Sequence Pattern : Example...

scala> ////////////////////////////////////////////////////////////////

scala> //  All Reference Classes in Scala extends AnyRef

scala> ////////////////////////////////////////////////////////////////

scala> def patternFn(x: AnyRef): Unit = x match { //#315
     |     case List(1, _) => println("This is ; List(1, _)")
     |
     |     // Variable Binding : @ is used to bind a Variable #320
     |     case x @ List(2, _) => println("This is. -> " + x)
     |
     |     // _* represents : Can be any no of elements
     |     case List(3, _*) => println("This is .. -> " + x)
     | }
patternFn: (x: AnyRef)Unit

scala>

scala> patternFn(List(1, 2))
This is ; List(1, _)

scala> patternFn(List(2, 3))
This is. -> List(2, 3)

scala> patternFn(List(2, 3, 4, 5))
scala.MatchError: List(2, 3, 4, 5) (of class scala.collection.immutable.$colon$colon)
  at patternFn(<console>:23)
  ... 48 elided

scala> patternFn(List(3, 4, 5, 6, 7))
This is .. -> List(3, 4, 5, 6, 7)