another scala

gistfile1.scala

class Person(var firstName: String, var lastName: String, var address: Address) {
	def this() = this(null, null, null)
}
class Address(var city: String, var street: String) {
	def this() = this(null, null)
}
val persons = getAListSomewhere();
val filtered = for { p <- persons if p.address.city == "Kyiv"} yield p
val adresses = (for { p <- persons } yield p.address).toSet
val filteredAdresses = (for { p <- persons if p.address.city == "Kyiv" } yield p.address).toSet