Binder.scala

object Binder{
  implicit def navigationPathBindable(implicit longBinder: PathBindable[Long]) = new PathBindable[Navigation] {
  
      def bind(key: String, value: String): Either[String, Navigation] = {
          for{
              id <- longBinder.bind(key, value).right
              nav <- Navigation.getNavigation(id).toRight("Navigation not found").right
          } yield nav
      }
  
      def unbind(key: String, nav: Navigation): String = {
          longBinder.unbind(key, nav.id)
      }
  
  }
}

GenBinder.scala

object Binder{
    trait EnumBinder[A,B](implicit binder: PathBindable[B]) = new PathBindable[A] {

        def bind(key: String, value: String): Either[String, A] = {
            for{
                id <- binder.bind(key, value).right
                nav <- // TODO
            } yield nav
        }

        def unbind(key: String, nav: A): String = {
            longBinder.unbind(key, binder.unbind( //TODO ))
        }
    }

    implicit object totoBinder extends EnumBinder[Toto, Long]
}