; Several values are returned as one vector and taken apart by destructuring
(defn get-first-last [data]
(if (seq data)
[(first data) (last data)]
[-1 -1]))
(let [[first-item last-item] (get-first-last [2 3 5])]
; first-item is 2, last-item is 5
(println "first =" first-item)
(println "last =" last-item))