Merge pull request #2557 from topecongiro/vertical-layout-complex-attrs

[rust.git] / README.md

diff --git a/README.md b/README.md
index 4e4b14f473c853e6e74ac249e05b150a06384514..420859e90513df2a31060ae898c16d852bb56a11 100644 (file)
--- a/README.md
+++ b/README.md
@@ -1,16 +1,38 @@
-# rustfmt [![Build Status](https://travis-ci.org/rust-lang-nursery/rustfmt.svg)](https://travis-ci.org/rust-lang-nursery/rustfmt) [![Build Status](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rustfmt?svg=true)](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rustfmt)
+# rustfmt [![Build Status](https://travis-ci.org/rust-lang-nursery/rustfmt.svg)](https://travis-ci.org/rust-lang-nursery/rustfmt) [![Build Status](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rustfmt?svg=true)](https://ci.appveyor.com/project/nrc/rustfmt) [![crates.io](https://img.shields.io/crates/v/rustfmt-nightly.svg)](https://crates.io/crates/rustfmt-nightly) [![Travis Configuration Status](https://img.shields.io/travis/davidalber/rustfmt-travis.svg?label=travis%20example)](https://travis-ci.org/davidalber/rustfmt-travis)

 
 A tool for formatting Rust code according to style guidelines.
 
 If you'd like to help out (and you should, it's a fun project!), see
 
 A tool for formatting Rust code according to style guidelines.
 
 If you'd like to help out (and you should, it's a fun project!), see

-[Contributing.md](Contributing.md).
+[Contributing.md](Contributing.md) and our [Code of
+Conduct](CODE_OF_CONDUCT.md).
+
+We are changing the default style used by rustfmt. There is an ongoing [RFC
+process][fmt rfcs]. The last version using the old style was 0.8.6. From 0.9
+onwards, the RFC style is the default. If you want the old style back, you can
+use [legacy-rustfmt.toml](legacy-rustfmt.toml) as your rustfmt.toml.
+
+The current `master` branch uses libsyntax (part of the compiler). It is
+published as `rustfmt-nightly`. The `syntex` branch uses Syntex instead of
+libsyntax, it is published (for now) as `rustfmt`. Most development happens on
+the `master` branch, however, this only supports nightly toolchains. If you use
+stable or beta Rust toolchains, you must use the Syntex version (which is likely
+to be a bit out of date). Version 0.1 of rustfmt-nightly is forked from version
+0.9 of the syntex branch.
+
+You can use rustfmt in Travis CI builds. We provide a minimal Travis CI
+configuration (see [here](#checking-style-on-a-ci-server)) and verify its status
+using another repository. The status of that repository's build is reported by
+the "travis example" badge above.
+

 
 ## Quick start
 
 
 ## Quick start
 

+You can use `rustfmt` on Rust 1.24 and above.
+

 To install:
 
 ```
 To install:
 
 ```

-cargo install rustfmt
+rustup component add rustfmt-preview

 ```
 
 to run on a cargo project in the current working directory:
 ```
 
 to run on a cargo project in the current working directory:


@@ -19,36 +41,53 @@ to run on a cargo project in the current working directory:
 cargo fmt
 ```
 
 cargo fmt
 ```
 

-## Installation

 
 

-> **Note:** this method currently requires you to be running cargo 0.6.0 or
-> newer.
+## Limitations

 
 

-```
-cargo install rustfmt
-```
+Rustfmt tries to work on as much Rust code as possible, sometimes, the code
+doesn't even need to compile! As we approach a 1.0 release we are also looking
+to limit areas of instability; in particular, post-1.0, the formatting of most
+code should not change as Rustfmt improves. However, there are some things that
+Rustfmt can't do or can't do well (and thus where formatting might change
+significantly, even post-1.0). We would like to reduce the list of limitations
+over time.

 
 

-or if you're using [`rustup.rs`](https://www.rustup.rs/)
+The following list enumerates areas where Rustfmt does not work or where the
+stability guarantees do not apply (we don't make a distinction between the two
+because in the future Rustfmt might work on code where it currently does not):
+
+* a program where any part of the program does not parse (parsing is an early
+  stage of compilation and in Rust includes macro expansion).
+* Macro declarations and uses (current status: some macro declarations and uses
+  are formatted).
+* Comments, including any AST node with a comment 'inside' (Rustfmt does not
+  currently attempt to format comments, it does format code with comments inside, but that formatting may change in the future).
+* Rust code in code blocks in comments.
+* Any fragment of a program (i.e., stability guarantees only apply to whole
+  programs, even where fragments of a program can be formatted today).
+* Code containing non-ascii unicode characters (we believe Rustfmt mostly works
+  here, but do not have the test coverage or experience to be 100% sure).
+* Bugs in Rustfmt (like any software, Rustfmt has bugs, we do not consider bug
+  fixes to break our stability guarantees).

