Below you find a detailed visual guide on all the supported configuration options of rustfmt:
+## `array_width`
-## `indent_style`
+Maximum width of an array literal before falling back to vertical formatting.
-Indent on expressions or items.
+- **Default value**: `60`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
-- **Default value**: `"Block"`
-- **Possible values**: `"Block"`, `"Visual"`
-- **Stable**: No (tracking issue: #3346)
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `array_width` will take precedence.
-### Array
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
-#### `"Block"` (default):
+## `attr_fn_like_width`
-```rust
-fn main() {
- let lorem = vec![
- "ipsum",
- "dolor",
- "sit",
- "amet",
- "consectetur",
- "adipiscing",
- "elit",
- ];
-}
-```
+Maximum width of the args of a function-like attributes before falling back to vertical formatting.
-#### `"Visual"`:
+- **Default value**: `70`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
-```rust
-fn main() {
- let lorem = vec!["ipsum",
- "dolor",
- "sit",
- "amet",
- "consectetur",
- "adipiscing",
- "elit"];
-}
-```
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `attr_fn_like_width` will take precedence.
-### Control flow
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
-#### `"Block"` (default):
+## `binop_separator`
+
+Where to put a binary operator when a binary expression goes multiline.
+
+- **Default value**: `"Front"`
+- **Possible values**: `"Front"`, `"Back"`
+- **Stable**: No (tracking issue: [#3368](https://github.com/rust-lang/rustfmt/issues/3368))
+
+#### `"Front"` (default):
```rust
fn main() {
- if lorem_ipsum
- && dolor_sit
- && amet_consectetur
- && lorem_sit
- && dolor_consectetur
- && amet_ipsum
- && lorem_consectetur
- {
- // ...
- }
+ let or = foofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo
+ || barbarbarbarbarbarbarbarbarbarbarbarbarbarbarbar;
+
+ let sum = 123456789012345678901234567890
+ + 123456789012345678901234567890
+ + 123456789012345678901234567890;
+
+ let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+ ..bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;
}
```
-#### `"Visual"`:
+#### `"Back"`:
```rust
fn main() {
- if lorem_ipsum
- && dolor_sit
- && amet_consectetur
- && lorem_sit
- && dolor_consectetur
- && amet_ipsum
- && lorem_consectetur
- {
- // ...
- }
+ let or = foofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo ||
+ barbarbarbarbarbarbarbarbarbarbarbarbarbarbarbar;
+
+ let sum = 123456789012345678901234567890 +
+ 123456789012345678901234567890 +
+ 123456789012345678901234567890;
+
+ let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa..
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;
}
```
-See also: [`control_brace_style`](#control_brace_style).
+## `blank_lines_lower_bound`
-### Function arguments
+Minimum number of blank lines which must be put between items. If two items have fewer blank lines between
+them, additional blank lines are inserted.
-#### `"Block"` (default):
+- **Default value**: `0`
+- **Possible values**: *unsigned integer*
+- **Stable**: No (tracking issue: [#3382](https://github.com/rust-lang/rustfmt/issues/3382))
-```rust
-fn lorem() {}
+### Example
+Original Code (rustfmt will not change it with the default value of `0`):
-fn lorem(ipsum: usize) {}
+```rust
+#![rustfmt::skip]
-fn lorem(
- ipsum: usize,
- dolor: usize,
- sit: usize,
- amet: usize,
- consectetur: usize,
- adipiscing: usize,
- elit: usize,
-) {
- // body
+fn foo() {
+ println!("a");
+}
+fn bar() {
+ println!("b");
+ println!("c");
}
```
-#### `"Visual"`:
-
+#### `1`
```rust
-fn lorem() {}
-
-fn lorem(ipsum: usize) {}
+fn foo() {
-fn lorem(ipsum: usize,
- dolor: usize,
- sit: usize,
- amet: usize,
- consectetur: usize,
- adipiscing: usize,
- elit: usize) {
- // body
+ println!("a");
}
-```
-### Function calls
+fn bar() {
-#### `"Block"` (default):
+ println!("b");
-```rust
-fn main() {
- lorem(
- "lorem",
- "ipsum",
- "dolor",
- "sit",
- "amet",
- "consectetur",
- "adipiscing",
- "elit",
- );
+ println!("c");
}
```
-#### `"Visual"`:
+
+## `blank_lines_upper_bound`
+
+Maximum number of blank lines which can be put between items. If more than this number of consecutive empty
+lines are found, they are trimmed down to match this integer.
+
+- **Default value**: `1`
+- **Possible values**: any non-negative integer
+- **Stable**: No (tracking issue: [#3381](https://github.com/rust-lang/rustfmt/issues/3381))
+
+### Example
+Original Code:
```rust
-fn main() {
- lorem("lorem",
- "ipsum",
- "dolor",
- "sit",
- "amet",
- "consectetur",
- "adipiscing",
- "elit");
+#![rustfmt::skip]
+
+fn foo() {
+ println!("a");
}
-```
-### Generics
-#### `"Block"` (default):
-```rust
-fn lorem<
- Ipsum: Eq = usize,
- Dolor: Eq = usize,
- Sit: Eq = usize,
- Amet: Eq = usize,
- Adipiscing: Eq = usize,
- Consectetur: Eq = usize,
- Elit: Eq = usize,
->(
- ipsum: Ipsum,
- dolor: Dolor,
- sit: Sit,
- amet: Amet,
- adipiscing: Adipiscing,
- consectetur: Consectetur,
- elit: Elit,
-) -> T {
- // body
+fn bar() {
+ println!("b");
+
+
+ println!("c");
}
```
-#### `"Visual"`:
-
+#### `1` (default):
```rust
-fn lorem<Ipsum: Eq = usize,
- Dolor: Eq = usize,
- Sit: Eq = usize,
- Amet: Eq = usize,
- Adipiscing: Eq = usize,
- Consectetur: Eq = usize,
- Elit: Eq = usize>(
- ipsum: Ipsum,
- dolor: Dolor,
- sit: Sit,
- amet: Amet,
- adipiscing: Adipiscing,
- consectetur: Consectetur,
- elit: Elit)
- -> T {
- // body
+fn foo() {
+ println!("a");
}
-```
-#### Struct
+fn bar() {
+ println!("b");
-#### `"Block"` (default):
+ println!("c");
+}
+```
+#### `2`:
```rust
-fn main() {
- let lorem = Lorem {
- ipsum: dolor,
- sit: amet,
- };
+fn foo() {
+ println!("a");
}
-```
-#### `"Visual"`:
-```rust
-fn main() {
- let lorem = Lorem { ipsum: dolor,
- sit: amet };
+fn bar() {
+ println!("b");
+
+
+ println!("c");
}
```
-See also: [`struct_lit_single_line`](#struct_lit_single_line), [`indent_style`](#indent_style).
+See also: [`blank_lines_lower_bound`](#blank_lines_lower_bound)
-### Where predicates
+## `brace_style`
-#### `"Block"` (default):
+Brace style for items
+
+- **Default value**: `"SameLineWhere"`
+- **Possible values**: `"AlwaysNextLine"`, `"PreferSameLine"`, `"SameLineWhere"`
+- **Stable**: No (tracking issue: [#3376](https://github.com/rust-lang/rustfmt/issues/3376))
+
+### Functions
+
+#### `"SameLineWhere"` (default):
```rust
-fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
+fn lorem() {
+ // body
+}
+
+fn lorem(ipsum: usize) {
+ // body
+}
+
+fn lorem<T>(ipsum: T)
where
- Ipsum: Eq,
- Dolor: Eq,
- Sit: Eq,
- Amet: Eq,
+ T: Add + Sub + Mul + Div,
{
// body
}
```
-#### `"Visual"`:
+#### `"AlwaysNextLine"`:
```rust
-fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
- where Ipsum: Eq,
- Dolor: Eq,
- Sit: Eq,
- Amet: Eq
+fn lorem()
{
// body
}
-```
-## `use_small_heuristics`
-
-Whether to use different formatting for items and expressions if they satisfy a heuristic notion of 'small'.
+fn lorem(ipsum: usize)
+{
+ // body
+}
-- **Default value**: `"Default"`
-- **Possible values**: `"Default"`, `"Off"`, `"Max"`
-- **Stable**: Yes
+fn lorem<T>(ipsum: T)
+where
+ T: Add + Sub + Mul + Div,
+{
+ // body
+}
+```
-#### `Default` (default):
+#### `"PreferSameLine"`:
```rust
-enum Lorem {
- Ipsum,
- Dolor(bool),
- Sit { amet: Consectetur, adipiscing: Elit },
+fn lorem() {
+ // body
}
-fn main() {
- lorem(
- "lorem",
- "ipsum",
- "dolor",
- "sit",
- "amet",
- "consectetur",
- "adipiscing",
- );
-
- let lorem = Lorem {
- ipsum: dolor,
- sit: amet,
- };
- let lorem = Lorem { ipsum: dolor };
+fn lorem(ipsum: usize) {
+ // body
+}
- let lorem = if ipsum { dolor } else { sit };
+fn lorem<T>(ipsum: T)
+where
+ T: Add + Sub + Mul + Div, {
+ // body
}
```
-#### `Off`:
+### Structs and enums
+
+#### `"SameLineWhere"` (default):
```rust
-enum Lorem {
- Ipsum,
- Dolor(bool),
- Sit {
- amet: Consectetur,
- adipiscing: Elit,
- },
+struct Lorem {
+ ipsum: bool,
}
-fn main() {
- lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
+struct Dolor<T>
+where
+ T: Eq,
+{
+ sit: T,
+}
+```
- let lorem = Lorem {
- ipsum: dolor,
- sit: amet,
- };
+#### `"AlwaysNextLine"`:
- let lorem = if ipsum {
- dolor
- } else {
- sit
- };
+```rust
+struct Lorem
+{
+ ipsum: bool,
+}
+
+struct Dolor<T>
+where
+ T: Eq,
+{
+ sit: T,
}
```
-#### `Max`:
+#### `"PreferSameLine"`:
```rust
-enum Lorem {
- Ipsum,
- Dolor(bool),
- Sit { amet: Consectetur, adipiscing: Elit },
+struct Lorem {
+ ipsum: bool,
}
-fn main() {
- lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
-
- let lorem = Lorem { ipsum: dolor, sit: amet };
-
- let lorem = if ipsum { dolor } else { sit };
+struct Dolor<T>
+where
+ T: Eq, {
+ sit: T,
}
```
-## `binop_separator`
-
-Where to put a binary operator when a binary expression goes multiline.
