directors.scala

  case class Director(firstName: String, lastName: String, yearOfBirth: Int)

  case class Film(title: String, yearOfRelease: Int, imdbRating: Double, director: Director)

  val eastwood = new Director("Clint", "Eastwood", 1930)
  val mcTiernan = new Director("John", "McTiernan", 1951)
  val nolan = new Director("Christopher", "Nolan", 1970)
  val someBody = new Director("Just", "Some Body", 1990)

  val memento = new Film("Memento", 2000, 8.5, nolan)
  val darkKnight = new Film("Dark Knight", 2008, 9.0, nolan)
  val inception = new Film("Inception", 2010, 8.8, nolan)

  val highPlainsDrifter = new Film("High Plains Drifter", 1973, 7.7, eastwood)
  val outlawJoseyWales = new Film("The Outlaw Josey Wales", 1976, 7.9, eastwood)
  val unforgiven = new Film("Unforgiven", 1992, 8.3, eastwood)
  val granTorino = new Film("Gran Torino", 2008, 8.2, eastwood)
  val invictus = new Film("Invictus", 2009, 7.4, eastwood)

  val predator = new Film("Predator", 1987, 7.9, mcTiernan)
  val dieHard = new Film("Die Hard", 1988, 8.3, mcTiernan)
  val huntForRedOctober = new Film("The Hunt for Red October", 1990, 7.6, mcTiernan)
  val thomasCrownAffair = new Film("The Thomas Crown Affair", 1999, 6.8, mcTiernan)

 	val films = Seq(memento, darkKnight, inception, 
 	  highPlainsDrifter, outlawJoseyWales, unforgiven, granTorino, invictus,
 	  predator, dieHard, huntForRedOctober, thomasCrownAffair)

films.scala

case class Film(
  name: String,
  yearOfRelease: Int,
  imdbRating: Double)

case class Director(
  firstName: String,
  lastName: String,
  yearOfBirth: Int,
  films: Seq[Film])

val memento           = new Film("Memento", 2000, 8.5)
val darkKnight        = new Film("Dark Knight", 2008, 9.0)
val inception         = new Film("Inception", 2010, 8.8)

val highPlainsDrifter = new Film("High Plains Drifter", 1973, 7.7)
val outlawJoseyWales  = new Film("The Outlaw Josey Wales", 1976, 7.9)
val unforgiven        = new Film("Unforgiven", 1992, 8.3)
val granTorino        = new Film("Gran Torino", 2008, 8.2)
val invictus          = new Film("Invictus", 2009, 7.4)

val predator          = new Film("Predator", 1987, 7.9)
val dieHard           = new Film("Die Hard", 1988, 8.3)
val huntForRedOctober = new Film("The Hunt for Red October", 1990, 7.6)
val thomasCrownAffair = new Film("The Thomas Crown Affair", 1999, 6.8)

val eastwood = new Director("Clint", "Eastwood", 1930,
  Seq(highPlainsDrifter, outlawJoseyWales, unforgiven, granTorino, invictus))

val mcTiernan = new Director("John", "McTiernan", 1951,
  Seq(predator, dieHard, huntForRedOctober, thomasCrownAffair))

val nolan = new Director("Christopher", "Nolan", 1970,
  Seq(memento, darkKnight, inception))

val someGuy = new Director("Just", "Some Guy", 1990,
  Seq())

val directors = Seq(eastwood, mcTiernan, nolan, someGuy)