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Ben Boeckel 1bb927e46f Configurations: add colons to example section titles

2017-11-09 14:11:33 -05:00

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Configuring Rustfmt

Rustfmt is designed to be very configurable. You can create a TOML file called rustfmt.toml or .rustfmt.toml, place it in the project or any other parent directory and it will apply the options in that file.

A possible content of rustfmt.toml or .rustfmt.toml might look like this:

array_indent = "Block"
array_width = 80
reorder_imported_names = true

Configuration Options

Below you find a detailed visual guide on all the supported configuration options of rustfmt:

`array_horizontal_layout_threshold`

How many elements array must have before rustfmt uses horizontal layout.
Use this option to prevent a huge array from being vertically formatted.

Default value: 0
Possible values: any positive integer

Note: A value of 0 results in array_indent being applied regardless of a line's width.

`0` (default):

// Each element will be placed on its own line.
let a = vec![
    0,
    1,
    2,
    3,
    4,
    ...
    999,
    1000,
];

`1000`:

// Each element will be placed on the same line as much as possible.
let a = vec![
    0, 1, 2, 3, 4, ...
    ..., 999, 1000,
];

`array_indent`

Indent on arrays

Default value: "Block"
Possible values: "Block", "Visual"

`"Block"` (default):

let lorem = vec![
    "ipsum",
    "dolor",
    "sit",
    "amet",
    "consectetur",
    "adipiscing",
    "elit",
];

`"Visual"`:

let lorem = vec!["ipsum",
                 "dolor",
                 "sit",
                 "amet",
                 "consectetur",
                 "adipiscing",
                 "elit"];

`array_width`

Maximum width of an array literal before falling back to vertical formatting

Default value: 60
Possible values: any positive integer

Note: A value of 0 results in array_indent being applied regardless of a line's width.

Lines shorter than `array_width`:

let lorem = vec!["ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing", "elit"];

Lines longer than `array_width`:

See array_indent.

`attributes_on_same_line_as_field`

Try to put attributes on the same line as fields

Default value: true
Possible values: true, false

`true` (default):

struct Lorem {
    #[serde(rename = "Ipsum")] ipsum: usize,
    #[serde(rename = "Dolor")] dolor: usize,
    #[serde(rename = "Amet")] amet: usize,
}

`false`:

struct Lorem {
    #[serde(rename = "Ipsum")]
    ipsum: usize,
    #[serde(rename = "Dolor")]
    dolor: usize,
    #[serde(rename = "Amet")]
    amet: usize,
}

`attributes_on_same_line_as_variant`

Try to put attributes on the same line as variants

Default value: true
Possible values: true, false

`true` (default):

enum Lorem {
    #[serde(skip_serializing)] Ipsum,
    #[serde(skip_serializing)] Dolor,
    #[serde(skip_serializing)] Amet,
}

`false`:

enum Lorem {
    #[serde(skip_serializing)]
    Ipsum,
    #[serde(skip_serializing)]
    Dolor,
    #[serde(skip_serializing)]
    Amet,
}

`binop_separator`

Where to put a binary operator when a binary expression goes multiline.

Default value: "Front"
Possible values: "Front", "Back"

`"Front"` (default):

let or = foo
    || bar
    || foobar;

let sum = 1234
    + 5678
    + 910;

let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
    ..bbbbbbbbbbbbbbbbbbbbbbbbbbbbb;

`"Back"`:

let or = foo ||
    bar ||
    foobar;

let sum = 1234 +
    5678 +
    910;

let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa..
    bbbbbbbbbbbbbbbbbbbbbbbbbbbbb;

`chain_indent`

Indentation of chain

Default value: "Block"
Possible values: "Block", "Visual"

`"Block"` (default):

let lorem = ipsum
    .dolor()
    .sit()
    .amet()
    .consectetur()
    .adipiscing()
    .elit();

`"Visual"`:

let lorem = ipsum.dolor()
                 .sit()
                 .amet()
                 .consectetur()
                 .adipiscing()
                 .elit();

`chain_width`

Maximum length of a chain to fit on a single line

Default value: 60
Possible values: any positive integer

Lines shorter than `chain_width`:

let lorem = ipsum.dolor().sit().amet().consectetur().adipiscing().elit();

Lines longer than `chain_width`:

See chain_indent.

`chain_split_single_child`

Split a chain with a single child if its length exceeds chain_width.

Default value: false
Possible values: false, true

`false` (default):

let files = fs::read_dir("tests/coverage/source").expect("Couldn't read source dir");

`true`:

let files = fs::read_dir("tests/coverage/source")
    .expect("Couldn't read source dir");

`closure_block_indent_threshold`

How many lines a closure must have before it is block indented. -1 means never use block indent.

