granite-rust/docs/user/features.md

This documents is an index of features that rust-analyzer language server provides.

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 for Foo type in the current workspace
• #foo# searches for foo function in the current workspace
• #Foo* searches for Foo type among dependencies, excluding stdlib
• #foo#* searches for foo 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}};