-# libsyntax2.0
+# Rust Analyzer
-[](https://gitter.im/libsyntax2/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[](https://travis-ci.org/matklad/libsyntax2)
-[](https://ci.appveyor.com/project/matklad/libsyntax2/branch/master)
+[](https://travis-ci.org/matklad/rust-analyzer)
+[](https://ci.appveyor.com/project/matklad/rust-analyzer/branch/master)
-libsyntax2.0 is an **experimental** parser of the Rust language,
-intended for the use in IDEs.
-[RFC](https://github.com/rust-lang/rfcs/pull/2256).
+Rust Analyzer is an **experimental** modular compiler frontend for the
+Rust language, which aims to lay a foundation for excellent IDE
+support.
+It doesn't implement much of compiler functionality yet, but the
+white-space preserving Rust parser works, and there are significant
+chunks of overall architecture (indexing, on-demand & lazy
+computation, snapshotable world view) in place. Some basic IDE
+functionality is provided via a language server.
## Quick Start
+Rust analyzer builds on stable Rust >= 1.29.0.
+
```
+# run tests
$ cargo test
-$ cargo parse < crates/libsyntax2/src/lib.rs
-```
-
-
-## Trying It Out
-This installs experimental VS Code plugin
+# show syntax tree of a Rust file
+$ cargo run --package ra_cli parse < crates/ra_syntax/src/lib.rs
+# show symbols of a Rust file
+$ cargo run --package ra_cli symbols < crates/ra_syntax/src/lib.rs
```
-$ cargo install-code
-```
-
-It's better to remove existing Rust plugins to avoid interference.
-Warning: plugin is not intended for general use, has a lot of rough
-edges and missing features (notably, no code completion). That said,
-while originally libsyntax2 was developed in IntelliJ, @matklad now
-uses this plugin (and thus, libsytax2) to develop libsyntax2, and it
-doesn't hurt too much :-)
-
-### Features:
-
-* syntax highlighting (LSP does not have API for it, so impl is hacky
- and sometimes fall-backs to the horrible built-in highlighting)
-
-* commands (`ctrl+shift+p` or keybindings)
- - **Show Rust Syntax Tree** (use it to verify that plugin works)
- - **Rust Extend Selection** (works with multiple cursors)
- - **Rust Matching Brace** (knows the difference between `<` and `<`)
- - **Rust Parent Module**
- - **Rust Join Lines** (deals with trailing commas)
+To try out the language server, see [these
+instructions](./editors/README.md). Please note that the server is not
+ready for general use yet. If you are looking for a Rust IDE that
+works, use [IntelliJ
+Rust](https://github.com/intellij-rust/intellij-rust) or
+[RLS](https://github.com/rust-lang-nursery/rls). That being said, the
+basic stuff works, and rust analyzer is developed in the rust analyzer
+powered editor.
+
+
+## Current Status and Plans
+
+Rust analyzer aims to fill the same niche as the official [Rust
+Language Server](https://github.com/rust-lang-nursery/rls), but uses a
+significantly different architecture. More details can be found [in
+this
+thread](https://internals.rust-lang.org/t/2019-strategy-for-rustc-and-the-rls/8361),
+but the core issue is that RLS works in the "wait until user stops
+typing, run the build process, save the results of the analysis" mode,
+which arguably is the wrong foundation for IDE.
+
+Rust Analyzer is a hobby project at the moment, there's exactly zero
+guarantees that it becomes production-ready one day.
+
+The near/mid term plan is to work independently of the main rustc
+compiler and implement at least simplistic versions of name
+resolution, macro expansion and type inference. The purpose is two
+fold:
+
+* to quickly bootstrap usable and useful language server: solution
+ that covers 80% of Rust code will be useful for IDEs, and will be
+ vastly simpler than 100% solution.
-* **Go to symbol in file**
-
-* **Go to symbol in workspace** (no support for Cargo deps yet)
-
-* code actions:
- - Flip `,` in comma separated lists
- - Add `#[derive]` to struct/enum
- - Add `impl` block to struct/enum
- - Run tests at caret
+* to understand how the consumer-side of compiler API should look like
+ (especially it's on-demand aspects). If you have
+ `get_expression_type` function, you can write a ton of purely-IDE
+ features on top of it, even if the function is only partially
+ correct. Plugin in the precise function afterwards should just make
+ IDE features more reliable.
