open Batteries

class type number = object ('a)
  (* method plus: 'a -> 'a *)
end

class int_wrap (i: int) = object
  val i = i
end

class float_wrap (f: float) = object
  val f = f
end

let parse: string -> number = fun s ->
  if String.exists s "." then
    float_of_string s |> new float_wrap
  else
    int_of_string s |> new int_wrap