Addresses #3039
This essentially adds missing match arms. The algorithm for this
can get complicated rather quickly so bail in certain conditions
and rely on a PlaceholderPat.
The algorighm works as such:
- Iterate through the Enum Def Variants
- Attempt to see if the variant already exists as a match arm
- If yes, skip the enum variant. If no, include it.
- If it becomes complicated, rather than exhaustively deal with every
branch, mark it as a "partial match" and simply include the
placeholder.
Conditions for "complication":
- The match arm contains a match guard
- Any kind of nested destrucuring
Order the resulting merged match branches as such:
1. Provided match arms
2. Missing enum variant branch arms
3. End with Placeholder if required
- Add extra tests
This introduces the new type -- Semantics.
Semantics maps SyntaxNodes to various semantic info, such as type,
name resolution or macro expansions.
To do so, Semantics maintains a HashMap which maps every node it saw
to the file from which the node originated. This is enough to get all
the necessary hir bits just from syntax.
3108: Magic Completion for `impl Trait for` Associated Items r=matklad a=kdelorey
# Summary
This PR adds a set of magic completions to auto complete associated trait items (functions/consts/types).
## Notes
Since the assist and completion share the same logic when figuring out the associated items that are missing, a shared utility was created in the `ra_assists::utils` module.
Resolves#1046
As this is my first PR to the rust-analyzer project, I'm new to the codebase, feedback welcomed!
Co-authored-by: Kevin DeLorey <2295721+kdelorey@users.noreply.github.com>