-* **Go to definition** ("correct" for `mod foo;` decls, index-based for functions).
-
+The long term plan is to merge with the mainline rustc compiler,
+probably around the HIR boundary? That is, use rust analyzer for
+parsing, macro expansion and related bits of name resolution, but
+leave the rest (including type inference and trait selection) to the
+existing rustc.
## Code Walk-Through
-### `crates/libsyntax2`
+### `crates/ra_syntax`
+
+Rust syntax tree structure and parser. See
+[RFC](https://github.com/rust-lang/rfcs/pull/2256) for some design
+notes.
- `yellow`, red/green syntax tree, heavily inspired [by this](https://github.com/apple/swift/tree/ab68f0d4cbf99cdfa672f8ffe18e433fddc8b371/lib/Syntax)
- `grammar`, the actual parser
- `algo`: generic tree algorithms, including `walk` for O(1) stack
space tree traversal (this is cool) and `visit` for type-driven
visiting the nodes (this is double plus cool, if you understand how
- `Visitor` works, you understand libsyntax2).
-
+ `Visitor` works, you understand rust-analyzer).
+
+
+### `crates/ra_editor`
+
+All IDE features which can be implemented if you only have access to a
+single file. `ra_editor` could be used to enhance editing of Rust code
+without the need to fiddle with build-systems, file
+synchronization and such.
-### `crates/libeditor`
+In a sense, `ra_editor` is just a bunch of pure functions which take a
+syntax tree as an input.
-Most of IDE features leave here, unlike `libanalysis`, `libeditor` is
-single-file and is basically a bunch of pure functions.
+### `crates/salsa`
+An implementation of red-green incremental compilation algorithm from
+rust compiler. It makes all rust-analyzer features on-demand.
-### `crates/libanalysis`
+
+### `crates/ra_analysis`
A stateful library for analyzing many Rust files as they change.
-`WorldState` is a mutable entity (clojure's atom) which holds current
-state, incorporates changes and handles out `World`s --- immutable
-consistent snapshots of `WorldState`, which actually power analysis.
+`AnalysisHost` is a mutable entity (clojure's atom) which holds
+current state, incorporates changes and handles out `Analysis` --- an
+immutable consistent snapshot of world state at a point in time, which
+actually powers analysis.
-### `crates/server`
+### `crates/ra_lsp_server`
-An LSP implementation which uses `libanalysis` for managing state and
-`libeditor` for actually doing useful stuff.
+An LSP implementation which uses `ra_analysis` for managing state and
+`ra_editor` for actually doing useful stuff.
### `crates/cli`
### `crate/tools`
-Code-gen tasks, used to develop libsyntax2:
+Code-gen tasks, used to develop rust-analyzer:
- `cargo gen-kinds` -- generate `ast` and `syntax_kinds`
- `cargo gen-tests` -- collect inline tests from grammar
- `cargo install-code` -- build and install VS Code extension and server
-### `code`
+### `editors/code`
VS Code plugin
+## Performance
+
+Non-incremental, but seems pretty fast:
+
+```
+$ cargo build --release --package ra_cli
+$ wc -l ~/projects/rust/src/libsyntax/parse/parser.rs
+7546 /home/matklad/projects/rust/src/libsyntax/parse/parser.rs
+$ ./target/release/ra_cli parse < ~/projects/rust/src/libsyntax/parse/parser.rs --no-dump > /dev/null
+parsing: 21.067065ms
+```
+
+## Getting in touch
+
+@matklad can be found at Rust
+[discord](https://discordapp.com/invite/rust-lang), in
+#ides-and-editors.
+
+
## License
-libsyntax2 is primarily distributed under the terms of both the MIT license
-and the Apache License (Version 2.0).
+Rust analyzer is primarily distributed under the terms of both the MIT
+license and the Apache License (Version 2.0).
See LICENSE-APACHE and LICENSE-MIT for details.
projects / rust.git / blobdiff