Agenda for subgroup meeting - December 1, 2020

[tlively]

The next subgroup meeting is December 1, 2020 at 9am PST (6pm CET). As with other Wasm meetings, we'll host this on Zoom.

No registration required if you attended a previous meeting. Fill out the form here if it's your first time: https://forms.gle/JehrAB4gWbtHjybt9.

Please respond to this issue with topics for the agenda.

Agenda:

None yet.

[RossTate]

Would it be useful for me to give a presentation on undecidability of various type systems? I'll try to connect to well-known languages when possible. In particular, there are many simple features that we take for granted but which are actually undecidable (or at least for more complicated than one would realize), and it can be useful to be aware of these pitfalls and the existing techniques for hurdling over them.

[tlively]

Yes, this sounds useful. How long do you think the presentation would be?

[RossTate]

It's the sort of presentation that could easily be structured as a bunch of small lessons. This means I could just present however many lessons fit the available time and leave leftover lessons for some future meeting. So if no other agenda item comes up, I can take the whole hour, but this might be the sort of material that's best absorbed in smaller doses :)

[tlively]

That sounds great. Let's see what other agenda items come in and we can fill extra time with those mini-presentations as we see fit.

[RossTate]

Given the issue in #160, one thing I could give a presentation on is how to encode graph coloring into type-checking. Although that issue is specifically about multiple bounds and type annotations, the overall pattern is common and easy to fall into, so it'd be useful to have more eyes for catching the pattern. Follow that, it'd also make sense to give a presentation on how other systems address this problem and how those solutions can and cannot be adapted to WebAssembly.

But that combination would take a whole hour. So there are other type-theory presentations I could give in shorter time to leave room for another presentation.

[tlively]

Sounds good 👍 If anyone else has pressing topics to discuss, we can fit them in and do a shorter type-theory presentation, but otherwise lets do the full hour presentation.

[titzer]

I won't be able to attend, but +1 for providing a list of examples for undecidability.

[tlively]

The meeting notes PR has been created: WebAssembly/meetings#681