On May 8, 2013, at 8:46 AM, Andreas Rossberg wrote:

> On 8 May 2013 17:41, Allen Wirfs-Brock <allen at wirfs-brock.com> wrote:
>> 
>> On May 8, 2013, at 8:31 AM, Mark Miller wrote:
>> 
>>> What about your triangle argument?
>> 
>> There is another way:
>> 
>> let obj = Object.setPrototypeOf({x:0, y:0}, pointProto};
>> 
>> Let's keep {__proto__: foo} in the slightly  disrespectable  Annex B box.  That keeps it together with O.p.__proto and leaves room for future, more elegant object literal syntax extensions if we decided we really need them (and we probably won't).
> 
> Isn't Object.create the proper alternative to both {__proto__: } and
> triangle for objects? What has setPrototypeOf got to do with it? (And
> why is that on the table all of a sudden?)

I think that Brandon Benvie adequated addressed Object.create.

Regarding setPrototypeOf, once Mark agreed that the [[protoSetter]] function did not need to be Realm restricted it essentially became a publicly available API for modify the [[Prototype]] of arbitrary objects. 

      Object.getOwnPropertyDescriptor(Object.prototype, "__proto__").set.call(obj, proto)

There is a vocal part of the JS community who would prefer that the core language also offer Object.setPrototypeOf as the preferred alternative to the above:

       Object.setPrototypeOf(obj,proto)

This is only a cosmetic difference. But I agree that it is good cosmetics. Dynamic prototype modification seems to have won as a required feature of the language.  Since that is the case, consistancy suggests that we should  treat it cosmetically just like all the dynamic reflection operations defined on Object.

Allen

On May 8, 2013, at 8:46 AM, Andreas Rossberg wrote:

> Isn't `Object.create` the proper alternative to both `{__proto__: }` and
> triangle for objects? What has `setPrototypeOf` got to do with it? (And
> why is that on the table all of a sudden?)

I think that Brandon Benvie adequated addressed `Object.create`.

Regarding `setPrototypeOf`, once Mark agreed that the [[protoSetter]] function did not need to be Realm restricted it essentially became a publicly available API for modify the [[Prototype]] of arbitrary objects. 

```js
Object.getOwnPropertyDescriptor(Object.prototype, "__proto__").set.call(obj, proto)
```

There is a vocal part of the JS community who would prefer that the core language also offer `Object.setPrototypeOf` as the preferred alternative to the above:

```js
Object.setPrototypeOf(obj,proto)
```

This is only a cosmetic difference. But I agree that it is good cosmetics. Dynamic prototype modification seems to have won as a required feature of the language.  Since that is the case, consistancy suggests that we should  treat it cosmetically just like all the dynamic reflection operations defined on Object.