def visitorDesignPattern[A, B](assoc: List[(A, B)], fallThrough: => B) = (a: A) => assoc find (a==_) map (_._2) getOrElse fallThrough
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
def visitorDesignPattern[A, B](assoc: List[(A, B)], fallThrough: => B) = (a: A) => assoc find (a==_) map (_._2) getOrElse fallThrough