-
-- **Default value**: `"Front"`
-- **Possible values**: `"Front"`, `"Back"`
-- **Stable**: No (tracking issue: #3368)
+## `chain_width`
-#### `"Front"` (default):
-
-```rust
-fn main() {
- let or = foofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo
- || barbarbarbarbarbarbarbarbarbarbarbarbarbarbarbar;
+Maximum width of a chain to fit on one line.
- let sum = 123456789012345678901234567890
- + 123456789012345678901234567890
- + 123456789012345678901234567890;
+- **Default value**: `60`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
- let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
- ..bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;
-}
-```
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `chain_width` will take precedence.
-#### `"Back"`:
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
-```rust
-fn main() {
- let or = foofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo ||
- barbarbarbarbarbarbarbarbarbarbarbarbarbarbarbar;
+## `color`
- let sum = 123456789012345678901234567890 +
- 123456789012345678901234567890 +
- 123456789012345678901234567890;
+Whether to use colored output or not.
- let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa..
- bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;
-}
-```
+- **Default value**: `"Auto"`
+- **Possible values**: "Auto", "Always", "Never"
+- **Stable**: No (tracking issue: [#3385](https://github.com/rust-lang/rustfmt/issues/3385))
## `combine_control_expr`
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3369)
+- **Stable**: No (tracking issue: [#3369](https://github.com/rust-lang/rustfmt/issues/3369))
#### `true` (default):
- **Default value**: `80`
- **Possible values**: any positive integer
-- **Stable**: No (tracking issue: #3349)
+- **Stable**: No (tracking issue: [#3349](https://github.com/rust-lang/rustfmt/issues/3349))
**Note:** A value of `0` results in [`wrap_comments`](#wrap_comments) being applied regardless of a line's width.
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3384)
+- **Stable**: No (tracking issue: [#3384](https://github.com/rust-lang/rustfmt/issues/3384))
#### `false` (default):
- **Default value**: `"AlwaysSameLine"`
- **Possible values**: `"AlwaysNextLine"`, `"AlwaysSameLine"`, `"ClosingNextLine"`
-- **Stable**: No (tracking issue: #3377)
+- **Stable**: No (tracking issue: [#3377](https://github.com/rust-lang/rustfmt/issues/3377))
#### `"AlwaysSameLine"` (default):
## `disable_all_formatting`
-Don't reformat anything
+Don't reformat anything.
+
+Note that this option may be soft-deprecated in the future once the [ignore](#ignore) option is stabilized. Nightly toolchain users are encouraged to use [ignore](#ignore) instead when possible.
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3388)
+- **Stable**: Yes
+
+## `edition`
+
+Specifies which edition is used by the parser.
+
+- **Default value**: `"2015"`
+- **Possible values**: `"2015"`, `"2018"`, `"2021"`
+- **Stable**: Yes
+
+Rustfmt is able to pick up the edition used by reading the `Cargo.toml` file if executed
+through the Cargo's formatting tool `cargo fmt`. Otherwise, the edition needs to be specified
+in your config file:
+
+```toml
+edition = "2018"
+```
+
+## `empty_item_single_line`
+
+Put empty-body functions and impls on a single line
+
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3356](https://github.com/rust-lang/rustfmt/issues/3356))
+
+#### `true` (default):
+
+```rust
+fn lorem() {}
+
+impl Lorem {}
+```
+
+#### `false`:
+
+```rust
+fn lorem() {
+}
+
+impl Lorem {
+}
+```
+
+See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
+
+
+## `enum_discrim_align_threshold`
+
+The maximum length of enum variant having discriminant, that gets vertically aligned with others.
+Variants without discriminants would be ignored for the purpose of alignment.
+
+Note that this is not how much whitespace is inserted, but instead the longest variant name that
+doesn't get ignored when aligning.
+
+- **Default value** : 0
+- **Possible values**: any positive integer
+- **Stable**: No (tracking issue: [#3372](https://github.com/rust-lang/rustfmt/issues/3372))
+
+#### `0` (default):
+
+```rust
+enum Bar {
+ A = 0,
+ Bb = 1,
+ RandomLongVariantGoesHere = 10,
+ Ccc = 71,
+}
+
+enum Bar {
+ VeryLongVariantNameHereA = 0,
+ VeryLongVariantNameHereBb = 1,
+ VeryLongVariantNameHereCcc = 2,
+}
+```
+
+#### `20`:
+
+```rust
+enum Foo {
+ A = 0,
+ Bb = 1,
+ RandomLongVariantGoesHere = 10,
+ Ccc = 2,
+}
+
+enum Bar {
+ VeryLongVariantNameHereA = 0,
+ VeryLongVariantNameHereBb = 1,
+ VeryLongVariantNameHereCcc = 2,
+}
+```
+
## `error_on_line_overflow`
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3391)
+- **Stable**: No (tracking issue: [#3391](https://github.com/rust-lang/rustfmt/issues/3391))
See also [`max_width`](#max_width).
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3392)
+- **Stable**: No (tracking issue: [#3392](https://github.com/rust-lang/rustfmt/issues/3392))
## `fn_args_layout`
}
```
+## `fn_call_width`
-## `brace_style`
+Maximum width of the args of a function call before falling back to vertical formatting.
-Brace style for items
+- **Default value**: `60`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
-- **Default value**: `"SameLineWhere"`
-- **Possible values**: `"AlwaysNextLine"`, `"PreferSameLine"`, `"SameLineWhere"`
-- **Stable**: No (tracking issue: #3376)
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `fn_call_width` will take precedence.
-### Functions
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
-#### `"SameLineWhere"` (default):
+## `fn_single_line`
+
+Put single-expression functions on a single line
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3358](https://github.com/rust-lang/rustfmt/issues/3358))
+
+#### `false` (default):
```rust
-fn lorem() {
- // body
+fn lorem() -> usize {
+ 42
+}
+
+fn lorem() -> usize {
+ let ipsum = 42;
+ ipsum
+}
+```
+
+#### `true`:
+
+```rust
+fn lorem() -> usize { 42 }
+
+fn lorem() -> usize {
+ let ipsum = 42;
+ ipsum
+}
+```
+
+See also [`control_brace_style`](#control_brace_style).
+
+
+## `force_explicit_abi`
+
+Always print the abi for extern items
+
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: Yes
+
+**Note:** Non-"C" ABIs are always printed. If `false` then "C" is removed.
+
+#### `true` (default):
+
+```rust
+extern "C" {
+ pub static lorem: c_int;
+}
+```
+
+#### `false`:
+
+```rust
+extern {
+ pub static lorem: c_int;
+}
+```
+
+## `force_multiline_blocks`
+
+Force multiline closure and match arm bodies to be wrapped in a block
+
+- **Default value**: `false`
+- **Possible values**: `false`, `true`
+- **Stable**: No (tracking issue: [#3374](https://github.com/rust-lang/rustfmt/issues/3374))
+
+#### `false` (default):
+
+```rust
+fn main() {
+ result.and_then(|maybe_value| match maybe_value {
+ None => foo(),
+ Some(value) => bar(),
+ });
+
+ match lorem {
+ None => |ipsum| {
+ println!("Hello World");
+ },
+ Some(dolor) => foo(),
+ }
+}
+```
+
+#### `true`:
+
+```rust
+fn main() {
+ result.and_then(|maybe_value| {
+ match maybe_value {
+ None => foo(),
+ Some(value) => bar(),
+ }
+ });
+
+ match lorem {
+ None => {
+ |ipsum| {
+ println!("Hello World");
+ }
+ }
+ Some(dolor) => foo(),
+ }
}
+```
-fn lorem(ipsum: usize) {
- // body
-}
-fn lorem<T>(ipsum: T)
-where
- T: Add + Sub + Mul + Div,
-{
- // body
-}
-```
+## `format_code_in_doc_comments`
-#### `"AlwaysNextLine"`:
+Format code snippet included in doc comments.
-```rust
-fn lorem()
-{
- // body
-}
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3348](https://github.com/rust-lang/rustfmt/issues/3348))
-fn lorem(ipsum: usize)
-{
- // body
-}
+#### `false` (default):
-fn lorem<T>(ipsum: T)
-where
- T: Add + Sub + Mul + Div,
-{
- // body
+```rust
+/// Adds one to the number given.
+///
+/// # Examples
+///
+/// ```rust
+/// let five=5;
+///
+/// assert_eq!(
+/// 6,
+/// add_one(5)
+/// );
+/// # fn add_one(x: i32) -> i32 {
+/// # x + 1
+/// # }
+/// ```
+fn add_one(x: i32) -> i32 {
+ x + 1
}
```
-#### `"PreferSameLine"`:
+#### `true`
```rust
-fn lorem() {
- // body
+/// Adds one to the number given.
+///
+/// # Examples
+///
+/// ```rust
+/// let five = 5;
+///
+/// assert_eq!(6, add_one(5));
+/// # fn add_one(x: i32) -> i32 {
+/// # x + 1
+/// # }
+/// ```
+fn add_one(x: i32) -> i32 {
+ x + 1
}
+```
-fn lorem(ipsum: usize) {
- // body
-}
+## `format_generated_files`
-fn lorem<T>(ipsum: T)
-where
- T: Add + Sub + Mul + Div, {
- // body
-}
-```
+Format generated files. A file is considered generated
+if any of the first five lines contain a `@generated` comment marker.
-### Structs and enums
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#5080](https://github.com/rust-lang/rustfmt/issues/5080))
-#### `"SameLineWhere"` (default):
+## `format_macro_matchers`
-```rust
-struct Lorem {
- ipsum: bool,
-}
+Format the metavariable matching patterns in macros.
-struct Dolor<T>
-where
- T: Eq,
-{
- sit: T,
-}
-```
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3354](https://github.com/rust-lang/rustfmt/issues/3354))
-#### `"AlwaysNextLine"`:
+#### `false` (default):
```rust
-struct Lorem
-{
- ipsum: bool,
-}
-
-struct Dolor<T>
-where
- T: Eq,
-{
- sit: T,
+macro_rules! foo {
+ ($a: ident : $b: ty) => {
+ $a(42): $b;
+ };
+ ($a: ident $b: ident $c: ident) => {
+ $a = $b + $c;
+ };
}
```
-#### `"PreferSameLine"`:
+#### `true`:
```rust
-struct Lorem {
- ipsum: bool,
-}
-
-struct Dolor<T>
-where
- T: Eq, {
- sit: T,
+macro_rules! foo {
+ ($a:ident : $b:ty) => {
+ $a(42): $b;
+ };
+ ($a:ident $b:ident $c:ident) => {
+ $a = $b + $c;
+ };
}
```
+See also [`format_macro_bodies`](#format_macro_bodies).
+
-## `empty_item_single_line`
+## `format_macro_bodies`
-Put empty-body functions and impls on a single line
+Format the bodies of macros.
