f＃向对象表达式添加非接口函数

Question

假设我有一个接口ICache，它定义了两个函数Function1和Function2，我使用一个对象表达式来实现它，但我还想添加一个辅助函数：< / p>

let WebCache =
    {    new ICache with
         member __.HelperFunction = //this doesn't work!
         member __.Function1 = foo
         member __.Function2 = bar
    }

F＃似乎不允许您添加任何不属于该接口的方法。有解决方法吗？如果我想这样做，我首先应该不使用对象表达式吗？

Answer 1

您可以将辅助函数定义为对象表达式之外的普通（本地）函数：

let WebCache =
    let helper n = 
         printfn "Helping %" n
    { new ICache with
         member __.Function1 = helper 1
         member __.Function2 = helper 2 }