The only problem I see here is you can not emulate completely `new` with ES. Why Promise add some internal slots when called with new and it does not make the same when writing `var p = Object.create(Promise.prototype); Promise.call(p, fn);`?
On Thu, Aug 21, 2014 at 5:18 AM, Andrea Giammarchi < [email protected]> wrote: > To this I'd like to add that in ES6 you don't need to explicitly invoke > inherited class constructor but rather use `super` > > True is that this `new` story makes Mixins like constructors more > difficult to use as classes becuase these cannot be invoked via `.call` or > `.apply` directly and requires a very boring `init()` like method. > > Although there's nothing for mixins or their initialization in ES6 so it's > OKish ... > > Last, but not least, since you use instanceof, I'd like to underline in > ES5 capable browser you have another pattern. > > ```js > function SelfInstance() {'use strict'; > return this || new SelfInstance; > } > ``` > > no need to use the `instanceof` check when `this` could be undefined ^_^ > > Regards > > > > > On Wed, Aug 20, 2014 at 5:55 PM, Alex Kocharin <[email protected]> wrote: > >> >> 20.08.2014, 19:18, "Claude Pache" <[email protected]>: >> > Le 20 août 2014 à 16:56, Alex Kocharin <[email protected]> a écrit : >> >> But... why? >> >> >> >> I mean, every constructor can determine if it is called without `new` >> (that "this instanceof" check on top of every other constructor). So `new` >> keyword can really be removed from everywhere except in constructors >> themselves. >> >> >> >> Using `new` does create issues. For example, you can't write "new >> require('something').Constructor(blah)", and I don't even remember how to >> put brackets right. >> >> >> >> Why make people use it? >> > >> > According to http://esdiscuss.org/notes/2013-07-25 (search for >> "anti-pattern"), allowing constructors without `new` would break >> subclassing. >> >> 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? >> >> 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. >> > > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > >
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