Pattern Matching Beverages

  abstract class Dickmacher
  case class Beverage (name: String, cal: Int) extends Dickmacher
  case class Food (name: String, cal: Int) extends Dickmacher
  case class Meal (name: String, food: Food, drink: Beverage) extends Dickmacher
  case class Combo (starter: Dickmacher, main: Dickmacher) extends Dickmacher

  def countBeverages(food: Dickmacher) : Int = food match {
    case Beverage(_, x) => 1
    case Food(_, x) => 0
    case Meal(_, x, y) => 0
    case Combo(a: Food, b) => 0 + countBeverages(b)
    case Combo(a: Beverage, b) => 1 + countBeverages(b)
    case Combo(a: Meal, b) => 0 + countBeverages(b)
    case Combo(a: Combo, b) => 0 + countBeverages(b)
    case _ => throw new AssertionError();
  }
  
  val coke = Beverage("Cola Light", 50)
  val burger = Food("Big Mac", 400)
  
  
  val cokeLight = Beverage("Cola", 100)
  val wannaBeBurger = Food("Veggie Mac", 50)
  

  val cokeCombo = Combo(coke, cokeLight)
  println(countBeverages(cokeCombo))
  
  
  val burgerCombo = Combo(burger, wannaBeBurger)
  println(countBeverages(burgerCombo))
  
  
  val monsterCombo = Combo(Combo(burgerCombo, cokeCombo), Food("Nachspeise", 600));
  println(countBeverages(monsterCombo))