On Sun, Feb 2, 2014 at 5:27 PM, Allen Wirfs-Brock <[email protected]>wrote:
> I made the change in rev 22 to make the default constructor: return > super(...args) > > However that resulted in this bug: > https://bugs.ecmascript.org/show_bug.cgi?id=2491 from Arv: > > The problem arises when we extend an old school "class" where the code > does not > explicitly set constructor. > > function B() {} > B.prototype = { ... } > class C extends B {} > new C() instanceof C // false > > The reason why this fails is that `B.prototype.constructor === Object` so > `new > C()` returns `Object()`. > > The work around is to set `B.prototype.constructor = B` but I feel like the > problem, adding return added solved, is smaller than the problem it > introduces. > > > I'm inclined to agree with Arv's conclusion. What do you think? > I think this change should be removed. In fact, I didn't realize this was actually added to the spec draft--I haven't had the time to review this draft as I usually do. The fact that JavaScript currently requires `B.prototype.constructor = B` to get the right constructor is generally seen as a language bug (whether that's accurate or not, I don't care to argue the point, subjectively it sucks). While I completely understand the motivation for the requested change, it's an edge case at best and apparently I missed the part of the conversation where there was an agreement to make the change. Rick
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