I agree, but I think making it a language restriction would be very odd. Coming from ruby, I also tend to think that this might be a nice way to do it, for thin

I agree, but I think making it a language restriction would be very odd. Coming from ruby, I also tend to think that this might be a nice way to do it, for things taking a final optional callback argument. $.ajax('path', options) (data) -> # do something with the data But it does read less clearly, unfortunately.