Comment by osigurdson 20 hours ago
At least Go didn't take the dark path of having async / await keywords. In C# that is a real nightmare and necessary to use sync over async anti-patterns unless willing to re-write everything. I'm glad Zig took this "colorless" approach.
Synchronous Io also uses the Io instance now. The coloring is no longer "is it async?" it's "does it perform Io"?
This allows library authors to write their code in a manner that's agnostic to the Io runtime the user chooses, synchronous, threaded, evented with stackful coroutines, evented with stackless coroutines.
Except that now your library code lost context on how it runs. If you meant it to be sync and the caller gives you an multi threaded IO your code can fail in unexpected ways.
Where do you think the Io parameter comes from? If you change some function to do something async and now suddenly you require an Io instance. I don't see the difference between having to modify the call tree to be async vs modifying the call tree to pass in an Io token.