Stream: t-compiler/wg-nll

Topic: weekly meeting December 5


pnkfelix (Dec 05 2018 at 16:23, on Zulip):

FYI @WG-compiler-nll, im not 100% sure I’ll be available to run tonight’s meett

pnkfelix (Dec 05 2018 at 16:24, on Zulip):

Will try; but I’ll be on single parent duty at the time so it depends on collective sleep schedules of three children

pnkfelix (Dec 05 2018 at 20:20, on Zulip):

here's a ping to @WG-compiler-nll ; I'm hoping to be able to run the meeting (though my 2.5 year old has not yet fallen asleep, so its up in the air still...)

pnkfelix (Dec 05 2018 at 20:21, on Zulip):

but, yeah, the meeting is in ~9 minutes

pnkfelix (Dec 05 2018 at 20:33, on Zulip):

okay so lets see how this goes (i've got a bassinet right by my knees)

Santiago Pastorino (Dec 05 2018 at 20:33, on Zulip):

hi @pnkfelix :)

pnkfelix (Dec 05 2018 at 20:33, on Zulip):

as usual the triage paper is here

pnkfelix (Dec 05 2018 at 20:33, on Zulip):

so one thing I wanted to try to address in today's meeting

pnkfelix (Dec 05 2018 at 20:34, on Zulip):

is that some time ago I put up some "Triage links" in that document

pnkfelix (Dec 05 2018 at 20:34, on Zulip):

But the links as they were originally designed went stale; they were e.g. referecning the 2018 milestone, which is no longer something that is dictating our work flow

pnkfelix (Dec 05 2018 at 20:35, on Zulip):

I tried to update those links today (I literally just now made yet another change to them)

pnkfelix (Dec 05 2018 at 20:36, on Zulip):

but I noticed that at some point, I assume while I was on leave, we added an NLL-priority label?

pnkfelix (Dec 05 2018 at 20:36, on Zulip):

do we actually need such a label? Why didn't we use the combination of A-NLL + P-high to mean that?

pnkfelix (Dec 05 2018 at 20:37, on Zulip):

anyway I put up two separate links (for the P-high list and the NLL-priority list), because I don't know how to say "label:P-high OR label:NLL-priority" in the github issue search box.

pnkfelix (Dec 05 2018 at 20:39, on Zulip):

Anyway the good news is that we don't have any unassigned P-high nor NLL-priority issues

pnkfelix (Dec 05 2018 at 20:39, on Zulip):

so either we're doing great at assigning work, or badly at finding work to do.

pnkfelix (Dec 05 2018 at 20:39, on Zulip):

I did nominate #42574 for discussion

pnkfelix (Dec 05 2018 at 20:39, on Zulip):

because I wanted to figure out how we should tag it

pnkfelix (Dec 05 2018 at 20:41, on Zulip):

(I know a number of you have clamored for the improved diagnostics from NLL's region inference and bemoaned the fact that migration mode hides those improvements)

pnkfelix (Dec 05 2018 at 20:41, on Zulip):

Figuring out how we are going to label (i.e. categorize) bugs like this seems like an important part of the story for how we're going to motivate ditching the migration mode.

pnkfelix (Dec 05 2018 at 20:43, on Zulip):

If people have thoughts on how we should keep track of such things, I'm all ears. (Maybe its just a matter of treating it like all the other NLL-fixed-by-NLL bugs; which are supposed to stay open until NLL is the default in all editions)

pnkfelix (Dec 05 2018 at 20:44, on Zulip):

Hey, @Matthew Jasper regarding the gist you wrote on 2PB -- do you think that could be a path forward towards actually documenting them?

pnkfelix (Dec 05 2018 at 20:44, on Zulip):

(there's an issue somewhere that basically says "we need to document these darn things")

Matthew Jasper (Dec 05 2018 at 20:45, on Zulip):

I do want to get good NLL documentation for the Reference done at some point, but it's quite tiring writing it up.

pnkfelix (Dec 05 2018 at 20:46, on Zulip):

yeah doing docs well is hard

pnkfelix (Dec 05 2018 at 20:46, on Zulip):

(and often thankless)

Matthew Jasper (Dec 05 2018 at 20:46, on Zulip):

I guess also rustc-guide docs as well

blitzerr (Dec 05 2018 at 20:47, on Zulip):

Hmm.... People are definitely appreciate of good docs, @pnkfelix do you mean they are not vocally appreciative about it?

