/swc

Super-fast javascript to javascript compiler written in rust

Primary LanguageRustApache License 2.0Apache-2.0

babel

Make the web (development) faster.

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Travis Status Coverage Gitter

Supporting swc

Backers on Open Collective Sponsors on Open Collective

swc is a community-driven project, and is maintained by a group of volunteers. If you'd like to help support the future of the project, please consider:

  • Giving developer time on the project. (Message us on Gitter for guidance!)
  • Giving funds by becoming a sponsor (see below)!

Open Collective Sponsors

Become a sponsor and get your logo on our README on Github with a link to your site. [Become a sponsor]

Documentation

Check out the documentation in the website.

Installation

Currently this requires nightly version of rust.

npm i -D swc

or

yarn add --dev swc

Features

Parsers

  • es2019
  • jsx
  • typescript

Transforms

New generation javascript to old-days javascript.

  • es3

    • member-expression-literals
    • property-literals
    • reserved-words

  • es5

    • property-mutators

  • es2015

    • arrow-functions
    • block-scoped-functions
    • block-scoping
      • Note: this might be buggy (at this time)
    • classes
    • computed-properties
    • destructuring
    • duplicate-keys
    • for-of
    • function-name
    • instanceof
    • literals
    • new-target
    • object-super
    • parameters
    • shorthand-properties
    • spread
    • sticky regex (y flag)
    • template-literals
      • invalid escape sequences inside tagged template literals. (aka es2018)
    • typeof-symbol
    • unicode-regex

  • es2016

    • exponentiation-operator

  • es2017

    • async-to-generator

  • es2018

    • async-generator-functions
    • dotall-regex
    • object-rest-spread
      • Using symbol as a key
    • optional-catch-binding
    • unicode-property-regex

  • react

    • jsx

Performance

The lower bound of the speedup compared to babel is 16. The benchmarks were run on Macbook pro, dual core, 2.3GHz Intel Core i5, 16 GB ram

performance
swc (ffi) 1,086 ops/sec ±0.77% (84 runs sampled)
swc-optimize (ffi) 1,060 ops/sec ±0.63% (87 runs sampled)
swc (ffi, simd) 1,295 ops/sec ±0.87% (89 runs sampled)
swc-optimize (ffi, simd) 1,270 ops/sec ±0.24% (89 runs sampled)
babel 65.72 ops/sec ±6.45% (62 runs sampled)

Contributing

See CONTRIBUTING.md. You may also find the architecture documentation useful (ARCHITECTURE.md).

License

swc is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE-APACHE and LICENSE-MIT for details.