Re: [webkit-dev] Preferred style for checking for undefined in our built-in JavaScript code?

2016-02-01 Thread Yusuke SUZUKI
I've just prototyped bytecode intrinsic constants; enhancing bytecode intrinsic mechanism to accept the form `@xxx`. (not `@xxx(...)`, it is already introduced). And implement @undefined with this. https://bugs.webkit.org/show_bug.cgi?id=153737 On Tue, Dec 1, 2015 at 7:00 AM, Geoffrey Garen

Re: [webkit-dev] Preferred style for checking for undefined in our built-in JavaScript code?

2015-11-30 Thread Darin Adler
> On Nov 30, 2015, at 11:57 AM, Geoffrey Garen wrote: > > For the time being, I like “x === undefined”. > > Long term, I’d like us to switch to “x === @undefined”. > > We use @ to indicate reserved words in built-ins. Currently, “@undefined" > does not exist, but the

Re: [webkit-dev] Preferred style for checking for undefined in our built-in JavaScript code?

2015-11-30 Thread Geoffrey Garen
> Seems like we should not have to wait long for the “long term”. It seems that > the built-in compiler could start magically transforming “@undefined” instead > of magically transforming “undefined” any time we like; likely a simple find > and replace job. Or it could do both during a

Re: [webkit-dev] Preferred style for checking for undefined in our built-in JavaScript code?

2015-11-30 Thread Filip Pizlo
I’ve also been guilty of: if (xxx === void 0) This is slightly better than saying “undefined”, since that’s not actually a reserved word. I believe that all of these should perform the same. We should pick one based on what looks nicest and what has the most clear semantics. -Filip

Re: [webkit-dev] Preferred style for checking for undefined in our built-in JavaScript code?

2015-11-30 Thread Chris Aljoudi
FWIW, performance seems to be equivalent: http://jsperf.com/typeof-vs-undefined-check/39 Chris https://chrismatic.io/ > On Nov 30, 2015, at 1:01 PM, Geoffrey Garen wrote: > > For the time being, I like “x === undefined”. > > Long term, I’d like us to switch to “x ===

Re: [webkit-dev] Preferred style for checking for undefined in our built-in JavaScript code?

2015-11-30 Thread Geoffrey Garen
For the time being, I like “x === undefined”. Long term, I’d like us to switch to “x === @undefined”. We use @ to indicate reserved words in built-ins. Currently, “@undefined" does not exist, but the built-in compiler magically transforms “undefined” a safe reserved word. The typeof and void

Re: [webkit-dev] Preferred style for checking for undefined in our built-in JavaScript code?

2015-11-30 Thread Brian Burg
Web Inspector’s frontend code tends to use “x === undefined”, as we’ve found it the easiest to read. > On Nov 30, 2015, at 11:57 AM, Geoffrey Garen wrote: > > For the time being, I like “x === undefined”. > > Long term, I’d like us to switch to “x === @undefined”. > > We

Re: [webkit-dev] Preferred style for checking for undefined in our built-in JavaScript code?

2015-11-30 Thread Ryosuke Niwa
On Mon, Nov 30, 2015 at 11:37 AM, Darin Adler wrote: > I see the following in some code: > > if (xxx === undefined) FWIW, I always use this style. - R. Niwa ___ webkit-dev mailing list webkit-dev@lists.webkit.org