It depends. Using lazy data structures, transducers, or a number of other common tricks would turn it into one loop. Haskell, Clojure, Ruby, Scala, Swift, and m

It depends. Using lazy data structures, transducers, or a number of other common tricks would turn it into one loop. Haskell, Clojure, Ruby, Scala, Swift, and many other languages make it pretty easy to do.