It doesn't have a translator from JS to Coffee, I'm afraid. There isn't a one-to-one mapping (ie. detecting when you're actually using a for loop as an array comprehension).

As for watching a directory for changes, absolutely. Just pass "--watch" to the "coffee" executable. For example:

    coffee --compile --watch --output lib src/
    
    coffee -cw -o lib src/

Which will watch "src" for changes, and compile all ".coffee" files inside to ".js" files in "lib", preserving the directory structure.