Nonconstructors

[J Decker]

function Entity() {
if (this instanceof Entity) throw new Error("Please do not call with new");
}

oh the other side; you can bind this to a simple function call...


function f() {
}
var fWithThis = f.bind( {} /*Something to use as 'this' */ )

call with fWithThis()

and f's this will be the object you passed to bind.

On Mon, Apr 24, 2017 at 1:42 PM, Raul-Sebastian Mihăilă <
raul.mihaila at gmail.com> wrote:

> I have a dilemma. I like how typically the built-in methods are not
> constructors (like Array.prototype.forEach). I have cases in which I'm
> creating a function in which I want to use `this` but I would like the
> function to not be constructible. There are ways of doing this:
> - checking new.target - but you have to check and the last time I checked
> uglifyjs was failing because of it.
> - ({function() { ... }}).function - but this requires creating an object
> every time, so it's ugly.
>
> It would probably be too much to add a new kind of function definition,
> but I was wondering if anybody ever cared about this kind of things. For
> instance, would people usually expect frameworks/libaries or Javascript
> itself to not make functions constructible if they're not meant to be?
>
> _______________________________________________
> es-discuss mailing list
> es-discuss at mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
>
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