Question regarding ES5

Irakli Gozalishvili rfobic at gmail.com
Wed Feb 16 17:46:54 PST 2011


I have not found a way to cc people but here is the link for a bug report:

http://code.google.com/p/v8/issues/detail?id=1169

I think if you'll star it you'll get an updates over email.

Regards
--
Irakli Gozalishvili
Web: http://www.jeditoolkit.com/
Address: 29 Rue Saint-Georges, 75009 Paris, France <http://goo.gl/maps/3CHu>


On Thu, Feb 17, 2011 at 02:34, Brendan Eich <brendan at mozilla.com> wrote:

> Please do file that bug (issue) against V8, though :-P. You can cc: me as
> brendan at mozilla.org on it.
>
> /be
>
> On Feb 16, 2011, at 5:32 PM, Irakli Gozalishvili wrote:
>
> Thanks for the reply Allen,
>
> I was under the impression that inherited properties can be overridden,
> regardless of their write-ability on the __proto__.
>
> Also as far as I understand freeze will make properties including
> constructor non-confugurable, will I still be able  to override such
> properties using Object.defineProperty ?
>
> Also this was simplified example and it's not really possible to do the
> freeze after. Will try `Object.defineProprety` though.
>
> Thanks
> --
> Irakli Gozalishvili
> Web: http://www.jeditoolkit.com/
> Address: 29 Rue Saint-Georges, 75009 Paris, France<http://goo.gl/maps/3CHu>
>
>
> On Thu, Feb 17, 2011 at 02:21, Allen Wirfs-Brock <allen at wirfs-brock.com>wrote:
>
>> The error looks correct to me. By freezing Type.proto you make all its own
>> properties "read only".  One of those is the constructor that is
>> automatically created on every func.prototype object.  When you assign to
>> object.constructor you are trying to over-ride an inherited read-onoy
>> property.  ECMAScript has never allowed this.  You can say:
>>       Object.defineProperty(object,"constructor",{value: function Foo()
>> {}, /* any other attributes you want to set */});
>> to over-ride the inherited constructor property.
>> Or you can restructure you code so you do the freeze after you do the
>> assignment.
>>
>> On Feb 16, 2011, at 5:09 PM, Irakli Gozalishvili wrote:
>>
>> Hi,
>>
>> I've run into one issue and even after reading ES5 specs several times
>> it's not clear to me what should be an expected behavior:
>>
>> Currently on Firefox nightly following code:
>>
>> (function() {
>> "use strict";
>>
>> function Type() {}
>> Object.freeze(Type.prototype);
>> var object = Object.create(Type.prototype);
>> object.constructor = function Foo() {};
>>
>> return object
>> })();
>>
>> throws TypeError: object.constructor is read-only
>> while on chrome
>>
>> it returns object with constructor Foo
>>
>> I would like to know what is an expected behavior to fill a bug to an
>> appropriate project.
>>
>>
>> Thanks!
>> --
>> Irakli Gozalishvili
>> Web: http://www.jeditoolkit.com/
>> Address: 29 Rue Saint-Georges, 75009 Paris, France<http://goo.gl/maps/3CHu>
>> _______________________________________________
>> es-discuss mailing list
>> es-discuss at mozilla.org
>> https://mail.mozilla.org/listinfo/es-discuss
>>
>>
>>
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