2009/12/8 Brendan Eich <bren...@mozilla.com>: > On Dec 8, 2009, at 11:38 AM, Mike Samuel wrote: > >>> Agreed, but Erik's point here was about instanceof. Not only mutable >>> __proto__, but mutable bindings for constructors, and the issue of >>> multiple >>> global objects with their unrelated suites of builtin constructors, make >>> instanceof less than ideal for deciding "array-like". >> >> Ah ok. I agree with Erik then. Even moreso, instanceof doesn't work >> cross context. > > Yes (what I meant by "multiple global objects"). > > >>> In ES1-5, length is not enumerable for Array, String, and arguments >>> objects. >>> Anything array-like, same deal or it's not "like" enough. >> >> Maybe I'm imagining things, but I'm pretty sure that on some browsers >> length is enumerable on arr in >> var arr = [1,2,3] >> arr.length = 2; > > That would be a straight-up conformance bug: > > js> a = [1,2] > [1, 2] > js> a.length > 2 > js> for (i in a)print(i) > 0 > 1 > js> a.length = 0 > 0 > js> for (i in a)print(i) > js> > > Name names, take prisoners! Which browser(s)?
Sorry. I can't repeat it on anything I have installed. Maybe just a ghost of late-night-debugging-sessions past. > /be > _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
