Scala example source code file (bug960.scala)

This example Scala source code file (bug960.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

cons, cons, list, list, nil, nil, none, none, option, some

The Scala bug960.scala source code

sealed abstract class List[+a]
private case object Nil extends List[Nothing]
private final case class Cons[+a](head: a, tail: List[a])
extends List[a]

object List {
  def unapply[a](xs: List[a]): Option[(a, List[a])] = xs match {
    case Nil => None
    case Cons(x, xs) => Some(x, xs)
  }

  def unapply[a](xs: List[a]): Option[Null] = xs match {
    case Nil => Some(null)
    case Cons(_, _) => None
  }

  def foo[a](xs: List[a])  = xs match {
    case List(x, xs) => 7
  }
}