Default value: 7
Possible values: -1, or any positive integer

Closures shorter than `closure_block_indent_threshold`:

lorem_ipsum(|| {
                println!("lorem");
                println!("ipsum");
                println!("dolor");
                println!("sit");
                println!("amet");
            });

Closures longer than `closure_block_indent_threshold`:

lorem_ipsum(|| {
    println!("lorem");
    println!("ipsum");
    println!("dolor");
    println!("sit");
    println!("amet");
    println!("consectetur");
    println!("adipiscing");
    println!("elit");
});

Note: This option only takes effect when fn_call_indent is set to "Visual".

`combine_control_expr`

Combine control expressions with function calls.

Default value: true
Possible values: true, false

`true` (default):

fn example() {
    // If
    foo!(if x {
        foo();
    } else {
        bar();
    });

    // IfLet
    foo!(if let Some(..) = x {
        foo();
    } else {
        bar();
    });

    // While
    foo!(while x {
        foo();
        bar();
    });

    // WhileLet
    foo!(while let Some(..) = x {
        foo();
        bar();
    });

    // ForLoop
    foo!(for x in y {
        foo();
        bar();
    });

    // Loop
    foo!(loop {
        foo();
        bar();
    });
}

`false`:

`comment_width`

Maximum length of comments. No effect unlesswrap_comments = true.

Default value: 80
Possible values: any positive integer

Note: A value of 0 results in wrap_comments being applied regardless of a line's width.

Comments shorter than `comment_width`:

// Lorem ipsum dolor sit amet, consectetur adipiscing elit.

Comments longer than `comment_width`:

// Lorem ipsum dolor sit amet,
// consectetur adipiscing elit.

`condense_wildcard_suffixes`

Replace strings of _ wildcards by a single .. in tuple patterns

Default value: false
Possible values: true, false

`false` (default):

let (lorem, ipsum, _, _) = (1, 2, 3, 4);

`true`:

let (lorem, ipsum, ..) = (1, 2, 3, 4);

`control_style`

Indent style for control flow statements

Default value: "Rfc"
Possible values: "Rfc", "Legacy"

`"Rfc"` (default):

if lorem_ipsum &&
    dolor_sit &&
    amet_consectetur
{
    // ...
}

`"Legacy"`:

if lorem_ipsum &&
   dolor_sit &&
   amet_consectetur {
    // ...
}

`control_brace_style`

Brace style for control flow constructs

Default value: "AlwaysSameLine"
Possible values: "AlwaysNextLine", "AlwaysSameLine", "ClosingNextLine"

`"AlwaysSameLine"` (default):

if lorem {
    println!("ipsum!");
} else {
    println!("dolor!");
}

`"AlwaysNextLine"`:

if lorem
{
    println!("ipsum!");
}
else
{
    println!("dolor!");
}

`"ClosingNextLine"`:

if lorem {
    println!("ipsum!");
}
else {
    println!("dolor!");
}

`disable_all_formatting`

Don't reformat anything

Default value: false
Possible values: true, false

`error_on_line_overflow`

Error if unable to get all lines within max_width

Default value: true
Possible values: true, false

`fn_args_density`

Argument density in functions

Default value: "Tall"
Possible values: "Compressed", "CompressedIfEmpty", "Tall", "Vertical"

`"Tall"` (default):

trait Lorem {
    fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet);

    fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet) {
        // body
    }

    fn lorem(
        ipsum: Ipsum,
        dolor: Dolor,
        sit: Sit,
        amet: Amet,
        consectetur: Consectetur,
        adipiscing: Adipiscing,
        elit: Elit,
    );

    fn lorem(
        ipsum: Ipsum,
        dolor: Dolor,
        sit: Sit,
        amet: Amet,
        consectetur: Consectetur,
        adipiscing: Adipiscing,
        elit: Elit,
    ) {
        // body
    }
}

`"Compressed"`:

trait Lorem {
    fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet);

    fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet) {
        // body
    }

    fn lorem(
        ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet, consectetur: Consectetur,
        adipiscing: Adipiscing, elit: Elit,
    );

    fn lorem(
        ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet, consectetur: Consectetur,
        adipiscing: Adipiscing, elit: Elit,
    ) {
        // body
    }
}

`"CompressedIfEmpty"`:

trait Lorem {
    fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet);

    fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet) {
        // body
    }

    fn lorem(
        ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet, consectetur: Consectetur,
        adipiscing: Adipiscing, elit: Elit,
    );

    fn lorem(
        ipsum: Ipsum,
        dolor: Dolor,
        sit: Sit,
        amet: Amet,
        consectetur: Consectetur,
        adipiscing: Adipiscing,
        elit: Elit,
    ) {
        // body
    }
}

`"Vertical"`:

trait Lorem {
    fn lorem(ipsum: Ipsum,
             dolor: Dolor,
             sit: Sit,
             amet: Amet);

    fn lorem(ipsum: Ipsum,
             dolor: Dolor,
             sit: Sit,
             amet: Amet) {
        // body
    }

    fn lorem(ipsum: Ipsum,
             dolor: Dolor,
             sit: Sit,
             amet: Amet,
             consectetur: Consectetur,
             adipiscing: Adipiscing,
             elit: Elit);

    fn lorem(ipsum: Ipsum,
             dolor: Dolor,
             sit: Sit,
             amet: Amet,
             consectetur: Consectetur,
             adipiscing: Adipiscing,
             elit: Elit) {
        // body
    }
}

