add gohttp/app and http.HandlerFunc support

examples/main.go

@@ -11,10 +11,21 @@ func main() {
 
 	a.Use(logger.New())
 	a.Use(mount.New("/examples", serve.New("examples")))
-
-	a.Get("/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Write([]byte("hello"))
-	}))
+	a.Use(mount.New("/blog", blog()))
+	a.Use(mount.New("/hello", hello))
+	a.Get("/", http.HandlerFunc(hello))
 
 	a.Listen(":3000")
 }
+
+func blog() *app.App {
+	app := app.New()
+	app.Get("", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("posts\n"))
+	})
+	return app
+}
+
+func hello(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("hello\n"))
+}

mount.go

@@ -7,7 +7,8 @@ import "strings"
 type Constructor func(http.Handler) http.Handler
 
 // New mount middleware.
-func New(prefix string, mw Constructor) func(http.Handler) http.Handler {
+func New(prefix string, i interface{}) func(http.Handler) http.Handler {
+	mw := middleware(i)
 	return func(h http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			original := r.URL.Path
@@ -22,3 +23,23 @@ func New(prefix string, mw Constructor) func(http.Handler) http.Handler {
 		})
 	}
 }
+
+// Coerce into middleware.
+func middleware(h interface{}) func(http.Handler) http.Handler {
+	switch h.(type) {
+	case func(w http.ResponseWriter, r *http.Request):
+		h := http.HandlerFunc(h.(func(w http.ResponseWriter, r *http.Request)))
+		return func(_ http.Handler) http.Handler {
+			return http.HandlerFunc(h)
+		}
+	case http.Handler:
+		h := h.(http.Handler)
+		return func(_ http.Handler) http.Handler {
+			return h
+		}
+	case func(h http.Handler) http.Handler:
+		return h.(func(h http.Handler) http.Handler)
+	default:
+		panic("invalid middleware")
+	}
+}