On Apr 28, 2012, at 22:24, Axel Rauschmayer <[email protected]> wrote:
> The following two rules should be everything one has to know regarding
> callable entities, in ES.next:
> 1. Method: `this` is an implicit parameter => use a method definition.
> 2. Non-method function: `this` is not an implicit parameter => use an arrow
> function.
>
> In this light, I’d rewrite Kevin’s code slightly, because, conceptually,
> `localStorage ` is a non-method function:
> const localStorage = (obj) => {
>
> Object.extend(obj, {
If I understand correctly, this approach negates the need for a mixin function
entirely - localStorage could just be an old style mixin hash.
But either way this tosses out the benefits I get from functional mixins. By
invoking the mixin instead of copying it I can a) customize it's behavior by
passing it arguments b) have the mixin add "advice" (before, after, around) to
functions of the target object.
> I think Angus’ most important point is this:
>
>> Yes, people get confused by this binding; even though it is not hard to
>> learn the rules, and I know them very well, I still trip over them
>> sometimes. But unless we are going to introduce a "hella strict" mode that
>> reverts all previous rules of |this| binding, yet another rule will just add
>> to the morass.
>
> It would be my hope that we can replace all previous rules with the two rules
> above. `apply` will mostly be replaced by the spread operator, `call` will
> mostly be replaced by calling a value. Some code such as `forEach`
> implementations that previously needed to use `call` to simulate lexical
> scoping don’t need a `thisValue` parameter for array functions.
I admire the vision but in reality the boundary between ES5 and ES6 will be
messy and drawn out - there will be no clear cut switching point. Legacy code
must live alongside the new vision. Without a new strict mode which banishes
much of the old spec (and kills my functional mixins) I'm finding it hard not
to picture chaos. (and how do you shim => anyway?)
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