Uhm... isn't the whole point of an iterable object that you can already do the latter?

Maps and Sets don't have array-like methods like find, map, reduce, ... . If you want to implement them, the efficient way is better than the naïve one. This notebook provides an implementation that uses the efficient way.

Aaah, thank you, I misunderstood - I thought the examples showed how to use your notebook. Maybe clarify to "Example of what happens under the hood" or something like that?

I think it's clearer now, thanks for the advice.

The TC39 "Iterator Helpers" proposal (https://tc39.es/proposal-iterator-helpers) finally made it through to baseline in march 2025, making this notebook pointless.