Lenses, Scalaz and Scala

lenses.scala

val firstEventL = Lens.lensu[EventContainer, Event](
   (container, value) => container.copy(events = Seq(value) ++ container.events.tail), _.events.head)

val profileL = Lens.lensu[Event, Profile](
  (event, value) => event.copy(profile = value), _.profile)

val reservationL = Lens.lensu[Profile, Reservation](
  (profile, value) => profile.copy(reservation = value), _.reservation)

val settingAllProperties =
  firstEventL =>=
  { _.copy(eventTitle = "New Title") } andThen
  firstEventL >=> profileL =>=
  { _.copy(profileName = "New Profile Name") } andThen
  firstEventL >=> profileL >=> reservationL =>=
  {
    _.copy(
      reservationComments = "New Comments",
      spaceReservations = Seq(
        SpaceReservation(1111),
        SpaceReservation(2222)))
  } apply ec


val settingJustOneProperty = 
  firstEventL >=> profileL >=> reservationL =>=
  { _.copy(reservationComments = "New Comments") } apply ec