domenic at domenicdenicola.com (2013-09-08T00:54:01.129Z)
I am one of those on TC39 that want the visible flag. Since, in my view, the only non-mistaken need to preserve sloppy mode is as an ES3 compatibility mode and ES3 has no generators, I consider this flagging issue to be the important one. Yes, you have to read the function to know *what* it generates. But even before you've figured that out, your whole effort to read the function is different once you know you're reading a generator function. Better to know it early. Code is read much more than it is written -- at least code that matters.
On Sat, Aug 31, 2013 at 1:14 PM, Yuichi Nishiwaki < yuichi.nishiwaki at gmail.com> wrote: > OK, right. I understand my first propose does not work. :-| > So one more question is how about making '*' optional in strict mode? > (Should I separate the topic to another?) > > 2013/9/1 Brendan Eich <brendan at mozilla.com>: > > Let's not go in circles -- the primary reason for function* is because > yield > > is not reserved in JS and is used by web content as a plain identifier. > It > > is a low-precedence unary prefix operator, so cannot be contextually > > reserved by a grammatical restriction as "module" can. It needs opt-in > > syntax. > > > > Separately, some on TC39 want a flag on the function, in the head > syntax, to > > alert readers to the generator. That's a secondary reason, independent > and > > not as strong in my view. > I am one of those on TC39 that want the visible flag. Since, in my view, the only non-mistaken need to preserve sloppy mode is as an ES3 compatibility mode and ES3 has no generators, I consider this flagging issue to be the important one. Yes, you have to read the function to know *what* it generates. But even before you've figured that out, your whole effort to read the function is different once you know you're reading a generator function. Better to know it early. Code is read much more than it is written -- at least code that matters. > > > > There's nothing to "get" or "not get" about backward compatbility. It > just > > "is". :-| > > > > /be > > > >> Yuichi Nishiwaki <mailto:yuichi.nishiwaki at gmail.com> > >> August 31, 2013 12:55 PM > >> > >> I can't get the point, why you need to know if the function is a > >> generator or not at a glance? > >> > >> 1. Forcing users to mark the function as a generator is only a > >> duplication. It basically doesn't have any meaning other than > >> double-checking, and fundamental risk for the unintentional creation > >> is still not removed. > >> 2. Even if you know the function is a generator in early, you still > >> need to read the entire source code to get the information about what > >> the generator yields and when it stops. > >> _______________________________________________ > >> es-discuss mailing list > >> es-discuss at mozilla.org > >> https://mail.mozilla.org/listinfo/es-discuss > >> > >> Oliver Hunt <mailto:oliver at apple.com> > >> August 31, 2013 12:25 PM > >> > >> On Aug 31, 2013, at 12:15 PM, Yuichi Nishiwaki< > yuichi.nishiwaki at gmail.com> > >> wrote: > >> > >>> Hi all, I just found a post that the current generator syntax > >>> (function *) seems have decided in: > >>> > >>> https://mail.mozilla.org/pipermail/es-discuss/2011-July/015799.html > >>> > >>> According to the post, the biggest reason the star syntax is adopted > >>> for now is that you cannot write empty generators with star-less > >>> functions in a consistent simple way. But the situation has changed, > >>> and in the current spec (rev 17) yield* is now capable of taking any > >>> kind of iterator, so you can make empty generators just like > >>> > >>> ```js > >>> function * () { > >>> yield * []; > >>> } > >>> ``` > >>> > >>> This looks enough good and simple at least to me. And I wonder if even > >>> now generators still need to be declared with 'star's. What are the > >>> advantages of 'star'ed generators rather than 'star'-lesses? If not > >>> exist, shouldn't it be removed (for the simplicity)? > >>> > >> > >> The reason for the * is substantially (IIRC) to make it possible for an > >> engine > >> to help prevent developers from unintentionally creating a generator > >> function, > >> and to make it possible for someone attempting to use a function to > >> identify immediately > >> whether it is a generator or a regular function. > >> > >> --Oliver > >> > >>> Thank you. > >>> > >>> -- > >>> Yuichi Nishiwaki > >>> _______________________________________________ > >>> es-discuss mailing list > >>> es-discuss at mozilla.org > >>> https://mail.mozilla.org/listinfo/es-discuss > >> > >> > >> _______________________________________________ > >> es-discuss mailing list > >> es-discuss at mozilla.org > >> https://mail.mozilla.org/listinfo/es-discuss > >> > >> Yuichi Nishiwaki <mailto:yuichi.nishiwaki at gmail.com> > >> August 31, 2013 12:15 PM > >> > >> Hi all, I just found a post that the current generator syntax > >> (function *) seems have decided in: > >> > >> https://mail.mozilla.org/pipermail/es-discuss/2011-July/015799.html > >> > >> According to the post, the biggest reason the star syntax is adopted > >> for now is that you cannot write empty generators with star-less > >> functions in a consistent simple way. But the situation has changed, > >> and in the current spec (rev 17) yield* is now capable of taking any > >> kind of iterator, so you can make empty generators just like > >> > >> ```js > >> function * () { > >> yield * []; > >> } > >> ``` > >> > >> This looks enough good and simple at least to me. And I wonder if even > >> now generators still need to be declared with 'star's. What are the > >> advantages of 'star'ed generators rather than 'star'-lesses? If not > >> exist, shouldn't it be removed (for the simplicity)? > >> > >> Thank you. > >> > >> -- > >> Yuichi Nishiwaki > >> _______________________________________________ > >> es-discuss mailing list > >> es-discuss at mozilla.org > >> https://mail.mozilla.org/listinfo/es-discuss > >> > > > _______________________________________________ > es-discuss mailing list > es-discuss at mozilla.org > https://mail.mozilla.org/listinfo/es-discuss > -- Cheers, --MarkM -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20130831/30a26265/attachment.html>