Stream: wg-async-foundations

Topic: weekly meeting 2019.05.14


davidtwco (May 14 2019 at 17:05, on Zulip):

Is there a meeting today?

davidtwco (May 14 2019 at 17:05, on Zulip):

cc @WG-async-await

davidtwco (May 14 2019 at 17:05, on Zulip):

My calendar has an event for just now.

davidtwco (May 14 2019 at 17:12, on Zulip):

I suppose not. For anyone who shows up later, here's my update for this past week:

Taylor Cramer (May 14 2019 at 17:19, on Zulip):

@nikomatsakis did you have a chance to look into the lifetime issues on friday?

tmandry (May 14 2019 at 18:18, on Zulip):

On #52924 I'm nearly done, pending some discussion around the semantics of drop and StorageDead (see this topic)

tmandry (May 14 2019 at 18:18, on Zulip):

I plan to open a PR with only the MIR/analysis changes so we can discuss

Giles Cope (May 21 2019 at 17:12, on Zulip):

Sorry I've been ill, but better now. Shrank the problem to a smaller repro - I think the question is firstly is the span_bug! definitely a span_bug in this case as it's an existential type so maybe you wouldn't expect the type to be defined at that point?

Giles Cope (May 21 2019 at 17:16, on Zulip):

One thing I am very conscious of is that once we ship async await the very next thing people will be asking for / expecting is streams created by some form of async/generator/yield construct. At the moment what we're shipping supports Future but as far as I can see doesn't really support Stream.

Taylor Cramer (May 21 2019 at 17:20, on Zulip):

@Giles Cope It's fairly easy to add support for Stream. the issue is that a proper definition of the stream trait is one which requires GATs

Taylor Cramer (May 21 2019 at 17:20, on Zulip):

It's actually just a small handful of lines to make the existing system create asynchronous generators that implement the current Stream trait

Taylor Cramer (May 21 2019 at 17:20, on Zulip):

it's a lot more work to make it support a hypothetical Stream + borrowing

Giles Cope (May 21 2019 at 17:38, on Zulip):

Yep GAT looks non-trivial. I guess releasing non-borrowable async streams probably isn't a good idea incase the implications of the borrowed async streams might take us in a different direction and we ended up with two ways of doing things...

Last update: Nov 18 2019 at 01:45UTC