maybe you should do this: (defn add-author [book new-author] (update-in book [:authors] conj new-author)
Thanks, Di Xu 2014-10-29 19:01 GMT+08:00 Roelof Wobben <rwob...@hotmail.com>: > Hello, > > For a exercise I have to add something to the end of a existing map. > > So I thought this would work : > > (defn add-author [book new-author] > (assoc book (conj :authors new-author))) > > and call the function with : > > (add-author little-schemer {:name "Gerald J. Sussman"}) > > > then I see this error message : > > > ClassCastException clojure.lang.Keyword cannot be cast to > clojure.lang.IPersistentCollection clojure.core/conj (core.clj:83) > > > Roelof > > > > > -- > 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. > -- 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.