Matthew Jasper (Dec 05 2018 at 20:48, on Zulip):

Yes, and it's hard not to want to create rustc PRs after documenting the edge cases of many things.

Matthew Jasper (Dec 05 2018 at 20:49, on Zulip):

If people have thoughts on how we should keep track of such things, I'm all ears. (Maybe its just a matter of treating it like all the other NLL-fixed-by-NLL bugs; which are supposed to stay open until NLL is the default in all editions)

I think that just marking it with NLL-fixed-by-NLL or NLL-diagnostics is the way to go here.

pnkfelix (Dec 05 2018 at 20:50, on Zulip):

@blitzerr I just think that sometimes the effort expended "doing it right" is not actually visible to the end audience.

pnkfelix (Dec 05 2018 at 20:50, on Zulip):

(Consider the old adage about "forgive me for the length of this letter; I had not time to make it shorter")

pnkfelix (Dec 05 2018 at 20:51, on Zulip):

Okay anyway did anyone else want to discuss anything? @davidtwco , if I can tie off #56537 then I might be able to subsequently help you look at the fails in PR #55937

Matthew Jasper (Dec 05 2018 at 20:51, on Zulip):

... until NLL is the default in all editions

Do we still want to move to migrate on all editions for 1.33?

pnkfelix (Dec 05 2018 at 20:51, on Zulip):

is that the timeline? I have no idea

Jake Goulding (Dec 05 2018 at 20:52, on Zulip):

Oooh, 1.33, that's exciting

pnkfelix (Dec 05 2018 at 20:52, on Zulip):

I figured we would at least have to see what the feedback is once the edition is out.

davidtwco (Dec 05 2018 at 20:52, on Zulip):

Okay anyway did anyone else want to discuss anything? @davidtwco , if I can tie off #56537 then I might be able to subsequently help you look at the fails in PR #55937

That'd be great.

lqd (Dec 05 2018 at 20:52, on Zulip):

I'm guessing the feedback coming real soon with the edition will be key in deciding the timeline ?

pnkfelix (Dec 05 2018 at 20:52, on Zulip):

@lqd exactly what I was thinking

Matthew Jasper (Dec 05 2018 at 20:52, on Zulip):

The last time it was discussed, I think we were hoping to move to migrate on 2015 in 1.33, so that we had some edition feedback time.

Matthew Jasper (Dec 05 2018 at 20:53, on Zulip):

Do we think that any currently open issues would block it?

pnkfelix (Dec 05 2018 at 20:53, on Zulip):

I think it would make sense to maybe hope for the best, i.e. assume that everyone loves NLL and is clamoring for it to be turned on across the board

lqd (Dec 05 2018 at 20:53, on Zulip):

also interesting wrt to when to switch off of migrate mode

pnkfelix (Dec 05 2018 at 20:53, on Zulip):

and thus make our internal plans based on that best case scenario, in terms of how fast we should move

pnkfelix (Dec 05 2018 at 20:53, on Zulip):

which I guess is what then yields the 1.33 target version

pnkfelix (Dec 05 2018 at 20:54, on Zulip):

Do we think that any currently open issues would block it?

this is a good Q

davidtwco (Dec 05 2018 at 20:54, on Zulip):

I can't imagine that there are issues that wouldn't block NLL in 2018 but would in 2015?

