Are Options and named default arguments like oil and water in a Scala API?

Question

I\'m working on a Scala API (for Twilio, by the way) where operations have a pretty large amount of parameters and many of these have sensible default values. To reduce typi

Answer 1

Don't auto-convert anything to an Option. Using my answer here, I think you can do this nicely but in a typesafe way.

sealed trait NumDigits { /* behaviour interface */ }
sealed trait FallbackUrl { /* behaviour interface */ }
case object NoNumDigits extends NumDigits { /* behaviour impl */ }
case object NofallbackUrl extends FallbackUrl { /* behaviour impl */ }

implicit def int2numd(i : Int) = new NumDigits { /* behaviour impl */ }
implicit def str2fallback(s : String) = new FallbackUrl { /* behaviour impl */ }

class Gather(finishOnKey: Char = '#', 
              numDigits: NumDigits = NoNumDigits, // Infinite
              fallbackUrl: FallbackUrl = NoFallbackUrl, 
              timeout: Int = 5

Then you can call it as you wanted to - obviously adding your behaviour methods to FallbackUrl and NumDigits as appropriate. The main negative here is that it is a ton of boilerplate

Gather(numDigits = 4, fallbackUrl = "http://wibble.org")