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3356)
+- **Stable**: No (tracking issue: [#3355](https://github.com/rust-lang/rustfmt/issues/3355))
#### `true` (default):
```rust
-fn lorem() {}
-
-impl Lorem {}
+macro_rules! foo {
+ ($a: ident : $b: ty) => {
+ $a(42): $b;
+ };
+ ($a: ident $b: ident $c: ident) => {
+ $a = $b + $c;
+ };
+}
```
#### `false`:
```rust
-fn lorem() {
-}
-
-impl Lorem {
+macro_rules! foo {
+ ($a: ident : $b: ty) => { $a(42): $b; };
+ ($a: ident $b: ident $c: ident) => { $a=$b+$c; };
}
```
-See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
-
+See also [`format_macro_matchers`](#format_macro_matchers).
-## `enum_discrim_align_threshold`
-The maximum length of enum variant having discriminant, that gets vertically aligned with others.
-Variants without discriminants would be ignored for the purpose of alignment.
+## `format_strings`
-Note that this is not how much whitespace is inserted, but instead the longest variant name that
-doesn't get ignored when aligning.
+Format string literals where necessary
-- **Default value** : 0
-- **Possible values**: any positive integer
-- **Stable**: No (tracking issue: #3372)
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3353](https://github.com/rust-lang/rustfmt/issues/3353))
-#### `0` (default):
+#### `false` (default):
```rust
-enum Bar {
- A = 0,
- Bb = 1,
- RandomLongVariantGoesHere = 10,
- Ccc = 71,
-}
-
-enum Bar {
- VeryLongVariantNameHereA = 0,
- VeryLongVariantNameHereBb = 1,
- VeryLongVariantNameHereCcc = 2,
+fn main() {
+ let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet consectetur adipiscing";
}
```
-#### `20`:
+#### `true`:
```rust
-enum Foo {
- A = 0,
- Bb = 1,
- RandomLongVariantGoesHere = 10,
- Ccc = 2,
-}
-
-enum Bar {
- VeryLongVariantNameHereA = 0,
- VeryLongVariantNameHereBb = 1,
- VeryLongVariantNameHereCcc = 2,
+fn main() {
+ let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet \
+ consectetur adipiscing";
}
```
+See also [`max_width`](#max_width).
-## `fn_single_line`
+## `hard_tabs`
-Put single-expression functions on a single line
+Use tab characters for indentation, spaces for alignment
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3358)
+- **Stable**: Yes
#### `false` (default):
```rust
fn lorem() -> usize {
- 42
-}
-
-fn lorem() -> usize {
- let ipsum = 42;
- ipsum
+ 42 // spaces before 42
}
```
#### `true`:
```rust
-fn lorem() -> usize { 42 }
-
fn lorem() -> usize {
- let ipsum = 42;
- ipsum
+ 42 // tabs before 42
}
```
-See also [`control_brace_style`](#control_brace_style).
+See also: [`tab_spaces`](#tab_spaces).
+
+## `hex_literal_case`
+
+Control the case of the letters in hexadecimal literal values
+
+- **Default value**: `Preserve`
+- **Possible values**: `Upper`, `Lower`
+- **Stable**: No (tracking issue: [#5081](https://github.com/rust-lang/rustfmt/issues/5081))
+
+## `hide_parse_errors`
+
+Do not show parse errors if the parser failed to parse files.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3390](https://github.com/rust-lang/rustfmt/issues/3390))
+
+## `ignore`
+
+Skip formatting files and directories that match the specified pattern.
+The pattern format is the same as [.gitignore](https://git-scm.com/docs/gitignore#_pattern_format). Be sure to use Unix/forwardslash `/` style paths. This path style will work on all platforms. Windows style paths with backslashes `\` are not supported.
+
+- **Default value**: format every file
+- **Possible values**: See an example below
+- **Stable**: No (tracking issue: [#3395](https://github.com/rust-lang/rustfmt/issues/3395))
+
+### Example
+
+If you want to ignore specific files, put the following to your config file:
+
+```toml
+ignore = [
+ "src/types.rs",
+ "src/foo/bar.rs",
+]
+```
+
+If you want to ignore every file under `examples/`, put the following to your config file:
+
+```toml
+ignore = [
+ "examples",
+]
+```
+
+If you want to ignore every file under the directory where you put your rustfmt.toml:
+```toml
+ignore = ["/"]
+```
-## `where_single_line`
+## `imports_indent`
-Forces the `where` clause to be laid out on a single line.
+Indent style of imports
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3359)
+- **Default Value**: `"Block"`
+- **Possible values**: `"Block"`, `"Visual"`
+- **Stable**: No (tracking issue: [#3360](https://github.com/rust-lang/rustfmt/issues/3360))
-#### `false` (default):
+#### `"Block"` (default):
```rust
-impl<T> Lorem for T
-where
- Option<T>: Ipsum,
-{
- // body
-}
+use foo::{
+ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
+ zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,
+};
```
-#### `true`:
+#### `"Visual"`:
```rust
-impl<T> Lorem for T
-where Option<T>: Ipsum
-{
- // body
-}
+use foo::{xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
+ zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz};
```
-See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
+See also: [`imports_layout`](#imports_layout).
+## `imports_layout`
-## `force_explicit_abi`
+Item layout inside a imports block
-Always print the abi for extern items
+- **Default value**: "Mixed"
+- **Possible values**: "Horizontal", "HorizontalVertical", "Mixed", "Vertical"
+- **Stable**: No (tracking issue: [#3361](https://github.com/rust-lang/rustfmt/issues/3361))
-- **Default value**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: Yes
+#### `"Mixed"` (default):
-**Note:** Non-"C" ABIs are always printed. If `false` then "C" is removed.
+```rust
+use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
-#### `true` (default):
+use foo::{
+ aaaaaaaaaaaaaaaaaa, bbbbbbbbbbbbbbbbbb, cccccccccccccccccc, dddddddddddddddddd,
+ eeeeeeeeeeeeeeeeee, ffffffffffffffffff,
+};
+```
+
+#### `"Horizontal"`:
+
+**Note**: This option forces all imports onto one line and may exceed `max_width`.
```rust
-extern "C" {
- pub static lorem: c_int;
-}
+use foo::{xxx, yyy, zzz};
+
+use foo::{aaa, bbb, ccc, ddd, eee, fff};
```
-#### `false`:
+#### `"HorizontalVertical"`:
```rust
-extern {
- pub static lorem: c_int;
-}
+use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
+
+use foo::{
+ aaaaaaaaaaaaaaaaaa,
+ bbbbbbbbbbbbbbbbbb,
+ cccccccccccccccccc,
+ dddddddddddddddddd,
+ eeeeeeeeeeeeeeeeee,
+ ffffffffffffffffff,
+};
```
-## `format_strings`
+#### `"Vertical"`:
-Format string literals where necessary
+```rust
+use foo::{
+ xxx,
+ yyy,
+ zzz,
+};
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3353)
+use foo::{
+ aaa,
+ bbb,
+ ccc,
+ ddd,
+ eee,
+ fff,
+};
+```
-#### `false` (default):
+## `indent_style`
+
+Indent on expressions or items.
+
+- **Default value**: `"Block"`
+- **Possible values**: `"Block"`, `"Visual"`
+- **Stable**: No (tracking issue: [#3346](https://github.com/rust-lang/rustfmt/issues/3346))
+
+### Array
+
+#### `"Block"` (default):
```rust
fn main() {
- let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet consectetur adipiscing";
+ let lorem = vec![
+ "ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ "elit",
+ ];
}
```
-#### `true`:
+#### `"Visual"`:
```rust
fn main() {
- let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet \
- consectetur adipiscing";
+ let lorem = vec!["ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ "elit"];
}
```
-See also [`max_width`](#max_width).
-
-## `format_macro_matchers`
-
-Format the metavariable matching patterns in macros.
-
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3354)
+### Control flow
-#### `false` (default):
+#### `"Block"` (default):
```rust
-macro_rules! foo {
- ($a: ident : $b: ty) => {
- $a(42): $b;
- };
- ($a: ident $b: ident $c: ident) => {
- $a = $b + $c;
- };
+fn main() {
+ if lorem_ipsum
+ && dolor_sit
+ && amet_consectetur
+ && lorem_sit
+ && dolor_consectetur
+ && amet_ipsum
+ && lorem_consectetur
+ {
+ // ...
+ }
}
```
-#### `true`:
+#### `"Visual"`:
```rust
-macro_rules! foo {
- ($a:ident : $b:ty) => {
- $a(42): $b;
- };
- ($a:ident $b:ident $c:ident) => {
- $a = $b + $c;
- };
+fn main() {
+ if lorem_ipsum
+ && dolor_sit
+ && amet_consectetur
+ && lorem_sit
+ && dolor_consectetur
+ && amet_ipsum
+ && lorem_consectetur
+ {
+ // ...
+ }
}
```
-See also [`format_macro_bodies`](#format_macro_bodies).
-
-
-## `format_macro_bodies`
-
-Format the bodies of macros.
+See also: [`control_brace_style`](#control_brace_style).
-- **Default value**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3355)
+### Function arguments
-#### `true` (default):
+#### `"Block"` (default):
```rust
-macro_rules! foo {
- ($a: ident : $b: ty) => {
- $a(42): $b;
- };
- ($a: ident $b: ident $c: ident) => {
- $a = $b + $c;
- };
-}
-```
+fn lorem() {}
-#### `false`:
+fn lorem(ipsum: usize) {}
-```rust
-macro_rules! foo {
- ($a: ident : $b: ty) => { $a(42): $b; };
- ($a: ident $b: ident $c: ident) => { $a=$b+$c; };
+fn lorem(
+ ipsum: usize,
+ dolor: usize,
+ sit: usize,
+ amet: usize,
+ consectetur: usize,
+ adipiscing: usize,
+ elit: usize,
+) {
+ // body
}
```
-See also [`format_macro_matchers`](#format_macro_matchers).
+#### `"Visual"`:
+```rust
+fn lorem() {}
-## `hard_tabs`
+fn lorem(ipsum: usize) {}
-Use tab characters for indentation, spaces for alignment
+fn lorem(ipsum: usize,
+ dolor: usize,
+ sit: usize,
+ amet: usize,
+ consectetur: usize,
+ adipiscing: usize,
+ elit: usize) {
+ // body
+}
+```
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: Yes
+### Function calls
-#### `false` (default):
+#### `"Block"` (default):
```rust
-fn lorem() -> usize {
- 42 // spaces before 42
+fn main() {
+ lorem(
+ "lorem",
+ "ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ "elit",
+ );
}
```
-#### `true`:
+#### `"Visual"`:
```rust
-fn lorem() -> usize {
- 42 // tabs before 42
+fn main() {
+ lorem("lorem",
+ "ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ "elit");
}
```
-See also: [`tab_spaces`](#tab_spaces).
