Calling @netopyr's CoffeeScript javax.script engine from Groovy with @grab

groovyCoffee.groovy

@Grab('com.netopyr.coffee4java:coffee4java:1.0.0')
import javax.script.ScriptEngineManager

def coffeescript = new ScriptEngineManager().getEngineByName('coffeescript').factory.scriptEngine

assert coffeescript.eval('''\
square = (x) -> x * x
return square 3''') == 9

I have this silly idea few day ago that it would be fantastic if you can write some code in CoffeeScript instead of Groovy because as soon as you start to use CoffeeScript more you find a plethora of unnecessary brackets everywhere. I'm totally lame in writing anything non-trivial such as class loaders or or compilers but the idea is

1. have a .coffee file in similar structure as the groovy files (but maybe in src/main/coffee instead of src/main/groovy)
2. when requested (hooking to the class loader?) parse the .coffee file to CoffeeScript AST and from it generate either a .groovy file or directly the Groovy script on the fly using byte code manipulation

The point is to be able to call Groovy code from CoffeeScript and on the other hand to be able to declare classes in CoffeeScript which can be called later from Groovy.

And idea how to achieve with small effort e.g. global AST executed in very early phase?