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code | ||
emacs | ||
README.md |
Preqrequisites:
In order to build the VS Code plugin, you need to have node.js and npm with a minimum version of 10 installed. Please refer to node.js and npm documentation for installation instructions.
The experimental VS Code plugin can then be built and installed by executing the following commands:
$ git clone https://github.com/rust-analyzer/rust-analyzer.git --depth 1
$ cd rust-analyzer
$ cargo install-code
# for stdlib support
$ rustup component add rust-src
This will run cargo install --package ra_lsp_server
to install the server
binary into ~/.cargo/bin
, and then will build and install plugin from
editors/code
. See
this
for details. The installation is expected to just work, if it doesn't, report
bugs!
It's better to remove existing Rust plugins to avoid interference.
Rust Analyzer Specific Features
These features are implemented as extensions to the language server protocol. They are more experimental in nature and work only with VS Code.
Syntax highlighting
It overrides built-in highlighting, and works only with a specific theme
(zenburn). rust-analyzer.highlightingOn
setting can be used to disable it.
Go to symbol in workspace ctrl+t
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 forFoo
type in the current workspace#foo#
searches forfoo
function in the current workspace#Foo*
searches forFoo
type among dependencies, excludingstdlib
#foo#*
searches forfoo
function among dependencies.
That is, #
switches from "types" to all symbols, *
switches from the current
workspace to dependencies.
Commands ctrl+shift+p
Show Rust Syntax Tree
Shows the parse tree of the current file. It exists mostly for debugging rust-analyzer itself.
Extend Selection
Extends the current selection to the encompassing syntactic construct (expression, statement, item, module, etc). It works with multiple cursors. Do bind this command to a key, its super-useful! Expected to be upstreamed to LSP soonish: https://github.com/Microsoft/language-server-protocol/issues/613
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.
Parent Module
Navigates to the parent module of the current module.
Join Lines
Join selected lines into one, smartly fixing up whitespace and trailing commas.
Run
Shows 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!
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
Code Actions (Assists)
These are triggered in a particular context via light bulb. We use custom code on the VS Code side to be able to position cursor.
- Flip
,
// before:
fn foo(x: usize,<|> dim: (usize, usize))
// after:
fn foo(dim: (usize, usize), x: usize)
- Add
#[derive]
// before:
struct Foo {
<|>x: i32
}
// after:
#[derive(<|>)]
struct Foo {
x: i32
}
- Add
impl
// before:
struct Foo<'a, T: Debug> {
<|>t: T
}
// after:
struct Foo<'a, T: Debug> {
t: T
}
impl<'a, T: Debug> Foo<'a, T> {
<|>
}
- Change visibility
// before:
fn<|> foo() {}
// after
pub(crate) fn foo() {}
- Introduce variable:
// before:
fn foo() {
foo(<|>1 + 1<|>);
}
// after:
fn foo() {
let var_name = 1 + 1;
foo(var_name);
}
- Replace if-let with match:
// before:
impl VariantData {
pub fn is_struct(&self) -> bool {
if <|>let VariantData::Struct(..) = *self {
true
} else {
false
}
}
}
// after:
impl VariantData {
pub fn is_struct(&self) -> bool {
<|>match *self {
VariantData::Struct(..) => true,
_ => false,
}
}
}
- Split import
// before:
use algo:<|>:visitor::{Visitor, visit};
//after:
use algo::{<|>visitor::{Visitor, visit}};
LSP features
-
Go to definition: works correctly for local variables and some paths, falls back to heuristic name matching for other things for the time being.
-
Completion: completes paths, including dependencies and standard library. Does not handle glob imports and macros. Completes fields and inherent methods.
-
Outline alt+shift+o
-
Signature Info
-
Format document. Formats the current file with rustfmt. Rustfmt must be installed separately with
rustup component add rustfmt
. -
Hover shows types of expressions and docstings
-
Rename works for local variables
-
Code Lens for running tests
-
Folding
-
Diagnostics
- missing module for
mod foo;
with a fix to createfoo.rs
. - struct field shorthand
- unnecessary braces in use item
- missing module for
Performance
Rust Analyzer is expected to be pretty fast. Specifically, the initial analysis
of the project (i.e, when you first invoke completion or symbols) typically
takes dozen of seconds at most. After that, everything is supposed to be more or
less instant. However currently all analysis results are kept in memory, so
memory usage is pretty high. Working with rust-lang/rust
repo, for example,
needs about 5 gigabytes of ram.