On Mon, Jul 22, 2013 at 5:25 AM, Brendan Eich <[email protected]> wrote:
> This is the part we can't determine. "The web" is not just the > Google-indexable (by what user agent?) part, but paywalled and intranet > content as well. I've written before that finding true positives helps > reject a proposed incompatible change, but finding no positives does not > prove that we can make the change. > > Furthermore, the first browser to roll the dice and face breakage loses, > making implementors generally unwilling to take even likely-small risks. > This browser Prisoner's Dilemma can be helped by cooperation, e.g., among > TC39ers, but even then only for a big enough payoff. See the typeof null == > "null" attempt early in ES6 development for an example. > typeof null == "null" is a different case though. typeof is a requirement for checking the existence of pre-declared variables, so you could expect something like, if (typeof someVar === "object" && someVar === null), to appear at least in a few places on the web. Tab's saying that this proposal wouldn't break much (if anything) because code isn't written like this anywhere: it wouldn't be readable or reliable. Writing a < b < c in ES<=5 would be either stupidity or ignorance (in the case of the latter then this proposal would probably fix more code than it breaks). For equality, there might be a problem where code is written like, if (a === b === true), where a and b are something other than booleans. I could maybe see an outside chance that this appears somewhere on the web or an intranet, but maybe there's a way we can deal with it so it doesn't break backwards compatibility. "use chained comparisons";, anyone? ;-)
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