router.go

// Router implements http router.
type Router struct {
	//...
}

// RegisterHandler registers handler to the router.
func (router *Router) RegisterHandler(method, path string, handler http.HandlerFunc) {

}

// Handler returns handler mapped to method and path.
func (router *Router) Handler(method, path string) http.HandlerFunc {

}

// ServeHTTP implements the interface http.Handler.
func (router *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {

}

func main() {
	handler := func(w http.ResponseWriter, req *http.Request) {
		fmt.Fprint(w, "hello world")
	}
	router := &Router{}
	router.RegisterHandler("GET", "/", handler)

	http.ListenAndServe(":8080", router)
}