Don't know what you mean about "swapping", but here's a solution that generalizes to a tree of any finite depth, where each node is either a leaf element or a seqable (say, a vector) of any length:
(defn coord-of ([elems target] (coord-of elems target [])) ([elems target indexes] (first (keep-indexed (fn [i x] (cond (= x target) (conj indexes i) (seqable? x) (coord-of x target (conj indexes i)))) elems)))) Then, for example, cljs.user=> (coord-of [[] 11 [1 2 3] [4 5 6]] 5) [3 1] cljs.user=> (coord-of [[] 11 [1 2 3] [4 5 6]] 55) nil -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.