overhaul the coroutine system to avoid boxing

Coroutine/ActiveCoroutine.cs

@@ -4,12 +4,14 @@ using System.Collections.Generic;
 namespace Coroutine {
     public class ActiveCoroutine {
 
-        private readonly IEnumerator<IWait> enumerator;
+        private readonly IEnumerator<Wait> enumerator;
+        private Wait current;
+
         public bool IsFinished { get; private set; }
         public bool WasCanceled { get; private set; }
         public FinishCallback OnFinished;
 
-        internal ActiveCoroutine(IEnumerator<IWait> enumerator) {
+        internal ActiveCoroutine(IEnumerator<Wait> enumerator) {
             this.enumerator = enumerator;
         }
 
@@ -24,8 +26,7 @@ namespace Coroutine {
 
         internal bool Tick(double deltaSeconds) {
             if (!this.WasCanceled) {
-                var curr = this.enumerator.Current;
-                if (curr != null && curr.Tick(deltaSeconds))
+                if (this.current.Tick(deltaSeconds))
                     this.MoveNext();
             }
             return this.IsFinished;
@@ -33,22 +34,24 @@ namespace Coroutine {
 
         internal bool OnEvent(Event evt) {
             if (!this.WasCanceled) {
-                var curr = this.enumerator.Current;
-                if (curr != null && curr.OnEvent(evt))
+                if (this.current.OnEvent(evt))
                     this.MoveNext();
             }
             return this.IsFinished;
         }
 
-        private void MoveNext() {
+        internal bool MoveNext() {
             if (!this.enumerator.MoveNext()) {
                 this.IsFinished = true;
                 this.OnFinished?.Invoke(this);
+                return false;
             }
+            this.current = this.enumerator.Current;
+            return true;
         }
 
-        internal WaitType GetCurrentType() {
-            return this.enumerator.Current.GetWaitType();
+        internal bool IsWaitingForEvent() {
+            return this.current.IsWaitingForEvent();
         }
 
         public delegate void FinishCallback(ActiveCoroutine coroutine);

Coroutine/CoroutineHandler.cs

@@ -8,19 +8,23 @@ namespace Coroutine {
         private static readonly List<ActiveCoroutine> TickingCoroutines = new List<ActiveCoroutine>();
         private static readonly List<ActiveCoroutine> EventCoroutines = new List<ActiveCoroutine>();
 
-        public static ActiveCoroutine Start(IEnumerator<IWait> coroutine) {
-            if (!coroutine.MoveNext())
-                return null;
+        public static ActiveCoroutine Start(IEnumerable<Wait> coroutine) {
+            return Start(coroutine.GetEnumerator());
+        }
+
+        public static ActiveCoroutine Start(IEnumerator<Wait> coroutine) {
             var inst = new ActiveCoroutine(coroutine);
-            var type = inst.GetCurrentType();
-            if (type == WaitType.Tick)
-                TickingCoroutines.Add(inst);
-            else if (type == WaitType.Event)
-                EventCoroutines.Add(inst);
+            if (inst.MoveNext()) {
+                if (inst.IsWaitingForEvent()) {
+                    EventCoroutines.Add(inst);
+                } else {
+                    TickingCoroutines.Add(inst);
+                }
+            }
             return inst;
         }
 
-        public static void InvokeLater(IWait wait, Action action) {
+        public static void InvokeLater(Wait wait, Action action) {
             Start(InvokeLaterImpl(wait, action));
         }
 
@@ -29,7 +33,7 @@ namespace Coroutine {
                 var coroutine = TickingCoroutines[i];
                 if (coroutine.Tick(deltaSeconds)) {
                     TickingCoroutines.RemoveAt(i);
-                } else if (coroutine.GetCurrentType() != WaitType.Tick) {
+                } else if (coroutine.IsWaitingForEvent()) {
                     TickingCoroutines.RemoveAt(i);
                     EventCoroutines.Add(coroutine);
                 }
@@ -41,7 +45,7 @@ namespace Coroutine {
                 var coroutine = EventCoroutines[i];
                 if (coroutine.OnEvent(evt)) {
                     EventCoroutines.RemoveAt(i);
-                } else if (coroutine.GetCurrentType() != WaitType.Event) {
+                } else if (!coroutine.IsWaitingForEvent()) {
                     EventCoroutines.RemoveAt(i);
                     TickingCoroutines.Add(coroutine);
                 }
@@ -52,7 +56,7 @@ namespace Coroutine {
             return TickingCoroutines.Concat(EventCoroutines);
         }
 
-        private static IEnumerator<IWait> InvokeLaterImpl(IWait wait, Action action) {
+        private static IEnumerator<Wait> InvokeLaterImpl(Wait wait, Action action) {
             yield return wait;
             action();
         }

