map의 설명을 마치 고 저자는 이렇게 말합니다. "If you want an exercise that will really blow your hair back, try implementing map using reduce, and then do the same for filter and some after you read about them later in this chapter." 안해 볼 수 없겠죠 (defn map-by-reduce [f xs] (seq (reduce #(conj %1 (f %2)) [] xs))) (map-by-reduce inc [1 2 3 4]) ;; => (2 3 4 5) (def food-journal [{:month 1 :day 1 :human 5.3 :critter 2..