code: func routeToPage(c *router.Context) error {
  	path := c.Params.ByName("path")
  	switch chunks := strings.SplitN(path, "/+/", 2); {
  	case len(chunks) <= 1: // no '/+/' in path => prefix listing page
  		return prefixListingPage(c, path)
  	case len(chunks) == 2 && chunks[1] == "": // ends with '/+/' => package page
  		return packagePage(c, chunks[0])
  	case len(chunks) == 2: // has something after '/+/' => instance page
  		return instancePage(c, chunks[0], chunks[1])
  	default:
  		return status.Errorf(codes.InvalidArgument, "malformed page URL")
  	}
  }
docs: // routeToPage routes to an appropriate page depending on the request URL.