Coroutine/IWait.cs

@@ -1,18 +0,0 @@
-namespace Coroutine {
-    public interface IWait {
-
-        WaitType GetWaitType();
-
-        bool Tick(double deltaSeconds);
-
-        bool OnEvent(Event evt);
-
-    }
-
-    public enum WaitType {
-
-        Tick,
-        Event
-
-    }
-}

Coroutine/Wait.cs

@@ -0,0 +1,36 @@
+using System;
+
+namespace Coroutine {
+    public struct Wait {
+
+        private readonly Event evt;
+        private double seconds;
+
+        public Wait(Event evt) {
+            this.evt = evt;
+            this.seconds = 0;
+        }
+
+        public Wait(double seconds) {
+            this.seconds = seconds;
+            this.evt = null;
+        }
+
+        public Wait(TimeSpan time) : this(time.TotalSeconds) {
+        }
+
+        internal bool Tick(double deltaSeconds) {
+            this.seconds -= deltaSeconds;
+            return this.seconds <= 0;
+        }
+
+        internal bool OnEvent(Event evt) {
+            return evt == this.evt;
+        }
+
+        internal bool IsWaitingForEvent() {
+            return this.evt != null;
+        }
+
+    }
+}

Coroutine/WaitEvent.cs

@@ -1,25 +0,0 @@
-using System;
-
-namespace Coroutine {
-    public struct WaitEvent : IWait {
-
-        private readonly Event evt;
-
-        public WaitEvent(Event evt) {
-            this.evt = evt;
-        }
-
-        public WaitType GetWaitType() {
-            return WaitType.Event;
-        }
-
-        public bool Tick(double deltaSeconds) {
-            throw new NotSupportedException();
-        }
-
-        public bool OnEvent(Event evt) {
-            return evt == this.evt;
-        }
-
-    }
-}

Coroutine/WaitSeconds.cs

@@ -1,26 +0,0 @@
-using System;
-
-namespace Coroutine {
-    public struct WaitSeconds : IWait {
-
-        private double seconds;
-
-        public WaitSeconds(double seconds) {
-            this.seconds = seconds;
-        }
-
-        public WaitType GetWaitType() {
-            return WaitType.Tick;
-        }
-
-        public bool Tick(double deltaSeconds) {
-            this.seconds -= deltaSeconds;
-            return this.seconds <= 0;
-        }
-
-        public bool OnEvent(Event evt) {
-            throw new NotSupportedException();
-        }
-
-    }
-}

Test/Example.cs

@@ -14,11 +14,11 @@ namespace Test {
 
             CoroutineHandler.Start(EmptyCoroutine());
 
-            CoroutineHandler.InvokeLater(new WaitSeconds(10), () => {
+            CoroutineHandler.InvokeLater(new Wait(10), () => {
                 Console.WriteLine("Raising test event");
                 CoroutineHandler.RaiseEvent(TestEvent);
             });
-            CoroutineHandler.InvokeLater(new WaitEvent(TestEvent), () => Console.WriteLine("Test event received"));
+            CoroutineHandler.InvokeLater(new Wait(TestEvent), () => Console.WriteLine("Test event received"));
 
             var lastTime = DateTime.Now;
             while (true) {
@@ -29,24 +29,24 @@ namespace Test {
             }
         }
 
-        private static IEnumerator<IWait> WaitSeconds() {
+        private static IEnumerator<Wait> WaitSeconds() {
             Console.WriteLine("First thing " + DateTime.Now);
-            yield return new WaitSeconds(1);
+            yield return new Wait(1);
             Console.WriteLine("After 1 second " + DateTime.Now);
-            yield return new WaitSeconds(9);
+            yield return new Wait(9);
             Console.WriteLine("After 10 seconds " + DateTime.Now);
-            yield return new WaitSeconds(5);
+            yield return new Wait(5);
             Console.WriteLine("After 5 more seconds " + DateTime.Now);
-            yield return new WaitSeconds(10);
+            yield return new Wait(10);
             Console.WriteLine("After 10 more seconds " + DateTime.Now);
 
-            yield return new WaitSeconds(20);
+            yield return new Wait(20);
             Console.WriteLine("First coroutine done");
         }
 
-        private static IEnumerator<IWait> PrintEvery10Seconds(ActiveCoroutine first) {
+        private static IEnumerator<Wait> PrintEvery10Seconds(ActiveCoroutine first) {
             while (true) {
-                yield return new WaitSeconds(10);
+                yield return new Wait(10);
                 Console.WriteLine("The time is " + DateTime.Now);
                 if (first.IsFinished) {
                     Console.WriteLine("By the way, the first coroutine has finished!");
@@ -55,7 +55,7 @@ namespace Test {
             }
         }
 
-        private static IEnumerator<IWait> EmptyCoroutine() {
+        private static IEnumerator<Wait> EmptyCoroutine() {
             yield break;
         }