The real reason people need named arrow functions, the biggest use case is
for event handlers.
```js
let p = new Promise((resolve, reject) =>
setTimeout((x => () => x(x))(handler => {
onNotNeeded(() => clearTimeout(handler));
// `return` is to take advantage of TCO
return doSomethingAsync(err => {
if (err != null) return reject(err)
else return resolve();
});
}));
```
By the way, the way I created a self reference is a complete lambda
calculus hack.
<deviation>
If you'd like your eyes to bleed, here's one that is purely out if lambdas.
I couldn't help myself.
```js
let p = new Promise((resolve, reject) =>
setTimeout((x => () => x(x))(h =>
x => y => y(x()))(
onNotNeeded(() => clearTimeout(h)))(
doSomethingAsync(e =>
if (err != null) return reject(err)
else return resolve();
});
}));
```
On Tue, Aug 11, 2015, 20:45 Leonardo Wolter <leocwol...@gmail.com> wrote:
> Well, I found out arguments is actually a reserved word too haha
>
> About that:
>
> If they're not from the tiny set of remaining reserved words
> (enum, anyone?), they can be users' identifiers, and have to be based
> contextually on some enclosing syntax, like yield is.
>
> That could be it, right? Since it would be only available at arrow
> functions(anon functions too?)
>
> 2015-08-11 21:42 GMT-03:00 Leonardo Wolter <leocwol...@gmail.com>:
>
>> Yeah., that's what I meant.
>>
>> My proposal is not a keyword, but an hidden variable included at
>> functions (e.g. arguments).
>> Does arrow functions have any limitations about that?
>>
>> 2015-08-11 21:35 GMT-03:00 Daniel Ehrenberg <dehrenb...@chromium.org>:
>>
>>> I assume you mean more like this (without factorial):
>>>
>>> x.map((x) => do {
>>> if (x <= 1) {
>>> 1;
>>> } else {
>>> x * recur(x - 1)
>>> }
>>> });
>>>
>>> One issue is that it's hard to add keywords to JavaScript at this
>>> point. If they're not from the tiny set of remaining reserved words
>>> (enum, anyone?), they can be users' identifiers, and have to be based
>>> contextually on some enclosing syntax, like yield is.
>>>
>>> Another downside is that then, arrow functions have a distinct and
>>> less powerful method of recursing (e.g., nested functions won't be
>>> able to see the binding to the outer one).
>>>
>>> Dan
>>>
>>> On Tue, Aug 11, 2015 at 5:30 PM, Leonardo Wolter <leocwol...@gmail.com>
>>> wrote:
>>> > What about a clojure like recur hidden variable binded to the
>>> bottom-level
>>> > function?
>>> >
>>> > x.map(factorial(x) => do {
>>> > if (x <= 1) {
>>> > 1;
>>> > } else {
>>> > x * recur(x - 1)
>>> > }
>>> > });
>>> >
>>> > 2015-08-11 21:26 GMT-03:00 Daniel Ehrenberg <dehrenb...@chromium.org>:
>>> >>
>>> >> In addition to being hard to parse in general, I don't think this
>>> >> would play very well with the async/await proposal
>>> >> https://tc39.github.io/ecmascript-asyncawait/ , which wants to have
>>> >> arrow functions like
>>> >>
>>> >> async (x) => ...
>>> >>
>>> >> Because we can't count on async as a keyword, your proposal would
>>> >> create an ambiguity.
>>> >>
>>> >> On Tue, Aug 11, 2015 at 1:49 PM, Jacob Parker <
>>> jacobparker1...@gmail.com>
>>> >> wrote:
>>> >> > I did look, but couldn’t find anything on named arrow functions
>>> were not
>>> >> > included. I do sometimes find cases where I want recursion inside a
>>> class
>>> >> > function definition, and still need access to `this`. Was it just
>>> seen as
>>> >> > syntax bloat, or were there any complications to implementing it?
>>> >> >
>>> >> > Obviously a contrived example, but something like this (using do
>>> syntax
>>> >> > too)
>>> >> >
>>> >> > x.map(factorial(x) => do {
>>> >> > if (x <= 1) {
>>> >> > 1;
>>> >> > } else {
>>> >> > x * factorial(x - 1)
>>> >> > }
>>> >> > });
>>> >> >
>>> >> > _______________________________________________
>>> >> > es-discuss mailing list
>>> >> > es-discuss@mozilla.org
>>> >> > https://mail.mozilla.org/listinfo/es-discuss
>>> >> _______________________________________________
>>> >> es-discuss mailing list
>>> >> es-discuss@mozilla.org
>>> >> https://mail.mozilla.org/listinfo/es-discuss
>>> >
>>> >
>>>
>>
>>
> _______________________________________________
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> https://mail.mozilla.org/listinfo/es-discuss
>
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