iteratorhack.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using System.Collections.Generic;
using System.Collections;
using System.Net;

namespace test2
{
    public static class Extensions
    {
        public static Task Await(this Task task, TaskContext context)
        {
            task.ContinueWith(a => context.Continue());
            if (task.Status != TaskStatus.Running && task.Status != TaskStatus.WaitingForActivation)
                task.Start();
            return task;
        }
    }

    public class TaskContext
    {
        public void Continue()
        {
            if (!mEnumerator.MoveNext())
            {
                mAction();
            }
        }

        IEnumerable<Task> mTasks;
        IEnumerator<Task> mEnumerator;
        Action mAction;
        public void Attach(IEnumerable<Task> tasks, Action a)
        {
            mAction = a;
            mTasks = tasks;
            mEnumerator = mTasks.GetEnumerator();
            mEnumerator.MoveNext();
        }
    }

    class MainClass
    {
        static IEnumerable<Task> DoLongThing(TaskContext context)
        {
            Console.WriteLine("Thread: " + Thread.CurrentThread.ManagedThreadId);

            var search = new WebClient().DownloadStringTask("http://koush.tandtgaming.com//test/search.txt");
            yield return search.Await(context);
            Console.WriteLine("Thread: " + Thread.CurrentThread.ManagedThreadId);

            var url = "http://www.google.com/search?q=" + search.Result;
            var google = new WebClient().DownloadStringTask(url);
            yield return google.Await(context);
            Console.WriteLine("Thread: " + Thread.CurrentThread.ManagedThreadId);
            Console.WriteLine(google.Result);

            yield break;
        }

        public static void Main(string[] args)
        {
            bool done = false;

            var search = new WebClient().DownloadStringTask("http://koush.tandtgaming.com//test/search.txt");
            Console.WriteLine(search.Result);

            TaskContext context = new TaskContext();
            context.Attach(DoLongThing(context), () => done = true);

            while (!done)
            {
                Thread.Sleep(1000);
            }
        }
    }
}