Mark S. Miller
erights at google.com
Mon Dec 19 10:48:12 PST 2011
On Mon, Dec 19, 2011 at 10:21 AM, Xavier MONTILLET
<xavierm02.net at gmail.com>wrote:
> use version 6;
> and not
> "use version 6";
> ? Just to be sure ES 6 code breaks in old browsers ?
> And what do you mean by "opt-in for ES6" ? New syntax ? Everything in ES 6
> I'm thinking about weakmaps:
> - on the one hand, you want to use native weakmaps when available so
> you would want to "opt-in for ES6"
> - but on the other hand, you could also implement a weakmap "polyfill"
> that wouldnt be as efficient, that would suck the memory but still
> work, and have it work in older browsers
is a WeakMap polyfill that should work *transparently* in all ES5
conformant browsers. It is indeed not as efficient, but it's better than
you might expect ;).
Btw, where does the term "polyfill" come from?
> Therefore, setting the thing to do to "opt-in for ES6" to something
> not backward compatible doesn't seem like a good idea to me.
> On Mon, Dec 19, 2011 at 1:42 PM, David Bruant <bruant.d at gmail.com> wrote:
> > I did start a related thread a while ago .
> > Brendan's response  explained a few things:
> > "Please read RFC 4329:
> > http://tools.ietf.org/html/rfc4329
> > There will be *at least* a ;version=6 parameter you can use, probably
> > argued that we should align version numbers."
> > "Beyond the RFC 4329 version= parameter, we also want a pragma for
> > in-script-content version assertion:
> > use version 6;"
> > See the full response  for full context.
> > Besides an es-discuss thread, I think that what is really needed is an
> > harmony proposal. How to opt-in for ES6 is outside of the scope of pure
> > ECMAScript (especially if it's with playing with the HTML script tag
> > @type attribute), but let's face it, web devs need this information and
> > a wiki page on the topic would be handy.
> > At the time of reading Brendan's response, I didn't have anything to add
> > syntax features. Syntax features that are NOT backward compatible with
> > ES3. If you use one of these features, your script break in older
> > browsers (unlike new HTML elements and CSS rules).
> > I don't see an alternative to versionning. Smarter people are welcome to
> > jump in, I guess.
> > David
> > 
> > 
> > Le 19/12/2011 11:49, Peter van der Zee a écrit :
> >> https://lists.webkit.org/pipermail/webkit-dev/2011-December/018924.html
> >> ``use version 6;``
> >> In which thread on esdiscuss should I have read about that?
> >> - peter
> >> _______________________________________________
> >> 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
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