当F#记录的字段被声明为私有时，奇怪的可访问范围 [英] Weird accessibility scopes when F# record's fields are declared private

问题描述

当F#记录的字段部分被声明为私有时，我只是注意到了一种与之相反的直观行为. (这与

I just noticed a rather counter intuitive behaviour when the field part of an F# record is declared private. (This is related to Is it possible to make a field of a record private? or to make a member of record private?)

在此示例中...

type MyRec = 
    private  // Fields declared private, or at least I thought so.
        { a : int
          b : int }
    member x.A = x.a
    member private x.Both = x.a + x.b
    static member CreateMyRec(a, b) = { a = a; b = b }

let foo = MyRec.CreateMyRec(1,2)
let bar = foo.a     // No error. Huh?
let baz = foo.Both  // Error: not accessible.

...如预期的那样，在类型声明范围之外无法访问私有成员Both.但是，可以访问字段a.

...the private member Both is inaccessible outside the type declaration scope, as is expected. However, the field a is accessible.

如果将MyRec放在模块中，则该字段将变为该模块的私有字段.这就是您希望模块中的顶层声明表现出来的方式，但是我希望在类型中声明为private的任何内容对于该类型都是私有的，而不是对其封闭模块的私有.

If you put MyRec in a module, the fields become private to that module. That's how you'd expect a top level declaration in the module to behave, but I expected that anything declared private within a type, would be private to that type, not to its enclosing module.

这种行为实际上很奇怪吗，还是我在这里的推理中遗漏了一些东西?

Is this behaviour actually weird, or am I missing something in my reasoning here?

推荐答案

据我所知，这是一个文档不足的功能.但是，该规范的第10.5节可访问性注释 ，状态:

As far as I can tell, this is an under-documented feature. But, section 10.5 of the spec, Accessibility Annotations, states:

在类型，模块或模块中的类型表示形式上的私有表示对模块而言是私有的".

private on a type, module, or type representation in a module means "private to the module."

类型表示"是与记录字段相关的部分.

"type representation" being the part relevant to record fields.

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