 
 

-```
-rustup run nightly cargo install rustfmt
-```

 
 

-Usually cargo-fmt, which enables usage of Cargo subcommand `cargo fmt`, is
-installed alongside rustfmt. To only install rustfmt run
+## Installation

 
 ```
 
 ```

-cargo install --no-default-features rustfmt
+rustup component add rustfmt-preview

 ```
 ```

+

 ## Installing from source
 
 To install from source, first checkout to the tag or branch you want to install, then issue
 ```
 cargo install --path  .
 ```
 ## Installing from source
 
 To install from source, first checkout to the tag or branch you want to install, then issue
 ```
 cargo install --path  .
 ```

+

 This will install `rustfmt` in your `~/.cargo/bin`. Make sure to add `~/.cargo/bin` directory to
 your PATH variable.
 
 This will install `rustfmt` in your `~/.cargo/bin`. Make sure to add `~/.cargo/bin` directory to
 your PATH variable.
 

+

 ## Running
 
 You can run Rustfmt by just typing `rustfmt filename` if you used `cargo
 ## Running
 
 You can run Rustfmt by just typing `rustfmt filename` if you used `cargo


@@ -59,11 +98,12 @@ read data from stdin. Alternatively, you can use `cargo fmt` to format all
 binary and library targets of your crate.
 
 You'll probably want to specify the write mode. Currently, there are modes for
 binary and library targets of your crate.
 
 You'll probably want to specify the write mode. Currently, there are modes for

-diff, replace, overwrite, display, coverage, and checkstyle.
+`diff`, `replace`, `overwrite`, `display`, `coverage`, `checkstyle`, and `plain`.

 
 

-* `replace` Is the default and overwrites the original files after creating backups of the files.
-* `overwrite` Overwrites the original files _without_ creating backups.
+* `overwrite` Is the default and overwrites the original files _without_ creating backups.
+* `replace` Overwrites the original files after creating backups of the files.

 * `display` Will print the formatted files to stdout.
 * `display` Will print the formatted files to stdout.

+* `plain` Also writes to stdout, but with no metadata.

 * `diff` Will print a diff between the original files and formatted files to stdout.
          Will also exit with an error code if there are any differences.
 * `checkstyle` Will output the lines that need to be corrected as a checkstyle XML file,
 * `diff` Will print a diff between the original files and formatted files to stdout.
          Will also exit with an error code if there are any differences.
 * `checkstyle` Will output the lines that need to be corrected as a checkstyle XML file,


@@ -72,7 +112,7 @@ diff, replace, overwrite, display, coverage, and checkstyle.
 The write mode can be set by passing the `--write-mode` flag on
 the command line. For example `rustfmt --write-mode=display src/filename.rs`
 
 The write mode can be set by passing the `--write-mode` flag on
 the command line. For example `rustfmt --write-mode=display src/filename.rs`
 

-`cargo fmt` uses `--write-mode=replace` by default.
+`cargo fmt` uses `--write-mode=overwrite` by default.

 
 If you want to restrict reformatting to specific sets of lines, you can
 use the `--file-lines` option. Its argument is a JSON array of objects
 
 If you want to restrict reformatting to specific sets of lines, you can
 use the `--file-lines` option. Its argument is a JSON array of objects


@@ -96,7 +136,7 @@ are included as out of line modules from `src/lib.rs`.
 If `rustfmt` successfully reformatted the code it will exit with `0` exit
 status. Exit status `1` signals some unexpected error, like an unknown option or
 a failure to read a file. Exit status `2` is returned if there are syntax errors
 If `rustfmt` successfully reformatted the code it will exit with `0` exit
 status. Exit status `1` signals some unexpected error, like an unknown option or
 a failure to read a file. Exit status `2` is returned if there are syntax errors

-in the input files. `rustfmt` can't format syntatically invalid code. Finally,
+in the input files. `rustfmt` can't format syntactically invalid code. Finally,

 exit status `3` is returned if there are some issues which can't be resolved
 automatically. For example, if you have a very long comment line `rustfmt`
 doesn't split it. Instead it prints a warning and exits with `3`.
 exit status `3` is returned if there are some issues which can't be resolved
 automatically. For example, if you have a very long comment line `rustfmt`
 doesn't split it. Instead it prints a warning and exits with `3`.


@@ -108,9 +148,9 @@ You can run `rustfmt --help` for more information.
 
 * [Vim](https://github.com/rust-lang/rust.vim#formatting-with-rustfmt)
 * [Emacs](https://github.com/rust-lang/rust-mode)
 
 * [Vim](https://github.com/rust-lang/rust.vim#formatting-with-rustfmt)
 * [Emacs](https://github.com/rust-lang/rust-mode)

-* [Sublime Text 3](https://packagecontrol.io/packages/BeautifyRust)
+* [Sublime Text 3](https://packagecontrol.io/packages/RustFmt)

 * [Atom](atom.md)
 * [Atom](atom.md)

-* Visual Studio Code using [RustyCode](https://github.com/saviorisdead/RustyCode) or [vsc-rustfmt](https://github.com/Connorcpu/vsc-rustfmt)
+* Visual Studio Code using [vscode-rust](https://github.com/editor-rs/vscode-rust), [vsc-rustfmt](https://github.com/Connorcpu/vsc-rustfmt) or [rls_vscode](https://github.com/jonathandturner/rls_vscode) through RLS.

