Derive Equality on the semantic index after all#1218
Open
lionel- wants to merge 2 commits into
Open
Conversation
Allows Salsa comparisons without depending on it (as Update would)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
@DavisVaughan I thought we could use
no_eqinstead of the Eq/PartialEq derivation, but that's not the case. You still need either Eq, or derive/implementsalsa::Updatefor updating the value in the Salsa storage. The latter also does deep comparisons.I think Eq/PartialEq is better for oak_semantic because it feels useful to keep it completely independent of salsa.
One thing I've learned from ty is that they wrap symbol tables and use-def maps in
Arcso that the comparisons are cheap. We now do the same, hopefully that addresses your concern about performance.Also note that ty uses a
no_eqattribute on their AST pointer inDefinition. This needsDefinitionto be#[salsa::tracked](the attribute only applies inside salsa-managed structs) and an Update derive. In our case we don't need all this complexity since our AST pointer type is very cheap to compare (a kind and a range).