effects-examples VS context-s

Isn't a language described very similar to the (future) OCaml with effects (https://github.com/ocaml-multicore/effects-examples) added?

Sure. They probably don't mention coeffects so often because their effect system subsumes both effects (actions to be performed) and coeffects (information from the context), and it can do way more than what you're proposing. Here are some examples you may take a look. The dynamic state example in there could be adapted to act as coeffects (contexts) as you suggest. For coeffects in particular, this is a great resource. You may also be interested in Koka's documentation, as it was designed to be a language with effects and coeffects since the beginning (OCaml did only retrofit them recently).

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

Here's a post outlining the part that people are excited about. Here's the examples list if you'd like more concrete examples.

To be honest, though, despite it being cool that OCaml finally has a concrete multicore release date, I'm more interested in the effect handlers. After reading these slides and this article on the topic I realised OCaml getting support for algebraic effects is way more interesting than the parallelism support.

I think it's not discussed enough how things like language features shape how library APIs are formed. People usually seem to only consider the question "how would I use this feature?" and not "how would the standard library look like with this feature?", which is surprising given how much builtin libraries affect the pleasantness of a language.

One of the things I'm excited to see is the cap-std project for Rust [0] given what Pony [1] has demonstrated is possible with capabilities. I'm also hoping that languages like Koka [2] and OCaml [3] will demonstrate interesting use cases for algebraic effects.

[0] https://github.com/bytecodealliance/cap-std

[1] https://www.ponylang.io/discover

[2] https://koka-lang.github.io

[3] https://github.com/ocaml-multicore/effects-examples

Just randomly stumbled upon this example, which is exactly what you were asking about. It is a strongly-typed fork() that uses first-class effects.