7620: Support control flow in `extract_function` assist r=matklad a=cpud36
Support `return`ing from outer function, `break`ing and `continue`ing outer loops when extracting function.
# Example
Transforms
```rust
fn foo() -> i32 {
let items = [1,2,3];
let mut sum = 0;
for &item in items {
<|>if item == 42 {
break;
}<|>
sum += item;
}
sum
}
```
Into
```rust
fn foo() -> i32 {
let items = [1,2,3];
let mut sum = 0;
for &item in items {
if fun_name(item) {
break;
}
sum += item;
}
sum
}
fn fun_name(item: i32) -> bool {
if item == 42 {
return true;
}
false
}
```
# Features
Supported variants
- break and function does not return => uses `bool` and plain if
- break and function does return => uses `Option<T>` and matches on it
- break with value and function does not return => uses `Option<T>` and if let
- break with value and function does return => uses `Result<T, U>` and matches on t
- same for `return` and `continue`(but we can't continue with value)
Assist does handle nested loops and nested items(like functions, modules, impls)
Try `expr?` operator is allowed together with `return Err(_)` and `return None`.
`return expr` is not allowed.
# Not supported
## Mixing `return` with `break` or `continue`
If we have e.g. a `return` and a `break` in the selected code, it is unclear what the produced code should look like.
We can try `Result<T, Option<U>>` or something like that, but it isn't idiomatic, nor it is established. Otherwise, implementation
is relatively simple.
## `break` with label
Not sure how to handle different labels for multiple `break`s.
[edit] implemented try `expr?`
Co-authored-by: Vladyslav Katasonov <cpud47@gmail.com>
7535: Extract function assist r=cpud36 a=cpud36
This PR adds `extract function/method` assist. closes#5409.
# Supported features
Assist should support extracting from expressions(`1`, `2 + 2`, `loop { }`) and from a series of statements, e.g.:
```rust
foo();
$0bar();
baz();$0
quix();
```
Assist also supports extracting parameters, like:
```rust
fn foo() -> i32 {
let n = 1;
$0n + 1$0
}
// -
fn foo() -> i32 {
let n = 1;
fun_name(n)
}
fn fun_name(n: i32) -> i32 {
n + 1
}
```
Extracting methods also generally works.
Assist allows referencing outer variables, both mutably and immutably, and handles handles access to variables local to extracted function:
```rust
fn foo() {
let mut n = 1;
let mut m = 2;
let mut moved_v = Vec::new();
let mut ref_mut_v = Vec::new();
$0
n += 1;
let k = 1;
moved_v.push(n);
let r = &mut m;
ref_mut_v.push(*r);
let h = 3;
$0
n = ref_mut_v.len() + k;
n -= h + m;
}
// -
fn foo() {
let mut n = 1;
let mut m = 2;
let mut moved_v = Vec::new();
let mut ref_mut_v = Vec::new();
let (k, h) = fun_name(&mut n, moved_v, &mut m, &mut ref_mut_v);
n = ref_mut_v.len() + k;
n -= h + m;
}
fn fun_name(n: &mut i32, mut moved_v: Vec<i32>, m: &mut i32, ref_mut_v: &mut Vec<i32>) -> (i32, i32) {
*n += 1;
let k = 1;
moved_v.push(*n);
let r = m;
ref_mut_v.push(*r);
let h = 3;
(k, h)
}
```
So we handle both input and output paramters
# Showcase
# Working with non-`Copy` types
Consider the following example:
```rust
fn foo() {
let v = Vec::new();
$0
let n = v.len();
$0
let is_empty = v.is_empty();
}
```
`v` must be a parameter to extracted function.
The question is, what type should it have.
It could be `v: Vec<i32>`, or `v: &Vec<i32>`.
The former is incorrect for `Vec<i32>`, but the later is silly for `i32`.
To resolve this we need to know if the type implements `Copy` trait.
I didn't find any api available from assists to query this.
`hir_ty::method_resolution::implements` seems relevant, but is isn't publicly re-exported from `hir`.
# Star(`*`) token and pointer dereference
If I understand correctly, in order to create expression like `*p`, one should use `ast::make::expr_prefix(T![*], ...)`, which
in turn calls `token(T![*])`.
`token` does not have star in `tokens::SOURCE_FILE`, so this panics.
