Re: Proposal: spread assignment operator

[Jeremy Martin]

By way of context, some similar ideas have been previously discussed:

   -
   
https://esdiscuss.org/topic/picking-deconstructing-properties-into-object-literals
   -
   
https://esdiscuss.org/topic/destructuring-an-object-into-a-new-object-like-underscore-pick-but-esier
   -
   https://esdiscuss.org/topic/extended-dot-notation-pick-notation-proposal

FWIW, I actually do like the idea of being able to syntactically "reshape"
one object or array directly into another, and there's probably even a
cowpath argument to be made on the basis of so many `pick()`, `omit()`,
etc. implementations out there. On the other hand, per Isiah's comments,
we're at least 90% there already with Object.assign(), so it seems like the
value proposition could/should be developed a bit more on this.

On Wed, Apr 25, 2018 at 12:29 PM, Arutyunyan Artyom  wrote:

>
> I think it can be looks like: https://gist.github.com/artalar/
> ea8512546a3675648615a25e846096a6
>
> 25.04.2018, 18:58, "Isiah Meadows" :
>
> It doesn't. But with objects, it's not a cheap operation to simply
> duplicate, and they aren't normally immutable like primitives. Furthermore,
> why is it for objects, not arrays?
>
> (I'm pushing that second question as a point of potential confusion -
> remember the user.)
>
> On Wed, Apr 25, 2018, 11:45 Arutyunyan Artyom  wrote:
>
> spread assignment not mutate, it reassign, like "+=" and other.
>
> if (
> ('a = {...a,...b}'.length > 'a ...= b'.length) === ('n = n+1'.length > 'n
> += 1'.length)
> ) { console.log('why "addition assignment" is necessary, but "spread
> assignment" is not?'); }
>
>
>
>
> 25.04.2018, 18:21, "Isiah Meadows" :
>
> Note: `Object.assign` mutates its first argument and (with only obscure
> caveats) does exactly this. Not sure syntax is necessary here.
>
> Oh, and arrays also have the common idiom `array.push(...values)` (but
> they could use an `Array.prototype.pushAll` to avoid polluting arguments
> lists).
>
> On Wed, Apr 25, 2018, 09:24 Артём Арутюнян  wrote:
>
> I propose *spread assignment operator*:
>
> *var obj = { test1: 1 };*
> *var anotherObj = { test2: 2 };*
> *obj ...= { test2: 2 }; // == (obj = { ...obj, ...anotherObj })*
> *// { test1: 1, test2: 2 }*
>
> I'm surprised it wasn't in the original implementation
> ___
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> https://mail.mozilla.org/listinfo/es-discuss
>
>
> ___
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>
>


-- 
Jeremy Martin
661.312.3853
@jmar777  / @j 
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Re: Proposal: spread assignment operator

[Arutyunyan Artyom]

 I think it can be looks like: https://gist.github.com/artalar/ea8512546a3675648615a25e846096a6 25.04.2018, 18:58, "Isiah Meadows" :It doesn't. But with objects, it's not a cheap operation to simply duplicate, and they aren't normally immutable like primitives. Furthermore, why is it for objects, not arrays? (I'm pushing that second question as a point of potential confusion - remember the user.) On Wed, Apr 25, 2018, 11:45 Arutyunyan Artyom  wrote:spread assignment not mutate, it reassign, like "+=" and other. if (('a = {...a,...b}'.length > 'a ...= b'.length) === ('n = n+1'.length > 'n += 1'.length)) { console.log('why "addition assignment" is necessary, but "spread assignment" is not?'); }   25.04.2018, 18:21, "Isiah Meadows" :Note: `Object.assign` mutates its first argument and (with only obscure caveats) does exactly this. Not sure syntax is necessary here. Oh, and arrays also have the common idiom `array.push(...values)` (but they could use an `Array.prototype.pushAll` to avoid polluting arguments lists). On Wed, Apr 25, 2018, 09:24 Артём Арутюнян  wrote:I propose spread assignment operator: var obj = { test1: 1 };var anotherObj = { test2: 2 };obj ...= { test2: 2 }; // == (obj = { ...obj, ...anotherObj })// { test1: 1, test2: 2 } I'm surprised it wasn't in the original implementation___es-discuss mailing listes-discuss@mozilla.orghttps://mail.mozilla.org/listinfo/es-discuss___
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Re: Proposal: spread assignment operator

[Isiah Meadows]

It doesn't. But with objects, it's not a cheap operation to simply
duplicate, and they aren't normally immutable like primitives. Furthermore,
why is it for objects, not arrays?

