comparable

defprotocol Comparable do
  @moduledoc """
  Protocol which describes ordering relation for pair of types
  """

  @type t :: Comparable.t()
  @type ord :: :gt | :lt | :eq

  @doc """
  Accepts struct with fields :left and :right and returns ord value
  """
  @spec compare(t) :: ord
  def compare(left_and_right)
end