feat: Assist to replace generic with impl trait
This adds a new assist named "Replace named generic with impl". It is the inverse operation to the existing "Replace impl trait with generic" assist.
It allows to refactor the following statement:
```rust
// 👇 cursor
fn new<T$0: ToString>(input: T) -> Self {}
```
to be transformed into:
```rust
fn new(input: impl ToString) -> Self {}
```
* adds new helper function `impl_trait_type` to create AST node
* add method to remove an existing generic param type from param list
Closes#14626
This removes an existing generic param from the `GenericParamList`. It
also considers to remove the extra colon & whitespace to the previous
sibling.
* change order to get all param types first and mark them as mutable
before the first edit happens
* add helper function to remove a generic parameter
* fix test output
This adds a new assist named "replace named generic with impl" to move
the generic param type from the generic param list into the function
signature.
```rust
fn new<T: ToString>(input: T) -> Self {}
```
becomes
```rust
fn new(input: impl ToString) -> Self {}
```
The first step is to determine if the assist can be applied, there has
to be a match between generic trait param & function paramter types.
* replace function parameter type(s) with impl
* add new `impl_trait_type` function to generate the new trait bounds with `impl` keyword for use in the
function signature
fix: don't try determining type of token inside macro calls
When we're requested `Go to Type Definition`, we first downmap the token in question to tokens in every macro call expansion involved, and then determine the type of those mapped tokens by looking for the nearest ancestor node that is either expression or pattern (or a few others). This procedure has one flaw: When the downmapped token is inside another macro call, the nearest ancestor node to retrieve the type of is *that* macro call. That's not what we should return in general and therefore we should disregard it.
Notably, now that we expand built-in `format_arg!` and its family macros, we're always returning [`Arguments`] when one `Go to Type Definition` at `dbg!(variable$0)` along with the actual type of `variable` without this patch.
[`Arguments`]: https://doc.rust-lang.org/nightly/core/fmt/struct.Arguments.html
fix: assists no longer break indentation
Fixes https://github.com/rust-lang/rust-analyzer/issues/14674
These are _ad hoc_ patches for a number of assists that can produce incorrectly indented code, namely:
- generate_derive
- add_missing_impl_members
- add_missing_default_members
Some general solution is required in future, as the same problem arises in many other assists, e.g.
- replace_derive_with...
- generate_default_from_enum...
- generate_default_from_new
- generate_delegate_methods
(the list is incomplete)
Fix: a TODO and some clippy fixes
- fix(todo): implement IntoIterator for ArenaMap<IDX, V>
- chore: remove unused method
- fix: remove useless `return`s
- fix: various clippy lints
- fix: simplify boolean test to a single negation
fix: introduce new type var when expectation for ref pat is not ref
Fixes#14840
When we infer the type of ref patterns, its expected type may not be reference type: 1) expected type is an unresolved inference variable, or 2) expected type is erroneously other kind of type. In either case, we should produce a reference type with a new type variable rather than an error type so that we can continue inferring the inner patterns without further errors because of the (possible) type mismatch of this pattern.
fix: consider all tokens in macro expr when analyzing locals
Fixes#14687
2 fixes for `extract_function` assist (related closely enough that I squashed into one commit):
- Locals in macro expressions have been analyzed only when they are in the top-level token tree the macro call wraps. We should consider all descendant tokens.
- `self` in macro expressions haven't been analyzed.
