If I don't know what language you're talking about I can't help.

Well, I'll do that when I have enough time:-)
Thanks for the feedback!

Thanks for your solution! I'll mark this as resolved. :-)

Thanks for the feedback!

Before I made this kata, I solved several others that would have been easy without performance constraints. For example, generating Fibonacci numbers is trivial, but to compute the millionth Fibonacci, you have to come up with a much better algorithm.

I thought the problem wouldn't be interesting if I made the tests too easy, but you are right: This kata should be about a useful (and hopefully interesting) application of streams. Performance should be a secondary concern. I disabled the 3 million test. The hardest test now expects 1 million primes. I'm looking forward to your solution!

For the record: The best solution so far can generate over 40 million primes in under 7 seconds on the Codewars server.