`fn_args_indent`

Layout of function arguments and tuple structs

Default value: "Block"
Possible values: "Block", "Visual"

`"Block"` (default):

fn lorem() {}

fn lorem(ipsum: usize) {}

fn lorem(
    ipsum: usize,
    dolor: usize,
    sit: usize,
    amet: usize,
    consectetur: usize,
    adipiscing: usize,
    elit: usize,
) {
    // body
}

`"Visual"`:

fn lorem() {}

fn lorem(ipsum: usize) {}

fn lorem(ipsum: usize,
         dolor: usize,
         sit: usize,
         amet: usize,
         consectetur: usize,
         adipiscing: usize,
         elit: usize) {
    // body
}

`fn_args_paren_newline`

If function argument parenthesis goes on a newline

Default value: false
Possible values: true, false

`false` (default):

fn lorem(
    ipsum: Ipsum,
    dolor: Dolor,
    sit: Sit,
    amet: Amet,
) -> DolorSitAmetConsecteturAdipiscingElitLoremIpsumDolorSitAmetConsecteturAdipiscingElit {
    // body
}

`true`:

fn lorem
    (
    ipsum: Ipsum,
    dolor: Dolor,
    sit: Sit,
    amet: Amet,
) -> DolorSitAmetConsecteturAdipiscingElitLoremIpsumDolorSitAmetConsecteturAdipiscingElit {
    // body
}

`fn_brace_style`

Brace style for functions

Default value: "SameLineWhere"
Possible values: "AlwaysNextLine", "PreferSameLine", "SameLineWhere"

`"SameLineWhere"` (default):

fn lorem() {
    // body
}

fn lorem(ipsum: usize) {
    // body
}

fn lorem<T>(ipsum: T)
where
    T: Add + Sub + Mul + Div,
{
    // body
}

`"AlwaysNextLine"`:

fn lorem()
{
    // body
}

fn lorem(ipsum: usize)
{
    // body
}

fn lorem<T>(ipsum: T)
where
    T: Add + Sub + Mul + Div,
{
    // body
}

`"PreferSameLine"`:

fn lorem() {
    // body
}

fn lorem(ipsum: usize) {
    // body
}

fn lorem<T>(ipsum: T)
where
    T: Add + Sub + Mul + Div, {
    // body
}

`fn_call_indent`

Indentation for function calls, etc.

Default value: "Block"
Possible values: "Block", "Visual"

`"Block"` (default):

lorem(
    "lorem",
    "ipsum",
    "dolor",
    "sit",
    "amet",
    "consectetur",
    "adipiscing",
    "elit",
);

`"Visual"`:

lorem("lorem",
      "ipsum",
      "dolor",
      "sit",
      "amet",
      "consectetur",
      "adipiscing",
      "elit");

`fn_call_width`

Maximum width of the args of a function call before falling back to vertical formatting

Default value: 60
Possible values: any positive integer

Note: A value of 0 results in vertical formatting being applied regardless of a line's width.

Function call shorter than `fn_call_width`:

lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing", "elit");

Function call longer than `fn_call_width`:

See fn_call_indent.

`fn_empty_single_line`

Put empty-body functions on a single line

Default value: true
Possible values: true, false

`true` (default):

fn lorem() {}

`false`:

fn lorem() {
}

`fn_return_indent`

Location of return type in function declaration

Default value: "WithArgs"
Possible values: "WithArgs", "WithWhereClause"

`"WithArgs"` (default):

fn lorem(ipsum: Ipsum,
         dolor: Dolor,
         sit: Sit,
         amet: Amet,
         consectetur: Consectetur,
         adipiscing: Adipiscing)
         -> Elit
    where Ipsum: Eq
{
    // body
}

`"WithWhereClause"`:

fn lorem(ipsum: Ipsum,
         dolor: Dolor,
         sit: Sit,
         amet: Amet,
         consectetur: Consectetur,
         adipiscing: Adipiscing)
    -> Elit
    where Ipsum: Eq
{
    // body
}

Note: This option only takes effect when fn_call_indent is set to "Visual".

`fn_single_line`

Put single-expression functions on a single line

Default value: false
Possible values: true, false

`false` (default):

fn lorem() -> usize {
    42
}

fn lorem() -> usize {
    let ipsum = 42;
    ipsum
}

`true`:

fn lorem() -> usize { 42 }

fn lorem() -> usize {
    let ipsum = 42;
    ipsum
}

`force_explicit_abi`

Always print the abi for extern items

Default value: true
Possible values: true, false

Note: Non-"C" ABIs are always printed. If false then "C" is removed.

