Family Day update

Task/Executable-library/Scala/executable-library.scala

@@ -1,19 +1,20 @@
 object HailstoneSequence extends App { // Show it all, default number is 27.
-  def hailstone(n: Int): Stream[Int] =
-       n #:: (if (n == 1) Stream.empty else hailstone(if (n % 2 == 0) n / 2 else n * 3 + 1))
+  def hailstone(n: Int): LazyList[Int] =
+    n #:: (if (n == 1) LazyList.empty else hailstone(if (n % 2 == 0) n / 2 else n * 3 + 1))
 
   Hailstone.details(args.headOption.map(_.toInt).getOrElse(27))
   HailTest.main(Array())
 }
 
 object Hailstone extends App { // Compute a given or default number to Hailstone sequence
-  def details(nr: Int) = {
+  def details(nr: Int): Unit = {
     val collatz = HailstoneSequence.hailstone(nr)
 
     println(s"Use the routine to show that the hailstone sequence for the number: $nr.")
     println(collatz.toList)
     println(s"It has ${collatz.length} elements.")
   }
+
   details(args.headOption.map(_.toInt).getOrElse(27))
 }