note, I didn't test any of these, but they should work (possibly with a tweak or 2)
There's quite a few ways to do this, here's one. (defmulti add-item (fn [& args] (condp count args 0 :none 1 (class (first args)) :default)) (defmethod add-item :none (add-item nil nil)) (defmethod add-item Integer [id] (add-item id nil)) (defmethod add-item Map [props] (add-item nil props)) (defmethod add-item :default [id props] ( ; call some Java method ) Here's another (defmulti add-item (fn [& args] (map class args) (defmethod add-item [] (add-item nil nil)) (defmethod add-item [Integer] [id] (add-item id nil)) (defmethod add-item [Map] [props] (add-item nil props)) (defmethod add-item :default [id props] ( ; call some Java method ) Cheers, Jay On Sun, Apr 15, 2012 at 5:33 PM, James Thornton <james.thorn...@gmail.com> wrote: > How do you use defmulti to create a function with a variable number of args? > > For example, add-item is wrapping a Java method that can take a variable > number of args, and so here I am trying to make add-item take zero, one, or > two args. Notice there are two singe-arg funcs -- each taking a different > type... > > (defmulti add-item class) > (defmethod add-item [] (add-item nil nil)) > (defmethod add-item Integer [id] (add-item id nil)) > (defmethod add-item Map [props] (add-item nil props)) > (defmethod add-item :default [id props] ( ; call some Java method ) > > Unless I am overlooking something, I don't see anything on the Multimethods > page (http://clojure.org/multimethods) about defmulti or defmethod taking > a variable number of arguments -- they all take the same number of arguments > of different types. > > - James > > -- > 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 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
