This is a parser for the Ruby programming language. It is designed to be portable, error tolerant, and maintainable. It is written in C99 and has no dependencies.
The repository contains the infrastructure for both a shared library (libprism) and a native CRuby extension. The shared library has no bindings to CRuby itself, and so can be used by other projects. The native CRuby extension links against ruby.h, and so is suitable in the context of CRuby.
.
├── Makefile configuration to compile the shared library and native tests
├── Rakefile configuration to compile the native extension and run the Ruby tests
├── bin
│ ├── lex runs the lexer on a file or string, prints the tokens, and compares to ripper
│ ├── parse runs the parse on a file or string and prints the AST
│ └── prism a CLI for development and debugging
├── config.yml specification for tokens and nodes in the tree
├── doc documentation website
├── docs markdown documentation about the project
├── ext
│ └── prism
│ ├── extconf.rb configuration to generate the Makefile for the native extension
│ └── extension.c the native extension that interacts with libprism
├── fuzz files related to fuzz testing
├── gemfiles gemfiles used by different Ruby versions in CI
├── include
│ ├── prism header files for the shared library
│ └── prism.h main header file for the shared library
├── java Java bindings for the shared library
├── java-wasm Java WASM bindings for the shared library
├── javascript JavaScript WASM bindings for the shared library
├── lib
│ ├── prism Ruby library files
│ └── prism.rb main entrypoint for the Ruby library
├── rakelib various Rake tasks for the project
├── rbi RBI type signatures for the Ruby library
├── rust
│ ├── ruby-prism Rustified crate for the shared library
│ └── ruby-prism-sys FFI binding for Rust
├── sample
│ └── prism Sample code that uses the Ruby API for documentation purposes
├── sig RBS type signatures for the Ruby library
├── src
│ ├── util various utility files
│ └── prism.c main entrypoint for the shared library
├── templates contains ERB templates generated by templates/template.rb
│ └── template.rb generates code from the nodes and tokens configured by config.yml
└── test
└── prism
├── fixtures Ruby code used for testing
└── snapshots snapshots of generated syntax trees corresponding to fixtures
To compile the shared library, you will need:
- C99 compiler
- GNU make
- Ruby 2.7.0 or later
Once you have these dependencies, run:
bundle install
to fetch the Ruby dependencies. Finally, run:
bundle exec rake compile
to compile the shared library. It will be built in the build directory. To test that everything is working, run:
bin/parse -e "1 + 2"
to see the syntax tree for the expression 1 + 2.
See the CONTRIBUTING.md file for more information. We additionally have documentation about the overall design of the project as well as various subtopics.
- Build system
- Configuration
- CRuby compilation
- Design
- Encoding
- Fuzzing
- Heredocs
- JavaScript
- Local variable depth
- Mapping
- Parser translation
- Parsing rules
- Releasing
- Ripper translation
- Ruby API
- RubyParser translation
- Serialization
- Testing
Prism has been integrated into the majority of Ruby runtimes, many libraries, and some applications. Below is a list of some of the projects that use Prism:
- CRuby (via C)
- Garnet (via WASM)
- JRuby (via Java)
- Natalie (via C++ and Ruby)
- Opal (via Ruby and WASM)
- TruffleRuby (via Java)
- dispersion
- minifyrb
- packwerk (via parser translator)
- rbi
- rails
- repl_type_completor
- rubocop (via parser translator)
- ruby-lsp
- smart_todo
- sorbet-eraser
- synvert
- typeprof