package router import "net/http" type ProtocolRouter map[string]http.Handler // Implement the ServeHTTP method on our new type func (hs ProtocolRouter) ServeHTTP(w http.ResponseWriter, r *http.Request) { if handler := hs[r.Host]; handler != nil { handler.ServeHTTP(w, r) } else { http.Error(w, "Forbidden", 403) // Or Redirect? } }