optional_parens.coffee

# Apart from the basic niceties of being able to leave off 
# parens in clear calls...

print 10

alert "Hello #{name}"


# ... the reason why they're important to have in CoffeeScript 
# is because it allows our "block" syntax (single function body
# passed as the final argument to a call) to play nicely with
# significant whitespace:


fs.readFile "config/options.json", (err, contents) ->
  ... work with file here.


# Writing the above without the ability to leave off the
# parens which would otherwise have to wrap the function body 
# would defeat a large part of the purpose of significant 
# whitespace in the first place.

Done! jashkenas/coffeescript#2114

Another way to avoid the inconsistency is of course:

($ 'some selector').click (e) ->
    ...