Getting started with Clojure and functional programming. Looking at the slow example of adding numbers in a range from the not-yet-published programming Clojure book third edition, chapter 10.
How to add a println to this loop so that I can see the values of sum as they change?
; performance demo only, don't write code like this
(defn sum-to [n]
(loop [i 1 sum 0]
(if (<= i n)
(recur (inc i) (+ i sum))
sum)))