88e8b0a5fa
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>
|
||
|---|---|---|
| .. | ||
| add_explicit_type.rs | ||
| add_lifetime_to_type.rs | ||
| add_missing_impl_members.rs | ||
| add_turbo_fish.rs | ||
| apply_demorgan.rs | ||
| auto_import.rs | ||
| change_visibility.rs | ||
| convert_integer_literal.rs | ||
| early_return.rs | ||
| expand_glob_import.rs | ||
| extract_function.rs | ||
| extract_struct_from_enum_variant.rs | ||
| extract_variable.rs | ||
| fill_match_arms.rs | ||
| fix_visibility.rs | ||
| flip_binexpr.rs | ||
| flip_comma.rs | ||
| flip_trait_bound.rs | ||
| generate_default_from_enum_variant.rs | ||
| generate_derive.rs | ||
| generate_enum_match_method.rs | ||
| generate_from_impl_for_enum.rs | ||
| generate_function.rs | ||
| generate_getter_mut.rs | ||
| generate_getter.rs | ||
| generate_impl.rs | ||
| generate_new.rs | ||
| generate_setter.rs | ||
| infer_function_return_type.rs | ||
| inline_function.rs | ||
| inline_local_variable.rs | ||
| introduce_named_lifetime.rs | ||
| invert_if.rs | ||
| merge_imports.rs | ||
| merge_match_arms.rs | ||
| move_bounds.rs | ||
| move_guard.rs | ||
| move_module_to_file.rs | ||
| pull_assignment_up.rs | ||
| qualify_path.rs | ||
| raw_string.rs | ||
| remove_dbg.rs | ||
| remove_mut.rs | ||
| remove_unused_param.rs | ||
| reorder_fields.rs | ||
| reorder_impl.rs | ||
| replace_derive_with_manual_impl.rs | ||
| replace_if_let_with_match.rs | ||
| replace_impl_trait_with_generic.rs | ||
| replace_let_with_if_let.rs | ||
| replace_qualified_name_with_use.rs | ||
| replace_string_with_char.rs | ||
| replace_unwrap_with_match.rs | ||
| split_import.rs | ||
| toggle_ignore.rs | ||
| unmerge_use.rs | ||
| unwrap_block.rs | ||
| wrap_return_type_in_result.rs | ||
