Question

这是F＃中抽象成员的典型声明：

abstract member createEmployee : string -> string -> Employee

您可以定义参数类型，但不能定义它们的名称。没有名称，在实现接口时如何判断每个参数是什么？换句话说，您如何知道界面是否希望实现为1-或2 - ？

1-   member this.createEmployee firstName lastName = ...
2-   member this.createEmployee lastName firstName = ...

我是从错误的角度看待问题（习惯于C＃）？

Answer 1

怎么样：

abstract member createEmployee : firstName:string -> lastName:string -> Employee

Answer 2

这种语法非常适合IMO。我想用参数作为元组（比如C＃方法）来做这个，并且只有通过反复试验我才发现这个有效：

    abstract member PutChar : x:int * y:int * c:char * flag:Background -> unit

这个丑陋的变体也有效：

    abstract member PutChar : x : int * y : int * c : char * flag : Background -> unit

以下是所有感觉合理但却因同样错误而失败的事情 - Unexpected symbol ':' in member definition.：

    // ALL BAD vvv
    abstract member PutChar : (x:int * y:int * c:char * flag:Background) -> unit
    abstract member PutChar : (x:int, y:int, c:char, flag:Background) -> unit
    abstract member PutChar : (x:int) * (y:int) * (c:char) * (flag:Background) -> unit
    // ALL BAD ^^^

抽象声明中没有参数名称？

2 个答案: