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Question

有没有一种更简单的方法来使用F＃初始化这副牌？

let create() = [ 0..12 ]

type Suit = 
    | Spades of list<int>
    | Hearts of list<int>
    | Clubs of list<int>
    | Diamonds of list<int>

let spades = create() |> Spades
let hearts = create() |> Hearts
let clubs = create() |> Clubs
let diamonds = create() |> Diamonds

具体来说，我想简化这四种套装的初始化。有更简单的方法吗？

我可以列举这个有区别的联盟的类型并将其分配给某些“套牌”结构吗？

注：

我是F＃的新手。如果这个问题似乎无知，请原谅我。

Answer 1

我认为没有更简洁的方式，但我也不会模仿这样的扑克牌，因为它无法帮助使非法国家无法代表。举个例子，我可以这样做：

> Spades [-1; 10; 100];;
val it : Suit = Spades [-1; 10; 100]

这甚至意味着什么？

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相反，我可能会对这样的卡片进行建模：

type Suit = Diamonds | Hearts | Clubs | Spades
type Face =
    | Two | Three | Four | Five | Six | Seven | Eight | Nine | Ten
    | Jack | Queen | King | Ace

type Card = { Suit: Suit; Face: Face }

这样您就可以表达任何有效的卡：

> { Suit = Spades; Face = Ace };;
val it : Card = {Suit = Spades;
                 Face = Ace;}

另一方面，你无法表达invalid张卡片：

> { Suit = Spades; Face = Hundred };;

  { Suit = Spades; Face = Hundred };;
  ------------------------^^^^^^^

stdin(4,25): error FS0039: The value or constructor 'Hundred' is not defined

初始化在这个模型中看起来有点麻烦，但另一方面，下面的deck是一个不可变的值，所以一旦定义了，你就可以重新使用它了再一次。

let deck = [
    { Suit = Diamonds; Face = Two   };
    { Suit = Diamonds; Face = Three };
    { Suit = Diamonds; Face = Four  };
    { Suit = Diamonds; Face = Five  };
    { Suit = Diamonds; Face = Six   };
    { Suit = Diamonds; Face = Seven };
    { Suit = Diamonds; Face = Eight };
    { Suit = Diamonds; Face = Nine  };
    { Suit = Diamonds; Face = Ten   };
    { Suit = Diamonds; Face = Jack  };
    { Suit = Diamonds; Face = Queen };
    { Suit = Diamonds; Face = King  };
    { Suit = Diamonds; Face = Ace   };
    { Suit = Hearts;   Face = Two   };
    { Suit = Hearts;   Face = Three };
    { Suit = Hearts;   Face = Four  };
    { Suit = Hearts;   Face = Five  };
    { Suit = Hearts;   Face = Six   };
    { Suit = Hearts;   Face = Seven };
    { Suit = Hearts;   Face = Eight };
    { Suit = Hearts;   Face = Nine  };
    { Suit = Hearts;   Face = Ten   };
    { Suit = Hearts;   Face = Jack  };
    { Suit = Hearts;   Face = Queen };
    { Suit = Hearts;   Face = King  };
    { Suit = Hearts;   Face = Ace   };
    { Suit = Clubs;    Face = Two   };
    { Suit = Clubs;    Face = Three };
    { Suit = Clubs;    Face = Four  };
    { Suit = Clubs;    Face = Five  };
    { Suit = Clubs;    Face = Six   };
    { Suit = Clubs;    Face = Seven };
    { Suit = Clubs;    Face = Eight };
    { Suit = Clubs;    Face = Nine  };
    { Suit = Clubs;    Face = Ten   };
    { Suit = Clubs;    Face = Jack  };
    { Suit = Clubs;    Face = Queen };
    { Suit = Clubs;    Face = King  };
    { Suit = Clubs;    Face = Ace   };
    { Suit = Spades;   Face = Two   };
    { Suit = Spades;   Face = Three };
    { Suit = Spades;   Face = Four  };
    { Suit = Spades;   Face = Five  };
    { Suit = Spades;   Face = Six   };
    { Suit = Spades;   Face = Seven };
    { Suit = Spades;   Face = Eight };
    { Suit = Spades;   Face = Nine  };
    { Suit = Spades;   Face = Ten   };
    { Suit = Spades;   Face = Jack  };
    { Suit = Spades;   Face = Queen };
    { Suit = Spades;   Face = King  };
    { Suit = Spades;   Face = Ace   }; ]

虽然这看起来很乏味，但你只需写一次。由于deck是一个值，因此您可以将其设为属于模块的值。客户可以简单地使用这个值，而不必自己初始化一个套牌。

区分联盟初始化

1 个答案:

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