#+TITLE:   lang/rust
#+DATE:    June 5, 2019
#+SINCE:   {replace with next tagged release version}
#+STARTUP: inlineimages

* Table of Contents :TOC_3:noexport:
- [[#description][Description]]
  - [[#module-flags][Module Flags]]
  - [[#plugins][Plugins]]
  - [[#hacks][Hacks]]
- [[#prerequisites][Prerequisites]]
- [[#features][Features]]
- [[#configuration][Configuration]]
- [[#troubleshooting][Troubleshooting]]
  - [[#racer-installation-problems][Racer installation problems]]

* Description
Add support to Rust language and cargo commands inside emacs.

+ Code completion (~racer~)
+ Syntax checking (~flycheck~)
+ Snippets

** Module Flags
+ ~+lsp~ to add support Language server protocol.

** Plugins
+ [[https://github.com/rust-lang/rust-mode][Rust-mode]]
+ [[https://github.com/racer-rust/emacs-racer][Racer-mode]]
+ [[https://github.com/racer-rust/emacs-racer][Cargo-mode]]

** Hacks
{A list of internal modifications to included packages}

* Prerequisites
To get started with Rust, you can either use =rustup= and install rust with:

~curl https://sh.rustup.rs -sSf | sh~

Package manager is not recommended to install Nightly version of Rust what is
required for ~racer~ from [[https://github.com/racer-rust/racer#installation][version 2.1]] (more info in [[#Troubleshooting][Troubleshooting]])

Some features have additional dependencies:

+ The ~:editor format~ module uses ~rustfmt~ for rust files: ~rustup component
  add rustfmt-preview~
+ The following commands require:
  + ~cargo-process-check~: ~cargo install cargo-check~
  + ~cargo-process-clippy~: ~rustup component add clippy-preview~
  + ~cargo-process-{add,rm,upgrade}~: ~cargo install cargo-edit~

* Features
This module also supports LSP, it requires installation of Rust Language Server
[[https://github.com/rust-lang/rls][~RLS~]]. To enable this you need to enable ~lsp~ in ~:tools~ section in ~init.el~ file.

Keybindings

| Binding             | Description                 |
|---------------------+-----------------------------|
| ~<localleader> b a~ | ~cargo add~                 |
| ~<localleader> b b~ | ~cargo build~               |
| ~<localleader> b B~ | ~cargo bench~               |
| ~<localleader> b c~ | ~cargo check~               |
| ~<localleader> b C~ | ~cargo clippy~              |
| ~<localleader> b d~ | ~cargo doc~                 |
| ~<localleader> b r~ | ~cargo run~                 |
| ~<localleader> b s~ | ~cargo search~              |
| ~<localleader> b u~ | ~cargo update~              |
| ~<localleader> t a~ | ~cargo test~                |
| ~<localleader> t f~ | ~run tests in current file~ |
| ~<localleader> t t~ | ~run current test~          |

* TODO Configuration
How to configure this module, including common problems and how to address them.

* Troubleshooting
** Racer installation problems
Racer need now ([[https://github.com/racer-rust/racer#installation][From 2.1 version]]) nightly version of Rust

If you installed trough rustup
#+BEGIN_SRC sh
rustup toolchain add nightly

cargo +nightly install racer
#+END_SRC