Update examples

testsuite/dynload/poly/api/API.hs

@@ -0,0 +1,24 @@
+{-# OPTIONS -cpp #-}
+
+module API where
+
+import AltData.Typeable
+
+data Interface = Interface { 
+        equals :: forall t. Eq t => t -> t -> Bool
+     }
+
+--
+-- see how it hides the internal type.. but to compile GHC still checks
+-- the type.
+--
+instance Typeable Interface where
+#if __GLASGOW_HASKELL__ >= 603
+    typeOf i = mkTyConApp (mkTyCon "API.Interface") []
+#else
+    typeOf i = mkAppTy (mkTyCon "API.Interface") []
+#endif
+
+plugin :: Interface
+plugin = Interface  { equals = (==) }
+