New awaiters

Esyur/Core/AsyncAwaiterGeneric.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Esyur.Core
+{
+    public class AsyncAwaiter<T> : INotifyCompletion
+    {
+        Action callback = null;
+
+        AsyncException exception = null;
+
+        T result;
+
+        public AsyncAwaiter(AsyncReply<T> reply)
+        {
+            reply.Then(x =>
+            {
+                this.IsCompleted = true;
+                this.result = (T)x;
+                this.callback?.Invoke();
+            }).Error(x =>
+            {
+                exception = x;
+                this.IsCompleted = true;
+                this.callback?.Invoke();
+            });
+        }
+
+        public T GetResult()
+        {
+            if (exception != null)
+                throw exception;
+            return result;
+        }
+
+        public bool IsCompleted { get; private set; }
+
+        public void OnCompleted(Action continuation)
+        {
+            if (IsCompleted)
+                continuation?.Invoke();
+            else
+                // Continue....
+                callback = continuation;
+        }
+
+
+    }
+}
+