Scan.key.top: def of yaml-for-bend@0.1.1.0
Import: import yaml-for-bend@0.1.1.0/scan.bend as Scan
Lines 452-458 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=452&end_line=458

import Base
import yaml-for-bend@0.1.1.0/token.bend as T

# The possible key on top, which a ":" would make a key.
def key.top(keys: List<&2, SKey>) -> SKey:
  match keys:
    case Nil{}:
      SKey{False{}, False{}, 0n, T.Mark{0n, 0n, 0n}, False{}, None{}}
    case Con{k, rest}:
      k

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=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=yaml-for-bend@0.1.1.0/scan.bend&name=SKey
  https://jend.leeeet.dev/definition.txt?path=yaml-for-bend@0.1.1.0/token.bend&name=Mark