Scan.adv: def of yaml-for-bend@0.1.1.0
Import: import yaml-for-bend@0.1.1.0/scan.bend as Scan
Lines 283-290 of yaml-for-bend@0.1.1.0/scan.bend: https://jend.leeeet.dev/read.txt?path=yaml-for-bend@0.1.1.0/scan.bend&start_line=283&end_line=290

import Base

def adv(c: Cur) -> Cur:
  match c:
    case Cur{s, at, left}:
      match s:
        case SNil{}:
          Cur{SNil{}, at, left}
        case SCon{h, t}:
          Cur{t, past(at, h), Nat.sub(left, 1n)}

Uses (4):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=yaml-for-bend@0.1.1.0/scan.bend&name=Cur
  https://jend.leeeet.dev/definition.txt?path=yaml-for-bend@0.1.1.0/scan.bend&name=past