# Boa
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This is an experimental Javascript lexer, parser and interpreter written in Rust.
Currently, it has support for some of the language.
[![Build Status][build_badge]][build_link]
[![codecov ](https://codecov.io/gh/boa-dev/boa/branch/master/graph/badge.svg )](https://codecov.io/gh/boa-dev/boa)
[![ ](http://meritbadge.herokuapp.com/boa )](https://crates.io/crates/boa)
[![ ](https://docs.rs/Boa/badge.svg )](https://docs.rs/Boa/)
[build_badge]: https://img.shields.io/endpoint.svg?url=https%3A%2F%2Factions-badge.atrox.dev%2Fboa-dev%2Fboa%2Fbadge& style=flat
[build_link]: https://actions-badge.atrox.dev/boa-dev/boa/goto
## Live Demo (WASM)
< https: / / boa-dev . github . io / boa / >
You can get more verbose errors when running from the command line.
## Development documentation
You can check the internal development docs at < https: / / boa-dev . github . io / boa / doc > .
## Conformance
To know how much of the ECMAScript specification does Boa cover, you can check out results running the ECMASCript Test262 test suite [here ](https://boa-dev.github.io/boa/test262/ ).
## Benchmarks
See [Benchmarks ](https://boa-dev.github.io/boa/dev/bench/ ).
## Contributing
Please, check the [CONTRIBUTING.md ](CONTRIBUTING.md ) file to know how to
contribute in the project. You will need Rust installed and an editor. We have
some configurations ready for VSCode.
### Debugging
Check [debugging.md ](./docs/debugging.md ) for more info on debugging.
### Web Assembly
This interpreter can be exposed to javascript!
You can build the example locally with:
```
$ yarn install
$ yarn serve
```
In the console you can use `window.evaluate` to pass JavaScript in.
To develop on the web assembly side you can run `yarn serve` then go to `http://localhost:8080` .
## Roadmap
See [Milestones ](https://github.com/boa-dev/boa/milestones ).
## Changelog
See [CHANGELOG.md ](./CHANGELOG.md ).
## Usage
- Clone this repo.
- Run with `cargo run -- test.js` where `test.js` is an existing JS file.
- If any JS doesn't work then it's a bug. Please raise an issue!
## Profiling
See [Profiling ](./docs/profiling.md )
## Command-line Options
```
USAGE:
boa_cli [OPTIONS] [FILE]...
FLAGS:
-h, --help Prints help information
-V, --version Prints version information
OPTIONS:
-a, --dump-ast < FORMAT > Dump the abstract syntax tree (ast) to stdout with the given format [possible values: Debug, Json,
JsonPretty]
ARGS:
< FILE > ... The JavaScript file(s) to be evaluated
```
## Communication
Feel free to contact us on [Discord ](https://discord.gg/tUFFk9Y ).
## Example
![Example ](docs/img/latestDemo.gif )
## License
This project is licensed under the [Unlicense ](./LICENSE-UNLICENSE ) or [MIT ](./LICENSE-MIT ) licenses, at your option.