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在Fsharp应用程序中,我已将几个联合案例类型定义为

type A = A of String
type B = B of String
type C = C of String

我想定义一个函数来从union case实例中提取值.

let getValue( ctor: String-> 'a) = 
   ...implementation here

反正有没有完成这样的任务？谢谢.

有没有办法通过F#中的案例标识符比较受歧视的联盟？

type MyUnion =
| MyString of string
| MyInt of int

let x = MyString("hello")
let y = MyString("bye")
let z = MyInt(25)

let compareCases a b =
// compareCases x y = true
// compareCases x z = false
// compareCases y z = false

如何compareCases以通用方式实现功能？

即如下所示,但更通用(反射是可以的):

let compareCases a b =
  match a with
  | MyString(_) -> match b with | MyString(_) -> true | _ -> false
  | MyInt(_) -> match b with | …

在下面的真实世界的例子中我做了一个匹配:

type Style = Nice | Cool | Ugly
type Color = Blue | Yellow | Orange | Grey | Cyan
type ClothingProperties = Style * Color

type Clothes =
| Jeans of ClothingProperties
| Pullover of ClothingProperties
| Shirt of ClothingProperties

type Person =
| Person of string * Clothes

let team = [Person("Jan", Jeans (Cool, Blue)); Person("Pete", Shirt (Nice, Cyan)); Person("Harry", Pullover (Ugly, Grey))]

let matchPerson person=
    match person with
    | Person(name,  Jeans(Ugly,_) ) -> printfn "%s wears …