-
-
-## `imports_indent`
-
-Indent style of imports
-
-- **Default Value**: `"Block"`
-- **Possible values**: `"Block"`, `"Visual"`
-- **Stable**: No (tracking issue: #3360)
+### Generics
#### `"Block"` (default):
```rust
-use foo::{
- xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
- zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,
-};
+fn lorem<
+ Ipsum: Eq = usize,
+ Dolor: Eq = usize,
+ Sit: Eq = usize,
+ Amet: Eq = usize,
+ Adipiscing: Eq = usize,
+ Consectetur: Eq = usize,
+ Elit: Eq = usize,
+>(
+ ipsum: Ipsum,
+ dolor: Dolor,
+ sit: Sit,
+ amet: Amet,
+ adipiscing: Adipiscing,
+ consectetur: Consectetur,
+ elit: Elit,
+) -> T {
+ // body
+}
```
#### `"Visual"`:
```rust
-use foo::{xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
- zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz};
+fn lorem<Ipsum: Eq = usize,
+ Dolor: Eq = usize,
+ Sit: Eq = usize,
+ Amet: Eq = usize,
+ Adipiscing: Eq = usize,
+ Consectetur: Eq = usize,
+ Elit: Eq = usize>(
+ ipsum: Ipsum,
+ dolor: Dolor,
+ sit: Sit,
+ amet: Amet,
+ adipiscing: Adipiscing,
+ consectetur: Consectetur,
+ elit: Elit)
+ -> T {
+ // body
+}
```
-See also: [`imports_layout`](#imports_layout).
-
-## `imports_layout`
-
-Item layout inside a imports block
-
-- **Default value**: "Mixed"
-- **Possible values**: "Horizontal", "HorizontalVertical", "Mixed", "Vertical"
-- **Stable**: No (tracking issue: #3361)
+#### Struct
-#### `"Mixed"` (default):
+#### `"Block"` (default):
```rust
-use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
-
-use foo::{
- aaaaaaaaaaaaaaaaaa, bbbbbbbbbbbbbbbbbb, cccccccccccccccccc, dddddddddddddddddd,
- eeeeeeeeeeeeeeeeee, ffffffffffffffffff,
-};
+fn main() {
+ let lorem = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
+}
```
-#### `"Horizontal"`:
-
-**Note**: This option forces all imports onto one line and may exceed `max_width`.
+#### `"Visual"`:
```rust
-use foo::{xxx, yyy, zzz};
-
-use foo::{aaa, bbb, ccc, ddd, eee, fff};
+fn main() {
+ let lorem = Lorem { ipsum: dolor,
+ sit: amet };
+}
```
-#### `"HorizontalVertical"`:
+See also: [`struct_lit_single_line`](#struct_lit_single_line), [`indent_style`](#indent_style).
-```rust
-use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
+### Where predicates
-use foo::{
- aaaaaaaaaaaaaaaaaa,
- bbbbbbbbbbbbbbbbbb,
- cccccccccccccccccc,
- dddddddddddddddddd,
- eeeeeeeeeeeeeeeeee,
- ffffffffffffffffff,
-};
+#### `"Block"` (default):
+
+```rust
+fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
+where
+ Ipsum: Eq,
+ Dolor: Eq,
+ Sit: Eq,
+ Amet: Eq,
+{
+ // body
+}
```
-#### `"Vertical"`:
+#### `"Visual"`:
```rust
-use foo::{
- xxx,
- yyy,
- zzz,
-};
-
-use foo::{
- aaa,
- bbb,
- ccc,
- ddd,
- eee,
- fff,
-};
+fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
+ where Ipsum: Eq,
+ Dolor: Eq,
+ Sit: Eq,
+ Amet: Eq
+{
+ // body
+}
```
-## `merge_imports`
+## `inline_attribute_width`
-Merge multiple imports into a single nested import.
+Write an item and its attribute on the same line if their combined width is below a threshold
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3362)
+- **Default value**: 0
+- **Possible values**: any positive integer
+- **Stable**: No (tracking issue: [#3343](https://github.com/rust-lang/rustfmt/issues/3343))
-#### `false` (default):
+### Example
+#### `0` (default):
```rust
-use foo::{a, c, d};
-use foo::{b, g};
-use foo::{e, f};
+#[cfg(feature = "alloc")]
+use core::slice;
```
-#### `true`:
-
+#### `50`:
```rust
-use foo::{a, b, c, d, e, f, g};
+#[cfg(feature = "alloc")] use core::slice;
```
+## `license_template_path`
-## `match_block_trailing_comma`
-
-Put a trailing comma after a block based match arm (non-block arms are not affected)
+Check whether beginnings of files match a license template.
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3380)
+- **Default value**: `""`
+- **Possible values**: path to a license template file
+- **Stable**: No (tracking issue: [#3352](https://github.com/rust-lang/rustfmt/issues/3352))
-#### `false` (default):
+A license template is a plain text file which is matched literally against the
+beginning of each source file, except for `{}`-delimited blocks, which are
+matched as regular expressions. The following license template therefore
+matches strings like `// Copyright 2017 The Rust Project Developers.`, `//
+Copyright 2018 The Rust Project Developers.`, etc.:
-```rust
-fn main() {
- match lorem {
- Lorem::Ipsum => {
- println!("ipsum");
- }
- Lorem::Dolor => println!("dolor"),
- }
-}
```
-
-#### `true`:
-
-```rust
-fn main() {
- match lorem {
- Lorem::Ipsum => {
- println!("ipsum");
- },
- Lorem::Dolor => println!("dolor"),
- }
-}
+// Copyright {\d+} The Rust Project Developers.
```
-See also: [`trailing_comma`](#trailing_comma), [`match_arm_blocks`](#match_arm_blocks).
-
-## `max_width`
-
-Maximum width of each line
-
-- **Default value**: `100`
-- **Possible values**: any positive integer
-- **Stable**: Yes
+`\{`, `\}` and `\\` match literal braces / backslashes.
-See also [`error_on_line_overflow`](#error_on_line_overflow).
+## `match_arm_blocks`
-## `merge_derives`
+Controls whether arm bodies are wrapped in cases where the first line of the body cannot fit on the same line as the `=>` operator.
-Merge multiple derives into a single one.
+The Style Guide requires that bodies are block wrapped by default if a line break is required after the `=>`, but this option can be used to disable that behavior to prevent wrapping arm bodies in that event, so long as the body does not contain multiple statements nor line comments.
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: Yes
+- **Stable**: No (tracking issue: [#3373](https://github.com/rust-lang/rustfmt/issues/3373))
#### `true` (default):
-```rust
-#[derive(Eq, PartialEq, Debug, Copy, Clone)]
-pub enum Foo {}
-```
-
-#### `false`:
-
-```rust
-#[derive(Eq, PartialEq)]
-#[derive(Debug)]
-#[derive(Copy, Clone)]
-pub enum Foo {}
-```
-
-## `force_multiline_blocks`
-
-Force multiline closure and match arm bodies to be wrapped in a block
-
-- **Default value**: `false`
-- **Possible values**: `false`, `true`
-- **Stable**: No (tracking issue: #3374)
-
-#### `false` (default):
-
```rust
fn main() {
- result.and_then(|maybe_value| match maybe_value {
- None => foo(),
- Some(value) => bar(),
- });
-
match lorem {
- None => |ipsum| {
- println!("Hello World");
- },
- Some(dolor) => foo(),
+ ipsum => {
+ foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x)
+ }
+ dolor => println!("{}", sit),
+ sit => foo(
+ "foooooooooooooooooooooooo",
+ "baaaaaaaaaaaaaaaaaaaaaaaarr",
+ "baaaaaaaaaaaaaaaaaaaazzzzzzzzzzzzz",
+ "qqqqqqqqquuuuuuuuuuuuuuuuuuuuuuuuuuxxx",
+ ),
}
}
```
-#### `true`:
+#### `false`:
```rust
fn main() {
- result.and_then(|maybe_value| {
- match maybe_value {
- None => foo(),
- Some(value) => bar(),
- }
- });
-
match lorem {
- None => {
- |ipsum| {
- println!("Hello World");
- }
- }
- Some(dolor) => foo(),
+ lorem =>
+ foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x),
+ ipsum => println!("{}", sit),
+ sit => foo(
+ "foooooooooooooooooooooooo",
+ "baaaaaaaaaaaaaaaaaaaaaaaarr",
+ "baaaaaaaaaaaaaaaaaaaazzzzzzzzzzzzz",
+ "qqqqqqqqquuuuuuuuuuuuuuuuuuuuuuuuuuxxx",
+ ),
}
}
```
+See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
-## `newline_style`
+## `match_arm_leading_pipes`
-Unix or Windows line endings
+Controls whether to include a leading pipe on match arms
-- **Default value**: `"Auto"`
-- **Possible values**: `"Auto"`, `"Native"`, `"Unix"`, `"Windows"`
+- **Default value**: `Never`
+- **Possible values**: `Always`, `Never`, `Preserve`
- **Stable**: Yes
-#### `Auto` (default):
-
-The newline style is detected automatically on a per-file basis. Files
-with mixed line endings will be converted to the first detected line
-ending style.
-
-#### `Native`
-
-Line endings will be converted to `\r\n` on Windows and `\n` on all
-other platforms.
-
-#### `Unix`
-
-Line endings will be converted to `\n`.
-
-#### `Windows`
-
-Line endings will be converted to `\r\n`.
