20.08.2014, 22:47, "Brendan Eich" <[email protected]>: > Alex Kocharin wrote: >> Still doesn't make much sense... This pattern (this instanceof ...) breaks >> another pattern (BaseClass.call(this)). Why first one is deprecated, not the >> second one? > > Fair point, and a topic at the last TC39 meeting was to *finally* add a > way in JS to tell whether your constructor function was called via new > or directly. >> I mean, I was able to subclass such a class with prototype injection >> without any issues, and it feels more natural in javascript after all. > > You mean using `new`? Mileage varies, but I agree that client code that > uses `new` well can add clarity about costs and reference uniqueness > (lack of aliasing).
I mean, not using `new`. JS is a functional language after all, and having a function that can't be called as a function is weird. If constructor supports calling it without new, I can pass it around as a function, do this for example: ``` > ['foo', 'bar'].map(Error) [ [Error: foo], [Error: bar] ] ``` With mandatory `new` this would be much less elegant. I was about to construct realistically-looking chain with [fn1, fn2, fn3].map(Promise).forEach(addThenHandler), but FF already seem to throw on it. :( _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
