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

I find that when a question asks to use an Option to indicate an optional parameter, there's usually a more natural way to represent the missing parameter. So I'm going to change the interface a little here, and use default arguments to define the function and named parameters to call the function.

def restrict(amt:Double,
            floor:Double = Double.NegativeInfinity,
            cap:Double=Double.PositiveInfinity):Double =
    (amt min cap) max floor

Then you can call:

restrict(6)
restrict(6, floor = 7)
restrict(6, cap = 5)

(Another example of the same principle.)