Scala functional programming gymnastics

Question

I am trying to do the following in as little code as possible and as functionally as possible:

def restrict(floor : Option[Double], cap : Option[Double], amt : D         


        

Answer 1

Straightforward solution with plain Scala and anonymous lambda, without any mappings, folds, Double.{Min/Max}Value, and so on:

def restrict(floor : Option[Double], cap : Option[Double], amt : Double) : Double =
  ((x:Double) => x min cap.getOrElse(x))(amt max floor.getOrElse(amt))