case class copy 'method' with superclass

Question

I want to do something like this:

sealed abstract class Base(val myparam:String)

case class Foo(override val mypar         


        

Answer 1

Its an old problem, with an old solution,

https://code.google.com/p/scala-scales/wiki/VirtualConstructorPreSIP

made before the case class copy method existed.

So in reference to this problem each case class MUST be a leaf node anyway, so define the copy and a MyType / thisType plus the newThis function and you are set, each case class fixes the type. If you want to widen the tree/newThis function and use default parameters you'll have to change the name.

as an aside - I've been waiting for compiler plugin magic to improve before implementing this but type macros may be the magic juice. Search in the lists for Kevin's AutoProxy for a more detailed explanation of why my code never went anywhere