Closure Mode for CoffeeScript

[Michael Bolin]

I put together a Closure Mode for CoffeeScript that you can play with
here:

http://bolinfest.com/coffee/

I wasn't aware of UberScript (https://github.com/jstrachan/coffee-
script/blob/master/TypeAnnotations.md) until I was just about done, so
I felt like I should see my thing through and publish it anyway, but
perhaps efforts could be combined. If this can become an effective way
to write Closure Library code, I would definitely add support for it
in plovr.

Happy Friday,
Michael

[André Moraes]

MIchael, first of all, plovr made me look to closure-library with
better eyes than the last time I used, so thanks for that.

Now my question,
The generated source maps after the compilation step maps to the
coffescript or to the translated coffescript->javascript?

--
André Moraes
http://andredevchannel.blogspot.com/

[John Lenz]

Micheal, the one thing I see missing is a discussion regarding exports and externs?  Is it possible to export a coffee script methods?

[Michael Bolin]

If you're talking about plovr, then I believe the generated source
maps map to the translated coffeescript->javascript. What you are
talking about could be done as future work, though I think special
handling would have to be done to know which subset of the production
JS was from CoffeeScript and which subset was hand-written or was
generated from Closure Templates.

Out of curiosity, what are you using the source maps for? The Closure
Inspector? Debugging stack traces on the server? Something else?

[Michael Bolin]

Well, you could just call goog.exportSymbol/exportProperty directly in
CoffeeScript. Or you could create a JS file with the equivalent calls,
if you're more comfortable with that.

As previously discussed, I'm not the biggest fan of an @export
annotation that always exports (http://code.google.com/p/closure-
compiler/issues/detail?id=50). Unfortunately, I haven't had time to
implement how I think it should work, either, but when I do, I'll keep
CoffeeScript in mind!

[John Lenz]

I was thinking more specifically about the "quoted/unquoted" rules.  I don't use coffeescript myself (I read a tutorial) so I'm unclear on whether access type distinction is preserved.

In general I'm pretty excited about it being a front end for the Closure Compiler (this + UberScript's type additions).  I'm hoping it is possible to have coffeeScript generate a JsonML AST with source location information (which I believe would need to be added) to enable source mapping (the alternative requires using Rhino and building the compiler's AST directly using Java calls).

[André Moraes]

Rigth now I am not using source maps because the app is still in development.
But when it comes to production maybe this could be usefull.

It's a js 2d game engine using Canvas to render graphics, is more of a
experiment than a real project.
But if the tests show some good results this might become a real project.