pub fn either_bifunctor(
  ,
) -> bifunctor.Bifunctor(
  types.EitherBF,
  a,
  b,
  c,
  d,
  cat.Either(a, b),
  cat.Either(c, d),
)

let show_or_double = either_bifunctor().bimap(int.to_string, fn(x) { x * 2 })

Left(10)
|> show_or_double()
// -> should.equal(cat.Left("10"))
Right(10)
|> show_or_double()
// -> Right(20)

pub fn pair_bifunctor(
  ,
) -> bifunctor.Bifunctor(
  types.PairBF,
  a,
  b,
  c,
  d,
  cat.Pair(a, b),
  cat.Pair(c, d),
)

Pair(2, 3)
|> pair_bifunctor().bimap(fn(x) { x % 3 }, int.to_string)()
// -> Pair(2, "3")

pub fn tuple_bifunctor(
  ,
) -> bifunctor.Bifunctor(
  types.TupleBF,
  a,
  b,
  c,
  d,
  #(a, b),
  #(c, d),
)

#(6, False)
|> tuple_bifunctor().bimap(fn(x) { [x] }, fn(b) { bool.to_string(b) })()
// -> #([6], "False")