[philocalyst]

Summary

The end of the refactoring. The adoption half of #980 and #982, copying what #978 did for the synchronous fallible API. Docs, one example, and a dev shell, no library code.

Documentation

The Rust Adapters guide gets its async continuation: the direct AsyncAdapter / AsyncBasicAdapter path, the explicit FallibleAsyncAdapter path, and the two edge-error boundaries.

The weather example

trustfall/examples/weather moves to AsyncBasicAdapter and execute_query_async(), gated behind required-features = ["async"].

To be upfront about it: its data source is a local CSV file, so there is no IO to overlap here. The example earns its place by showing the shape of an async adapter, so stream construction, the helper imports, driving the result stream; it's not actually quicker. If you'd want a better example, I can make one, just was getting tired, lmao.

Migration

None. Documentation, one example, and a dev shell.

Stack

Final PR in the stack. Depends on #982.

1. Execute synchronous queries on a stream kernel #976 — stream execution kernel
2. Make adapter errors first-class #977 — first-class adapter errors
3. Document fallible adapters and adopt them in the live demo #978 — fallible adapter docs and demo
4. Give each failed row its own error #979 — row-ordered error propagation
5. Expose the stream kernel as a native async API #980 — native async adapters
6. Add async adapter ergonomics and ordered concurrent helpers #982 — async ergonomics
7. YOU HERE — async docs and the weather example

Thanks for reading all seven of these. I know it's a lot to put in front of someone at once. If you'd like a different approach, let me know.

Validation

(CI CHECKS)

• Workspace tests, clippy, rustdoc, and formatting, with and without --all-features
• Weather example builds under --all-features