`true` (default):

extern "C" {
    pub static lorem: c_int;
}

`false`:

extern {
    pub static lorem: c_int;
}

`force_format_strings`

Always format string literals

Default value: false
Possible values: true, false

See format_strings.

`format_strings`

Format string literals where necessary

Default value: false
Possible values: true, false

`false` (default):

let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit";

`true`:

let lorem =
    "ipsum dolor sit amet consectetur \
     adipiscing elit lorem ipsum dolor sit";

`generics_indent`

Indentation of generics

Default value: "Block"
Possible values: "Block", "Visual"

`"Block"` (default):

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"`:

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
}

`hard_tabs`

Use tab characters for indentation, spaces for alignment

Default value: false
Possible values: true, false

`false` (default):

fn lorem() -> usize {
    42 // spaces before 42
}

`true`:

fn lorem() -> usize {
	42 // tabs before 42
}

`impl_empty_single_line`

Put empty-body implementations on a single line

Default value: true
Possible values: true, false

`true` (default):

impl Lorem {}

`false`:

impl Lorem {
}

`indent_match_arms`

Indent match arms instead of keeping them at the same indentation level as the match keyword

Default value: true
Possible values: true, false

`true` (default):

match lorem {
    Lorem::Ipsum => (),
    Lorem::Dolor => (),
    Lorem::Sit => (),
    Lorem::Amet => (),
}

`false`:

match lorem {
Lorem::Ipsum => (),
Lorem::Dolor => (),
Lorem::Sit => (),
Lorem::Amet => (),
}

`imports_indent`

Indent style of imports

Default Value: "Visual"
Possible values: "Block", "Visual"

`"Visual"` (default):

use foo::{xxx,
          yyy,
          zzz};

`"Block"`:

use foo::{
    xxx,
    yyy,
    zzz,
};

`imports_layout`

Item layout inside a imports block

Default value: "Mixed"
Possible values: "Horizontal", "HorizontalVertical", "Mixed", "Vertical"

`"Mixed"` (default):

use foo::{xxx, yyy, zzz};

use foo::{aaa, bbb, ccc,
          ddd, eee, fff};

`"Horizontal"`:

Note: This option forces to put everything on one line and may exceeds max_width.

use foo::{xxx, yyy, zzz};

use foo::{aaa, bbb, ccc, ddd, eee, fff};

`"HorizontalVertical"`:

use foo::{xxx, yyy, zzz};

use foo::{aaa,
          bbb,
          ccc,
          ddd,
          eee,
          fff};

`"Vertical"`:

use foo::{xxx,
          yyy,
          zzz};

use foo::{aaa,
          bbb,
          ccc,
          ddd,
          eee,
          fff};

`item_brace_style`

Brace style for structs and enums

Default value: "SameLineWhere"
Possible values: "AlwaysNextLine", "PreferSameLine", "SameLineWhere"

`"SameLineWhere"` (default):

struct Lorem {
    ipsum: bool,
}

struct Dolor<T>
    where T: Eq
{
    sit: T,
}

`"AlwaysNextLine"`:

struct Lorem
{
    ipsum: bool,
}

struct Dolor<T>
    where T: Eq
{
    sit: T,
}

`"PreferSameLine"`:

struct Lorem {
    ipsum: bool,
}

struct Dolor<T>
    where T: Eq {
    sit: T,
}

`match_arm_forces_newline`

Consistently put match arms (block based or not) in a newline.

Default value: false
Possible values: true, false

`false` (default):

match x {
    // a non-empty block
    X0 => {
        f();
    }
    // an empty block
    X1 => {}
    // a non-block
    X2 => println!("ok"),
}

`true`:

match x {
    // a non-empty block
    X0 => {
        f();
    }
    // an empty block
    X1 =>
        {}
    // a non-block
    X2 => {
        println!("ok")
    }
}

`match_block_trailing_comma`

Put a trailing comma after a block based match arm (non-block arms are not affected)

Default value: false
Possible values: true, false

`false` (default):

match lorem {
    Lorem::Ipsum => {
        println!("ipsum");
    }
    Lorem::Dolor => println!("dolor"),
}

`true`:

match lorem {
    Lorem::Ipsum => {
        println!("ipsum");
    },
    Lorem::Dolor => println!("dolor"),
}

`match_pattern_separator_break_point`

Put a match sub-patterns' separator (|) in front or back.

Default value: "Back"
Possible values: "Back", "Front"

`"Back"` (default):

match m {
    Variant::Tag |
    Variant::Tag2 |
    Variant::Tag3 |
    Variant::Tag4 |
    Variant::Tag5 |
    Variant::Tag6 => {}
}

`Front`:

match m {
    Variant::Tag
    | Variant::Tag2
    | Variant::Tag3
    | Variant::Tag4
    | Variant::Tag5
    | Variant::Tag6 => {}
}

`max_width`

Maximum width of each line

Default value: 100
Possible values: any positive integer

`merge_derives`

Merge multiple derives into a single one.

