Totally agree with your point, but just a quick note: using the thread-first -> macro won't work in this case, instead you'd use the thread-last macro ->>. Also

Totally agree with your point, but just a quick note: using the thread-first -> macro won't work in this case, instead you'd use the thread-last macro ->>. Also Clojure doesn't have a sum function, so you'd actually use (reduce +).