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def combinations[T](k: Int, list: List[T]) : List[List[T]] = {
     |   list match {
     |     case Nil => Nil
     |     case head :: xs =>
     |       if (k <= 0 || k > list.length) {
     |         Nil
     |       } else if (k == 1) {
     |         list.map(List(_))
     |       } else {
     |         combinations(k-1, xs).map(head :: _) ::: combinations(k, xs)
     |       }
     |   }
     | }
combinations: [T](Int,List[T])List[List[T]]
 
scala> case class S99Int(val i: Int) {
     |
     |   def isPrime : Boolean = {
     |     if (i <= 1) false
     |     else if (i == 2) true
     |     else !(2 to (i-1)).exists(x => i % x == 0)
     |   }
     |
     |   def goldbach : Option[List[Int]] = {
     |     val primes = (3 to i).filter(x => S99Int(x).isPrime).toList
     |     combinations(2, primes).find(_.foldLeft(0)((a,b) => a+b) == i)
     |   }
     |
     | }
defined class S99Int
 
scala> implicit def i2S99(i: Int) : S99Int = new S99Int(i)
i2S99: (Int)S99Int
 
scala> def printGoldbachListLimited(r: Range, lowerBound: Int) = {
     |   r.foreach(i => i.goldbach match {
     |     case Some(List(a,b)) if a > lowerBound => println("%d = %d + %d".format(i,a,b))
     |     case _ =>
     |   })
     | }
printGoldbachListLimited: (Range,Int)Unit
 
scala> def printGoldbachList(r: Range) = {
     |   printGoldbachListLimited(r, 0)
     | }
printGoldbachList: (Range)Unit

Main.scala:1: error: expected class or object definition
def combinations[T](k: Int, list: List[T]) : List[List[T]] = {
^
Main.scala:14: error: expected class or object definition
combinations: [T](Int,List[T])List[List[T]]
^
Main.scala:16: error: expected class or object definition
scala> case class S99Int(val i: Int) {
^
Main.scala:30: error: expected class or object definition
defined class S99Int
^
Main.scala:32: error: expected class or object definition
scala> implicit def i2S99(i: Int) : S99Int = new S99Int(i)
^
Main.scala:33: error: expected class or object definition
i2S99: (Int)S99Int
^
Main.scala:35: error: expected class or object definition
scala> def printGoldbachListLimited(r: Range, lowerBound: Int) = {
^
Main.scala:41: error: expected class or object definition
printGoldbachListLimited: (Range,Int)Unit
^
Main.scala:43: error: expected class or object definition
scala> def printGoldbachList(r: Range) = {
^
Main.scala:46: error: expected class or object definition
printGoldbachList: (Range)Unit
^
10 errors found

Standard output is empty