-
-## `normalize_comments`
-
-Convert /* */ comments to // comments where possible
-
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3350)
-
-#### `false` (default):
+#### `Never` (default):
+```rust
+// Leading pipes are removed from this:
+// fn foo() {
+// match foo {
+// | "foo" | "bar" => {}
+// | "baz"
+// | "something relatively long"
+// | "something really really really realllllllllllllly long" => println!("x"),
+// | "qux" => println!("y"),
+// _ => {}
+// }
+// }
+
+// Becomes
+fn foo() {
+ match foo {
+ "foo" | "bar" => {}
+ "baz"
+ | "something relatively long"
+ | "something really really really realllllllllllllly long" => println!("x"),
+ "qux" => println!("y"),
+ _ => {}
+ }
+}
+```
+#### `Always`:
```rust
-// Lorem ipsum:
-fn dolor() -> usize {}
+// Leading pipes are emitted on all arms of this:
+// fn foo() {
+// match foo {
+// "foo" | "bar" => {}
+// "baz"
+// | "something relatively long"
+// | "something really really really realllllllllllllly long" => println!("x"),
+// "qux" => println!("y"),
+// _ => {}
+// }
+// }
-/* sit amet: */
-fn adipiscing() -> usize {}
+// Becomes:
+fn foo() {
+ match foo {
+ | "foo" | "bar" => {}
+ | "baz"
+ | "something relatively long"
+ | "something really really really realllllllllllllly long" => println!("x"),
+ | "qux" => println!("y"),
+ | _ => {}
+ }
+}
```
-#### `true`:
-
+#### `Preserve`:
```rust
-// Lorem ipsum:
-fn dolor() -> usize {}
+fn foo() {
+ match foo {
+ | "foo" | "bar" => {}
+ | "baz"
+ | "something relatively long"
+ | "something really really really realllllllllllllly long" => println!("x"),
+ | "qux" => println!("y"),
+ _ => {}
+ }
-// sit amet:
-fn adipiscing() -> usize {}
+ match baz {
+ "qux" => {}
+ "foo" | "bar" => {}
+ _ => {}
+ }
+}
```
-## `remove_nested_parens`
+## `match_block_trailing_comma`
-Remove nested parens.
+Put a trailing comma after a block based match arm (non-block arms are not affected)
-- **Default value**: `true`,
+- **Default value**: `false`
- **Possible values**: `true`, `false`
- **Stable**: Yes
+#### `false` (default):
-#### `true` (default):
```rust
fn main() {
- (foo());
+ match lorem {
+ Lorem::Ipsum => {
+ println!("ipsum");
+ }
+ Lorem::Dolor => println!("dolor"),
+ }
}
```
-#### `false`:
+#### `true`:
+
```rust
fn main() {
- ((((foo()))));
+ match lorem {
+ Lorem::Ipsum => {
+ println!("ipsum");
+ },
+ Lorem::Dolor => println!("dolor"),
+ }
}
```
+See also: [`trailing_comma`](#trailing_comma), [`match_arm_blocks`](#match_arm_blocks).
+
+## `max_width`
-## `reorder_imports`
+Maximum width of each line
-Reorder import and extern crate statements alphabetically in groups (a group is
-separated by a newline).
+- **Default value**: `100`
+- **Possible values**: any positive integer
+- **Stable**: Yes
+
+See also [`error_on_line_overflow`](#error_on_line_overflow).
+
+## `merge_derives`
+
+Merge multiple derives into a single one.
- **Default value**: `true`
- **Possible values**: `true`, `false`
#### `true` (default):
```rust
-use dolor;
-use ipsum;
-use lorem;
-use sit;
+#[derive(Eq, PartialEq, Debug, Copy, Clone)]
+pub enum Foo {}
```
#### `false`:
```rust
-use lorem;
-use ipsum;
-use dolor;
-use sit;
+#[derive(Eq, PartialEq, Debug, Copy, Clone)]
+pub enum Bar {}
+
+#[derive(Eq, PartialEq)]
+#[derive(Debug)]
+#[derive(Copy, Clone)]
+pub enum Foo {}
```
+## `imports_granularity`
-## `reorder_modules`
+How imports should be grouped into `use` statements. Imports will be merged or split to the configured level of granularity.
-Reorder `mod` declarations alphabetically in group.
+- **Default value**: `Preserve`
+- **Possible values**: `Preserve`, `Crate`, `Module`, `Item`, `One`
+- **Stable**: No (tracking issue: [#4991](https://github.com/rust-lang/rustfmt/issues/4991))
-- **Default value**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: Yes
+#### `Preserve` (default):
-#### `true` (default)
+Do not change the granularity of any imports and preserve the original structure written by the developer.
```rust
-mod a;
-mod b;
-
-mod dolor;
-mod ipsum;
-mod lorem;
-mod sit;
+use foo::b;
+use foo::b::{f, g};
+use foo::{a, c, d::e};
+use qux::{h, i};
```
-#### `false`
+#### `Crate`:
-```rust
-mod b;
-mod a;
+Merge imports from the same crate into a single `use` statement. Conversely, imports from different crates are split into separate statements.
-mod lorem;
-mod ipsum;
-mod dolor;
-mod sit;
+```rust
+use foo::{
+ a, b,
+ b::{f, g},
+ c,
+ d::e,
+};
+use qux::{h, i};
```
-**Note** `mod` with `#[macro_export]` will not be reordered since that could change the semantics
-of the original source code.
-
-## `reorder_impl_items`
-
-Reorder impl items. `type` and `const` are put first, then macros and methods.
-
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3363)
+#### `Module`:
-#### `false` (default)
+Merge imports from the same module into a single `use` statement. Conversely, imports from different modules are split into separate statements.
```rust
-struct Dummy;
-
-impl Iterator for Dummy {
- fn next(&mut self) -> Option<Self::Item> {
- None
- }
-
- type Item = i32;
-}
+use foo::b::{f, g};
+use foo::d::e;
+use foo::{a, b, c};
+use qux::{h, i};
```
-#### `true`
-
-```rust
-struct Dummy;
+#### `Item`:
-impl Iterator for Dummy {
- type Item = i32;
+Flatten imports so that each has its own `use` statement.
- fn next(&mut self) -> Option<Self::Item> {
- None
- }
-}
+```rust
+use foo::a;
+use foo::b;
+use foo::b::f;
+use foo::b::g;
+use foo::c;
+use foo::d::e;
+use qux::h;
+use qux::i;
```
-## `report_todo`
+#### `One`:
-Report `TODO` items in comments.
+Merge all imports into a single `use` statement as long as they have the same visibility.
-- **Default value**: `"Never"`
-- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
-- **Stable**: No (tracking issue: #3393)
+```rust
+pub use foo::{x, y};
+use {
+ bar::{
+ a,
+ b::{self, f, g},
+ c,
+ d::e,
+ },
+ qux::{h, i},
+};
+```
-Warns about any comments containing `TODO` in them when set to `"Always"`. If
-it contains a `#X` (with `X` being a number) in parentheses following the
-`TODO`, `"Unnumbered"` will ignore it.
+## `merge_imports`
-See also [`report_fixme`](#report_fixme).
+This option is deprecated. Use `imports_granularity = "Crate"` instead.
-## `report_fixme`
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
-Report `FIXME` items in comments.
+#### `false` (default):
-- **Default value**: `"Never"`
-- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
-- **Stable**: No (tracking issue: #3394)
+```rust
+use foo::{a, c, d};
+use foo::{b, g};
+use foo::{e, f};
+```
-Warns about any comments containing `FIXME` in them when set to `"Always"`. If
-it contains a `#X` (with `X` being a number) in parentheses following the
-`FIXME`, `"Unnumbered"` will ignore it.
+#### `true`:
-See also [`report_todo`](#report_todo).
+```rust
+use foo::{a, b, c, d, e, f, g};
+```
-## `skip_children`
+## `newline_style`
-Don't reformat out of line modules
+Unix or Windows line endings
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3389)
+- **Default value**: `"Auto"`
+- **Possible values**: `"Auto"`, `"Native"`, `"Unix"`, `"Windows"`
+- **Stable**: Yes
-## `space_after_colon`
+#### `Auto` (default):
-Leave a space after the colon.
+The newline style is detected automatically on a per-file basis. Files
+with mixed line endings will be converted to the first detected line
+ending style.
-- **Default value**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3366)
+#### `Native`
-#### `true` (default):
+Line endings will be converted to `\r\n` on Windows and `\n` on all
+other platforms.
-```rust
-fn lorem<T: Eq>(t: T) {
- let lorem: Dolor = Lorem {
- ipsum: dolor,
- sit: amet,
- };
-}
-```
+#### `Unix`
-#### `false`:
+Line endings will be converted to `\n`.
-```rust
-fn lorem<T:Eq>(t:T) {
- let lorem:Dolor = Lorem {
- ipsum:dolor,
- sit:amet,
- };
-}
-```
+#### `Windows`
-See also: [`space_before_colon`](#space_before_colon).
+Line endings will be converted to `\r\n`.
-## `space_before_colon`
+## `normalize_comments`
-Leave a space before the colon.
+Convert /* */ comments to // comments where possible
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3365)
+- **Stable**: No (tracking issue: [#3350](https://github.com/rust-lang/rustfmt/issues/3350))
#### `false` (default):
```rust
-fn lorem<T: Eq>(t: T) {
- let lorem: Dolor = Lorem {
- ipsum: dolor,
- sit: amet,
- };
-}
+// Lorem ipsum:
+fn dolor() -> usize {}
+
+/* sit amet: */
+fn adipiscing() -> usize {}
```
#### `true`:
```rust
-fn lorem<T : Eq>(t : T) {
- let lorem : Dolor = Lorem {
- ipsum : dolor,
- sit : amet,
- };
-}
-```
+// Lorem ipsum:
+fn dolor() -> usize {}
-See also: [`space_after_colon`](#space_after_colon).
+// sit amet:
+fn adipiscing() -> usize {}
+```
-## `struct_field_align_threshold`
+## `normalize_doc_attributes`
-The maximum diff of width between struct fields to be aligned with each other.
+Convert `#![doc]` and `#[doc]` attributes to `//!` and `///` doc comments.
-- **Default value** : 0
-- **Possible values**: any non-negative integer
-- **Stable**: No (tracking issue: #3371)
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3351](https://github.com/rust-lang/rustfmt/issues/3351))
-#### `0` (default):
+#### `false` (default):
```rust
-struct Foo {
- x: u32,
- yy: u32,
- zzz: u32,
-}
+#![doc = "Example documentation"]
+
+#[doc = "Example item documentation"]
+pub enum Bar {}
+
+/// Example item documentation
+pub enum Foo {}
```
-#### `20`:
+#### `true`:
```rust
-struct Foo {
- x: u32,
- yy: u32,
- zzz: u32,
-}
+//! Example documentation
+
+/// Example item documentation
+pub enum Foo {}
```
-## `spaces_around_ranges`
+## `overflow_delimited_expr`
-Put spaces around the .., ..=, and ... range operators
+When structs, slices, arrays, and block/array-like macros are used as the last
+argument in an expression list, allow them to overflow (like blocks/closures)
+instead of being indented on a new line.
