Add real salsa dependency to twill-check #42

New issue

Closed

opened 2026-08-20 19:06:07 +00:00 by jacksonopp · 0 comments

jacksonopp commented

2026-08-20 19:06:07 +00:00

Owner

Use the real salsa crate (salsa-rs), not a hand-rolled memoization layer, for the checker's incremental architecture.

Decided in #1's discussion: salsa's auto-discovered dependency tracking (recording what each tracked fn reads, invalidating exactly the affected downstream queries) is the actual hard part project-plan.md's Step 9 note warns about. A hand-rolled cache without that tracking just defers the same problem to Step 9 under worse conditions. rust-analyzer is built on the same crate for the same IDE-incremental-frontend shape, so it's proven for this use case.

Scope: add the salsa dependency to the workspace/crate, pick and pin a version, confirm it builds against rustc 1.97 / edition 2021.

Use the real salsa crate (salsa-rs), not a hand-rolled memoization layer, for the checker's incremental architecture. Decided in #1's discussion: salsa's auto-discovered dependency tracking (recording what each tracked fn reads, invalidating exactly the affected downstream queries) is the actual hard part project-plan.md's Step 9 note warns about. A hand-rolled cache without that tracking just defers the same problem to Step 9 under worse conditions. rust-analyzer is built on the same crate for the same IDE-incremental-frontend shape, so it's proven for this use case. Scope: add the salsa dependency to the workspace/crate, pick and pin a version, confirm it builds against rustc 1.97 / edition 2021.

jacksonopp added this to the Step 2: Core Type Checker milestone

2026-08-20 19:06:07 +00:00

jacksonopp added the

user-story

label

2026-08-20 19:06:07 +00:00

jacksonopp referenced this issue

2026-08-20 19:06:17 +00:00

Design the checker crate skeleton (crates/twill-check) #1

jacksonopp added this to the twill project

2026-08-20 19:06:38 +00:00

jacksonopp referenced this issue from a pull request that will close it,