Design meeting: Effect-Generic Trait Declarations

[yoshuawuyts]

Summary

Hey all, it's been a minute since @rust-lang/initiative-keyword-generics has presented anything to T-lang. We've done a fair bit of work since last time we chatted, working on a series of four or so draft RFCs paving an incremental path to solving most of Rust's effect problems.

I'd love it if we could start by reading through the first draft RFC covering effect-generic trait definitions. This is a small, incremental step that we believe should be independently implementable from a broader system, and carries value on its own.

In terms of scheduling: if the first week in September is available that would be ideal. Otherwise perhaps something in October? Thanks!

Background reading

• Extending Rust's effect system - describes the motivation + gradual progression of proposals.
• Associated Effects: Flexible Abstractions for Effectful Programming - PLDI24 paper implementing effect-polymorphism for traits in the Flix programming language.
• The new effects desugaring in the compiler - explains how the refactor for ~const Trait now works in the compiler. This enables us to leverage this for more effects than just const.

About this issue

This issue corresponds to a lang-team design meeting proposal. It corresponds to a possible topic of discussion that may be scheduled for deeper discussion during one of our design meetings.

[oli-obk]

We need to update the RFC first to reflect the latest effect design (assoc types instead of const generic bool params )

Edit: oh I thought this was the effects repo, not thr lang repo 🙈

[yoshuawuyts]

Taking this off the lang calendar for now. Having had several meetings with the Flix folks conveyed most of what I was hoping to achieve by meeting.