It throws because it calls the compare function on the value you are checking and one or more values in the ordered set, and compare throws when called with 2 values that are of different enough types.
https://github.com/jafingerhut/thalia/blob/master/doc/project-docs/clojure.core-1.5.1/clojure.core/compare.md Nicola Mometto recently created ticket http://dev.clojure.org/jira/browse/CLJ-1242 and wrote a patch for it that would catch such exceptions in some cases, perhaps for contains? calls, too, and cause them to return false instead of throwing. It hasn't been Vetted, so it remains to be seen what the Clojure developers answer to your "should" question is. Andy On Sat, Aug 3, 2013 at 6:47 AM, Jay Fields <j...@jayfields.com> wrote: > This: (contains? (sorted-map 1 2 3 4) :a) > Results in this: ClassCastException java.lang.Long cannot be cast to > clojure.lang.Keyword clojure.lang.Keyword.compareTo (Keyword.java:102) > > -- > -- > 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/groups/opt_out. > > > -- -- 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/groups/opt_out.
