I applaud the attention for generator functions ( they're JS' lazy construct, and I love love love 'em ), but this does not feel like a complete kata.

If you're going to turn this into a kata ( which is about on par with renaming a built-in ), explain what streaming is ( to you, because to the best of my knowledge, it's not standard JS fare ), and what solver is expected to do about it.

Also, lose the class ( this is not Java ), and specify that the '.' counts as a digit.

I rather suspect this will be retired soon though.