KeyedLens example

BandData.scala

case class Person(name: String)

case class Guitar(strings: Int, tuning: String, gauges: List[Double])

case class Band(name: String,
                members: Map[Person, Guitar],
                otherPeopleWhoSupportTheGuitarists: Set[Person]) // Just ask Yngwie

// Sample data

val acle = Person("Acle")
val james = Person("James")

val gauge6 = List(0.010, 0.013, 0.017, 0.026, 0.036, 0.046)
val gauge7 = List(0.011, 0.014, 0.018, 0.028, 0.038, 0.049, 0.059)

val band = Band("Tesseract"
             , Map(  acle -> Guitar(7, "BEADGBE", gauge7),
                    james -> Guitar(6, "EADGBE", gauge6))
             , Set(Person("Jay"), Person("Amos"), Person("Ashe")))