Why CoffeeScript Isn't the Answer

What is the question for which CoffeeScript is a compelling answer?

"I needed to speak to Germans, so I learned French and spoke through a French-German interpreter. Things were occasionally lost in translation and somteimes I couldn't get my point across, but French is prettier. Can I recreate this experience in code?"

"My team can't learn to write `var` or `===`. Can we just learn a new language instead?"

"Indentation speaks to my aesthetic sensibilities, but braces do NOT! What fits my needs?"

"I don't want to use JavaScript. Fortunately, since I never make coding errors, I'll never need to debug transpiled JavaScript. What's the right language for me?"

Seriously, though, what is the problem that CoffeeScript solves?

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?

So you would use curly braces and commas to specify an object, and then be confused when CoffeeScript doesn't get it?

After a year you didn't figure out that its a best practice to leave off the parenthesis in just the outermost function call, but to include them in the other calls on a line to make things clear?

After a year, you didn't realize that with the CoffeeScript scoping rules, you couldn't just throw in a global at the last second without looking carefully to see if it was used somewhere else?

After a year, you still hadn't learned about function binding with fat arrow?

After a year, you still hadn't learned that the existential operator (?) means you don't have to use typeof nearly as much?

Section "full of surprises": http://ruoyusun.com/2013/03/17/my-take-on-coffeescript.html

http://ceronman.com/2012/09/17/coffeescript-less-typing-bad-...

And here's an old HN comment of my own which described a few representative difficulties: https://news.ycombinator.com/item?id=4518892

Also, there's no such thing as a global in CoffeeScript (unless you explicitly specify window.xyz), since everything is scoped to the file. And that's the point -- it's ridiculous to have to "look carefully" at all your code to see if functions further down share a variable name inside of them. In JavaScript, you don't need to worry about that because you know "var" scopes each variable to its function, regardless of whether a higher function or global variable uses the same name. In CoffeeScript, you suddenly do have to worry about that, which is fairly insidious and bug-prone behavior.

So you are saying that none of those particular issues are problems you are having today with CoffeeScript or were problems for most of the year?

In which case, what problems did you have?

Edit: it looks like in another thread you are pointing out some random and unmaintainable code examples that are ambiguous and saying that its hard to know how they will be interpreted by the compiler. Its hard to know how those examples would be interpreted by anyone, or why you would write code like that and create that problem for yourself.