Add product and sum types

interfaces/serializable.js

@@ -0,0 +1,27 @@
+import { fnType } from "../type_registry.js";
+import {Type, Function} from "../metacircular.js";
+
+import {Bool, Int} from "./symbols.js";
+
+export const addInt = x => y => x + y;
+export const mulInt = x => y => x * y;
+export const eqInt  = x => y => x === y;
+
+const Int_to_Int  = fnType({in: Int, out: Int });
+const Int_to_Bool = fnType({in: Int, out: Bool});
+export const Int_to_Int_to_Int  = fnType({in: Int, out: Int_to_Int});
+export const Int_to_Int_to_Bool = fnType({in: Int, out: Int_to_Bool});
+
+
+export const ModuleInt = [
+  {i: Int                , t: Type               },
+
+  {i: Int_to_Int_to_Int  , t: Function           },
+  {i: Int_to_Int_to_Bool , t: Function           },
+  {i: Int_to_Int         , t: Function           },
+  {i: Int_to_Bool        , t: Function           },
+
+  {i: addInt             , t: Int_to_Int_to_Int  },
+  {i: mulInt             , t: Int_to_Int_to_Int  },
+  {i: eqInt              , t: Int_to_Int_to_Bool },
+];