Coffeescript unusable with Svelte 5

[nilskp]

Makes me very sad.

[nilskp]

Frankly, CS variable handling is by far the most common reason I've heard, over the years, for people dropping CS.

It's 2026 now, perhaps it's time to allow let and const, which is the primary reason it's unusable with Svelte, and IME the reason CS is not used more in general.

Could CS2 be extended to do this, or would we need a CS3?