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3367)
+- **Stable**: No (tracking issue: [#3370](https://github.com/rust-lang/rustfmt/issues/3370))
#### `false` (default):
```rust
-fn main() {
- let lorem = 0..10;
- let ipsum = 0..=10;
+fn example() {
+ foo(ctx, |param| {
+ action();
+ foo(param)
+ });
- match lorem {
- 1..5 => foo(),
- _ => bar,
- }
+ foo(
+ ctx,
+ Bar {
+ x: value,
+ y: value2,
+ },
+ );
- match lorem {
- 1..=5 => foo(),
- _ => bar,
- }
+ foo(
+ ctx,
+ &[
+ MAROON_TOMATOES,
+ PURPLE_POTATOES,
+ ORGANE_ORANGES,
+ GREEN_PEARS,
+ RED_APPLES,
+ ],
+ );
- match lorem {
- 1...5 => foo(),
- _ => bar,
- }
+ foo(
+ ctx,
+ vec![
+ MAROON_TOMATOES,
+ PURPLE_POTATOES,
+ ORGANE_ORANGES,
+ GREEN_PEARS,
+ RED_APPLES,
+ ],
+ );
}
```
#### `true`:
```rust
-fn main() {
- let lorem = 0 .. 10;
- let ipsum = 0 ..= 10;
+fn example() {
+ foo(ctx, |param| {
+ action();
+ foo(param)
+ });
- match lorem {
- 1 .. 5 => foo(),
- _ => bar,
- }
+ foo(ctx, Bar {
+ x: value,
+ y: value2,
+ });
- match lorem {
- 1 ..= 5 => foo(),
- _ => bar,
- }
+ foo(ctx, &[
+ MAROON_TOMATOES,
+ PURPLE_POTATOES,
+ ORGANE_ORANGES,
+ GREEN_PEARS,
+ RED_APPLES,
+ ]);
- match lorem {
- 1 ... 5 => foo(),
- _ => bar,
- }
+ foo(ctx, vec![
+ MAROON_TOMATOES,
+ PURPLE_POTATOES,
+ ORGANE_ORANGES,
+ GREEN_PEARS,
+ RED_APPLES,
+ ]);
}
```
-## `struct_lit_single_line`
+## `remove_nested_parens`
-Put small struct literals on a single line
+Remove nested parens.
-- **Default value**: `true`
+- **Default value**: `true`,
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3357)
+- **Stable**: Yes
-#### `true` (default):
+#### `true` (default):
```rust
fn main() {
- let lorem = Lorem { foo: bar, baz: ofo };
+ (foo());
}
```
#### `false`:
-
```rust
fn main() {
- let lorem = Lorem {
- foo: bar,
- baz: ofo,
- };
+ (foo());
+
+ ((((foo()))));
}
```
-See also: [`indent_style`](#indent_style).
-
-## `tab_spaces`
+## `reorder_impl_items`
-Number of spaces per tab
+Reorder impl items. `type` and `const` are put first, then macros and methods.
-- **Default value**: `4`
-- **Possible values**: any positive integer
-- **Stable**: Yes
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3363](https://github.com/rust-lang/rustfmt/issues/3363))
-#### `4` (default):
+#### `false` (default)
```rust
-fn lorem() {
- let ipsum = dolor();
- let sit = vec![
- "amet consectetur adipiscing elit amet",
- "consectetur adipiscing elit amet consectetur.",
- ];
+struct Dummy;
+
+impl Iterator for Dummy {
+ fn next(&mut self) -> Option<Self::Item> {
+ None
+ }
+
+ type Item = i32;
+}
+
+impl Iterator for Dummy {
+ type Item = i32;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ None
+ }
}
```
-#### `2`:
+#### `true`
```rust
-fn lorem() {
- let ipsum = dolor();
- let sit = vec![
- "amet consectetur adipiscing elit amet",
- "consectetur adipiscing elit amet consectetur.",
- ];
+struct Dummy;
+
+impl Iterator for Dummy {
+ type Item = i32;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ None
+ }
}
```
-See also: [`hard_tabs`](#hard_tabs).
+## `reorder_imports`
+Reorder import and extern crate statements alphabetically in groups (a group is
+separated by a newline).
-## `trailing_comma`
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: Yes
-How to handle trailing commas for lists
+#### `true` (default):
-- **Default value**: `"Vertical"`
-- **Possible values**: `"Always"`, `"Never"`, `"Vertical"`
-- **Stable**: No (tracking issue: #3379)
+```rust
+use dolor;
+use ipsum;
+use lorem;
+use sit;
+```
-#### `"Vertical"` (default):
+#### `false`:
```rust
-fn main() {
- let Lorem { ipsum, dolor, sit } = amet;
- let Lorem {
- ipsum,
- dolor,
- sit,
- amet,
- consectetur,
- adipiscing,
- } = elit;
-}
+use lorem;
+use ipsum;
+use dolor;
+use sit;
```
-#### `"Always"`:
+## `group_imports`
+
+Controls the strategy for how imports are grouped together.
+
+- **Default value**: `Preserve`
+- **Possible values**: `Preserve`, `StdExternalCrate`, `One`
+- **Stable**: No (tracking issue: [#5083](https://github.com/rust-lang/rustfmt/issues/5083))
+
+#### `Preserve` (default):
+
+Preserve the source file's import groups.
```rust
-fn main() {
- let Lorem { ipsum, dolor, sit, } = amet;
- let Lorem {
- ipsum,
- dolor,
- sit,
- amet,
- consectetur,
- adipiscing,
- } = elit;
-}
+use super::update::convert_publish_payload;
+use chrono::Utc;
+
+use alloc::alloc::Layout;
+use juniper::{FieldError, FieldResult};
+use uuid::Uuid;
+
+use std::sync::Arc;
+
+use broker::database::PooledConnection;
+
+use super::schema::{Context, Payload};
+use crate::models::Event;
+use core::f32;
```
-#### `"Never"`:
+#### `StdExternalCrate`:
+
+Discard existing import groups, and create three groups for:
+1. `std`, `core` and `alloc`,
+2. external crates,
+3. `self`, `super` and `crate` imports.
```rust
-fn main() {
- let Lorem { ipsum, dolor, sit } = amet;
- let Lorem {
- ipsum,
- dolor,
- sit,
- amet,
- consectetur,
- adipiscing
- } = elit;
-}
+use alloc::alloc::Layout;
+use core::f32;
+use std::sync::Arc;
+
+use broker::database::PooledConnection;
+use chrono::Utc;
+use juniper::{FieldError, FieldResult};
+use uuid::Uuid;
+
+use super::schema::{Context, Payload};
+use super::update::convert_publish_payload;
+use crate::models::Event;
```
-See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
+#### `One`:
-## `trailing_semicolon`
+Discard existing import groups, and create a single group for everything
-Add trailing semicolon after break, continue and return
+```rust
+use super::schema::{Context, Payload};
+use super::update::convert_publish_payload;
+use crate::models::Event;
+use alloc::alloc::Layout;
+use broker::database::PooledConnection;
+use chrono::Utc;
+use core::f32;
+use juniper::{FieldError, FieldResult};
+use std::sync::Arc;
+use uuid::Uuid;
+```
+
+## `reorder_modules`
+
+Reorder `mod` declarations alphabetically in group.
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3378)
+- **Stable**: Yes
+
+#### `true` (default)
-#### `true` (default):
```rust
-fn foo() -> usize {
- return 0;
-}
+mod a;
+mod b;
+
+mod dolor;
+mod ipsum;
+mod lorem;
+mod sit;
```
-#### `false`:
+#### `false`
+
```rust
-fn foo() -> usize {
- return 0
-}
+mod b;
+mod a;
+
+mod lorem;
+mod ipsum;
+mod dolor;
+mod sit;
```
-## `type_punctuation_density`
+**Note** `mod` with `#[macro_export]` will not be reordered since that could change the semantics
+of the original source code.
-Determines if `+` or `=` are wrapped in spaces in the punctuation of types
+## `report_fixme`
-- **Default value**: `"Wide"`
-- **Possible values**: `"Compressed"`, `"Wide"`
-- **Stable**: No (tracking issue: #3364)
+Report `FIXME` items in comments.
-#### `"Wide"` (default):
+- **Default value**: `"Never"`
+- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
+- **Stable**: No (tracking issue: [#3394](https://github.com/rust-lang/rustfmt/issues/3394))
-```rust
-fn lorem<Ipsum: Dolor + Sit = Amet>() {
- // body
-}
-```
+Warns about any comments containing `FIXME` in them when set to `"Always"`. If
+it contains a `#X` (with `X` being a number) in parentheses following the
+`FIXME`, `"Unnumbered"` will ignore it.
-#### `"Compressed"`:
+See also [`report_todo`](#report_todo).
-```rust
-fn lorem<Ipsum: Dolor+Sit=Amet>() {
- // body
-}
-```
-## `use_field_init_shorthand`
+## `report_todo`
-Use field initialize shorthand if possible.
+Report `TODO` items in comments.
+
+- **Default value**: `"Never"`
+- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
+- **Stable**: No (tracking issue: [#3393](https://github.com/rust-lang/rustfmt/issues/3393))
+
+Warns about any comments containing `TODO` in them when set to `"Always"`. If
+it contains a `#X` (with `X` being a number) in parentheses following the
+`TODO`, `"Unnumbered"` will ignore it.
+
+See also [`report_fixme`](#report_fixme).
+
+## `required_version`
+
+Require a specific version of rustfmt. If you want to make sure that the
+specific version of rustfmt is used in your CI, use this option.
+
+- **Default value**: `CARGO_PKG_VERSION`
+- **Possible values**: any published version (e.g. `"0.3.8"`)
+- **Stable**: No (tracking issue: [#3386](https://github.com/rust-lang/rustfmt/issues/3386))
+
+## `skip_children`
+
+Don't reformat out of line modules
- **Default value**: `false`
- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3389](https://github.com/rust-lang/rustfmt/issues/3386))
+
+## `single_line_if_else_max_width`
+
+Maximum line length for single line if-else expressions. A value of `0` (zero) results in if-else expressions always being broken into multiple lines. Note this occurs when `use_small_heuristics` is set to `Off`.
+
+- **Default value**: `50`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
- **Stable**: Yes
-#### `false` (default):
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `single_line_if_else_max_width` will take precedence.
-```rust
-struct Foo {
- x: u32,
- y: u32,
- z: u32,
-}
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
-fn main() {
- let x = 1;
- let y = 2;
- let z = 3;
- let a = Foo { x: x, y: y, z: z };
-}
-```
+## `space_after_colon`
-#### `true`:
+Leave a space after the colon.
+
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3366](https://github.com/rust-lang/rustfmt/issues/3366))
+
+#### `true` (default):
```rust
-struct Foo {
- x: u32,
- y: u32,
- z: u32,
+fn lorem<T: Eq>(t: T) {
+ let lorem: Dolor = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
}
+```
-fn main() {
- let x = 1;
- let y = 2;
- let z = 3;
- let a = Foo { x, y, z };
+#### `false`:
+
+```rust
+fn lorem<T:Eq>(t:T) {
+ let lorem:Dolor = Lorem {
+ ipsum:dolor,
+ sit:amet,
+ };
}
```
-## `use_try_shorthand`
+See also: [`space_before_colon`](#space_before_colon).