Default value: true
Possible values: true, false

`true` (default):

#[derive(Eq, PartialEq, Debug, Copy, Clone)]
pub enum Foo {}

`false`:

#[derive(Eq, PartialEq)]
#[derive(Debug)]
#[derive(Copy, Clone)]
pub enum Foo {}

`multiline_closure_forces_block`

Force multiline closure bodies to be wrapped in a block

Default value: false
Possible values: false, true

`false` (default):

result.and_then(|maybe_value| match maybe_value {
    None => ...,
    Some(value) => ...,
})

`true`:


result.and_then(|maybe_value| {
    match maybe_value {
        None => ...,
        Some(value) => ...,
    }
})

`multiline_match_arm_forces_block`

Force multiline match arm bodies to be wrapped in a block

Default value: false
Possible values: false, true

`false` (default):

match lorem {
    None => if ipsum {
        println!("Hello World");
    },
    Some(dolor) => ...,
}

`true`:

match lorem {
    None => {
        if ipsum {
            println!("Hello World");
        }
    }
    Some(dolor) => ...,
}

`newline_style`

Unix or Windows line endings

Default value: "Unix"
Possible values: "Native", "Unix", "Windows"

`normalize_comments`

Convert /* */ comments to // comments where possible

Default value: false
Possible values: true, false

`false` (default):

// Lorem ipsum:
fn dolor() -> usize {}

/* sit amet: */
fn adipiscing() -> usize {}

`true`:

// Lorem ipsum:
fn dolor() -> usize {}

// sit amet:
fn adipiscing() -> usize {}

`reorder_imported_names`

Reorder lists of names in import statements alphabetically

Default value: false
Possible values: true, false

`false` (default):

use super::{lorem, ipsum, dolor, sit};

`true`:

use super::{dolor, ipsum, lorem, sit};

`reorder_imports`

Reorder import statements alphabetically

Default value: false
Possible values: true, false

`false` (default):

use lorem;
use ipsum;
use dolor;
use sit;

`true`:

use dolor;
use ipsum;
use lorem;
use sit;

`reorder_imports_in_group`

Reorder import statements in group

Default value: false
Possible values: true, false

Note: This option takes effect only when reorder_imports is set to true.

`false` (default):

use std::mem;
use std::io;

use lorem;
use ipsum;
use dolor;
use sit;

`true`:

use std::io;
use std::mem;

use dolor;
use ipsum;
use lorem;
use sit;

`single_line_if_else_max_width`

Maximum line length for single line if-else expressions.

Default value: 50
Possible values: any positive integer

Note: A value of 0 results in if-else expressions being broken regardless of their line's width.

Lines shorter than `single_line_if_else_max_width`:

let lorem = if ipsum { dolor } else { sit };

Lines longer than `single_line_if_else_max_width`:

let lorem = if ipsum {
    dolor
} else {
    sit
};

`skip_children`

Don't reformat out of line modules

Default value: false
Possible values: true, false

`space_after_bound_colon`

Leave a space after the colon in a trait or lifetime bound

Default value: true
Possible values: true, false

`true` (default):

fn lorem<T: Eq>(t: T) {
    // body
}

`false`:

fn lorem<T:Eq>(t: T) {
    // body
}

`struct_field_align_threshold`

The maximum diff of width between struct fields to be aligned with each other.

Default value : 0
Possible values: any positive integer

`0` (default):

struct Foo {
    x: u32,
    yy: u32,
    zzz: u32,
}

`20`:

struct Foo {
    x:   u32,
    yy:  u32,
    zzz: u32,
}

`space_after_struct_lit_field_colon`

Leave a space after the colon in a struct literal field

Default value: true
Possible values: true, false

`true` (default):

let lorem = Lorem {
    ipsum: dolor,
    sit: amet,
};

`false`:

let lorem = Lorem {
    ipsum:dolor,
    sit:amet,
};

`space_after_type_annotation_colon`

Leave a space after the colon in a type annotation

Default value: true
Possible values: true, false

`true` (default):

fn lorem<T: Eq>(t: T) {
    let ipsum: Dolor = sit;
}

`false`:

fn lorem<T: Eq>(t:T) {
    let ipsum:Dolor = sit;
}

`space_before_bound`

Leave a space before the colon in a trait or lifetime bound

Default value: false
Possible values: true, false

`false` (default):

fn lorem<T: Eq>(t: T) {
    let ipsum: Dolor = sit;
}

`true`:

fn lorem<T : Eq>(t: T) {
    let ipsum: Dolor = sit;
}

`space_before_struct_lit_field_colon`

Leave a space before the colon in a struct literal field

Default value: false
Possible values: true, false

`false` (default):

let lorem = Lorem {
    ipsum: dolor,
    sit: amet,
};

`true`:

let lorem = Lorem {
    ipsum : dolor,
    sit : amet,
};

