3 [![Build Status](https://travis-ci.org/matklad/rust-analyzer.svg?branch=master)](https://travis-ci.org/matklad/rust-analyzer)
4 [![Build status](https://ci.appveyor.com/api/projects/status/j56x1hbje8rdg6xk/branch/master?svg=true)](https://ci.appveyor.com/project/matklad/rust-analyzer/branch/master)
7 Rust Analyzer is an **experimental** modular compiler frontend for the
8 Rust language, which aims to lay a foundation for excellent IDE
11 It doesn't implement much of compiler functionality yet, but the
12 white-space preserving Rust parser works, and there are significant
13 chunks of overall architecture (indexing, on-demand & lazy
14 computation, snapshotable world view) in place. Some basic IDE
15 functionality is provided via a language server.
19 Rust analyzer builds on stable Rust >= 1.29.0.
25 # show syntax tree of a Rust file
26 $ cargo run --package ra_cli parse < crates/ra_syntax/src/lib.rs
28 # show symbols of a Rust file
29 $ cargo run --package ra_cli symbols < crates/ra_syntax/src/lib.rs
32 To try out the language server, see [these
33 instructions](./editors/README.md). Please note that the server is not
34 ready for general use yet. If you are looking for a Rust IDE that
36 Rust](https://github.com/intellij-rust/intellij-rust) or
37 [RLS](https://github.com/rust-lang-nursery/rls). That being said, the
38 basic stuff works, and rust analyzer is developed in the rust analyzer
42 ## Current Status and Plans
44 Rust analyzer aims to fill the same niche as the official [Rust
45 Language Server](https://github.com/rust-lang-nursery/rls), but
46 better. It was created because @matklad is not satisfied with RLS
47 original starting point and current direction. More details can be
49 thread](https://internals.rust-lang.org/t/2019-strategy-for-rustc-and-the-rls/8361).
50 The core issue is that RLS works in the "wait until user stops typing,
51 run the build process, save the results of the analysis" mode, which
52 arguably is the wrong foundation for IDE (see the thread for details).
54 Rust Analyzer is a hobby project at the moment, there's exactly zero
55 guarantees that it becomes production-ready one day.
57 The near/mid term plan is to work independently of the main rustc
58 compiler and implement at least simplistic versions of name
59 resolution, macro expansion and type inference. The purpose is two
62 * to quickly bootstrap usable and useful language server: solution
63 that covers 80% of Rust code will be useful for IDEs, and will be
64 vastly simpler than 100% solution.
66 * to understand how the consumer-side of compiler API should look like
67 (especially it's on-demand aspects). If you have
68 `get_expression_type` function, you can write a ton of purely-IDE
69 features on top of it, even if the function is only partially
70 correct. Plugin in the precise function afterwards should just make
71 IDE features more reliable.
73 The long term plan is to merge with the mainline rustc compiler,
74 probably around the HIR boundary? That is, use rust analyzer for
75 parsing, macro expansion and related bits of name resolution, but
76 leave the rest (including type inference and trait selection) to the
81 ### `crates/ra_syntax`
83 Rust syntax tree structure and parser. See
84 [RFC](https://github.com/rust-lang/rfcs/pull/2256) for some design
87 - `yellow`, red/green syntax tree, heavily inspired [by this](https://github.com/apple/swift/tree/ab68f0d4cbf99cdfa672f8ffe18e433fddc8b371/lib/Syntax)
88 - `grammar`, the actual parser
89 - `parser_api/parser_impl` bridges the tree-agnostic parser from `grammar` with `yellow` trees
90 - `grammar.ron` RON description of the grammar, which is used to
91 generate `syntax_kinds` and `ast` modules.
92 - `algo`: generic tree algorithms, including `walk` for O(1) stack
93 space tree traversal (this is cool) and `visit` for type-driven
94 visiting the nodes (this is double plus cool, if you understand how
95 `Visitor` works, you understand rust-analyzer).
98 ### `crates/ra_editor`
100 All IDE features which can be implemented if you only have access to a
101 single file. `ra_editor` could be used to enhance editing of Rust code
102 without the need to fiddle with build-systems, file
103 synchronization and such.
105 In a sense, `ra_editor` is just a bunch of pure functions which take a
106 syntax tree as an input.
110 An implementation of red-green incremental compilation algorithm from
111 rust compiler. It makes all rust-analyzer features on-demand.
114 ### `crates/ra_analysis`
116 A stateful library for analyzing many Rust files as they change.
117 `AnalysisHost` is a mutable entity (clojure's atom) which holds
118 current state, incorporates changes and handles out `Analysis` --- an
119 immutable consistent snapshot of world state at a point in time, which
120 actually powers analysis.
123 ### `crates/ra_lsp_server`
125 An LSP implementation which uses `ra_analysis` for managing state and
126 `ra_editor` for actually doing useful stuff.
131 A CLI interface to libsyntax
135 Code-gen tasks, used to develop rust-analyzer:
137 - `cargo gen-kinds` -- generate `ast` and `syntax_kinds`
138 - `cargo gen-tests` -- collect inline tests from grammar
139 - `cargo install-code` -- build and install VS Code extension and server
148 Non-incremental, but seems pretty fast:
151 $ cargo build --release --package ra_cli
152 $ wc -l ~/projects/rust/src/libsyntax/parse/parser.rs
153 7546 /home/matklad/projects/rust/src/libsyntax/parse/parser.rs
154 $ ./target/release/ra_cli parse < ~/projects/rust/src/libsyntax/parse/parser.rs --no-dump > /dev/null
160 @matklad can be found at Rust
161 [discord](https://discordapp.com/invite/rust-lang), in
167 Rust analyzer is primarily distributed under the terms of both the MIT
168 license and the Apache License (Version 2.0).
170 See LICENSE-APACHE and LICENSE-MIT for details.