My biggest problem is that because it lacks firm rules in a lot of area, CoffeeScript is a language that is not always intuitive. With JavaScript it's pretty si

My biggest problem is that because it lacks firm rules in a lot of area, CoffeeScript is a language that is not always intuitive. With JavaScript it's pretty simple to know the rules; they are completely uniform. Not so with CoffeeScript. Here's my biggest gripe: greet = (greeting, person) -> "#{greeting} #{person}!" greet "Hello", "world" That's simple. A function that takes 2 parameters, separated by a comma. But wait, here's another: longRunning = (onsuccess, onerror) -> dosomething (e) -> if not e.error? onsuccess() else onerror() And the implementation: longRunning () -> "Yippee!" () -> "Oh noes" A function with 2 parameters, this time separated by a carriage return, not commas. How would one know that intuitively? That some times functions parameters are separated by commas and some times by carriage returns? Or that some times function calls have to include the () (when they have no parameters) and some times they don't (when they do have parameters)? I'm sure these things become second nature over time, but learning them will result in a lot of trips to StackOverflow as you wonder why your code doesn't behave as expected.