一个参数的默认值如何引用另一个参数?如果不能,如何解决?
case class A(val x:Int, val y:Int = x*2)
错误(足够合理):
scala> case class B(val x:Int, val y:Int = x*2)
<console>:7: error: not found: value x
case class B(val x:Int, val y:Int = x*2)
^