On Oct 14, 2013, at 4:21 PM, Andrea Giammarchi wrote:
> my last memories on the topic are these:
>
> ```javascript
>
> var obj = JSON.parse('{"__proto__":[]}');
> obj instanceof Array; // false
> obj.__proto__ instanceof Array; // true
> // since the proto is a property, not a magic thing
> obj.__proto__ = 123; // da hell will happen, only Allen knows ^_^
>
> ```
>
> And since latter should simply set the property named `"__proto__"` as value
> `123` I got confused with this dual way to deal with an object when it comes
> from JSON world (then has a property defined as value, not the inherited
> set/get from Object.prototype)
>
> As summary, `JSON.parse` over `"__proto__"` is similar to:
> ```javascript
>
> var o = {};
> Object.defineProperty(o, '__proto__', {
> value: 123,
> enumerable: true,
> writable: true,
> configurable: true
> });
>
> ```
>
> Which means in such case the property `"__proto__"` will fail with such
> object while `Object.setPrototypeOf` won't which is the reason I keep
> suggesting the latest to make the intent explicit.
>
> Not arguing or anything, just speaking out loudly my confusion with that
> property as string part.
>
I think you are over thinking this:
Assuming that Annex B.2.2.1 and B.3.1 are implemented: here are the cases of
interest:
let o1 = {__proto__: p}; // o1 inherits from p
let o2 = {"__proto__": p}; // o2 inherits from p
let o3 = {["__proto__"]: p};// o3 inherits from Object.prototype, has own data
property "__proto__" whose value is p.
let o4 = JSON.parse('{"__proto__": "value"}');
//o4 inherits from Object.prototype, has own data property "__proto__"
whose value is "value"
//assuming that Object.prototype.__proto__ has not been tamper with:
let o5 = new Object;
o5.__proto__ = p ; //o5 inherits from p
let o6 =new Object;
o6["__proto__"] = p; //o6 inherits from p
Allen
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