Hdr.len.ok.pick: def of bend-toon-codec@0.1.0.0
Import: import bend-toon-codec@0.1.0.0/src/hdr.bend as Hdr
Lines 136-145 of bend-toon-codec@0.1.0.0/src/hdr.bend: https://jend.leeeet.dev/read.txt?path=bend-toon-codec@0.1.0.0/src/hdr.bend&start_line=136&end_line=145

import Base

def len.ok.pick(+empty: Bool, +zero: Bool, +lead0: Bool, +ds: String) -> Bool:
  match empty zero lead0:
    case True{} _ _:
      False{}
    case False{} True{} _:
      True{}
    case False{} False{} True{}:
      False{}
    case False{} False{} False{}:
      Nat.is_le(String.length(ds), 9n)

Uses (4):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_le
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.length