pnkfelix (Dec 05 2018 at 20:55, on Zulip):

for turning on migrate mode in all editions, I would imagine we would probably only consider NLL-sound issues

pnkfelix (Dec 05 2018 at 20:55, on Zulip):

there are still 8 open issues there: https://github.com/rust-lang/rust/issues?utf8=%E2%9C%93&q=is%3Aissue+is%3Aopen+label%3AA-NLL+label%3ANLL-sound

pnkfelix (Dec 05 2018 at 20:55, on Zulip):

though ... let me go untag that from #54528

Matthew Jasper (Dec 05 2018 at 20:56, on Zulip):

Also https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3ANLL-complete ? Most don't seem to be that important, as they're not regressions

pnkfelix (Dec 05 2018 at 20:57, on Zulip):

the reason I'm skipping NLL-complete is that migrate mode means we can lower their priority

pnkfelix (Dec 05 2018 at 20:57, on Zulip):

The NLL-complete issues should block turning off migrate mode

pnkfelix (Dec 05 2018 at 20:57, on Zulip):

I don't think we have a target date for that yet

pnkfelix (Dec 05 2018 at 20:58, on Zulip):

(though, as you point out, the set of NLL-complete issues is indeed quite ... short ... seems ... too short ...?)

Matthew Jasper (Dec 05 2018 at 20:58, on Zulip):

#51915 is the only "regression" that's marked NLL-complete

Matthew Jasper (Dec 05 2018 at 20:58, on Zulip):

Well, a lot got moved to NLL-polonius

Jake Goulding (Dec 05 2018 at 20:58, on Zulip):

does "turning off migrate mode" imply "delete old AST borrowck"?

pnkfelix (Dec 05 2018 at 20:59, on Zulip):

@Jake Goulding I'd say that turning off migrate mode is certainly a prereq for deleting the old AST borrowck

Jake Goulding (Dec 05 2018 at 20:59, on Zulip):

(or at least unlock it)

Jake Goulding (Dec 05 2018 at 20:59, on Zulip):

yeah

Jake Goulding (Dec 05 2018 at 20:59, on Zulip):

Cause I bet that some contributors here would be very excited for that job ;-)

Matthew Jasper (Dec 05 2018 at 20:59, on Zulip):

All the things I want to remove...

Matthew Jasper (Dec 05 2018 at 21:00, on Zulip):

It's not as easy as it sounds though

pnkfelix (Dec 05 2018 at 21:00, on Zulip):

okay well that's 30 min

Matthew Jasper (Dec 05 2018 at 21:00, on Zulip):

I'm think more :knife: :grinning:

pnkfelix (Dec 05 2018 at 21:00, on Zulip):

and I think I covered everything I wanted to...

Keith Yeung (Dec 05 2018 at 21:01, on Zulip):

should we now turn our focus to :frog:?

Matthew Jasper (Dec 05 2018 at 21:01, on Zulip):

Well, some people already have

Jake Goulding (Dec 05 2018 at 21:02, on Zulip):

s/turn our focus/leap on over to/

lqd (Dec 05 2018 at 21:02, on Zulip):

niko has done exciting things lately for polonius :)

Matthew Jasper (Dec 05 2018 at 21:02, on Zulip):

I think that it's definitely something that should be back to active development.

lqd (Dec 05 2018 at 21:03, on Zulip):

I'm also assuming there would some edition related feedback and NLL work soon, instead of completely switching over to polonius ofc

Keith Yeung (Dec 05 2018 at 21:04, on Zulip):

yeah, thursday is gonna be a big day

Keith Yeung (Dec 05 2018 at 21:04, on Zulip):

which is... 2 days from now

Keith Yeung (Dec 05 2018 at 21:04, on Zulip):

no, tomorrow

Matthew Jasper (Dec 05 2018 at 21:05, on Zulip):

I think that's all I wanted to discuss then

lqd (Dec 05 2018 at 21:06, on Zulip):

then good evening / good afternoon everyone :wave:

Last update: Nov 21 2019 at 13:20UTC