My favourite thing about Haskell concurrency is that there are no colored functions [0]. Writing code in IO, or Async, or the next big thing (asychronous higher-order effect system of the future??), doesn't require language support like Python or Rust.
The one construct that unlocks this lack of colored functions, STM, did require runtime support (as opposed to language support), which at least is transparent to downstream developers
The one construct that unlocks this lack of colored functions, STM, did require runtime support (as opposed to language support), which at least is transparent to downstream developers
[0]: https://journal.stuffwithstuff.com/2015/02/01/what-color-is-...