`space_before_type_annotation`

Leave a space before the colon in a type annotation

Default value: false
Possible values: true, false

`false` (default):

fn lorem<T: Eq>(t: T) {
    let ipsum: Dolor = sit;
}

`true`:

fn lorem<T: Eq>(t : T) {
    let ipsum : Dolor = sit;
}

`spaces_around_ranges`

Put spaces around the .. and ... range operators

Default value: false
Possible values: true, false

`false` (default):

let lorem = 0..10;

`true`:

let lorem = 0 .. 10;

`spaces_within_angle_brackets`

Put spaces within non-empty generic arguments

Default value: false
Possible values: true, false

`false` (default):

fn lorem<T: Eq>(t: T) {
    // body
}

`true`:

fn lorem< T: Eq >(t: T) {
    // body
}

`spaces_within_parens`

Put spaces within non-empty parentheses

Default value: false
Possible values: true, false

`false` (default):

fn lorem<T: Eq>(t: T) {
    let lorem = (ipsum, dolor);
}

`true`:

fn lorem<T: Eq>( t: T ) {
    let lorem = ( ipsum, dolor );
}

`spaces_within_square_brackets`

Put spaces within non-empty square brackets

Default value: false
Possible values: true, false

`false` (default):

let lorem: [usize; 2] = [ipsum, dolor];

`true`:

let lorem: [ usize; 2 ] = [ ipsum, dolor ];

`struct_lit_multiline_style`

Multiline style on literal structs

Default value: "PreferSingle"
Possible values: "ForceMulti", "PreferSingle"

`"PreferSingle"` (default):

let lorem = Lorem { ipsum: dolor, sit: amet };

`"ForceMulti"`:

let lorem = Lorem {
    ipsum: dolor,
    sit: amet,
};

`struct_lit_indent`

Style of struct definition

Default value: "Block"
Possible values: "Block", "Visual"

`"Block"` (default):

let lorem = Lorem {
    ipsum: dolor,
    sit: amet,
};

`"Visual"`:

let lorem = Lorem { ipsum: dolor,
                    sit: amet, };

`struct_lit_width`

Maximum width in the body of a struct lit before falling back to vertical formatting

Default value: 18
Possible values: any positive integer

Note: A value of 0 results in vertical formatting being applied regardless of a line's width.

Lines shorter than `struct_lit_width`:

let lorem = Lorem { ipsum: dolor, sit: amet };

Lines longer than `struct_lit_width`:

See struct_lit_indent.

`struct_variant_width`

Maximum width in the body of a struct variant before falling back to vertical formatting

Default value: 35
Possible values: any positive integer

Note: A value of 0 results in vertical formatting being applied regardless of a line's width.

Struct variants shorter than `struct_variant_width`:

enum Lorem {
    Ipsum,
    Dolor(bool),
    Sit { amet: Consectetur, adipiscing: Elit },
}

Struct variants longer than `struct_variant_width`:

enum Lorem {
    Ipsum,
    Dolor(bool),
    Sit {
        amet: Consectetur,
        adipiscing: Elit,
    },
}

`tab_spaces`

Number of spaces per tab

Default value: 4
Possible values: any positive integer

`4` (default):

fn lorem() {
    let ipsum = dolor();
    let sit = vec![
        "amet consectetur adipiscing elit."
    ];
}

`2`:

fn lorem() {
  let ipsum = dolor();
  let sit = vec![
    "amet consectetur adipiscing elit."
  ];
}

`take_source_hints`

Retain some formatting characteristics from the source code

Default value: false
Possible values: true, false

`false` (default):

lorem
    .ipsum()
    .dolor(|| { sit.amet().consectetur().adipiscing().elit(); });

`true`:

lorem
    .ipsum()
    .dolor(|| {
               sit.amet()
                   .consectetur()
                   .adipiscing()
                   .elit();
           });

Note: This only applies if the call chain within the inner closure had already been formatted on separate lines before running rustfmt.

`trailing_comma`

How to handle trailing commas for lists

Default value: "Vertical"
Possible values: "Always", "Never", "Vertical"

`"Vertical"` (default):

let Lorem { ipsum, dolor, sit } = amet;
let Lorem {
    ipsum,
    dolor,
    sit,
    amet,
    consectetur,
    adipiscing,
} = elit;

`"Always"`:

let Lorem { ipsum, dolor, sit, } = amet;
let Lorem {
    ipsum,
    dolor,
    sit,
    amet,
    consectetur,
    adipiscing,
} = elit;

`"Never"`:

let Lorem { ipsum, dolor, sit } = amet;
let Lorem {
    ipsum,
    dolor,
    sit,
    amet,
    consectetur,
    adipiscing
} = elit;

`trailing_semicolon`

Add trailing semicolon after break, continue and return

Default value: true
Possible values: true, false

`true` (default):

fn foo() -> usize {
    return 0;
}

`false`:

fn foo() -> usize {
    return 0
}

`type_punctuation_density`

Determines if + or = are wrapped in spaces in the punctuation of types

Default value: "Wide"
Possible values: "Compressed", "Wide"

`"Wide"` (default):

fn lorem<Ipsum: Dolor + Sit = Amet>() {
	// body
}

`"Compressed"`:

fn lorem<Ipsum: Dolor+Sit=Amet>() {
	// body
}

`use_try_shorthand`

Replace uses of the try! macro by the ? shorthand

Default value: false
Possible values: true, false

`false` (default):

let lorem = try!(ipsum.map(|dolor|dolor.sit()));

`true`:

let lorem = ipsum.map(|dolor| dolor.sit())?;

`where_density`

Density of a where clause.

