Object.getOwnPropertyDescriptors(O) ? // plural

[Andrea Giammarchi]

up ?


On Sun, Mar 2, 2014 at 5:43 PM, Andrea Giammarchi <
andrea.giammarchi at gmail.com> wrote:

> Brandon I take your answer as +1, thanks.
>
> I've also "gisted" a possible/basic polyfill here:
> https://gist.github.com/WebReflection/9317065
>
> Cheers
>
>
> On Sun, Mar 2, 2014 at 5:16 PM, Andrea Giammarchi <
> andrea.giammarchi at gmail.com> wrote:
>
>> actually, since `Object.getOwnPropertyDescriptor` accepts `Symbols` too
>> as second argument, the equivalent with current ES6 would be even more
>> prolix than that
>>
>> ```javascript
>>
>> var shallowCopy = Object.create(
>>   Object.getPrototypeOf(originalObject),
>>    Object.getOwnPropertyNames(originalObject).concat(
>>   Object.getOwnPropertySymbols(originalObject)
>>   ).reduce(function (descriptors, name) {
>>     descriptors[name] = Object.getOwnPropertyDescriptor(
>>       originalObject, name
>>     );
>>     return descriptors;
>>   }, {})
>> );
>>
>> ```
>>
>> assuming Symbols will be definable through descriptors ... all this VS
>>
>> ```javascript
>> var shallowCopy = Object.create(
>>   Object.getPrototypeOf(originalObject),
>>   Object.getOwnPropertyDescriptors(originalObject)
>> );
>> ```
>>
>> which I believe is a win.
>>
>> Thanks
>>
>>
>> On Sun, Mar 2, 2014 at 5:01 PM, Andrea Giammarchi <
>> andrea.giammarchi at gmail.com> wrote:
>>
>>> I wonder if by any chance this could sneak into ES6 ... we have only
>>> singular version here:
>>>
>>> https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.getownpropertydescriptor
>>>
>>> **rationale**
>>> The easiest way to create a shallow copy of a generic object could be:
>>>
>>> ```javascript
>>> var shallowCopy = Object.create(
>>>   Object.getPrototypeOf(originalObject),
>>>   Object.getOwnPropertyDescriptors(originalObject)
>>> );
>>> ```
>>>
>>> Today what we have to do this instead:
>>>
>>> ```javascript
>>> var shallowCopy = Object.create(
>>>   Object.getPrototypeOf(originalObject),
>>>   Object.getOwnPropertyNames(originalObject).reduce(
>>>   function (descriptors, name) {
>>>     descriptors[name] = Object.getOwnPropertyDescriptor(
>>>       originalObject, name
>>>     );
>>>     return descriptors;
>>>   }, {})
>>> );
>>> ```
>>>
>>> I see latter pattern as sort of unnecessary overhead that could be also
>>> much faster in core and polyfilled in the meanwhile.
>>>
>>> Thoughts ?
>>>
>>> Cheers
>>>
>>>
>>>
>>>
>>>
>>
>
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