I wasn’t saying JavaScript is bad at what it does! The title isn’t “why JS iterators are bad compared to Rust iterators”. I simply am trying to explain what “lazy” means in the context of iterators.

I used (and now regret) JS iterators as a contrast to lazy iterators. I’m aware you can make them lazy and I’m aware that 2n is insignificant in big O - all I was trying to do is explain what “Lazy” means in the context of iterators.