Default value: "CompressedIfEmpty"
Possible values: "Compressed", "CompressedIfEmpty", "Tall", "Vertical"

`"CompressedIfEmpty"` (default):

trait Lorem {
    fn ipsum<Dolor>(dolor: Dolor) -> Sit
    where Dolor: Eq;

    fn ipsum<Dolor>(dolor: Dolor) -> Sit
    where
        Dolor: Eq,
    {
        // body
    }
}

`"Compressed"`:

trait Lorem {
    fn ipsum<Dolor>(dolor: Dolor) -> Sit
    where Dolor: Eq;

    fn ipsum<Dolor>(dolor: Dolor) -> Sit
    where Dolor: Eq {
        // body
    }
}

`"Tall"`:

trait Lorem {
    fn ipsum<Dolor>(dolor: Dolor) -> Sit
    where
        Dolor: Eq;

    fn ipsum<Dolor>(dolor: Dolor) -> Sit
    where
        Dolor: Eq,
    {
        // body
    }
}

Note: where_density = "Tall" currently produces the same output as where_density = "Vertical".

`"Vertical"`:

trait Lorem {
    fn ipsum<Dolor>(dolor: Dolor) -> Sit
        where Dolor: Eq;

    fn ipsum<Dolor>(dolor: Dolor) -> Sit
        where Dolor: Eq
    {
        // body
    }
}

Note: where_density = "Vertical" currently produces the same output as where_density = "Tall".

`where_layout`

Element layout inside a where clause

Default value: "Vertical"
Possible values: "Horizontal", "HorizontalVertical", "Mixed", "Vertical"

`"Vertical"` (default):

fn lorem<Ipsum, Dolor>(ipsum: Ipsum, dolor: Dolor)
    where Ipsum: IpsumDolorSitAmet,
          Dolor: DolorSitAmetConsectetur
{
    // body
}

fn lorem<Ipsum, Dolor, Sit, Amet>(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet)
    where Ipsum: IpsumDolorSitAmet,
          Dolor: DolorSitAmetConsectetur,
          Sit: SitAmetConsecteturAdipiscing,
          Amet: AmetConsecteturAdipiscingElit
{
    // body
}

`"Horizontal"`:

fn lorem<Ipsum, Dolor>(ipsum: Ipsum, dolor: Dolor)
    where Ipsum: IpsumDolorSitAmet, Dolor: DolorSitAmetConsectetur
{
    // body
}

fn lorem<Ipsum, Dolor, Sit, Amet>(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet)
    where Ipsum: IpsumDolorSitAmet, Dolor: DolorSitAmetConsectetur, Sit: SitAmetConsecteturAdipiscing, Amet: AmetConsecteturAdipiscingElit
{
    // body
}

`"HorizontalVertical"`:

fn lorem<Ipsum, Dolor>(ipsum: Ipsum, dolor: Dolor)
    where Ipsum: IpsumDolorSitAmet, Dolor: DolorSitAmetConsectetur
{
    // body
}

fn lorem<Ipsum, Dolor, Sit, Amet>(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet)
    where Ipsum: IpsumDolorSitAmet,
          Dolor: DolorSitAmetConsectetur,
          Sit: SitAmetConsecteturAdipiscing,
          Amet: AmetConsecteturAdipiscingElit
{
    // body
}

`"Mixed"`:

fn lorem<Ipsum, Dolor>(ipsum: Ipsum, dolor: Dolor)
    where Ipsum: IpsumDolorSitAmet, Dolor: DolorSitAmetConsectetur
{
    // body
}

fn lorem<Ipsum, Dolor, Sit, Amet>(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet)
    where Ipsum: IpsumDolorSitAmet, Dolor: DolorSitAmetConsectetur,
          Sit: SitAmetConsecteturAdipiscing, Amet: AmetConsecteturAdipiscingElit
{
    // body
}

Note: This option only takes effect when where_style is set to "Legacy".

`where_pred_indent`

Indentation style of a where predicate

Default value: "Visual"
Possible values: "Block", "Visual"

`"Visual"` (default):

fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
    where Ipsum: Eq,
          Dolor: Eq,
          Sit: Eq,
          Amet: Eq
{
    // body
}

`"Block"`:

fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
    where Ipsum: Eq,
        Dolor: Eq,
        Sit: Eq,
        Amet: Eq
{
    // body
}

Note: This option only takes effect when where_style is set to "Legacy".

