> Indeed, Object.pick would be very promising, but it could indeed break some codes!
Adding to *`Object`* (the function) is fine (usually, a survey would be needed). For instance, `Object.values` was added in ES2017. It's adding to *`Object.prototype`* that's impossible. Important distinction. -- T.J. Crowder *Farsight Software Ltd | 20-22 Wenlock Road, London N1 7GU | Company #8393428 [email protected] <[email protected]> | Direct: +44 (0)20 3627 4231 | Mobile: +44 (0)7717 842 414* If you've received this message in error, please let us know by forwarding it to [email protected] and then delete it from your system. Please don't copy it or disclose its contents to anyone. Separately, note that email sent over the internet without a digital signature may be modified en route. On Fri, Mar 17, 2017 at 12:53 PM, Felipe Nascimento de Moura < [email protected]> wrote: > Well...this is a major problem, then! > Indeed, Object.pick would be very promising, but it could indeed break > some codes! > > On Fri, Mar 17, 2017 at 9:48 AM, Michał Wadas <[email protected]> > wrote: > >> It's impossible to add new methods on Object.prototype because it would >> be web-breaking - I have seen code that test for typeof arr.map === >> 'function' >> >> On Set topic, I have written basic proposal for this >> <https://github.com/Ginden/set-methods>, but it was ignored so I didn't >> write formal spec. >> >> On 17/03/17 13:36, James Treworgy wrote: >> >> I think a good solution that doesn't require new syntax would be >> map/filter methods on the Object prototype that return a new object, e.g. >> >> let subset = { a:1, b:2, c:3 }.filter(([key])=>['b'].includes(key)) >> // subset = { b: 2 } >> >> let subset = { 1:1, b:2, c:3 }.map(([key, value])=>[key, value * 2]) >> // subset = { a:2, b:4. c:6 } >> >> Actually I'd like this to be available on Map too. I've always thought it >> was interesting that the Map and Set objects do not natively include >> map/filter operations -- or maybe even most of the Array prototype methods >> as applicable. And for Sets, basic set operations like >> except/distinct/union. >> >> But a Javascript object is just a Map, really, or I guess one could say >> that a Map is just an object with a few enhancements. It's surprising that >> there is no native operation built in to directly convert between Maps and >> objects given their conceptual similarity. In either case though it would >> be nice to be able to apply standard processing rules that one applies to >> Maps conceptually to an Object (and a Map) natively, like filter and map. >> >> >> >> On Fri, Mar 17, 2017 at 8:04 AM, Felipe Nascimento de Moura < >> [email protected]> wrote: >> >>> Hi. >>> Interesting to know that it has already been discussed. >>> >>> I know we could create a function to do similar things, but I think the >>> language itself has evolved so well, this is a use case it could fit >>> somehow. >>> >>> I think there could be different approaches for that, like >>> >>> Object.pick([ 'a', 'c' ], { a: 1, b: 2, c: 3 }) >>> >>> or >>> >>> let x = {a, c}{ a: 1, b: 2, c: 3 } >>> >>> or >>> >>> let {a, c} as x = { a: 1, b: 2, c: 3 } >>> >>> or >>> >>> >>> let x = { a: 1, b: 2, c: 3 }{a, c} >>> >>> or >>> >>> let x = { a: 1, b: 2, c: 3 }['a', 'c'] >>> >>> Would you consider any of those as an interesting option? >>> >>> thanks. >>> >>> >>> >>> On Fri, Mar 17, 2017 at 7:25 AM, peter miller <[email protected]> >>> wrote: >>> >>>> Hi, >>>> >>>> There seems to be little appetite for taking it up, in spite of it being >>>>> (IMHO) a very common use case. >>>>> >>>> >>>> I'll second it being common in my code. My personal highlights would be >>>> assigning to this: >>>> >>>> ``` >>>> this.{x,y,z} = a; >>>> ``` >>>> >>>> and combining it with property spreading: >>>> >>>> ``` >>>> const result = { a, b, ...x.{ y, z }, ...p.{ q, r } }; >>>> ``` >>>> >>>> Peter >>>> >>>> -- >>>> "There were drawings, and sheets of paper with writing on them, and it >>>> seemed that they were the sustenance of life, that here were the warlocks, >>>> almost the vehicles of destruction of man's life, but at the same time the >>>> very reason for his living." --- Maeve Gilmore/Titus Awakes. >>>> >>>> _______________________________________________ >>>> es-discuss mailing list >>>> [email protected] >>>> https://mail.mozilla.org/listinfo/es-discuss >>>> >>> >>> >>> >>> -- >>> [ ]s >>> >>> *--* >>> >>> *Felipe N. Moura* >>> Web Developer, Google Developer Expert >>> <https://developers.google.com/experts/people/felipe-moura>, Founder of >>> BrazilJS <https://braziljs.org/> and Nasc <http://nasc.io/>. >>> >>> Website: http://felipenmoura.com / http://nasc.io/ >>> Twitter: @felipenmoura <http://twitter.com/felipenmoura> >>> Facebook: http://fb.com/felipenmoura >>> LinkedIn: http://goo.gl/qGmq >>> --------------------------------- >>> *Changing the world* is the least I expect from myself! >>> >>> _______________________________________________ >>> es-discuss mailing list >>> [email protected] >>> https://mail.mozilla.org/listinfo/es-discuss >>> >>> >> >> >> _______________________________________________ >> es-discuss mailing >> [email protected]https://mail.mozilla.org/listinfo/es-discuss >> >> >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >> > > > -- > [ ]s > > *--* > > *Felipe N. Moura* > Web Developer, Google Developer Expert > <https://developers.google.com/experts/people/felipe-moura>, Founder of > BrazilJS <https://braziljs.org/> and Nasc <http://nasc.io/>. > > Website: http://felipenmoura.com / http://nasc.io/ > Twitter: @felipenmoura <http://twitter.com/felipenmoura> > Facebook: http://fb.com/felipenmoura > LinkedIn: http://goo.gl/qGmq > --------------------------------- > *Changing the world* is the least I expect from myself! > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > >
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