// one more implicit example ...
// http://scala.sygneca.com/patterns/pimp-my-library

class ListExtensions[A](xs : List[A]) {
    def headOr(f : => A) : A = xs match {
        case h :: _ => h
        case Nil    => f
    }
}

implicit def listExtensions[A](xs : List[A]) = new ListExtensions(xs)

// println(List(1,2,3).headOr(0))     ==> 1
// println(Nil.headOr(0))             ==> 0