(original author of that article here)<p>This is a blast from the past! And indeed, I use Eio these days to do direct-style IO; you can see an example of a HTTP/1.1 parser done in that style, and there's nary a monad in sight! <a href="https://tangled.org/anil.recoil.org/ocaml-requests/blob/main/lib/h1/http_read.ml" rel="nofollow">https://tangled.org/anil.recoil.org/ocaml-requests/blob/main...</a><p>OCaml's effects are similar to thethe delimcc hack used in the article, except that it's nicely integrated into OCaml 5 and very high performance; basically a stack switch: <a href="https://anil.recoil.org/papers/2021-pldi-retroeff.pdf" rel="nofollow">https://anil.recoil.org/papers/2021-pldi-retroeff.pdf</a>