I had to add `*` to `SOURCE_FILE` to make it work.
Correct me if this is not intended way to do this.
# Lowering access `value -> mut ref -> shared ref`
Consider the following example:
```rust
fn foo() {
let v = Vec::new();
$0 let n = v.len(); $0
}
```
`v` is not used after extracted function body, so both `v: &Vec<i32>` and `v: Vec<i32>` would work.
Currently the later would be chosen.
We can however check the body of extracted function and conclude that `v: &Vec<i32>` is sufficient.
Using `v: &Vec<i32>`(that is a minimal required access level) might be a better default.
I am unsure.
# Cleanup
The assist seems to be reasonably handling most of common cases.
If there are no concerns with code it produces(i.e. with test cases), I will start cleaning up
[edit]
added showcase
Co-authored-by: Vladyslav Katasonov <cpud47@gmail.com>
7291: Wrap remaining self/super/crate in Name{Ref} r=matklad a=Veykril
That should be the remaining special casing for `self` 🎉
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>
7218: Fix typos r=Veykril a=regexident
Apart from the very last commit on this PR (which fixes a public type's name) all changes are non-breaking.
Co-authored-by: Vincent Esche <regexident@gmail.com>
6587: SSR: Support statement matching and replacing r=davidlattimore a=MarijnS95
For #3186
Hi!
This is a smaller initial patchset that came up while working on support for statement lists (and my first time working on RA 😁). It has me stuck on trailing semicolons for which I hope to receive some feedback. Matching (and replacing) `let` bindings with a trailing semicolon works fine, but trying to omit these (to make patterns more ergonomic) turns out more complex than expected.
The "optional trailing semicolon solution" implemented in this PR is ugly because `Matcher::attempt_match_token` should only consume a trailing `;` when parsing `let` bindings to prevent other code from breaking. That at the same time has a nasty side-effect of `;` ending up in the matched code: any replacements on that should include the trailing semicolon as well even if it was not in the pattern. A better example is in the tests:
3ae1649c24/crates/ssr/src/tests.rs (L178-L184)
The end result to achieve is (I guess) allowing replacement of let bindings without trailing semicolon like `let x = $a ==>> let x = 1` (but including them on both sides is still fine), and should make replacement in a macro call (where `foo!(let a = 2;)` for a `$x:stmt` is invalid syntax) possible as well. That should allow to enable/fix these tests:
3ae1649c24/crates/ssr/src/tests.rs (L201-L214)
A possible MVP of this PR might be to drop this optional `;' handling entirely and only allow an SSR pattern/template with semicolons on either side.
Co-authored-by: Marijn Suijten <marijn@traverseresearch.nl>
7010: Update ungrammar for const block patterns r=matklad a=Veykril
Fixes#6848
Adds const blocks and const block patterns to the AST and parses them.
Blocked on https://github.com/rust-analyzer/ungrammar/pull/17/, will merge that PR there once this one gets the OK so I can remove the local ungrammar dependency path and fix the Cargo.lock.
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>
6896: Node-ify lifetimes r=jonas-schievink a=Veykril
Let's see if this passes the tests 🤞
Depends on https://github.com/rust-analyzer/ungrammar/pull/15
Co-authored-by: Jonas Schievink <jonasschievink@gmail.com>
Co-authored-by: Jonas Schievink <jonas.schievink@ferrous-systems.com>
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>
6897: Basic support for macros 2.0 r=jonas-schievink a=jonas-schievink
This adds support for (built-in-only) macros 2.0, and removes some hacks used for builtin derives, which are declared via macros 2.0 in libcore.
First steps for https://github.com/rust-analyzer/rust-analyzer/issues/2248.
Blocked on https://github.com/rust-analyzer/ungrammar/pull/16.
Co-authored-by: Jonas Schievink <jonasschievink@gmail.com>
Co-authored-by: Jonas Schievink <jonas.schievink@ferrous-systems.com>
6719: Use items can also have doc comments r=matklad a=Veykril
Prior to this change modules show more docs than they have cause they inherit the docs from documented use items inside of them.
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>
6649: Accept more than just the standard rust literal suffixes in *Number::suffix r=matklad a=Veykril
I am not entirely sure whether to keep or remove the `SUFFIXES` but I figured we can always bring them back once they are needed.
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>
