f# - 一个对象是否可以访问同一类的另一个对象的私有(private)字段/函数？

Question

我知道这在 C# 中是可能的，它产生简单而高效的代码。 --- 同一类的两个对象可以访问彼此的私有(private)部分。

class c1
{
    private int A;

    public void test(c1 c)
    {
        c.A = 5;
    }
}

但这在 F# 中似乎是不可能的，是真的吗？

type c1()
     let A = 0
     member test (c: c1) = c.A

Answer 1

有趣的问题。它似乎适用于显式字段，但不适用于 let 绑定(bind):

// Works
type c1 =
    val private A : int
    new(a) = { A = a }
    member m.test(c : c1) = c.A

let someC1 = new c1(1)
let someMoreC1 = new c1(42);
let theAnswer = someC1.test someMoreC1

// Doesn't work
type c2() =
    let mutable A = 42
    // Compiler error: The field, constructor or member 'A' is not defined
    member m.test(c : c2) = c.A