Call/CC in Rx

CallCC.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace CallCC
{
    /// <summary>An attempt to understand Call/CC in Rx</summary>
    class Program
    {
        static void Main(string[] args)
        {
            // Imperative
            Console.WriteLine("Starting imperative sample...\n\n");

            Console.WriteLine("Really delete?");
            var response = Console.ReadLine() ?? "NO";
            if (response.ToUpperInvariant() == "YES")
                Console.WriteLine("Deleted!");
            else
                Console.WriteLine("Deleted action aborted.");

            Console.ReadLine();

            // CPS
            Console.WriteLine("\n\nStarting CPS sample...\n\n");
            var cpsDisposable =
                new YesNoMessage("Really delete?").Render()
                    .Subscribe(result =>
                                   {
                                       if (result)
                                           new InfoMessage("Deleted!").Render();
                                       else
                                           new InfoMessage("Deleted action aborted.").Render();
                                   });

            cpsDisposable.Dispose();

            Console.ReadKey();

            // Call/CC 1
            Console.WriteLine("\n\nStarting Call/CC sample...\n\n");
            if (Observable.Create<bool>(o => new YesNoMessage("Really delete?").Render().Subscribe(o).Dispose).NextValue().Get())
                Observable.Create<bool>(o => new InfoMessage("Deleted!").Render().Subscribe(o).Dispose);
            else
                Observable.Create<bool>(o => new InfoMessage("Deleted action aborted.").Render().Subscribe(o).Dispose);

            Console.ReadKey();
        }
    }

    class InfoMessage
    {
        protected readonly string _message;

        public InfoMessage(string message)
        {
            _message = message;
        }

        public virtual IObservable<bool> Render()
        {
            Console.WriteLine(_message);
            return UserResponses().ToObservable()
                .Select(response => true);
        }

        protected IEnumerable<string> UserResponses()
        {
            while(true)
            {
                yield return Console.ReadLine();
            }
        }
    }

    class YesNoMessage : InfoMessage
    {
        public YesNoMessage(string message) : base(message)
        {
        }

        public override IObservable<bool> Render()
        {
            Console.WriteLine(_message);
            return UserResponses().ToObservable()
                .Select(response => response.ToUpperInvariant() == "YES" ? true : false);
        }
    }
}