-Replace uses of the try! macro by the ? shorthand
+## `space_before_colon`
+
+Leave a space before the colon.
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: Yes
+- **Stable**: No (tracking issue: [#3365](https://github.com/rust-lang/rustfmt/issues/3365))
#### `false` (default):
```rust
-fn main() {
- let lorem = try!(ipsum.map(|dolor| dolor.sit()));
+fn lorem<T: Eq>(t: T) {
+ let lorem: Dolor = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
}
```
#### `true`:
```rust
-fn main() {
- let lorem = ipsum.map(|dolor| dolor.sit())?;
+fn lorem<T : Eq>(t : T) {
+ let lorem : Dolor = Lorem {
+ ipsum : dolor,
+ sit : amet,
+ };
}
```
-## `format_code_in_doc_comments`
+See also: [`space_after_colon`](#space_after_colon).
-Format code snippet included in doc comments.
+## `spaces_around_ranges`
+
+Put spaces around the .., ..=, and ... range operators
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3348)
+- **Stable**: No (tracking issue: [#3367](https://github.com/rust-lang/rustfmt/issues/3367))
#### `false` (default):
```rust
-/// Adds one to the number given.
-///
-/// # Examples
-///
-/// ```rust
-/// let five=5;
-///
-/// assert_eq!(
-/// 6,
-/// add_one(5)
-/// );
-/// # fn add_one(x: i32) -> i32 {
-/// # x + 1
-/// # }
-/// ```
-fn add_one(x: i32) -> i32 {
- x + 1
+fn main() {
+ let lorem = 0..10;
+ let ipsum = 0..=10;
+
+ match lorem {
+ 1..5 => foo(),
+ _ => bar,
+ }
+
+ match lorem {
+ 1..=5 => foo(),
+ _ => bar,
+ }
+
+ match lorem {
+ 1...5 => foo(),
+ _ => bar,
+ }
}
```
-#### `true`
+#### `true`:
```rust
-/// Adds one to the number given.
-///
-/// # Examples
-///
-/// ```rust
-/// let five = 5;
-///
-/// assert_eq!(6, add_one(5));
-/// # fn add_one(x: i32) -> i32 {
-/// # x + 1
-/// # }
-/// ```
-fn add_one(x: i32) -> i32 {
- x + 1
+fn main() {
+ let lorem = 0 .. 10;
+ let ipsum = 0 ..= 10;
+
+ match lorem {
+ 1 .. 5 => foo(),
+ _ => bar,
+ }
+
+ match lorem {
+ 1 ..= 5 => foo(),
+ _ => bar,
+ }
+
+ match lorem {
+ 1 ... 5 => foo(),
+ _ => bar,
+ }
}
```
-## `wrap_comments`
+## `struct_field_align_threshold`
-Break comments to fit on the line
+The maximum diff of width between struct fields to be aligned with each other.
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3347)
+- **Default value** : 0
+- **Possible values**: any non-negative integer
+- **Stable**: No (tracking issue: [#3371](https://github.com/rust-lang/rustfmt/issues/3371))
-#### `false` (default):
+#### `0` (default):
```rust
-// Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
+struct Foo {
+ x: u32,
+ yy: u32,
+ zzz: u32,
+}
```
-#### `true`:
+#### `20`:
```rust
-// Lorem ipsum dolor sit amet, consectetur adipiscing elit,
-// sed do eiusmod tempor incididunt ut labore et dolore
-// magna aliqua. Ut enim ad minim veniam, quis nostrud
-// exercitation ullamco laboris nisi ut aliquip ex ea
-// commodo consequat.
+struct Foo {
+ x: u32,
+ yy: u32,
+ zzz: u32,
+}
```
-## `match_arm_blocks`
+## `struct_lit_single_line`
-Wrap the body of arms in blocks when it does not fit on the same line with the pattern of arms
+Put small struct literals on a single line
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3373)
+- **Stable**: No (tracking issue: [#3357](https://github.com/rust-lang/rustfmt/issues/3357))
#### `true` (default):
```rust
fn main() {
- match lorem {
- true => {
- foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x)
- }
- false => println!("{}", sit),
- }
+ let lorem = Lorem { foo: bar, baz: ofo };
}
```
```rust
fn main() {
- match lorem {
- true =>
- foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x),
- false => println!("{}", sit),
- }
+ let lorem = Lorem {
+ foo: bar,
+ baz: ofo,
+ };
}
```
-See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
+See also: [`indent_style`](#indent_style).
-## `overflow_delimited_expr`
+## `struct_lit_width`
-When structs, slices, arrays, and block/array-like macros are used as the last
-argument in an expression list, allow them to overflow (like blocks/closures)
-instead of being indented on a new line.
+Maximum width in the body of a struct literal before falling back to vertical formatting. A value of `0` (zero) results in struct literals always being broken into multiple lines. Note this occurs when `use_small_heuristics` is set to `Off`.
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3370)
+- **Default value**: `18`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
-#### `false` (default):
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `struct_lit_width` will take precedence.
-```rust
-fn example() {
- foo(ctx, |param| {
- action();
- foo(param)
- });
+See also [`max_width`](#max_width), [`use_small_heuristics`](#use_small_heuristics), and [`struct_lit_single_line`](#struct_lit_single_line)
- foo(
- ctx,
- Bar {
- x: value,
- y: value2,
- },
- );
+## `struct_variant_width`
- foo(
- ctx,
- &[
- MAROON_TOMATOES,
- PURPLE_POTATOES,
- ORGANE_ORANGES,
- GREEN_PEARS,
- RED_APPLES,
- ],
- );
+Maximum width in the body of a struct variant before falling back to vertical formatting. A value of `0` (zero) results in struct literals always being broken into multiple lines. Note this occurs when `use_small_heuristics` is set to `Off`.
- foo(
- ctx,
- vec![
- MAROON_TOMATOES,
- PURPLE_POTATOES,
- ORGANE_ORANGES,
- GREEN_PEARS,
- RED_APPLES,
- ],
- );
-}
-```
+- **Default value**: `35`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
-#### `true`:
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `struct_variant_width` will take precedence.
-```rust
-fn example() {
- foo(ctx, |param| {
- action();
- foo(param)
- });
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
- foo(ctx, Bar {
- x: value,
- y: value2,
- });
+## `tab_spaces`
- foo(ctx, &[
- MAROON_TOMATOES,
- PURPLE_POTATOES,
- ORGANE_ORANGES,
- GREEN_PEARS,
- RED_APPLES,
- ]);
+Number of spaces per tab
- foo(ctx, vec![
- MAROON_TOMATOES,
- PURPLE_POTATOES,
- ORGANE_ORANGES,
- GREEN_PEARS,
- RED_APPLES,
- ]);
+- **Default value**: `4`
+- **Possible values**: any positive integer
+- **Stable**: Yes
+
+#### `4` (default):
+
+```rust
+fn lorem() {
+ let ipsum = dolor();
+ let sit = vec![
+ "amet consectetur adipiscing elit amet",
+ "consectetur adipiscing elit amet consectetur.",
+ ];
}
```
-## `blank_lines_upper_bound`
+#### `2`:
-Maximum number of blank lines which can be put between items. If more than this number of consecutive empty
-lines are found, they are trimmed down to match this integer.
+```rust
+fn lorem() {
+ let ipsum = dolor();
+ let sit = vec![
+ "amet consectetur adipiscing elit amet",
+ "consectetur adipiscing elit amet consectetur.",
+ ];
+}
+```
-- **Default value**: `1`
-- **Possible values**: any non-negative integer
-- **Stable**: No (tracking issue: #3381)
+See also: [`hard_tabs`](#hard_tabs).
-### Example
-Original Code:
-```rust
-#![rustfmt::skip]
+## `trailing_comma`
-fn foo() {
- println!("a");
-}
+How to handle trailing commas for lists
+- **Default value**: `"Vertical"`
+- **Possible values**: `"Always"`, `"Never"`, `"Vertical"`
+- **Stable**: No (tracking issue: [#3379](https://github.com/rust-lang/rustfmt/issues/3379))
+#### `"Vertical"` (default):
-fn bar() {
- println!("b");
+```rust
+fn main() {
+ let Lorem { ipsum, dolor, sit } = amet;
+ let Lorem {
+ ipsum,
+ dolor,
+ sit,
+ amet,
+ consectetur,
+ adipiscing,
+ } = elit;
+}
+```
+#### `"Always"`:
- println!("c");
+```rust
+fn main() {
+ let Lorem { ipsum, dolor, sit, } = amet;
+ let Lorem {
+ ipsum,
+ dolor,
+ sit,
+ amet,
+ consectetur,
+ adipiscing,
+ } = elit;
}
```
-#### `1` (default):
+#### `"Never"`:
+
```rust
-fn foo() {
- println!("a");
+fn main() {
+ let Lorem { ipsum, dolor, sit } = amet;
+ let Lorem {
+ ipsum,
+ dolor,
+ sit,
+ amet,
+ consectetur,
+ adipiscing
+ } = elit;
}
+```
-fn bar() {
- println!("b");
+See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
- println!("c");
+## `trailing_semicolon`
+
+Add trailing semicolon after break, continue and return
+
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3378](https://github.com/rust-lang/rustfmt/issues/3378))
+
+#### `true` (default):
+```rust
+fn foo() -> usize {
+ return 0;
}
```
-#### `2`:
+#### `false`:
```rust
-fn foo() {
- println!("a");
+fn foo() -> usize {
+ return 0
}
+```
+## `type_punctuation_density`
-fn bar() {
- println!("b");
+Determines if `+` or `=` are wrapped in spaces in the punctuation of types
+- **Default value**: `"Wide"`
+- **Possible values**: `"Compressed"`, `"Wide"`
+- **Stable**: No (tracking issue: [#3364](https://github.com/rust-lang/rustfmt/issues/3364))
- println!("c");
+#### `"Wide"` (default):
+
+```rust
+fn lorem<Ipsum: Dolor + Sit = Amet>() {
+ // body
+}
+```
+
+#### `"Compressed"`:
+
+```rust
+fn lorem<Ipsum: Dolor+Sit=Amet>() {
+ // body
}
```
-See also: [`blank_lines_lower_bound`](#blank_lines_lower_bound)
+## `unstable_features`
+
+Enable unstable features on the unstable channel.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3387](https://github.com/rust-lang/rustfmt/issues/3387))
-## `blank_lines_lower_bound`
+## `use_field_init_shorthand`
-Minimum number of blank lines which must be put between items. If two items have fewer blank lines between
-them, additional blank lines are inserted.
