This document is an index of features that the rust-analyzer language server provides. Shortcuts are for the default VS Code layout. If there's no shortcut, you can use Ctrl+Shift+P to search for the corresponding action. ### Workspace Symbol ctrl+t Uses fuzzy-search to find types, modules and functions by name across your project and dependencies. This is **the** most useful feature, which improves code navigation tremendously. It mostly works on top of the built-in LSP functionality, however `#` and `*` symbols can be used to narrow down the search. Specifically, - `Foo` searches for `Foo` type in the current workspace - `foo#` searches for `foo` function in the current workspace - `Foo*` searches for `Foo` type among dependencies, including `stdlib` - `foo#*` searches for `foo` function among dependencies That is, `#` switches from "types" to all symbols, `*` switches from the current workspace to dependencies. ### Document Symbol ctrl+shift+o Provides a tree of the symbols defined in the file. Can be used to * fuzzy search symbol in a file (super useful) * draw breadcrumbs to describe the context around the cursor * draw outline of the file ### On Typing Assists Some features trigger on typing certain characters: - typing `let =` tries to smartly add `;` if `=` is followed by an existing expression - Enter inside comments automatically inserts `///` - typing `.` in a chain method call auto-indents ### Extend Selection Extends the current selection to the encompassing syntactic construct (expression, statement, item, module, etc). It works with multiple cursors. This is a relatively new feature of LSP: https://github.com/Microsoft/language-server-protocol/issues/613, check your editor's LSP library to see if this feature is supported. ### Go to Definition Navigates to the definition of an identifier. ### Go to Implementation Navigates to the impl block of structs, enums or traits. Also implemented as a code lens. ### Go to Type Defintion Navigates to the type of an identifier. ### Commands ctrl+shift+p #### Run Shows a popup suggesting to run a test/benchmark/binary **at the current cursor location**. Super useful for repeatedly running just a single test. Do bind this to a shortcut! #### Parent Module Navigates to the parent module of the current module. #### Matching Brace If the cursor is on any brace (`<>(){}[]`) which is a part of a brace-pair, moves cursor to the matching brace. It uses the actual parser to determine braces, so it won't confuse generics with comparisons. #### Join Lines Join selected lines into one, smartly fixing up whitespace and trailing commas. #### Show Syntax Tree Shows the parse tree of the current file. It exists mostly for debugging rust-analyzer itself. #### Expand Macro Recursively Shows the full macro expansion of the macro at current cursor. #### Status Shows internal statistic about memory usage of rust-analyzer. #### Show RA Version Show current rust-analyzer version. #### Run Garbage Collection Manually triggers GC. #### Start Cargo Watch Start `cargo watch` for live error highlighting. Will prompt to install if it's not already installed. #### Stop Cargo Watch Stop `cargo watch`. #### Structural Seach and Replace Search and replace with named wildcards that will match any expression. The syntax for a structural search replace command is ` ==>> `. A `$:expr` placeholder in the search pattern will match any expression and `$` will reference it in the replacement. Available via the command `rust-analyzer.ssr`. ```rust // Using structural search replace command [foo($a:expr, $b:expr) ==>> ($a).foo($b)] // BEFORE String::from(foo(y + 5, z)) // AFTER String::from((y + 5).foo(z)) ``` ### Assists (Code Actions) Assists, or code actions, are small local refactorings, available in a particular context. They are usually triggered by a shortcut or by clicking a light bulb icon in the editor. See [assists.md](./assists.md) for the list of available assists. ### Magic Completions In addition to usual reference completion, rust-analyzer provides some ✨magic✨ completions as well: Keywords like `if`, `else` `while`, `loop` are completed with braces, and cursor is placed at the appropriate position. Even though `if` is easy to type, you still want to complete it, to get ` { }` for free! `return` is inserted with a space or `;` depending on the return type of the function. When completing a function call, `()` are automatically inserted. If a function takes arguments, the cursor is positioned inside the parenthesis. There are postifx completions, which can be triggerd by typing something like `foo().if`. The word after `.` determines postifx completion. Possible variants are: - `expr.if` -> `if expr {}` - `expr.match` -> `match expr {}` - `expr.while` -> `while expr {}` - `expr.ref` -> `&expr` - `expr.refm` -> `&mut expr` - `expr.not` -> `!expr` - `expr.dbg` -> `dbg!(expr)` There also snippet completions: #### Inside Expressions - `pd` -> `println!("{:?}")` - `ppd` -> `println!("{:#?}")` #### Inside Modules - `tfn` -> `#[test] fn f(){}` ### Code Highlighting Experimental feature to let rust-analyzer highlight Rust code instead of using the default highlighter. #### Rainbow Highlighting Experimental feature that, given code highlighting using rust-analyzer is active, will pick unique colors for identifiers. ### Code hints Rust-analyzer has two types of hints to show the information about the code: * hover hints, appearing on hover on any element. These contain extended information on the hovered language item. * inlay hints, shown near the element hinted directly in the editor. Two types of inlay hints are displayed currently: * type hints, displaying the minimal information on the type of the expression (if the information is available) * parameter name hints, displaying the names of the parameters in the corresponding methods #### VS Code In VS Code, the following settings can be used to configure the inlay hints: * `rust-analyzer.inlayHintOpts.displayType` configure which types of inlay hints are shown. * `rust-analyzer.inlayHintOpts.maxLength` — shortens the hints if their length exceeds the value specified. If no value is specified (`null`), no shortening is applied. **Note:** VS Code does not have native support for inlay hints [yet](https://github.com/microsoft/vscode/issues/16221) and the hints are implemented using decorations. This approach has limitations, the caret movement and bracket highlighting near the edges of the hint may be weird: [1](https://github.com/rust-analyzer/rust-analyzer/issues/1623), [2](https://github.com/rust-analyzer/rust-analyzer/issues/3453).