3 releases
0.17.3 | Sep 26, 2023 |
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0.17.1 | Sep 26, 2023 |
0.17.0 | Jul 8, 2023 |
#1351 in Parser implementations
12,333 downloads per month
Used in 8 crates
(3 directly)
5.5MB
34K
SLoC
Boa
This is an experimental Javascript lexer, parser and interpreter written in Rust. Currently, it has support for some of the language.
Live Demo (WASM)
https://boajs.dev/boa/playground/
You can get more verbose errors when running from the command line.
Conformance
To know how much of the ECMAScript specification does Boa cover, you can check out results running the ECMASCript Test262 test suite here.
Contributing
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.
Debugging
Check debugging.md for more info on debugging.
Web Assembly
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 http://localhost:8080
.
Usage
- Clone this repo.
- Run with
cargo run -- test.js
in the project root directory wheretest.js
is a path to an existing JS file with any valid JS code. - If any JS doesn't work then it's a bug. Please raise an issue!
Example
Command-line Options
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`
-m, --module Treats the input files as modules
-r, --root <ROOT> Root path from where the module resolver will try to load the modules [default: .]
-h, --help Print help (see more with '--help')
-V, --version Print version
Roadmap
See Milestones.
Benchmarks
See Benchmarks.
Profiling
See Profiling.
Changelog
See CHANGELOG.md.
Communication
Feel free to contact us on Discord.
License
This project is licensed under the Unlicense or MIT licenses, at your option.
lib.rs
:
Boa's boa_parser
crate is a parser targeting the latest ECMAScript language specification.
Crate Overview
This crate contains implementations of a Lexer
and a Parser
for the ECMAScript
language. The lexical grammar and the syntactic grammar being targeted are
fully defined in the specification. See the links provided for more information.
Dependencies
~8MB
~145K SLoC