9 KiB
Assists
Cursor position or selection is signified by ┃ character.
add_custom_impl
Adds impl block for derived trait.
// BEFORE
#[derive(Deb┃ug, Display)]
struct S;
// AFTER
#[derive(Display)]
struct S;
impl Debug for S {
}
add_derive
Adds a new #[derive()] clause to a struct or enum.
// BEFORE
struct Point {
x: u32,
y: u32,┃
}
// AFTER
#[derive()]
struct Point {
x: u32,
y: u32,
}
add_explicit_type
Specify type for a let binding.
// BEFORE
fn main() {
let x┃ = 92;
}
// AFTER
fn main() {
let x: i32 = 92;
}
add_function
Adds a stub function with a signature matching the function under the cursor.
// BEFORE
struct Baz;
fn baz() -> Baz { Baz }
fn foo() {
bar┃("", baz());
}
// AFTER
struct Baz;
fn baz() -> Baz { Baz }
fn foo() {
bar("", baz());
}
fn bar(arg: &str, baz: Baz) {
unimplemented!()
}
add_hash
Adds a hash to a raw string literal.
// BEFORE
fn main() {
r#"Hello,┃ World!"#;
}
// AFTER
fn main() {
r##"Hello, World!"##;
}
add_impl
Adds a new inherent impl for a type.
// BEFORE
struct Ctx<T: Clone> {
data: T,┃
}
// AFTER
struct Ctx<T: Clone> {
data: T,
}
impl<T: Clone> Ctx<T> {
}
add_impl_default_members
Adds scaffold for overriding default impl members.
// BEFORE
trait Trait {
Type X;
fn foo(&self);
fn bar(&self) {}
}
impl Trait for () {
Type X = ();
fn foo(&self) {}┃
}
// AFTER
trait Trait {
Type X;
fn foo(&self);
fn bar(&self) {}
}
impl Trait for () {
Type X = ();
fn foo(&self) {}
fn bar(&self) {}
}
add_impl_missing_members
Adds scaffold for required impl members.
// BEFORE
trait Trait<T> {
Type X;
fn foo(&self) -> T;
fn bar(&self) {}
}
impl Trait<u32> for () {┃
}
// AFTER
trait Trait<T> {
Type X;
fn foo(&self) -> T;
fn bar(&self) {}
}
impl Trait<u32> for () {
fn foo(&self) -> u32 { unimplemented!() }
}
add_new
Adds a new inherent impl for a type.
// BEFORE
struct Ctx<T: Clone> {
data: T,┃
}
// AFTER
struct Ctx<T: Clone> {
data: T,
}
impl<T: Clone> Ctx<T> {
fn new(data: T) -> Self { Self { data } }
}
apply_demorgan
Apply De Morgan's law.
This transforms expressions of the form !l || !r into !(l && r).
This also works with &&. This assist can only be applied with the cursor
on either || or &&, with both operands being a negation of some kind.
This means something of the form !x or x != y.
// BEFORE
fn main() {
if x != 4 ||┃ !y {}
}
// AFTER
fn main() {
if !(x == 4 && y) {}
}
auto_import
If the name is unresolved, provides all possible imports for it.
// BEFORE
fn main() {
let map = HashMap┃::new();
}
// AFTER
use std::collections::HashMap;
fn main() {
let map = HashMap::new();
}
change_visibility
Adds or changes existing visibility specifier.
// BEFORE
┃fn frobnicate() {}
// AFTER
pub(crate) fn frobnicate() {}
convert_to_guarded_return
Replace a large conditional with a guarded return.
// BEFORE
fn main() {
┃if cond {
foo();
bar();
}
}
// AFTER
fn main() {
if !cond {
return;
}
foo();
bar();
}
fill_match_arms
Adds missing clauses to a match expression.
// BEFORE
enum Action { Move { distance: u32 }, Stop }
fn handle(action: Action) {
match action {
┃
}
}
// AFTER
enum Action { Move { distance: u32 }, Stop }
fn handle(action: Action) {
match action {
Action::Move { distance } => {}
Action::Stop => {}
}
}
flip_binexpr
Flips operands of a binary expression.
// BEFORE
fn main() {
let _ = 90 +┃ 2;
}
// AFTER
fn main() {
let _ = 2 + 90;
}
flip_comma
Flips two comma-separated items.
// BEFORE
fn main() {
((1, 2),┃ (3, 4));
}
// AFTER
fn main() {
((3, 4), (1, 2));
}
flip_trait_bound
Flips two trait bounds.
// BEFORE
fn foo<T: Clone +┃ Copy>() { }
// AFTER
fn foo<T: Copy + Clone>() { }
inline_local_variable
Inlines local variable.
// BEFORE
fn main() {
let x┃ = 1 + 2;
x * 4;
}
// AFTER
fn main() {
(1 + 2) * 4;
}
introduce_variable
Extracts subexpression into a variable.
