IcedCoffeeScript

This is certainly a development to applaud, but for me, the most important feature about async JS programming is to be able to catch errors in the asynchronous code, and do it without code clutter. So I hope that if this gets accepted to mainline CoffeScript, it will provide for a working try/catch around the await/defer, along with caller+callee stacktraces capturing (at least in debug mode). At that point, it will be hard for me to not justify the use of one compilation layer above JavaScript, which currently certainly is, and even so with await/defer.

Asynchronous error handling without clutter is why I created LAEH, have a look if you want: https://github.com/ypocat/laeh2

EDIT: To clarify - an uncaught error in async handler means your Node.js is going down (unless you use the catch-all handler, which is an even poorer practice). In browser it means your callback never returns, leaving you in void (with a short an ambiguous stacktrace) to search where the problem is.

Hi Jeremy,

streamline.js already fits the bill, including your golden rule: the core idea was precisely to generate the callbacks that the developer would write otherwise.

Today it works with both CoffeeScript and Javascript, but in a decoupled way: the streamline transformation is applied to the JS generated by the CS compiler. It could easily be repackaged as a CS language extension.

It has been around for more than a year and the CS+streamline combination is powering at least one live site: http://www.thethingdom.com/

Bruno