(I'm pushing that second question as a point of potential confusion -
remember the user.)

On Wed, Apr 25, 2018, 11:45 Arutyunyan Artyom  wrote:

> spread assignment not mutate, it reassign, like "+=" and other.
>
> if (
> ('a = {...a,...b}'.length > 'a ...= b'.length) === ('n = n+1'.length > 'n
> += 1'.length)
> ) { console.log('why "addition assignment" is necessary, but "spread
> assignment" is not?'); }
>
>
>
> 25.04.2018, 18:21, "Isiah Meadows" :
>
> Note: `Object.assign` mutates its first argument and (with only obscure
> caveats) does exactly this. Not sure syntax is necessary here.
>
> Oh, and arrays also have the common idiom `array.push(...values)` (but
> they could use an `Array.prototype.pushAll` to avoid polluting arguments
> lists).
>
> On Wed, Apr 25, 2018, 09:24 Артём Арутюнян  wrote:
>
> I propose *spread assignment operator*:
>
> *var obj = { test1: 1 };*
> *var anotherObj = { test2: 2 };*
> *obj ...= { test2: 2 }; // == (obj = { ...obj, ...anotherObj })*
> *// { test1: 1, test2: 2 }*
>
> I'm surprised it wasn't in the original implementation
> ___
> es-discuss mailing list
> es-discuss@mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
>
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Re: Proposal: spread assignment operator

[Arutyunyan Artyom]

spread assignment not mutate, it reassign, like "+=" and other. if (('a = {...a,...b}'.length > 'a ...= b'.length) === ('n = n+1'.length > 'n += 1'.length)) { console.log('why "addition assignment" is necessary, but "spread assignment" is not?'); }   25.04.2018, 18:21, "Isiah Meadows" :Note: `Object.assign` mutates its first argument and (with only obscure caveats) does exactly this. Not sure syntax is necessary here. Oh, and arrays also have the common idiom `array.push(...values)` (but they could use an `Array.prototype.pushAll` to avoid polluting arguments lists). On Wed, Apr 25, 2018, 09:24 Артём Арутюнян  wrote:I propose spread assignment operator: var obj = { test1: 1 };var anotherObj = { test2: 2 };obj ...= { test2: 2 }; // == (obj = { ...obj, ...anotherObj })// { test1: 1, test2: 2 } I'm surprised it wasn't in the original implementation___es-discuss mailing listes-discuss@mozilla.orghttps://mail.mozilla.org/listinfo/es-discuss___
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Re: Proposal: spread assignment operator

[Isiah Meadows]

Note: `Object.assign` mutates its first argument and (with only obscure
caveats) does exactly this. Not sure syntax is necessary here.

Oh, and arrays also have the common idiom `array.push(...values)` (but they
could use an `Array.prototype.pushAll` to avoid polluting arguments lists).

On Wed, Apr 25, 2018, 09:24 Артём Арутюнян  wrote:

> I propose *spread assignment operator*:
>
> *var obj = { test1: 1 };*
> *var anotherObj = { test2: 2 };*
> *obj ...= { test2: 2 }; // == (obj = { ...obj, ...anotherObj })*
> *// { test1: 1, test2: 2 }*
>
> I'm surprised it wasn't in the original implementation
> ___
> es-discuss mailing list
> es-discuss@mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
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Proposal: spread assignment operator

[Артём Арутюнян]

I propose spread assignment operator: var obj = { test1: 1 };var anotherObj = { test2: 2 };obj ...= { test2: 2 }; // == (obj = { ...obj, ...anotherObj })// { test1: 1, test2: 2 } I'm surprised it wasn't in the original implementation
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