F# + recieve message DU instead of object. about orleankka HOT 3 CLOSED

type GrainMessage<'t> = | Msg of 't | Timer of Timer  | ..
type TypedGrain<'t> () =
 inherit  ActorGrain() 
 abstract member this.TypedReceive ( msg: GrainMessage<'t>)
 override this.Receive (message) =
  match message with 
  | :? 't as msg -> this.TypedReceive(GrainMessage(msg))
  | :? Timer as msg -> this.TypedReceive(GrainMessage ( msg))
 .. etc

type ActorMsg<'t> =
    | Msg of 't
    | Timer of Orleankka.Timer
    | Reminder of Orleankka.Reminder
    | Activate of Orleankka.Activate
    | Deactivate of Orleankka.Deactivate

[<AbstractClass>]
type TypedActor<'a>() =
    inherit ActorGrain()
    abstract member ReceiveT: ActorMsg<'a> -> System.Threading.Tasks.Task<obj> 
    override this.Receive(msg:obj) = task {
      match msg with
      | :? 'a as m -> return! this.ReceiveT (Msg m)
      | :? Orleankka.Timer as t -> return! this.ReceiveT( Timer t)
      | :? Orleankka.Activate as a -> return! this.ReceiveT ( Activate a)
      | :? Orleankka.Deactivate as d -> return! this.ReceiveT( Deactivate d)
      | _ -> return unhandled() }

type HelloGrain (loggerFactory:ILoggerFactory) =
  inherit TypedActor<HelloMessages>()
  let log = loggerFactory.CreateLogger(typeof<HelloGrain>)
  interface IHello
  override this.ReceiveT(msg) = task {
    match msg with
    | Msg(Hi)-> 
        log.LogInformation("Client asked to say Hi!")
        return some "Oh, hi!"
    | Msg(Hello s) ->
        log.LogInformation (sprintf "Client asked to say Hello to %s" s)
        return sprintf "Hello, %s" s |> some
    | Msg(Bue) -> 
        log.LogInformation ("Client wants to go")
        return none()
    | _ ->  return unhandled()
  }