ecmascript

This is a rust crate to help you with ECMAScript 2017 v9.0. It provides a parser and an AST (abstract syntax tree) implementation. We also provide some macros to construct the AST so you can do interesting things like optimization!

Usage

Add this to your Cargo.toml:

[dependencies]
ecmascript = "0.1"

Then put this in your crate root:

extern crate ecmascript;

Example

This example reads a file, parses it, and then prints out a minified version.

The file reading is taken from the std::fs::File docs

extern crate ecmascript;

use std::fs::File;
use std::io::prelude::*;

fn main() -> std::io::Result<()> {
    // read foo.js
    let mut file = File::open("foo.js")?;
    let mut contents = String::new();
    file.read_to_string(&mut contents)?;

    // parse it
    let ast = ecmascript::parse(&contents).unwrap();
    println!("{:?}", ast);
}

API Reference

Docs are hosted on docs.rs.

About

ecmascript is used to parse a JavaScript module, and perform some operations on it. For example, concatenating modules together, uglifying the variable names, pretty printing uglified code, etc.

Features (Planned)

• ECMAScript 2017 v9.0 support (WIP)
  • We are actively developing this library to be up to date!
• JSX Extended Support (WIP)
  • JSX is meant to be an additive extension to the language
• AST Pretty Printer (WIP)
  • This supports minification options, such as 0 whitespace
• AST rewrite rules (WIP)
  • Eg. Constant folding, translating to older versions of the language, etc.

Testing

To test everything, just run this command:

cargo test

Or to run a single test,

cargo test --test <test_name>

Linting

To lint your code, use clippy. Its as easy as running once you have it installed!

cargo clippy

References

• http://www.ecma-international.org/ecma-262/9.0/

License

MIT © Nick Dujay