F#构造函数语法-覆盖和扩充新

as this :

type OpenCloseClass() =
    member this.Open(x) = printfn "opened %d" x
    member this.Close() = printfn "closed"

open System

type DisposableOpenCloseClass(openargs) as this = 
    inherit OpenCloseClass() 
    do this.Open(openargs)
    interface IDisposable 
        with member this.Dispose() = this.Close() 

let f() =
    use docc = new DisposableOpenCloseClass(42)
    printfn "inside"

f()

正如布莱恩所建议的,你可以使用 as this 条款。然而,在F#中,通常只有在有充分理由的情况下才建议使用子类(继承)(例如,需要实现某个虚拟类并将其传递给.NET库)。

如果我在实现你的例子,我可能更喜欢函数返回 IDisposable 使用简单的 对象表达式

let disposableOpenClose(openargs) = 
  let oc = new OpenCloseClass() 
  oc.Open(openargs)  
  { new IDisposable with
      member this.Dispose() = oc.Close() }

let f() =
  use docc = disposableOpenClose(42)
  printfn "inside"

从某种意义上说,这只是个人偏好,但我认为这是一个首选选项,因为它比使用继承更简单(尽管我没有任何文档可以链接到这里:-))。另外,编译后的代码可能会简单一些,因为 像这样