`where_style`

Overall strategy for where clauses

Default value: "Rfc"
Possible values: "Rfc", "Legacy"

`"Rfc"` (default):

fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
where
    Ipsum: Eq,
    Dolor: Eq,
    Sit: Eq,
    Amet: Eq,
{
    // body
}

`"Legacy"`:

fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
    where Ipsum: Eq,
          Dolor: Eq,
          Sit: Eq,
          Amet: Eq
{
    // body
}

`wrap_comments`

Break comments to fit on the line

Default value: false
Possible values: true, false

`false` (default):

// 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.

`true`:

// 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.

`wrap_match_arms`

Wrap the body of arms in blocks when it does not fit on the same line with the pattern of arms

Default value: true
Possible values: true, false

`true` (default):

match lorem {
    true => {
        foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x)
    }
    false => println!("{}", sit),
}

`false`:

match lorem {
    true =>
        foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x),
    false => println!("{}", sit),
}

`write_mode`

What Write Mode to use when none is supplied: Replace, Overwrite, Display, Diff, Coverage

Default value: "Overwrite"
Possible values: "Checkstyle", "Coverage", "Diff", "Display", "Overwrite", "Plain", "Replace"

41 KiB Raw Blame History

Configuring Rustfmt

Configuration Options

array_horizontal_layout_threshold

0 (default):

1000:

array_indent

"Block" (default):

"Visual":

array_width

Lines shorter than array_width:

Lines longer than array_width:

attributes_on_same_line_as_field

true (default):

false:

attributes_on_same_line_as_variant

true (default):

false:

binop_separator

"Front" (default):

"Back":

chain_indent

"Block" (default):

"Visual":

chain_width

Lines shorter than chain_width:

Lines longer than chain_width:

chain_split_single_child

false (default):

true:

closure_block_indent_threshold

Closures shorter than closure_block_indent_threshold:

Closures longer than closure_block_indent_threshold:

combine_control_expr

true (default):

false:

comment_width

Comments shorter than comment_width:

Comments longer than comment_width:

condense_wildcard_suffixes

false (default):

true:

control_style

"Rfc" (default):

"Legacy":

control_brace_style

"AlwaysSameLine" (default):

"AlwaysNextLine":

"ClosingNextLine":

disable_all_formatting

error_on_line_overflow

fn_args_density

"Tall" (default):

"Compressed":

"CompressedIfEmpty":

"Vertical":

fn_args_indent

"Block" (default):

"Visual":

fn_args_paren_newline

false (default):

true:

fn_brace_style

"SameLineWhere" (default):

"AlwaysNextLine":

"PreferSameLine":

fn_call_indent

"Block" (default):

"Visual":

fn_call_width

Function call shorter than fn_call_width:

Function call longer than fn_call_width:

fn_empty_single_line

true (default):

false:

fn_return_indent

"WithArgs" (default):

"WithWhereClause":

fn_single_line

false (default):

41 KiB

Raw Blame History

`array_horizontal_layout_threshold`

`0` (default):

`1000`:

`array_indent`

`"Block"` (default):

`"Visual"`:

`array_width`

Lines shorter than `array_width`:

Lines longer than `array_width`:

`attributes_on_same_line_as_field`

`true` (default):

`false`:

`attributes_on_same_line_as_variant`

`true` (default):

`false`:

`binop_separator`

`"Front"` (default):

`"Back"`:

`chain_indent`

`"Block"` (default):

`"Visual"`:

`chain_width`

Lines shorter than `chain_width`:

Lines longer than `chain_width`:

`chain_split_single_child`

`false` (default):

`true`:

`closure_block_indent_threshold`

Closures shorter than `closure_block_indent_threshold`:

Closures longer than `closure_block_indent_threshold`:

`combine_control_expr`

`true` (default):

`false`:

`comment_width`

Comments shorter than `comment_width`:

Comments longer than `comment_width`:

`condense_wildcard_suffixes`

`false` (default):

`true`:

`control_style`

`"Rfc"` (default):

`"Legacy"`:

`control_brace_style`

`"AlwaysSameLine"` (default):

`"AlwaysNextLine"`:

`"ClosingNextLine"`:

`disable_all_formatting`

`error_on_line_overflow`

`fn_args_density`

`"Tall"` (default):

`"Compressed"`:

`"CompressedIfEmpty"`:

`"Vertical"`:

`fn_args_indent`

`"Block"` (default):

`"Visual"`:

`fn_args_paren_newline`

`false` (default):

`true`:

`fn_brace_style`

`"SameLineWhere"` (default):

`"AlwaysNextLine"`:

`"PreferSameLine"`:

`fn_call_indent`

`"Block"` (default):

`"Visual"`:

`fn_call_width`

Function call shorter than `fn_call_width`:

Function call longer than `fn_call_width`:

`fn_empty_single_line`

`true` (default):

`false`:

`fn_return_indent`

`"WithArgs"` (default):

`"WithWhereClause"`:

`fn_single_line`

`false` (default):

`true`:

`force_explicit_abi`