eioio VS ocaml-effects-tutorial

the actual project (Readme has some code samples): https://github.com/ocaml-multicore/eio

For 5.0+ you might want to look at https://github.com/ocaml-multicore/eio for how effects can make async much more pleasant

Great post! I would love to see this extended to OCaml 5 (with eio) and Haskell

Second, effects enable a new style of concurrency libraries like eio that forgoes the need to wrap every asynchronous computation in a monad.

> This is realllly unidiomatic in real world Haskell.

Whether idiomatic or not does not matter. It proves my point:

IO won't save you, and even very mundane effects are not part of the game…

Idris is the "better Haskell" sure, but the effect tracking is still part of the uncanny valley (still IO monad based).

Koka is a toy, and Frank mostly "only a paper" (even there is some code out there).

The "Frank concept" is to some degree implemented in the Unison language, though:

https://www.unison-lang.org/learn/fundamentals/abilities/

Having a notion of co-effects (or however you please to call them) is imho actually much more important than talking about effects (as effects are in fact neither values nor types—something that all the IO kludges get wrong).

I think the first practicable approach in the mainstream about this topic will be what gets researched and developed for Scala. The main take away is that you need to look at things form the co-effects side first and foremost!

In case anybody is interested in what happens in Scala land in this regard:

https://www.slideshare.net/slideshow/embed_code/key/aLE9M37d...

https://docs.scala-lang.org/scala3/reference/experimental/cc...

But also the development in OCaml seems interesting:

https://github.com/ocaml-multicore/eio#design-note-capabilit...

Look mom, "effects", but without the monad headache!

To enable access to all these features, an exciting new library called Eio is being developed. It uses a new paradigm of direct-style concurrent I/O programming, without the need for monads or async/await, thus avoiding the function colour problem.

I found this tutorial: https://github.com/ocamllabs/ocaml-effects-tutorial

Good question!

https://github.com/ocaml-multicore/effects-examples has links to tutorials and examples for how effects can be used.

There's also some slides from KC's talk on effect handlers https://kcsrk.info/slides/handlers_edinburgh.pdf and materials from the CUFP 17 tutorial: https://github.com/ocamllabs/ocaml-effects-tutorial

https://gopiandcode.uk/logs/log-bye-bye-monads-algebraic-eff... this is also a great introduction

There are lots of informations in "Concurrent Programming with Effect Handlers" (https://github.com/ocamllabs/ocaml-effects-tutorial) on what it looks like and how it's implemented. There are also more recent informations on the September 2021 edition of the Multicore OCaml newsletter: https://discuss.ocaml.org/t/multicore-ocaml-september-2021-e..., with a link to a paper about effects in OCaml.