$$ scala
Welcome to Scala version 2.9.0.final (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_22).
Type in expressions to have them evaluated.
Type :help for more information.

scala> def repeat(count: Int = 1, x: Boolean = true)(thunk: => Double) : Unit = (0 until count).foreach(_ => thunk)
repeat: (count: Int, x: Boolean)(thunk: => Double)Unit

scala> def repeat(thunk: => Double) : Unit = repeat()(thunk)
<console>:8: error: not enough arguments for method repeat: (thunk: => Double)Unit.
Unspecified value parameter thunk.
       def repeat(thunk: => Double) : Unit = repeat()(thunk)
                                                   ^

object Control {
  def repeat(count: Int = 1, x: Boolean = true)(thunk: => Double) : Unit = (0 until count).foreach(_ => thunk)
  def repeat(thunk: => Double) : Unit = repeat()(thunk)
}

scalac repeat.scala