Hello Swift community,
For the second, focused re-review of SE-0382: Expression Macros, an enhancement was incorporated to make the expansion(of:in:) requirement async. There was no feedback on this specific change and the steering group accepted it as written. The same enhancement was carried forward to SE-0389 and subsequently accepted there for attached macros as well.
To date, however, this enhancement has never been implemented, both due to implementation complexity and because the model where macro operations have back-and-forth communication with the compiler has not been borne out.
In line with our "shrink-to-fit" process, we are incorporating edits to SE-0382 and SE-0389 that reflect the API as implemented. Notably, this does not necessarily preclude "async-ified" APIs being included at some point in the future, but it would not be as part of these proposals.
Xiaodi Wu
Review Manager, SE-0382