Ecma/TC39 Meeting – May 23 2013

link May 23 Meeting Notes

(by Erik Arvidsson)

John Neumann (JN), Allen Wirfs-Brock (AWB), Eric Ferraiuolo (EF), Erik Arvidsson (EA), Luke Hoban (LH), Doug Crockford (DC), Yehuda Katz (YK), Sam Tobin-Hochstadt (STH), Alex Russell (AR), Dave Herman (DH) (calling in), Bernd Mathiske (BM), Andreas Rossberg (ARB), Mark Miller (MM), Tom Van Cutsem (TVC), Istvan Sebestyen (IS)

link Promises vs Monads

MM: ...Continuing from yesterday


STH: Don't like resolve but not willing to die on this hill.

AR: DOM has a bunch of ad hoc APIs to do promise like things.

YK: Mozilla is also actively working on APIs using promises.

AR: A lot of methods today return void so we can change these to return a promise. This is forward compatible.

AR: then does recursive unwrapping...

link ES6, ES7, ES8... Mark's Strawman Roadmap

LH: The important part is not the features but the process.

AWB: Can things be decoupled?

LH: These kind of structural questions are the important part

MM: Suggests "concurrency" to be the main theme.

AWB: Thought about the event loop. All we need is a processing queue... put things in the front and the back.

DH: Only need to add to the back.


STH: The callback is called at some later point.

AR: Don't think we need to specify the order.

STH: If we are going to specify promises etc we need to be able to specify things in detail. We can be loose in ES6 and then come back in ES7 and provide a more tight spec.

DH: We could specify the pending events as a set or something. Not sure if there is a consensus that we want a fast small ES7. Not opposed to a modularized approach.

AR: Are there any browsers that are not shipping stable ES6 features today.

YK: Yes. V8.

AWB: Where we have problem today is that there is a lot of interdependency.

MM: These ("concurrency") are coupled together to the event loop

AWB: We can do it as a separate non 262 spec

DH: Opposed to a separate spec. Introduces versioning confusion.

AWB: Roll up

DH: Think of all the extra overhead.

STH: Big difference with 402 since it was run by different people.

LH: Lack of confidence in new features has been an issue for implementers. Good exceptions were Object.observe and Proxies where the wiki contained a mostly complete spec.

AWB: We need to have wiki proposals be deltas to the spec.

TVC: We could have "stable" wiki pages. These would have complete spec deltas.

DH: Very concerned about over modularizing.

AWB: We need to find a way to work faster and be less monolithic.

DH: Agree. ES6 process has blocked implementation work.

LH: We are not committed to our designs.

STH: We are not resolving issues until we start to spec. We are not getting feedback until engines starts to implement.

EA: The problem is that we didn't start to spec things until very late. We had agreements on features long before there was any spec drafts for them.

YK: More from our champions before we get to concensus.

ARB: Lots of the proposals were very vague.

AWB: The more complete spec you bring to tc39 the better chance you have to reach consensus.

ARB: Lack of early spec leads to lack of early implementations...

AWB: ...which leads to lack of feedback.

LH: Not more work, just doing the work earlier before things pile up too much.

DH: Need to look at the dependency graph. Hold of the work of later feature.

ARB: We need to higher bar before we accept proposals.

MM: What we agreed to 2 years ago was that the features are the one we want to spend work on speccing.

LH: Less features to bite of.

DH: A lot of us have a hard time not getting too engage in too many features.

YK: if we focused more effort on managing the overall complexity instead of getting stuck on a lot of technical discussions (and nit picking).

DH: Object.observe and Proxy moved fast but are fairly isolated features

TVC: Didn't involve syntax.

AWB: With ES6 we had a long backlog.

DH: A language will have smaller and smaller complexity budgets as it grows.

AR: ES future needs events

DH: Since this is Mark's wishlist people will throw in their pet features.

MM: This is the direction I am going to work.

LH: There is a page on the wiki outlining the goals.

LH: Looking for 2 things: Something that would allow earlier implementations. Have not brought proposals (over the last 2 years) because we have been blocked by ES6.

LH: When is the appropriate time to bring new proposals to TC39?

AWB: We are free to do what we want. We can issue 6.1, 6.2 etc or technical reports which would serve as a recommendation.

DH: We cannot exclusively work on ES6.

YK: Time at f2f is the most important. Champions can go off and do what they want.

DH: Suggests adding non ES6 items to the agenda. We will prioritize the non ES6 stuff we can get to given our limited time.

YK: We should reinstate the rule that agenda items needs links to wiki pages.

YK: Spec language is good but examples at the top are a must.

ARB: Add step after proposal. For example "stable" or "spec" which a proposal gets promoted to once there is a spec draft, good enough to start implementing.

DH: Strawman: Anything goes.

YK: Proposals used to mean approved.

DH: 3 sections: strawman, proposal, spec/candidate. Keep strawman. Work on improving as a proposal, and when mature enough promoted to next level.