.net - 如何在 F# 中使用其他方法创建接口

Question

我正在尝试在 IEvent 之上创建一个需要其他方法的接口，如下所示：

type Varying<'t> = 
    abstract member Get : unit -> 't
    abstract member Set : 't -> unit
    abstract member AddHandler : Handler<'t> -> unit
    abstract member RemoveHandler : Handler<'t> -> unit
    member v.Add(f) = v.AddHandler(new Handler<_>(fun _ x -> f x))
    interface IEvent<'t> with
        member c.AddHandler(h) = c.AddHandler(h)
        member c.RemoveHandler(h) = c.RemoveHandler(h)
        member c.Add(f) = c.Add(f)

我添加了Get&Set方法。问题是 F# 编译器希望我实现抽象成员：

没有为“抽象成员 Varying.AddHandler : Handler<'t> -> unit”提供实现

但是这种类型的要点是成员是抽象的。我究竟做错了什么？

Answer 1

您可以在定义中添加[<AbstractClass>]标签：

> [<AbstractClass>]
- type Varying<'t> =
-     abstract member Get : unit -> 't
-     abstract member Set : 't -> unit
-     abstract member AddHandler : Handler<'t> -> unit
-     abstract member RemoveHandler : Handler<'t> -> unit
-     member v.Add(f) = v.AddHandler(new Handler<_>(fun _ x -> f x))
-     interface IEvent<'t> with
-         member c.AddHandler(h) = c.AddHandler(h)
-         member c.RemoveHandler(h) = c.RemoveHandler(h)
-         member c.Add(f) = c.Add(f)
- ;;

type Varying<'t> =
  class
    abstract member AddHandler : Handler<'t> -> unit
    abstract member Get : unit -> 't
    abstract member RemoveHandler : Handler<'t> -> unit
    abstract member Set : 't -> unit
    interface IEvent<'t>
    member Add : f:('t -> unit) -> unit
  end