+Use field initialize shorthand if possible.
-- **Default value**: `0`
-- **Possible values**: *unsigned integer*
-- **Stable**: No (tracking issue: #3382)
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: Yes
-### Example
-Original Code (rustfmt will not change it with the default value of `0`):
+#### `false` (default):
```rust
-#![rustfmt::skip]
-
-fn foo() {
- println!("a");
+struct Foo {
+ x: u32,
+ y: u32,
+ z: u32,
}
-fn bar() {
- println!("b");
- println!("c");
+
+fn main() {
+ let x = 1;
+ let y = 2;
+ let z = 3;
+ let a = Foo { x, y, z };
+ let b = Foo { x: x, y: y, z: z };
}
```
-#### `1`
-```rust
-fn foo() {
+#### `true`:
- println!("a");
+```rust
+struct Foo {
+ x: u32,
+ y: u32,
+ z: u32,
}
-fn bar() {
-
- println!("b");
-
- println!("c");
+fn main() {
+ let x = 1;
+ let y = 2;
+ let z = 3;
+ let a = Foo { x, y, z };
}
```
+## `use_small_heuristics`
-## `required_version`
-
-Require a specific version of rustfmt. If you want to make sure that the
-specific version of rustfmt is used in your CI, use this option.
-
-- **Default value**: `CARGO_PKG_VERSION`
-- **Possible values**: any published version (e.g. `"0.3.8"`)
-- **Stable**: No (tracking issue: #3386)
-
-## `hide_parse_errors`
-
-Do not show parse errors if the parser failed to parse files.
+This option can be used to simplify the management and bulk updates of the granular width configuration settings ([`fn_call_width`](#fn_call_width), [`attr_fn_like_width`](#attr_fn_like_width), [`struct_lit_width`](#struct_lit_width), [`struct_variant_width`](#struct_variant_width), [`array_width`](#array_width), [`chain_width`](#chain_width), [`single_line_if_else_max_width`](#single_line_if_else_max_width)), that respectively control when formatted constructs are multi-lined/vertical based on width.
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3390)
+Note that explicitly provided values for the width configuration settings take precedence and override the calculated values determined by `use_small_heuristics`.
-## `color`
+- **Default value**: `"Default"`
+- **Possible values**: `"Default"`, `"Off"`, `"Max"`
+- **Stable**: Yes
-Whether to use colored output or not.
+#### `Default` (default):
+When `use_small_heuristics` is set to `Default`, the values for the granular width settings are calculated as a ratio of the value for `max_width`.
+
+The ratios are:
+* [`fn_call_width`](#fn_call_width) - `60%`
+* [`attr_fn_like_width`](#attr_fn_like_width) - `70%`
+* [`struct_lit_width`](#struct_lit_width) - `18%`
+* [`struct_variant_width`](#struct_variant_width) - `35%`
+* [`array_width`](#array_width) - `60%`
+* [`chain_width`](#chain_width) - `60%`
+* [`single_line_if_else_max_width`](#single_line_if_else_max_width) - `50%`
+
+For example when `max_width` is set to `100`, the width settings are:
+* `fn_call_width=60`
+* `attr_fn_like_width=70`
+* `struct_lit_width=18`
+* `struct_variant_width=35`
+* `array_width=60`
+* `chain_width=60`
+* `single_line_if_else_max_width=50`
+
+and when `max_width` is set to `200`:
+* `fn_call_width=120`
+* `attr_fn_like_width=140`
+* `struct_lit_width=36`
+* `struct_variant_width=70`
+* `array_width=120`
+* `chain_width=120`
+* `single_line_if_else_max_width=100`
-- **Default value**: `"Auto"`
-- **Possible values**: "Auto", "Always", "Never"
-- **Stable**: No (tracking issue: #3385)
+```rust
+enum Lorem {
+ Ipsum,
+ Dolor(bool),
+ Sit { amet: Consectetur, adipiscing: Elit },
+}
-## `unstable_features`
+fn main() {
+ lorem(
+ "lorem",
+ "ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ );
-Enable unstable features on the unstable channel.
+ let lorem = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
+ let lorem = Lorem { ipsum: dolor };
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3387)
+ let lorem = if ipsum { dolor } else { sit };
+}
+```
-## `license_template_path`
+#### `Off`:
+When `use_small_heuristics` is set to `Off`, the granular width settings are functionally disabled and ignored. See the documentation for the respective width config options for specifics.
-Check whether beginnings of files match a license template.
+```rust
+enum Lorem {
+ Ipsum,
+ Dolor(bool),
+ Sit {
+ amet: Consectetur,
+ adipiscing: Elit,
+ },
+}
-- **Default value**: `""`
-- **Possible values**: path to a license template file
-- **Stable**: No (tracking issue: #3352)
+fn main() {
+ lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
-A license template is a plain text file which is matched literally against the
-beginning of each source file, except for `{}`-delimited blocks, which are
-matched as regular expressions. The following license template therefore
-matches strings like `// Copyright 2017 The Rust Project Developers.`, `//
-Copyright 2018 The Rust Project Developers.`, etc.:
+ let lorem = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
+ let lorem = if ipsum {
+ dolor
+ } else {
+ sit
+ };
+}
```
-// Copyright {\d+} The Rust Project Developers.
-```
-
-`\{`, `\}` and `\\` match literal braces / backslashes.
-## `ignore`
+#### `Max`:
+When `use_small_heuristics` is set to `Max`, then each granular width setting is set to the same value as `max_width`.
-Skip formatting files and directories that match the specified pattern.
-The pattern format is the same as [.gitignore](https://git-scm.com/docs/gitignore#_pattern_format).
+So if `max_width` is set to `200`, then all the width settings are also set to `200`.
+* `fn_call_width=200`
+* `attr_fn_like_width=200`
+* `struct_lit_width=200`
+* `struct_variant_width=200`
+* `array_width=200`
+* `chain_width=200`
+* `single_line_if_else_max_width=200`
-- **Default value**: format every file
-- **Possible values**: See an example below
-- **Stable**: No (tracking issue: #3395)
+```rust
+enum Lorem {
+ Ipsum,
+ Dolor(bool),
+ Sit { amet: Consectetur, adipiscing: Elit },
+}
-### Example
+fn main() {
+ lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
-If you want to ignore specific files, put the following to your config file:
+ let lorem = Lorem { ipsum: dolor, sit: amet };
-```toml
-ignore = [
- "src/types.rs",
- "src/foo/bar.rs",
-]
+ let lorem = if ipsum { dolor } else { sit };
+}
```
-If you want to ignore every file under `examples/`, put the following to your config file:
-```toml
-ignore = [
- "examples",
-]
-```
+See also:
+* [`max_width`](#max_width)
+* [`fn_call_width`](#fn_call_width)
+* [`attr_fn_like_width`](#attr_fn_like_width)
+* [`struct_lit_width`](#struct_lit_width)
+* [`struct_variant_width`](#struct_variant_width)
+* [`array_width`](#array_width)
+* [`chain_width`](#chain_width)
+* [`single_line_if_else_max_width`](#single_line_if_else_max_width)
-If you want to ignore every file under the directory where you put your rustfmt.toml:
+## `use_try_shorthand`
-```toml
-ignore = ["/"]
-```
+Replace uses of the try! macro by the ? shorthand
-## `edition`
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: Yes
-Specifies which edition is used by the parser.
+#### `false` (default):
-- **Default value**: `2015`
-- **Possible values**: `2015`, `2018`
-- **Stable**: Yes
+```rust
+fn main() {
+ let lorem = ipsum.map(|dolor| dolor.sit())?;
-Rustfmt is able to pick up the edition used by reading the `Cargo.toml` file if executed
-through the Cargo's formatting tool `cargo fmt`. Otherwise, the edition needs to be specified
-in your config file:
+ let lorem = try!(ipsum.map(|dolor| dolor.sit()));
+}
+```
-```toml
-edition = "2018"
+#### `true`:
+
+```rust
+fn main() {
+ let lorem = ipsum.map(|dolor| dolor.sit())?;
+}
```
## `version`
- **Default value**: `One`
- **Possible values**: `One`, `Two`
-- **Stable**: No (tracking issue: #3383)
+- **Stable**: No (tracking issue: [#3383](https://github.com/rust-lang/rustfmt/issues/3383))
### Example
version = "Two"
```
-## `normalize_doc_attributes`
+## `where_single_line`
-Convert `#![doc]` and `#[doc]` attributes to `//!` and `///` doc comments.
+Forces the `where` clause to be laid out on a single line.
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3351)
+- **Stable**: No (tracking issue: [#3359](https://github.com/rust-lang/rustfmt/issues/3359))
#### `false` (default):
```rust
-#![doc = "Example documentation"]
-
-#[doc = "Example item documentation"]
-pub enum Foo {}
+impl<T> Lorem for T
+where
+ Option<T>: Ipsum,
+{
+ // body
+}
```
#### `true`:
```rust
-//! Example documentation
-
-/// Example item documentation
-pub enum Foo {}
+impl<T> Lorem for T
+where Option<T>: Ipsum
+{
+ // body
+}
```
-## `inline_attribute_width`
+See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
-Write an item and its attribute on the same line if their combined width is below a threshold
-- **Default value**: 0
-- **Possible values**: any positive integer
-- **Stable**: No (tracking issue: #3343)
+## `wrap_comments`
-### Example
+Break comments to fit on the line
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3347](https://github.com/rust-lang/rustfmt/issues/3347))
+
+#### `false` (default):
-#### `0` (default):
```rust
-#[cfg(feature = "alloc")]
-use core::slice;
+// Lorem ipsum dolor sit amet, consectetur adipiscing elit,
+// sed do eiusmod tempor incididunt ut labore et dolore
+// magna aliqua. Ut enim ad minim veniam, quis nostrud
+// exercitation ullamco laboris nisi ut aliquip ex ea
+// commodo consequat.
+
+// Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
```
-#### `50`:
+#### `true`:
+
```rust
-#[cfg(feature = "alloc")] use core::slice;
+// Lorem ipsum dolor sit amet, consectetur adipiscing elit,
+// sed do eiusmod tempor incididunt ut labore et dolore
+// magna aliqua. Ut enim ad minim veniam, quis nostrud
+// exercitation ullamco laboris nisi ut aliquip ex ea
+// commodo consequat.
```
+# Internal Options
+
## `emit_mode`
Internal option
## `make_backup`
Internal option, use `--backup`
+
+## `print_misformatted_file_names`
+
+Internal option, use `-l` or `--files-with-diff`
projects / rust.git / blobdiff