1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9

def s := "hello world"

#eval s.toList.map (λ x ↦
  let bx := x.toUInt8.toBitVec
  List.range 8
    |>.map λ y ↦
      if bx.getMsbD y then " " else "")
  |>.flatten
  |> "f".intercalate