3960: ellipsis in tuple patterns r=JoshMcguigan a=JoshMcguigan
This PR lowers ellipsis in tuple patterns. It fixes a bug in the way ellipsis were previously lowered (by replacing the ellipsis with a single `Pat::Wild` no matter how many items the `..` was taking the place of).
It also uses this new information to properly handle `..` in tuple struct patterns when perform match statement exhaustiveness checks.
While this PR provides the building blocks for match statement exhaustiveness checks for tuples, there are some additional challenges there, so that is still unimplemented (unlike tuple structs).
Co-authored-by: Josh Mcguigan <joshmcg88@gmail.com>
E.g.
```
trait Trait {
type Item: SomeOtherTrait;
}
```
Note that these don't simply desugar to where clauses; as I understand it, where
clauses have to be proved by the *user* of the trait, but these bounds are proved
by the *implementor*. (Also, where clauses on associated types are unstable.)
Like `Iterator<Item: SomeTrait>`.
This is an unstable feature, but it's used in the standard library e.g. in the
definition of Flatten, so we can't get away with not implementing it :)
This fixes the a bug when merging imports from the second line when it already has a comma it would previously insert a comma.
There's probably a better way to check for a COMMA.
This also ends up with a weird indentation, but rust-fmt can easily deal with it so I'm not sure how to resolve that.
Closes#3832
3938: fix missing match arm false positive r=flodiebold a=JoshMcguigan
This fixes#3932 by skipping the missing match arm diagnostic in the case any of the match arms don't type check properly against the match expression.
I think this is the appropriate behavior for this diagnostic, since `is_useful` relies on all match arms being well formed, and the case of a malformed match arm should probably be handled by a different diagnostic.
Co-authored-by: Josh Mcguigan <joshmcg88@gmail.com>
3955: Align grammar for record patterns and literals r=matklad a=matklad
The grammar now looks like this
[name_ref :] pat
bors r+
🤖
Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>
3925: Implement assist "Reorder field names" r=matklad a=geoffreycopin
This PR implements the "Reorder record fields" assist as discussed in issue #3821 .
Adding a `RecordFieldPat` variant to the `Pat` enum seemed like the easiest way to handle the `RecordPat` children as a single sequence of elements, maybe there is a better way ?
Co-authored-by: Geoffrey Copin <copin.geoffrey@gmail.com>
3944: Look up trait impls by self type r=matklad a=flodiebold
This speeds up inference in analysis-stats by ~30% (even more with the recursive solver).
There's a slight difference in inferred types, which I think comes from pre-existing wrong handling of error types in impls, so I think it's fine.
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
