[kcsrk]

Rather than a full effect system, we're very likely to have lexically scoped "checked" effects with the help of modal types. I briefly talked about it at the end of my ICFP keynote: https://icfp22.sigplan.org/details/icfp-2022-papers/48/Retro...

There are other cool stuff that is being worked on, which I am very excited about: https://discuss.ocaml.org/t/jane-street-compiler-development.... Hopefully, we will see many of these make it into OCaml 6.

[jon_smark]

Thanks for the reply. I hope that the array and list comprehensions land soon in upstream; it's a useful and hopefully not-too-controversial feature.

I'm more ambivalent regarding the local allocations and the unboxed types. I totally understand why they'd be useful when you are trying to squeeze every last drop of performance, but they do require a not-so-trivial complexification of the language.

[kcsrk]

The local types are less invasive than the full support for typed effects. In particular, they are opt-in and associated complexity is pay-as-you-go. In my initial experiments, they seemed pretty nice to program with.