Destructuring an object into a new object (like Underscore pick but ESier)

[/#!/JoePea]

Bob, the benefit of your proposed syntax would be that the object
identifier comes first instead of last, so the reader can see the intent of
the code sooner:

```js
let newObj = {...obj.{foo, bar}, quux:4}
```

/#!/JoePea
On Feb 19, 2016 9:55 AM, "Bob Myers" <rtm at gol.com> wrote:

> Indeed, this is the exact objective of the pick notation which I proposed
> about six months ago, and have now greatly refined and also implemented a
> proof-of-concept.
>
> In the previous incarnation, I called this a "pick operator" and
> represented it with `#`, but now I treat it as an extension of dot notation.
>
> What you want is represented as something like
>
> ```js
> let newObj = obj.{foo, bar};
> ```
>
> See https://github.com/rtm/js-pick-notation/blob/master/docs/intro.md for
> a friendly intro. That repo also contains a spec and the POC with tests.
>
> Regards,
> Bob Myers
>
> On Fri, Feb 19, 2016 at 11:02 PM, Zacqary Adam Xeper <
> zacqary.xeper at datadoghq.com> wrote:
>
>> So let's say I have:
>> let obj = {foo: 1, bar: 2, baz: 3}
>>
>> And I want to initialize a new object that looks like:
>> {foo: obj.foo, bar: obj.bar, quux: 4}
>>
>> I can create a new object with ALL of these properties using a spread
>> operator:
>> let newObj = {...obj, quux: 4}
>>
>> But if I want to initialize a new object that pulls in just the foo and
>> bar properties, I have to type this whole structure out:
>> let newObj = {foo: obj.foo, bar: obj.bar, quux: 4}
>>
>> Or, if I want to use shorthand property names, I can use a destructuring
>> statement, but then I have to type all the property names twice:
>> let {foo, bar} = obj;
>> let newObj = {foo, bar, quux: 4};
>>
>> Underscore.js has a pick function, which looks like this:
>> let newObj = {..._(obj).pick(["foo", "bar"]), quux: 4};
>>
>> but that requires Underscore as a dependency and the syntax is still
>> pretty annoying. I feel like this is a common enough task — especially when
>> trying to avoid mutating data — that there ought to be a native ES way of
>> doing this.
>>
>> For example, taking a cue from the computed property syntax:
>> let newObj = { {foo, bar}: obj, quux: 4 }
>>
>> This also echoes ordinary destructuring syntax, where the variable names
>> are on the left of the equals sign and the object is on the right. Here,
>> it's the same, except for initializing objects.
>>
>> _______________________________________________
>> es-discuss mailing list
>> es-discuss at mozilla.org
>> https://mail.mozilla.org/listinfo/es-discuss
>>
>>
>
> _______________________________________________
> es-discuss mailing list
> es-discuss at mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20160219/f76c3588/attachment.html>