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Jeremy Martin (2013-07-15T15:41:40.000Z)
Ahh, thanks. Somehow I read that as `Object(undefined)` ->
ObjectCreate(undefined)` -> throw, but that's not the case.

On Mon, Jul 15, 2013 at 11:39 AM, Mark S. Miller <erights at google.com> wrote:

> Object(undefined) would still not throw:
> http://people.mozilla.org/~jorendorff/es6-draft.html#sec-15.2.1.1 step 1
>
>
> On Mon, Jul 15, 2013 at 8:37 AM, Jeremy Martin <jmar777 at gmail.com> wrote:
>
>> > That's unpleasant. [...] Much old code will break.
>>
>> Indeed.  I hadn't actually noticed that change until just now.  It looks
>> like ES6 code can take advantage of Object.isObject(), which seems to
>> delegate the work to Type(*x*) [1].  It wasn't overwhelmingly clear to
>> me, but I would assume `Object.isObject('foo') === false` and
>> `Object.isObject(new String('foo')) === true`.
>>
>> Has anyone surveyed/looked into what the fallout of throwing on stuff
>> like `Object(undefined)` will be?
>>
>> [1] http://people.mozilla.org/~jorendorff/es6-draft.html#sec-8
>>
>> On Mon, Jul 15, 2013 at 11:09 AM, Mark S. Miller <erights at google.com>wrote:
>>
>>> I see. That's unpleasant. In ES5, Object(x) can never throw, and so the
>>> code paths using |x === Object(x)| are not prepared for a throw. Much old
>>> code will break.
>>>
>>>
>>> On Mon, Jul 15, 2013 at 8:01 AM, Jeremy Martin <jmar777 at gmail.com>wrote:
>>>
>>>> > s === Object(s)
>>>>
>>>> This should throw a TypeError.  In the case of a Symbol, `Object(*value
>>>> *)` results in `ToObject(*value*)` [1].  And, in the case of Symbol,
>>>> ToObject should throw a TypeError [2].
>>>>
>>>> [1] http://people.mozilla.org/~jorendorff/es6-draft.html#sec-15.2.1.1
>>>> [2] http://people.mozilla.org/~jorendorff/es6-draft.html#sec-9.1.9
>>>>
>>>> On Mon, Jul 15, 2013 at 10:48 AM, Mark S. Miller <erights at google.com>wrote:
>>>>
>>>>>  Given that s is a Symbol and b is a Bignum, is
>>>>>
>>>>>     s === Object(s)
>>>>>
>>>>> ?
>>>>>
>>>>> Is
>>>>>
>>>>>     b === Object(b)
>>>>>
>>>>>  ?
>>>>>
>>>>> The reason I ask is that x === Object(x) is often used to distinguish
>>>>> primitive values from objects. The other thing that's often used is typeof,
>>>>> but these uses of typeof usually assume that the full range of possible
>>>>> answers is already known. If we're going to be expanding the typeof
>>>>> answers, then we need guidance on how to write this test now (es5) such
>>>>> that it stays robust.
>>>>>
>>>>>
>>>>> --
>>>>>     Cheers,
>>>>>     --MarkM
>>>>>
>>>>> _______________________________________________
>>>>> es-discuss mailing list
>>>>> es-discuss at mozilla.org
>>>>> https://mail.mozilla.org/listinfo/es-discuss
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Jeremy Martin
>>>> 661.312.3853
>>>> http://devsmash.com
>>>> @jmar777
>>>>
>>>
>>>
>>>
>>> --
>>>     Cheers,
>>>     --MarkM
>>>
>>
>>
>>
>> --
>> Jeremy Martin
>> 661.312.3853
>> http://devsmash.com
>> @jmar777
>>
>
>
>
> --
>     Cheers,
>     --MarkM
>



-- 
Jeremy Martin
661.312.3853
http://devsmash.com
@jmar777
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domenic at domenicdenicola.com (2013-07-23T17:38:28.977Z)
Ahh, thanks. Somehow I read that as `Object(undefined)` -> `ObjectCreate(undefined)` -> throw, but that's not the case.
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