router/regex.go
func RegEx(path string) *regex {
	r, err := regexp.Compile(path)
	if err != nil {
		panic(err)
	}
	return &regex{
		r: r,
	}
}
func RegEx(path string) *regex {
	r, err := regexp.Compile(path)
	if err != nil {
		panic(err)
	}
	return &regex{
		r: r,
	}
}
// RegEx matches path using regular patterns.
// TODO Dumpping sub-patterns into url.Values.