Instead of simple numbering, we hash important bits, like the name of the item.
This will allow for much better incrementality, e.g. when you add an item. Currently, this invalidates the IDs of all following items, which invalidates pretty much everything.
feat: add preliminary support for `+ use<..>` `precise_capturing` syntax
## Summary
This PR adds basic support for the following syntax.
```rs
fn captures<'a: 'a, 'b: 'b, T>() -> impl Sized + use<'b, T> {}
// ~~~~~~~~~~~~~~~~~~~~~~~
// This opaque type does not capture `'a`.
fn outlives<'o, T: 'o>(_: T) {}
fn caller<'o, 'a, 'b: 'o, T: 'o>() {
// ~~
// ^ Note that we don't need `'a: 'o`.
outlives::<'o>(captures::<'a, 'b, T>());
}
```
Related to #17598
Before this commit `UseTree::remove_unnecessary_braces` removed the braces
around `{self}` in `use x::y::{self};` but `use x::y::self;` is not valid
rust.
`cargo clippy --fix`
This PR is the result of running `cargo clippy --fix && cargo fmt` in the root of the repository. I did not manually review all the changes, but just skimmed through a few of them. The tests still pass, so it seems fine.
fix: Fix `ast::Path::segments` implementation
calling `ast::Path::segments` on a qualifier currently returns all the segments of the top path instead of just the segments of the qualifier.
The issue can be summarized by the simple failing test below:
```rust
#[test]
fn path_segments() {
//use ra_ap_syntax::ast;
let path: ast::Path = ...; // e.g. `ast::Path` for "foo::bar::item".
let path_segments: Vec<_> = path.segments().collect();
let qualifier_segments: Vec<_> = path.qualifier().unwrap().segments().collect();
assert_eq!(path_segments.len(), qualifier_segments.len() + 1); // Fails because `LHS = RHS`.
}
```
This PR:
- Fixes the implementation of `ast::Path::segments`
- Fixes `ast::Path::segments` callers that either implicitly relied on behavior of previous implementation or exhibited other "wrong" behavior directly related to the result of `ast::Path::segments` (all callers have been reviewed, only one required modification)
- Removes unnecessary (and now unused) `ast::Path::segments` alternatives
fix: rewrite code_action `generate_delegate_trait`
I've made substantial enhancements to the "generate delegate trait" code action in rust-analyzer. Here's a summary of the changes:
#### Resolved the "Can’t find CONST_ARG@158..159 in AstIdMap" error
Fix#15804, fix#15968, fix#15108
The issue stemmed from an incorrect application of PathTransform in the original code. Previously, a new 'impl' was generated first and then transformed, causing PathTransform to fail in locating the correct AST node, resulting in an error. I rectified this by performing the transformation before generating the new 'impl' (using make::impl_trait), ensuring a step-by-step transformation of associated items.
#### Rectified generation of `Self` type
`generate_delegate_trait` is unable to properly handle trait with `Self` type.
Let's take the following code as an example:
```rust
trait Trait {
fn f() -> Self;
}
struct B {}
impl Trait for B {
fn f() -> B { B{} }
}
struct S {
b: B,
}
```
Here, if we implement `Trait` for `S`, the type of `f` should be `() -> Self`, i.e. `() -> S`. However we cannot automatically generate a function that constructs `S`.
To ensure that the code action doesn't generate delegate traits for traits with Self types, I add a function named `has_self_type` to handle it.
#### Extended support for generics in structs and fields within this code action
The former version of `generate_delegate_trait` cannot handle structs with generics properly. Here's an example:
```rust
struct B<T> {
a: T
}
trait Trait<T> {
fn f(a: T);
}
impl<T1, T2> Trait<T1> for B<T2> {
fn f(a: T1) -> T2 { self.a }
}
struct A {}
struct S {
b$0 : B<A>,
}
```
The former version will generates improper code:
```rust
impl<T1, T2> Trait<T1, T2> for S {
fn f(&self, a: T1) -> T1 {
<B as Trait<T1, T2>>::f( &self.b , a)
}
}
```
The rewritten version can handle generics properly:
```rust
impl<T1> Trait<T1> for S {
fn f(&self, a: T1) -> T1 {
<B<A> as Trait<T1>>::f(&self.b, a)
}
}
```
See more examples in added unit tests.
I enabled support for generic structs in `generate_delegate_trait` through the following steps (using the code example provided):
1. Initially, to prevent conflicts between the generic parameters in struct `S` and the ones in the impl of `B`, I renamed the generic parameters of `S`.
2. Then, since `B`'s parameters are instantiated within `S`, the original generic parameters of `B` needed removal within `S` (to avoid errors from redundant parameters). An important consideration here arises when Trait and B share parameters in `B`'s impl. In such cases, these shared generic parameters cannot be removed.
3. Next, I addressed the matching of types between `B`'s type in `S` and its type in the impl. Given that some generic parameters in the impl are instantiated in `B`, I replaced these parameters with their instantiated results using PathTransform. For instance, in the example provided, matching `B<A>` and `B<T2>`, where `T2` is instantiated as `A`, I replaced all occurrences of `T2` in the impl with `A` (i.e. apply the instantiated generic arguments to the params).
4. Finally, I performed transformations on each assoc item (also to prevent the initial issue) and handled redundant where clauses.
For a more detailed explanation, please refer to the code and comments. I welcome suggestions and any further questions!
