From d5de65fdb1802cdf498d65d93397f290813c377c Mon Sep 17 00:00:00 2001 From: muqiuhan Date: Tue, 9 Sep 2025 06:17:00 +0000 Subject: deploy: 9665097f0fa0dae9f92123fac54d26c0818758a5 --- .../index.html" | 1 - 1 file changed, 1 deletion(-) (limited to '2025/03/13') diff --git "a/2025/03/13/\351\242\206\345\237\237\351\251\261\345\212\250\350\256\276\350\256\241\344\270\255\347\232\204\342\200\234\350\201\232\345\220\210\346\240\271\342\200\235/index.html" "b/2025/03/13/\351\242\206\345\237\237\351\251\261\345\212\250\350\256\276\350\256\241\344\270\255\347\232\204\342\200\234\350\201\232\345\220\210\346\240\271\342\200\235/index.html" index 35e8670e..4f96ab6d 100644 --- "a/2025/03/13/\351\242\206\345\237\237\351\251\261\345\212\250\350\256\276\350\256\241\344\270\255\347\232\204\342\200\234\350\201\232\345\220\210\346\240\271\342\200\235/index.html" +++ "b/2025/03/13/\351\242\206\345\237\237\351\251\261\345\212\250\350\256\276\350\256\241\344\270\255\347\232\204\342\200\234\350\201\232\345\220\210\346\240\271\342\200\235/index.html" @@ -207,7 +207,6 @@

用 F# 来描述，以订单管理为例，大概写一下：

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type OrderStatus = 
  | New
  | Shipped
  | Delivered
  | Cancelled

type OrderItem (productName: string, price: float, quantity: int) = 
  do
    if quantity <= 0 then
      failwith "Quantity must be positive"
  
  member public this.ProductName = productName
  member public this.Price = price
  member public this.Quantity = quantity
  member public this.TotalPrice () = price * quantity

type Order (id: int, customerName: string) = 
  let mutable status = OrderStatus.New
  let mutable orderItems = []

  member public this.Id = id
  member public this.CustomerName = customerName
  member public this.Status = status
  member public this.OrderItems = orderItems

  member public this.AddItem (item: OrderItem, price: float, quantity: int) =
    if quantity <= 0 then
      failwith "Quantity must be positive"
    
    orderItems <- orderItems @ [OrderItem(item.ProductName, price, quantity)]

  member public this.ChangeStatus (status: OrderStatus) =
    this.Status <- status

  member public this.TotalPrice () =
    orderItems |> List.sumBy (fun item -> item.TotalPrice())

  member public this.GetTotalPrice () =
    orderItems |> List.sumBy (fun item -> item.TotalPrice())
-

在这个例子中，Order 是聚合根，它通过 AddItem 方法来添加订单项，保证每个订单项符合业务规则。同时，聚合根 Order 还负责订单状态的管理，例如通过 ChangeStatus 方法来更新订单状态。OrderItem 是聚合内的一个实体，表示订单项，它通过 GetTotalPrice 方法来计算每个订单项的总价。外部系统只能通过 Order 聚合根来访问和操作订单项，而不能直接访问或修改 OrderItem

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