tj.crowder at farsightsoftware.com (2017-03-17T13:05:28.075Z)
> 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
> 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 tj.crowder at farsightsoftware.com <tj.crowder at farsightsoftware.com> | 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 info at farsightsoftware.com 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 < felipenmoura at gmail.com> 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 <michalwadas at gmail.com> > 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 < >> felipenmoura at gmail.com> 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 <fuchsia.groan at virgin.net> >>> 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 >>>> es-discuss at mozilla.org >>>> 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 >>> es-discuss at mozilla.org >>> https://mail.mozilla.org/listinfo/es-discuss >>> >>> >> >> >> _______________________________________________ >> es-discuss mailing listes-discuss at mozilla.orghttps://mail.mozilla.org/listinfo/es-discuss >> >> >> >> _______________________________________________ >> es-discuss mailing list >> es-discuss at mozilla.org >> 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 > 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/20170317/7dceaacb/attachment-0001.html>