Normalise size expressions during unification. #2281
Draft
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Outdated suggestions cannot be applied.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.
This allows arithmetic expressions involving constant integers to be considered equal, e.g. 3+2 now unifies with 5 (or with 6-1 for that matter).
This is a fairly safe extension, because it only applies to cases that would previously have been an error, and it only makes size expressions smaller. It is also conservative in the sense that it does not constrain future extensions to e.g. allow algebraic rearrangement of sizes during unification.