def do_notation(input, chainer) do
  input
  |> normalize()
  |> Enum.reverse()
  |> Witchcraft.Foldable.left_fold(fn
    continue, {:let, _, [{:=, _, [assign, value]}]} ->
      quote do: unquote(value) |> (fn unquote(assign) -> unquote(continue) end).()

    continue, {:<-, _, [assign, value]} ->
      quote do
        apply(unquote(chainer), [unquote(value), fn unquote(assign) -> unquote(continue) end])
      end

    continue, value ->
      quote do
        apply(unquote(chainer), [unquote(value), fn _ -> unquote(continue) end])
      end
  end)
end