Well, it took me a while to perhaps get what you were telling me here. In my case I I had something like
(defn foo [ & {:keys [bar ... more keys ...] :or {bar 1}} ] ...) and I wanted to know whether the user had explicilty invoked foo with :bar. What wasn't clear to me was that :as solved this problem. Reading http://clojure.org/special_forms#Special Forms--Binding Forms (Destructuring)-Map binding destructuring I guess I can see that it's telling me :as shows things that weren't in the init-form, but that's with hindsight. So, to emulated common lisp 'supplied-p' semantics, you can check the :as form, which will **not** contain :or values for keywords. E.g. user> (defn bar [ & {:keys [baz] :or {baz 'baz} :as all-keys} ] (println baz all-keys)) #'user/bar user> (bar :bof 1) baz {:bof 1} nil And not that the all-keys form does not show a binding for baz, and that's what I wanted. Just fyi in case anybody searches topics for 'supplied-p' again. On Saturday, June 21, 2014 7:22:13 PM UTC-4, Jason Felice wrote: > > If you destructure the parameters like this: > (defn f [& {:as a-map}] ...) > > You can use map primitives on a-map. But you can also supply defaults > here. > On Jun 20, 2014 2:14 PM, "Dave Tenny" <dave....@gmail.com <javascript:>> > wrote: > >> What is the commonly accepted technique for declaring/using 'supplied-p' >> type lambda list functionality in clojure? >> >> >> http://www.ai.mit.edu/projects/iiip/doc/CommonLISP/HyperSpec/Body/sec_3-4-1.html >> >> >> I have some clojure functions with a large number of keywords and various >> defaults, I want to know if a keyword was specified by the caller (rather >> than defaulted) in some cases. >> >> Certainly I could implement my own destructuring macros that did this, >> but I'd like to avoid reinventing a wheel here if I can, and also to know >> the idiomatic clojure way to do it. >> >> Thanks for any tips. >> >> >> -- >> You received this message because you are subscribed to the Google >> Groups "Clojure" group. >> To post to this group, send email to clo...@googlegroups.com >> <javascript:> >> Note that posts from new members are moderated - please be patient with >> your first post. >> To unsubscribe from this group, send email to >> clojure+u...@googlegroups.com <javascript:> >> 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+u...@googlegroups.com <javascript:>. >> 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.