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

This works fine for me:

sealed abstract class Base { def copy(myparam: String): Base }

case class Foo(myparam:String) extends Base {
  override def copy(x: String = myparam) = Foo(x)
}

def copyBase(x: Base) = x.copy("changed")

copyBase(Foo("abc")) //Foo(changed)