internal: Migrate more assists to use the structured snippet API
Continuing from #14979
Migrates the following assists:
- `generate_derive`
- `wrap_return_type_in_result`
- `generate_delegate_methods`
As a bonus, `generate_delegate_methods` now generates the function and impl block at the correct indentation 🎉.
Feature: Add a memory layout viewer
**Motivation**: rustc by default doesn't enforce a particular memory layout, however it can be useful to see what it is doing under the hood, or if using a particular repr ensure it is behaving how you want it to. This command provides a way to visually explore memory layouts of structures.
**Example**:
this structure:
```rust
struct X {
x: i32,
y: u8,
z: Vec<bool>,
w: usize,
}
```
produces this output:
<img width="692" alt="image" src="https://github.com/rust-lang/rust-analyzer/assets/22418744/e0312233-18a7-4bb9-ae5b-7b52fcff158a">
**Work yet to be done**:
- tests (see below)
- html is mildly janky (see below)
- enums and unions are viewed flatly, how should they be represented?
- should niches be marked somehow?
This was written for my own use, and the jank is fine for me, but in its current state it is probably not ready to merge mostly because it is missing tests, and also because the code quality is not great. However, before I spend time fixing those things idk if this is even something wanted, if it is I am happy to clean it up, if not that's cool too.
`does_not_fill_wildcard_with_wildcard`
and `does_not_fill_wildcard_with_partial_wildcard_and_wildcard`
both made no modifications to the code,
which is a problem for mutable ast porting as it generates a best-effort
minimal set of text edits,
and assists require at least one text edit.
Stop inserting semicolon when extracting match arm
# Overview
Extracting a match arm value that has type unit into a function, when a
comma already follows the match arm value, results in an invalid (syntax
error) semicolon added between the newly generated function's generated
call and the comma.
# Example
Running this extraction
```rust
fn main() {
match () {
_ => $0()$0,
};
}
```
would lead to
```rust
fn main() {
match () {
_ => fun_name();,
};
}
fn fun_name() {
}
```
# Issue / Fix details
This happens because when there is no comma, rust-analyzer would simply
add the comma and wouldn't even try to evaluate whether it needs to add
a semicolon. But when the comma is there, it proceeds to evaluate
whether it needs to add a semicolon and it looks like the evaluation
logic erroneously ignores the possibility that we're in a match arm.
IIUC it never makes sense to add a semicolon when we're extracting from
a match arm value, so I've adjusted the logic to always decide against
adding a semicolon when we're in a match arm
Remind user to check $PATH after installation.
fixes#14882 . I don't think that this is the correct wording to express this but I at least wanted to take the initiative :)
# Overview
Extracting a match arm value that has type unit into a function, when a
comma already follows the match arm value, results in an invalid (syntax
error) semicolon added between the newly generated function's generated
call and the comma.
# Example
Running this extraction
```rust
fn main() {
match () {
_ => $0()$0,
};
}
```
would lead to
```rust
fn main() {
match () {
_ => fun_name();,
};
}
fn fun_name() {
}
```
# Issue / Fix details
This happens because when there is no comma, rust-analyzer would simply
add the comma and wouldn't even try to evaluate whether it needs to add
a semicolon. But when the comma is there, it proceeds to evaluate
whether it needs to add a semicolon and it looks like the evaluation
logic erroneously ignores the possibility that we're in a match arm.
IIUC it never makes sense to add a semicolon when we're extracting from
a match arm value, so I've adjusted the logic to always decide against
adding a semicolon when we're in a match arm
Can actually split out adding the functions from getting the impl to
update or create thanks to being able to refer to the impl ast node.
FIXME Context:
Unfortunately we can't adjust the indentation of the newly added function
inside of `ast::AssocItemList::add_item` since for some reason the `todo!()`
placeholder generated by `add_missing_impl_members` and
`replace_derive_with_manual_impl` gets indented weirdly.
