Chaining two functions () -> Task and A->Task

Answer 1

In case you are familiar with LINQ (and the Monad concept behind it), then below is a simple Task monad which will allow you to compose the Tasks.

Monad implementation:

public static class TaskMonad
    {
        public static Task ToTask(this T t)
        {
            return new Task(() => t);
        }

        public static Task SelectMany(this Task task, Func> f)
        {
            return new Task(() =>
            {
                task.Start();
                var t = task.Result;
                var ut = f(t);
                ut.Start();
                return ut.Result;
            });
        }

        public static Task SelectMany(this Task task, Func> f, Func c)
        {
            return new Task(() =>
            {
                task.Start();
                var t = task.Result;
                var ut = f(t);
                ut.Start();
                var utr = ut.Result;
                return c(t, utr);
            });            
        }
    }

Usage example:

        public static void Main(string[] arg)
        {
            var result = from a in getA()
                         from b in getB(a)
                         select b;
            result.Start();
            Console.Write(result.Result);
        }