I often have to manipulate keywords and symbols. A symbol name needs a string appended in a macro, a keyword uses underscores instead of dashes.
In order to do this, I usually transform them into a string, do some manipulation, and then turn the result back into a keyword/symbol. This pattern shows up enough that I created the multimethod below (defmulti modify (fn [& args] (class (second args)))) (defmethod modify clojure.lang.Keyword [f k] (keyword (f (name k)))) (defmethod modify clojure.lang.Symbol [f s] (symbol (f (name s)))) (defmethod modify :default [f s] (f s)) What this lets me do is use a string library to manipulate keywords/ symbols. For example ;wraps .toLowerCase user=>(downcase "ABC") "abc" ;Expected behavior w/strings user=>(modify downcase "ABC") "abc" user=>(modify downcase :ABC) :abc user=>(modify downcase 'ABC) abc As you can see, it works on both keywords & symbols without missing a beat. Now, let's take it a step further: (defn super-downcase [input] (modify downcase input)) user=>(super-downcase "ABC") "abc" user=>(super-downcase :ABC) :abc user=>(super-downcase 'ABC) abc super-downcase works on all three types, and we now have a new layer of abstraction in our string function. Add some macro-fu, et voila - a unified string/keyword/symbol library. You can play with the code here: http://github.com/francoisdevlin/devlinsf-clojure-utils Check the lib.sfd.str-utils namespace. Feel free to use the idea as you see fit. Hope this helps, Sean -- 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
