I thought another option would be to use a `partition-all` transducer (and conj'ing a result list that way), but it seems those don't support step sizes. Maybe that internally could be as efficient as running along iterators in an imperative style

https://ask.clojure.org/index.php/2422/transducer-for-partit...

https://ask.clojure.org/index.php/13187/there-currently-opti...

https://clojure.atlassian.net/browse/CLJ-2797

Hopefully gets added to the language some day..