Exploring Gleam, a type-safe language on the BEAM(christopher.engineering)

    # let foo ~bar:baz = baz + 42;;
    val foo : bar:int -> int = <fun>
    # foo ~bar:12765;;
    - : int = 12807

    # let bar = 42;;
    val bar : int = 42
    # foo ~bar;;
    - : int = 84

    # let test ?(arg=5) () = arg;;
    val test : ?arg:int -> unit -> int = <fun>
    # let arg = None;;
    val arg : 'a option = None
    # test ?arg ();;
    - : int = 5

    # let arg = 5;;
    val arg : int = 5
    # test ~arg ();;
    - : int = 5

    # test;;
    - : ?arg:int -> unit -> int = <fun>
    # test ();;
    - : int = 5

    defmodule Calculator do
      use ExActor.GenServer

      defstart start_link, do: initial_state(0)

      defcast inc(x), state: state, do: new_state(state + x)
      defcast dec(x), state: state, do: new_state(state - x)

      defcall get, state: state, do: reply(state)

      defcast stop, do: stop_server(:normal)
    end

  fn handle_async_task(message ...) {
    case message {
      Increment(client) -> {

  handle_cast(R=#message{type=increment}, S) -> work_module:increment(R, S);
  handle_cast(R=#message{type=decrement}, S) -> work_module:decrement(R, S).