On Fri, Jul 19, 2013 at 1:21 PM, Rick Waldron <[email protected]> wrote: > On Fri, Jul 19, 2013 at 1:35 PM, Tab Atkins Jr. <[email protected]> > wrote: >> >> On Thu, Jul 18, 2013 at 4:34 PM, Andy Earnshaw <[email protected]> >> wrote: >> > It's potentially a breaking change, because >> > >> > 0 < 1 < 1 >> > >> > evaluates to false in current implementations because >> > >> > (0 < 1) < 1 >> >> Luckily, this is false in the chained operations too, since "(0 < 1) >> && (1 < 1)" evaluates to false. >> >> One problem is that in current Javascript, the equality and the >> comparison operators are at different precedence levels. Python puts >> them at the same level, so that chaining can be purely left-to-right. >> There's a decent chance that code does indeed depend on this, due to >> testing equality of a comparison with a bool (which is stupid, but >> people do it). > > While this is all true, the simple answer is: > > var a = 1, b = 2, c = 3; > a < b < c; // true > > is already valid JavaScript and can't be co-opted to express new runtime > evaluation semantics.
Well, that's a bad example, because it's true with chained operators too. Let c = 1.5, though, and you get different behavior. This type of code is broken in the first place, though. Are we assuming that it's prevalent enough to cause problems? ~TJ _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
