On Thu Nov 27 2014 at 11:39:17 AM Dmitry Lomov <dslo...@chromium.org> wrote:
> On Thu, Nov 27, 2014 at 11:01 AM, Drew Wilson <atwil...@chromium.org> > wrote: > >> >> >> On Thu, Nov 27, 2014 at 10:35 AM, Dmitry Lomov <dslo...@chromium.org> >> wrote: >> >>> >>> >>> On Thu, Nov 27, 2014 at 10:13 AM, Drew Wilson <atwil...@chromium.org> >>> wrote: >>> >>>> What impact do we expect on web compatibility from apps that may >>>> already be adding attributes named "include", etc to their String objects? >>>> >>>> I think that adding attributes that Firefox is already shipping should >>>> be relatively safe, but I'm very leery about being the first browser to add >>>> new attributes. What can we do to avoid a repeat of >>>> http://crbug.com/409858? Do we have any stats for how often these >>>> attributes are already in use in web pages (tricky, since some apps are >>>> legitimately using them for polyfill purposes)? >>>> >>> Correct, this is tricky. We do not have stats (and it is unclear how to >>> get those stats). >>> 'contains' was renamed to 'includes' precisely to reduce possible web >>> compat breakage. >>> Unfortunately we will not know of any breakage until we ship this - it >>> has been available under a flag for some time, but it looks like nobody >>> tests with 'Experimental Javascript features' enabled. >>> Therefore enabling it early on canary in Chrome 41 process is our best >>> mitigation in this particular case. >>> >> >> I'm not sure "let's just launch this and see who complains" is an >> acceptable path forward given that this specific approach was tried last >> release with Array.values and blew up in our face. Why do we think this >> time will be any different? >> > >> Can we perhaps restrict this to canary + dev channel (and maybe the first >> beta cut), but hold off on shipping to Stable until we find a way to >> generate stats? >> > > Shipping this now is de facto canary + dev. > I do not know of a way to generate stats for this (unfortunately). > You can collect stats via i::Isolate::CountUsage() > > >> Just making this change with no stats around conflicts would be like the >> blink team deprecating an API without first measuring how often it's used. >> > > > I disagree. This does not deprecate anything. > > >> >>> >>> Going forward, we have recently changed the definition of 'Experimental >>> Javascript fetaures' in Chrome to mean 'enable staged features' (per our >>> process https://developers.google.com/v8/launchprocess). >>> This means that this flag really enables only those features that we >>> consider quite mature, in particular they are expected to be stable and >>> implementation of them must be complete. >>> With that, we plan to evangelize enabling this flag among the power >>> users, so that we hear about any breakage early. >>> >> >> Can we set "enable staged features" for the Dev channel by default to >> increase usage? I don't actually think this will solve the problem since >> experience has shown us that not enough users run on that channel to catch >> all of the incompatibility issues, but at least it's a start. >> > > That would be great - I am sympathetic to that; but we typically have no > feature distinction between Canary/Dev and subsequent Beta. > > >> >> >>> >>> Dmitry >>> >>> >>> >>>> >>>> On Thu, Nov 27, 2014 at 9:27 AM, Dmitry Lomov <dslo...@chromium.org> >>>> wrote: >>>> >>>>> [FYI +blink-dev] >>>>> >>>>> ES6 extends String.prototype with several methods: repeat, startsWith, >>>>> endsWith, includes, codePointAt) and adds String.fromCodePoint method. >>>>> >>>>> Firefox ships codePointAt and fromCodePoint since release 29 [1], >>>>> startsWith and endsWith since release 17 [2], and repeat since release 24 >>>>> [3]. >>>>> >>>>> 'include' was previously named 'contains' and has been renamed at the >>>>> last TC39 meeting. Firefox shipped 'contains' since release 17. >>>>> >>>>> These methods has been available under a flag for a while, and were >>>>> staged in Chrome 40. >>>>> >>>>> [1] https://developer.mozilla.org/en-US/Firefox/Releases/29 >>>>> [2] https://developer.mozilla.org/en-US/Firefox/Releases/17 >>>>> [3] https://developer.mozilla.org/en-US/Firefox/Releases/24 >>>>> >>>>> Owners: yang...@chromium.org, dslo...@chromium.org >>>>> >>>> >>>> >>> >> -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
