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