rust-analyzer/CONTRIBUTING.md

The project is in its early stages: contributions are welcome and would be very helpful, but the project is not yet optimized for contribution. Moreover, it is doubly experimental, so there's no guarantee that any work here would reach production. That said, here are some areas where contributions would be especially welcome:

• Designing internal data structures: RFC only outlines the constraints, it's an open question how to satisfy them in the optimal way. See ARCHITECTURE.md for current design questions.

• Porting libsyntax parser to rust-analyzer: currently rust-analyzer parses only a tiny subset of Rust. This should be fixed by porting parsing functions from libsyntax one by one. Take a look at the libsyntax parser for "what to port" and at the Kotlin parser for "how to port".

• Writing validators: by design, rust-analyzer is very lax about the input. For example, the lexer happily accepts unclosed strings. The idea is that there should be a higher level visitor, which walks the syntax tree after parsing and produces all the warnings. Alas, there's no such visitor yet :( Would you like to write one? :)

• Creating tests: it would be tremendously helpful to read each of libsyntax and rust-analyzer parser functions and crate a small separate test cases to cover each and every edge case.

• Building stuff with rust-analyzer: it would be really cool to compile rust-analyzer to WASM and add client side syntax validation to rust playground!

Do take a look at the issue tracker.

If you don't know where to start, or have any questions or suggestions, don't hesitate to chat at Gitter!

Code generation

Some of the components of this repository are generated through automatic processes. These are outlined below:

• gen-kinds: The kinds of tokens are reused in several places, so a generator is used. This process uses tera to generate, using data in grammar.ron, the files:
  • ast/generated.rs in ra_syntax based on ast/generated.tera.rs
  • syntax_kinds/generated.rs in ra_syntax based on syntax_kinds/generated.tera.rs