F# vs Zahardzhan's C# actors

myactors.cs

// type Message = Finished | Msg of int * Message MailboxProcessor

// let (<--) (m:MailboxProcessor<_>) x = m.Post(x)

// let ping iters (outbox : Message MailboxProcessor) =
//    MailboxProcessor.Start(fun inbox ->
//        let rec loop n = async {
//            match n with
//            | 0 -> outbox.Post Finished
//                   printfn "ping finished"
//                   return ()
//            | _ -> outbox <-- Msg(n, inbox)
//                   let! msg = inbox.Receive()
//                   printfn "ping received pong"
//                   return! loop(n-1)}
//        loop iters)

// let pong() =
//    MailboxProcessor.Start(fun inbox ->
//        let rec loop () = async {
//            let! msg = inbox.Receive()
//            match msg with
//            | Finished ->
//                printfn "pong finished"
//                return ()
//            | Msg(n, outbox) ->
//                printfn "pong received ping"
//                outbox <-- Msg(n, inbox)
//                return! loop() }

//        loop())

// ping 100 <| pong() |> ignore
// System.Console.ReadLine() |> ignore

// ---------------------------------------------------
// ---------------------------------------------------



static class Program {
    struct Finished { }
    struct Msg { public int N; public Actor Sender; }

    static Actor Ping(int iters, Actor pong) {
        return Actor.Startup(self => {
               var i = iters;
         loop: if (i == 0) {
                   pong.Send(new Finished { });
                   Console.WriteLine("ping finished");
               } else {
                   pong.Send(new Msg { N = i, Sender = self });
                   var msg = self.Receive<Msg>();
                   Console.WriteLine("ping received pong");
                   i--; goto loop;
               }
        });
    }

    static Actor Pong() {
        return Actor.Startup(self => {
          loop: var msg = self.Receive<object>();
                if (msg is Finished) {
                    Console.WriteLine("pong finished");
                    return;
                } else if (msg is Msg) {
                    var n = ((Msg)msg).N;
                    var sender = ((Msg)msg).Sender;
                    Console.WriteLine("pong received ping");
                    sender.Send(new Msg { N = n, Sender = self });
                    goto loop;
                }
        });
    }

    static void Main() {
        Ping(100, Pong());
        Console.ReadLine();
    }
}

Хочешь нормальных акторов на C# — сделай их сам.