struct \fruit =
  | $apple
  | $orange
  | $banana

struct \optional 'a =
  | $some & 'a
  | $none

struct \result[#move] 'a 'b =
  | & 'a
  | $error  & 'b

struct \complex[#value] =
  & \float
  & \float

struct \task =
  & name : \string
  & duration : \float?

class \employee =
  & name : \string
  & role :
  ( | $director
      & importance : \float
      & share : \float
    | $manager
      & productivity :
      ( \productivity
        | $.low
        | $.average
        | $.high
          & duration : \float
          & sleep-on-work :
          ( \sleep-on-work
            | $..yes
            | $..no
          ))
      & salary : \int
    | $programmer
      & skills : \float
      & current-task : \optional[task]
      & salary : \int)


class \bag =
  &
  ( | $apple
    | $orange
    | $banana)
  & bag-type :
  ( | $small
    | $medium
      & weight-kg : \int
      & weight-g : \int
      & weight-mg : \int
    | $big)
  & other-things : \array[something]