sweet.js

Hygienic Macros for JavaScript!

• Read a tutorial on macros.
• Read the documentation at sweetjs.org.
• Play with the editor.
• Hang out on IRC #sweet.js at irc.mozilla.org.
• Try out other macros.

Getting started

Install sweet.js with npm:

$ npm install -g sweet.js

And compile your sweet macro enhanced code:

$ sjs --output compiled.js my_sweet_code.js

Sharing

You can collect your macros into a single module file to share with your other code or on npm. Full details here but the basic idea is to define your macros in a file macros.js and use the export keyword:

// macros.js
macro m { ... }
export m;

Then compile using the --module flag:

sjs --module /macros.js my_sweet_code.js

The --module also looks up along the npm path so you can install macro modules from npm (using lambda-chop as an example):

npm install lambda-chop
sjs --module lambda-chop/macros my_sweet_code.js

If you want to share your macros on npm we recommend using the sweet-macros keyword to make macros easy to find.

Hacking

Install the dev dependencies:

$ npm install

Build and run the tests:

$ grunt

Sweet.js is self hosted so you hack on the files in src/ using the version of sweet.js already built in lib/. When you are happy with your hacking, grunt dist will build a new version of sweet.js and put it into lib/.

Slightly confusing but the process goes like this:

<hack hack hack>
$ grunt
<tests fail!>
<hack hack hack>
$ grunt
<tests pass!>
$ grunt dist
$ git add lib/
$ git commit -m "sweet!"

Credits

Built on top of esprima and escodegen. Contributors are awesome!