 
 ## Checking style on a CI server
 
 
 ## Checking style on a CI server
 


@@ -119,22 +159,18 @@ when a pull request contains unformatted code. Using `--write-mode=diff` instruc
 rustfmt to exit with an error code if the input is not formatted correctly.
 It will also print any found differences.
 
 rustfmt to exit with an error code if the input is not formatted correctly.
 It will also print any found differences.
 

-A minimal Travis setup could look like this:
+A minimal Travis setup could look like this (requires Rust 1.24.0 or greater):

 
 ```yaml
 language: rust
 
 ```yaml
 language: rust

-cache: cargo

 before_script:
 before_script:

-- export PATH="$PATH:$HOME/.cargo/bin"
-- which rustfmt || cargo install rustfmt
+- rustup component add rustfmt-preview

 script:
 script:

-- cargo fmt -- --write-mode=diff
+- cargo fmt --all -- --write-mode=diff

 - cargo build
 - cargo test
 ```
 
 - cargo build
 - cargo test
 ```
 

-Note that using `cache: cargo` is optional but highly recommended to speed up the installation.
-

 ## How to build and test
 
 `cargo build` to build.
 ## How to build and test
 
 `cargo build` to build.


@@ -153,16 +189,13 @@ directory and it will apply the options in that file. See `rustfmt
 --config-help` for the options which are available, or if you prefer to see
 visual style previews, [Configurations.md](Configurations.md).
 
 --config-help` for the options which are available, or if you prefer to see
 visual style previews, [Configurations.md](Configurations.md).
 

-By default, Rustfmt uses a style which (mostly) conforms to the
-[Rust style guidelines](https://doc.rust-lang.org/1.12.0/style/README.html).
-There are many details which the style guidelines do not cover, and in these
-cases we try to adhere to a style similar to that used in the
-[Rust repo](https://github.com/rust-lang/rust). Once Rustfmt is more complete, and
-able to re-format large repositories like Rust, we intend to go through the Rust
-RFC process to nail down the default style in detail.
+By default, Rustfmt uses a style which conforms to the [Rust style guide][style
+guide] that has been formalized through the [style RFC
+process][fmt rfcs].

 
 

-If there are styling choices you don't agree with, we are usually happy to add
-options covering different styles. File an issue, or even better, submit a PR.
+Configuration options are either stable or unstable. Stable options can always
+be used, while unstable ones are only available on a nightly toolchain, and opt-in.
+See [Configurations.md](Configurations.md) for details.

 
 
 ## Tips
 
 
 ## Tips


@@ -175,12 +208,35 @@ options covering different styles. File an issue, or even better, submit a PR.
     ```
 * When you run rustfmt, place a file named `rustfmt.toml` or `.rustfmt.toml` in
   target file directory or its parents to override the default settings of
     ```
 * When you run rustfmt, place a file named `rustfmt.toml` or `.rustfmt.toml` in
   target file directory or its parents to override the default settings of

-  rustfmt.
+  rustfmt. You can generate a file containing the default configuration with
+  `rustfmt --dump-default-config rustfmt.toml` and customize as needed.

 * After successful compilation, a `rustfmt` executable can be found in the
   target directory.
 * If you're having issues compiling Rustfmt (or compile errors when trying to
   install), make sure you have the most recent version of Rust installed.
 
 * After successful compilation, a `rustfmt` executable can be found in the
   target directory.
 * If you're having issues compiling Rustfmt (or compile errors when trying to
   install), make sure you have the most recent version of Rust installed.
 

+* If you get an error like `error while loading shared libraries` while starting
+  up rustfmt you should try the following:
+
+  On Linux:
+
+  ```
+  export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH
+  ```
+
+  On MacOS:
+
+  ```
+  export DYLD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$DYLD_LIBRARY_PATH
+  ```
+
+  On Windows (Git Bash/Mingw):
+
+  ```
+  export PATH=$(rustc --print sysroot)/lib/rustlib/x86_64-pc-windows-gnu/lib/:$PATH
+  ```
+
+  (Substitute `x86_64` by `i686` and `gnu` by `msvc` depending on which version of rustc was used to install rustfmt).

 
 ## License
 
 
 ## License
 


@@ -188,3 +244,7 @@ Rustfmt is distributed under the terms of both the MIT license and the
 Apache License (Version 2.0).
 
 See [LICENSE-APACHE](LICENSE-APACHE) and [LICENSE-MIT](LICENSE-MIT) for details.
 Apache License (Version 2.0).
 
 See [LICENSE-APACHE](LICENSE-APACHE) and [LICENSE-MIT](LICENSE-MIT) for details.

+
+[rust]: https://github.com/rust-lang/rust
+[fmt rfcs]: https://github.com/rust-lang-nursery/fmt-rfcs
+[style guide]: https://github.com/rust-lang-nursery/fmt-rfcs/blob/master/guide/guide.md