You're right that the scoping rules in CoffeeScript are unintuitive for someone coming from a statically-typed, declare-everything paradigm. But I'd hesitate to call it a problem. It's a feature not a bug that the same symbol in nested scopes always refers to the same variable. As I said previously, I believe code that relies on variable shadowing to work correctly is broken.

I've been hit by the scoping rules many times, but every time I ask myself why I'm using identifiers like i, j or x to refer to different variables in nested scopes anyway. Names like that should be reserved for only the tightest of scopes.

Is there another aspect of the scoping rules that you're referring to?