1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
|
# Assists
Cursor position or selection is signified by `┃` character.
## `add_derive`
Adds a new `#[derive()]` clause to a struct or enum.
```rust
// BEFORE
struct Point {
x: u32,
y: u32,┃
}
// AFTER
#[derive()]
struct Point {
x: u32,
y: u32,
}
```
## `add_explicit_type`
Specify type for a let binding.
```rust
// BEFORE
fn main() {
let x┃ = 92;
}
// AFTER
fn main() {
let x: i32 = 92;
}
```
## `add_impl`
Adds a new inherent impl for a type.
```rust
// 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.
```rust
// BEFORE
trait T {
Type X;
fn foo(&self);
fn bar(&self) {}
}
impl T for () {
Type X = ();
fn foo(&self) {}┃
}
// AFTER
trait T {
Type X;
fn foo(&self);
fn bar(&self) {}
}
impl T for () {
Type X = ();
fn foo(&self) {}
fn bar(&self) {}
}
```
## `add_impl_missing_members`
Adds scaffold for required impl members.
```rust
// BEFORE
trait T {
Type X;
fn foo(&self);
fn bar(&self) {}
}
impl T for () {┃
}
// AFTER
trait T {
Type X;
fn foo(&self);
fn bar(&self) {}
}
impl T for () {
fn foo(&self) { unimplemented!() }
}
```
## `apply_demorgan`
Apply [De Morgan's law](https://en.wikipedia.org/wiki/De_Morgan%27s_laws).
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`.
```rust
// BEFORE
fn main() {
if x != 4 ||┃ !y {}
}
// AFTER
fn main() {
if !(x == 4 && y) {}
}
```
## `change_visibility`
Adds or changes existing visibility specifier.
```rust
// BEFORE
┃fn frobnicate() {}
// AFTER
pub(crate) fn frobnicate() {}
```
## `convert_to_guarded_return`
Replace a large conditional with a guarded return.
```rust
// 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.
```rust
// 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.
```rust
// BEFORE
fn main() {
let _ = 90 +┃ 2;
}
// AFTER
fn main() {
let _ = 2 + 90;
}
```
## `flip_comma`
Flips two comma-separated items.
```rust
// BEFORE
fn main() {
((1, 2),┃ (3, 4));
}
// AFTER
fn main() {
((3, 4), (1, 2));
}
```
## `inline_local_variable`
Inlines local variable.
```rust
// BEFORE
fn main() {
let x┃ = 1 + 2;
x * 4;
}
// AFTER
fn main() {
(1 + 2) * 4;
}
```
## `introduce_variable`
Extracts subexpression into a variable.
```rust
// BEFORE
fn main() {
┃(1 + 2)┃ * 4;
}
// AFTER
fn main() {
let var_name = (1 + 2);
var_name * 4;
}
```
## `merge_match_arms`
Merges identical match arms.
```rust
// 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.
```rust
// 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.
```rust
// 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.
```rust
// 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() },
_ => (),
}
}
```
|
