scala扩展Stack不起作用

Question

这有效

class Deck {
  var cards : Stack[Card] = new Stack[Card]
  for (card <- Card.possibleCards.keySet; suit <- Card.suits) {
    cards.push(new Card(card, suit))
  }
}

但这不是

class Deck[Card] extends Stack[Card] {
  for (card <- Card.possibleCards.keySet; suit <- Card.suits) {
    push(new Card(card, suit))
  }
}

我收到此错误：

error: class type required but Card found

有人可以告诉我为什么吗？

Answer 1

这只是一个语法错误，我需要从Deck中删除类声明卡。 像这样

class Deck extends Stack[Card] {
  for (card <- Card.possibleCards.keySet; suit <- Card.suits) {
    push(new Card(card, suit))
  }
}