; P16 Drop every N'th element from a list.

(def a (list "a" "b" "c" "d" "e" "f" "g" "h" "i" "k"))

(func drop-n (lst n)
    (drop-n lst n (list) n))

(func drop-n (lst :nil n acc idx)
    acc)

(func drop-n (lst :{:any} n acc idx)
    (if (eq? 1 idx)
        (drop-n (rest lst) n acc n)  ; reset n, don't add to acc
        (drop-n (rest lst) n (append acc (first lst)) (-- idx))))

(func -- (num) (- num 1))

(print (->string a))
(print (->string (drop-n a 3)))