Vectors Haskell and Scala

vector.hs

module Vector where

data Vector = Vector Int Int

add (Vector x0 y0) (Vector x1 y1) = Vector (x0+x1) (y0+y1)

inverse (Vector x0 y0) =  Vector (-x0) (-y0)

subtract v0 = add v0 . inverse
-- the above is equivalent to `subtract v0 v1 = add v0 (inverse v1)

vector.scala

object Vector { // This  is like a namespace
  case class Vector(x:Int, y:Int) {
    def add(r:Vector) = r match {
       case Vector(x1, y1) => Vector(x+x1, y+y1)
    }
    def inverse = Vector(-x, -y)
    def substract(r:Vector) = add(r.inverse)
  }
  
  def examples = {
    val topRight = Vector(1,1)
    val topLeft  = Vector(-1,1)
    assert(topRight.add(topLeft) == Vector(0,2))
  }
}