This is an experimental Javascript lexer, parser and interpreter written in Rust. Currently, it has support for some of the language.

https://boajs.dev/boa/playground/

You can get more verbose errors when running from the command line.

To know how much of the ECMAScript specification does Boa cover, you can check out results running the ECMASCript Test262 test suite here.

Please, check the 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.

Check debugging.md for more info on debugging.

This interpreter can be exposed to JavaScript! You can build the example locally with:

npm run build

In the console you can use window.evaluate to pass JavaScript in. To develop on the web assembly side you can run:

npm run serve

then go to https://localhost:8080.

• Clone this repo.
• Run with cargo run -- test.js where test.js is an existing JS file with any JS valid code.
• If any JS doesn't work then it's a bug. Please raise an issue!

Usage: boa [OPTIONS] [FILE]...

Arguments:
  [FILE]...  The JavaScript file(s) to be evaluated

Options:
      --strict                        Run in strict mode
  -a, --dump-ast [<FORMAT>]           Dump the AST to stdout with the given format [possible values: debug, json, json-pretty]
  -t, --trace                         Dump the AST to stdout with the given format
      --vi                            Use vi mode in the REPL
  -O, --optimize
      --optimizer-statistics
      --flowgraph [<FORMAT>]          Generate instruction flowgraph. Default is Graphviz [possible values: graphviz, mermaid]
      --flowgraph-direction <FORMAT>  Specifies the direction of the flowgraph. Default is top-top-bottom [possible values: top-to-bottom, bottom-to-top, left-to-right, right-to-left]
      --debug-object                  Inject debugging object `$boa`
  -h, --help                          Print help (see more with '--help')
  -V, --version                       Print version

See Milestones.

See Benchmarks.

See Profiling.

See CHANGELOG.md.

Feel free to contact us on Discord.

This project is licensed under the Unlicense or MIT licenses, at your option.