// BEFORE
fn main() {
┃(1 + 2)┃ * 4;
}
// AFTER
fn main() {
let var_name = (1 + 2);
var_name * 4;
}
invert_if
Apply invert_if
This transforms if expressions of the form if !x {A} else {B} into if x {B} else {A}
This also works with !=. This assist can only be applied with the cursor
on if.
// BEFORE
fn main() {
if┃ !y { A } else { B }
}
// AFTER
fn main() {
if y { B } else { A }
}
make_raw_string
Adds r# to a plain string literal.
// BEFORE
fn main() {
"Hello,┃ World!";
}
// AFTER
fn main() {
r#"Hello, World!"#;
}
make_usual_string
Turns a raw string into a plain string.
// BEFORE
fn main() {
r#"Hello,┃ "World!""#;
}
// AFTER
fn main() {
"Hello, \"World!\"";
}
merge_imports
Merges two imports with a common prefix.
// BEFORE
use std::┃fmt::Formatter;
use std::io;
// AFTER
use std::{fmt::Formatter, io};
merge_match_arms
Merges identical match arms.
// BEFORE
enum Action { Move { distance: u32 }, Stop }
fn handle(action: Action) {
match action {
┃Action::Move(..) => foo(),
Action::Stop => foo(),
}
}
// AFTER
enum Action { Move { distance: u32 }, Stop }
fn handle(action: Action) {
match action {
Action::Move(..) | Action::Stop => foo(),
}
}
move_arm_cond_to_match_guard
Moves if expression from match arm body into a guard.
// BEFORE
enum Action { Move { distance: u32 }, Stop }
fn handle(action: Action) {
match action {
Action::Move { distance } => ┃if distance > 10 { foo() },
_ => (),
}
}
// AFTER
enum Action { Move { distance: u32 }, Stop }
fn handle(action: Action) {
match action {
Action::Move { distance } if distance > 10 => foo(),
_ => (),
}
}
move_bounds_to_where_clause
Moves inline type bounds to a where clause.
// BEFORE
fn apply<T, U, ┃F: FnOnce(T) -> U>(f: F, x: T) -> U {
f(x)
}
// AFTER
fn apply<T, U, F>(f: F, x: T) -> U where F: FnOnce(T) -> U {
f(x)
}
move_guard_to_arm_body
Moves match guard into match arm body.
// BEFORE
enum Action { Move { distance: u32 }, Stop }
fn handle(action: Action) {
match action {
Action::Move { distance } ┃if distance > 10 => foo(),
_ => (),
}
}
// AFTER
enum Action { Move { distance: u32 }, Stop }
fn handle(action: Action) {
match action {
Action::Move { distance } => if distance > 10 { foo() },
_ => (),
}
}
remove_dbg
Removes dbg!() macro call.
// BEFORE
fn main() {
┃dbg!(92);
}
// AFTER
fn main() {
92;
}
remove_hash
Removes a hash from a raw string literal.
// BEFORE
fn main() {
r#"Hello,┃ World!"#;
}
// AFTER
fn main() {
r"Hello, World!";
}
remove_mut
Removes the mut keyword.
// BEFORE
impl Walrus {
fn feed(&mut┃ self, amount: u32) {}
}
// AFTER
impl Walrus {
fn feed(&self, amount: u32) {}
}
replace_if_let_with_match
Replaces if let with an else branch with a match expression.
// BEFORE
enum Action { Move { distance: u32 }, Stop }
fn handle(action: Action) {
┃if let Action::Move { distance } = action {
foo(distance)
} else {
bar()
}
}
// AFTER
enum Action { Move { distance: u32 }, Stop }
fn handle(action: Action) {
match action {
Action::Move { distance } => foo(distance),
_ => bar(),
}
}
replace_let_with_if_let
Replaces let with an if-let.
// BEFORE
fn main(action: Action) {
┃let x = compute();
}
fn compute() -> Option<i32> { None }
// AFTER
fn main(action: Action) {
if let Some(x) = compute() {
}
}
fn compute() -> Option<i32> { None }
replace_qualified_name_with_use
Adds a use statement for a given fully-qualified name.
// BEFORE
fn process(map: std::collections::┃HashMap<String, String>) {}
// AFTER
use std::collections::HashMap;
fn process(map: HashMap<String, String>) {}
replace_unwrap_with_match
Replaces unwrap a match expression. Works for Result and Option.
// BEFORE
enum Result<T, E> { Ok(T), Err(E) }
fn main() {
let x: Result<i32, i32> = Result::Ok(92);
let y = x.┃unwrap();
}
// AFTER
enum Result<T, E> { Ok(T), Err(E) }
fn main() {
let x: Result<i32, i32> = Result::Ok(92);
let y = match x {
Ok(a) => a,
_ => unreachable!(),
};
}
split_import
Wraps the tail of import into braces.
// BEFORE
use std::┃collections::HashMap;
// AFTER
use std::{collections::HashMap};