F＃添加非接口功能到對象表達式

Question

說我有它定義兩個函數，Function1和Function2和我使用對象表達式來實現它的接口ICache，但我也希望添加一個輔助函數：

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

F＃似乎不允許你添加任何不屬於界面的方法。有沒有解決方法？如果我想這樣做，我是不是應該首先使用對象表達式？

Answer 1

您可以定義輔助函數作爲一個普通的（本地）函數的對象表達之外：

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