gistfile1.txt

# solution for tests on https://pastebin.com/BEdkvnHz

(de noRed (X) (not (match (list '@X ~(chop ":\"red\"") '@Y) X)))

(de parse (Input)
   (let (Input (list (chop Input)) C NIL)
           (recur NIL
              (make
                 (while (and (setq C (pop Input)) (<> "}" C) (<> "]" C))
                    (if (or (= C "{") (= C "[")) (link (recurse)) (link C)) ) ) ) ) )
(de filterRed (L)
   (recur (L)
      (make
         (for C L
            (link
               (if (not (atom C))
                  (if (noRed C) (recurse C))
                  C ) ) ) ) ) )


(de sumNum (Lst)
        (let Lst (fish 'atom Lst)
                (sum format (apply split (diff Lst (chop "1234567890-")) Lst)) ))

(de part2 (Str)
   (sumNum (filterRed (parse Str))) )

(test 6 (part2 " [1,2,3]"))
(test 4 (part2 "[1,{\"c\":\"red\",\"b\":2},3]"))
(test 0 (part2 "{\"d\":\"red\",\"e\":[1,2,3,4],\"f\":5}"))
(test 6 (part2 "[1,\"red\",5] "))