Thanks for clarification Tom, I've also added the main two _features_ this method in the first gist I've posted but here a quick recap:
```javascript // for shallow object copy var shallowCopy = Object.create( Object.getPrototypeOf(origin), Object.getOwnPropertyDescriptors(origin) ); // for traits / mixin Object.defineProperties( target, Object.getOwnPropertyDescriptors(origin) ); // respecting ES5 symmetry Object.defineProperty(O, name, descriptor); descriptor as Object.getOwnPropertyDescriptor(O, name) Object.defineProperties(O, descriptors); descriptors as Object.getOwnPropertyDescriptors(O) ``` Hope this one help presenting the what, the why, and the how. Best Regards On Wed, Mar 5, 2014 at 10:39 AM, Tom Van Cutsem <[email protected]> wrote: > Object.getOwnPropertyDescriptors(obj) makes sense to me. As noted > somewhere upstream, it's symmetrical to Object.defineProperties. > > When I designed traits.js, which was heavily based on property > descriptors, I even added it to the library's public API, under the > slightly shorter name Object.getOwnProperties(obj), cf. < > http://traitsjs.org/api.html> > > Brendan asked me whether Object.getOwnPropertyDescriptors would > necessitate a derived trap for proxies. I think the answer is no, just like > Object.defineProperties(proxy) triggers just the proxy's > getOwnPropertyNames trap, and then the defineProperty trap for each > property, Object.getOwnPropertyDescriptors(proxy) would trigger the > getOwnPropertyNames trap, followed by calls to the getOwnPropertyDescriptor > trap for each individual property. > > Cheers, > Tom > > > > > 2014-03-05 1:38 GMT+01:00 Andrea Giammarchi <[email protected]>: > >> You are right, I've realized it after posting ... `Object.assign(target, >> source)` via `Get` and `Put` is basically the equivalent of a classic >> `for/in` with `hasOwnProperty` check ... well, once again, in ES6 >> `Object.getOwnPropertyDescriptors(O)` seems to be a solution for other >> cases too (shallow copy of properties, shallow clone, not just for/in) plus >> yes, `Object.mixin(target, source)` might be simplified as well via this >> proposal, that's a good point ... so 3 problems solved at once! :-) >> >> >> On Tue, Mar 4, 2014 at 4:02 PM, Claude Pache <[email protected]>wrote: >> >>> >>> >>> Le 5 mars 2014 à 00:18, Andrea Giammarchi <[email protected]> >>> a écrit : >>> >>> >>> Also please note that this proposal simplifies [Object.assign(target, >>> source)]( >>> https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.assign) >>> too since latter one is basically: >>> >>> ```javascript >>> Object.defineProperties( >>> target, >>> Object.getOwnPropertyDescriptors(source) >>> ); >>> ``` >>> >>> >>> No. `Object.assign` (1) uses the semantics of the assignment operator >>> `=` (for example, it makes a difference in case of setters), and (2) copies >>> only enumerable properties. Did you think about `Object.mixin`? >>> >>> --Claude >>> >> >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >> >
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