You could use this: (defn non-existing-key [mp] (inc (reduce max (keys mp))))
For example: (non-existing-key {1 "a" 2 "b"}) => 3 -- 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