On Tue, Nov 20, 2012 at 10:31 PM, Rick Waldron <waldron.r...@gmail.com> wrote: > On Tue, Nov 20, 2012 at 2:45 PM, Tab Atkins Jr. <jackalm...@gmail.com> > wrote: >> >> On Mon, Nov 19, 2012 at 9:46 PM, Brendan Eich <bren...@mozilla.com> wrote: >> > Tab Atkins Jr. wrote: >> >> If we did this, the only reason to continue subclassing Map is to get >> >> instanceof checks to work. Is this acceptable? >> > >> > I think it's either irrelevant (no one tests 'aUrlQuery instanceof Map') >> > or else a potential problem (cross-frame instanceof). >> >> People *do* perform those checks, though. For example, in a method >> that accepts either an array or other things, a quick "foo instanceof >> Array" check is a clear, easy way to check what you've got. > > > Be careful there, it's incredibly rare to see code that does that—which is
I don't agree. I see often see instanceof, both with Array and with other objects. This danger you and everybody speaks of only applies to cross-frame scripts. And while this danger is real (and I don't mean to make it sound like it isn't), I think you should first consider the amount of people actually doing cross frame scripting because it's not something most people touch frequently, if at all. Any studies to get such numbers? - peter _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
