9108: Don't show extract into variable assist for unit expressions r=jonas-schievink a=brandondong
**Reproduction:**
```rust
fn main() {
let mut i = 3;
$0if i >= 0 {
i += 1;
} else {
i -= 1;
}$0
}
```
1. Select the snippet of code between the $0's.
2. The extract into variable assist shows up, pushing down the more useful extract into function assist.
3. The resulting output of selecting the extract into variable assist is valid but with the extracted variable having the unit type:
```rust
fn main() {
let mut i = 3;
let var_name = if i >= 0 {
i += 1;
} else {
i -= 1;
};
var_name
}
```
**Fix:**
- Don't show the extract into variable assist for unit expressions. I could not think of any scenarios where such a variable extraction would be desired.
Co-authored-by: Brandon <brandondong604@hotmail.com>
9112: Fix some bugs in `extract_struct_from_enum_variant` assist r=Veykril a=Veykril
bors r+
Fixes#9100Fixes#9099
Kind of fixes #9109, it now copies all the generics might be incorrect if the variant doesn't use all of them)
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>
9111: fix: make "extract type alias" place extracted type alias outside of impl r=jonas-schievink a=jonas-schievink
bors r+
Co-authored-by: Jonas Schievink <jonasschievink@gmail.com>
8717: Update match checking algorithm r=iDawer a=iDawer
I've recently got interest in the match checking to extend the current algo to support reporting witnesses of non-exhaustiveness.
It appears the algo is outdated from rustc's implementation. I decided to rewrite it based on the latest rustc's version. It is a diff-based port to ra codebase. That means you can diff-compare these files to rustc.
I'm striving to keep minimal ra-related changes in the algo to make it easier to backport future changes from the upstream.
Based on upstream algorithm of version rust-lang/rust 1.52.0-nightly (25c15cdbe 2021-04-22)
https://github.com/rust-lang/rust/blob/25c15cdbe/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs
The goal of this PR is to cover the current `missing-match-arm` diagnostic.
What is remaining to do:
- [x] Error handling. The errors that are unrelated to match checking will be handled before the check. Just like how it made in rustc.
- [x] Lowering `hir_def::expr::Pat` to `hir_ty::diagnostics::match_check::Pat`. rustc's match checking works on top of `rustc_mir_build::thir::Pat`, which is lowered from `hir::Pat` and carries some extra semantics used by the check. All unrelated checks are done there. RA could use this to rule out running the check on unimplemented cases (`Pat::ConstBlock`, etc).
- [x] ~~Proper~~Loose typecheck of match arm patterns (https://github.com/rust-analyzer/rust-analyzer/pull/8840, https://github.com/rust-analyzer/rust-analyzer/pull/8875).
- [x] Tests from `hir_ty::diagnostics::match_check::tests`.
- [x] Clean up `todo`s
- [x] Test run on real repos https://github.com/rust-analyzer/rust-analyzer/pull/8717#issuecomment-847120265.
Co-authored-by: Dawer <7803845+iDawer@users.noreply.github.com>
