32, acc: Maybe<&2, U32>) -> Maybe<&2, U32>:
42  match acc:
43    case None{}:
44      None{}
45    case Some{v}:
46      Bool.pick(Maybe<&2, U32>, U32.is_lt(d, 10), Some{(v * 10 + d : U32)}, None{})