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javascriptcompiler-constructionecmascript-harmony

ECMAScript:Harmony / ES6 to JavaScript compiler

After reading Peter's article on JavaScript I noticed

Brendan Eich stated that one the goals for Harmony is to be a better target for to-JavaScript compilers.

There are currently two popular compilers with some vague ES:Harmony compliance:

Although CoffeeScript has some compliance it's not designed to be an ES:Harmony compiler so it's not useful to this end.

Tracuer seems to be sticking more rigorously to the ES:Harmony specification but I don't know whether it intends to become a full ES:Harmony compiler.

Since the aim is to to compile ES6 down to ES3 it would also need to support ES5 features (and probably a switch whether to compile ES5 to ES3 or ES6 to ES3).

  1. Are there currently any other projects aiming to create a full ES:Harmony to ES3 compiler?
  2. Is it wise to start writing such a compiler knowing that the standard is young / unstable / in flux.
  3. Are there currently any ES5 -> ES3 compilers?

I've left a question on the Traceur mailing list.

The aim of such a compiler would be backwards compatibility with ES3. Not full emulation of ES5 and ES6 in ES3.

Solution

  • Continuum has implemented most of the relevant features and should run in es3 browsers (like older IEs).