nth is used by the clojure printer (see print-method). Try the following code: (do (ConsCell. 1 nil) :ok)
It looks like you have to implement Sequential in order to get nth working on your datasctructure. суббота, 28 июля 2012 г., 10:33:48 UTC+6 пользователь JvJ написал: > > I'm trying to create a new ISeq type, just to try to get the hang of > extending sequences. It's not working, though. As far as I can tell, I've > implemented all necessary methods. However, I still get an error when > attempting to create an instance of the type. > > When I enter the following in the REPL: > (ConsCell. 1 nil) > > The repl complains about the nth function not being supported. However, > I'm not sure how to go about implementing it. Any ideas? > > (deftype ConsCell [car cdr] > clojure.lang.ISeq > (first > [this] (-> this .car)) > (next > [this] (-> this .cdr)) > (more > [this] (-> this .cdr)) > (cons > [this obj] (ConsCell. obj this)) > (seq > [this] this) > (equiv > [this other] false) > (count > [this] > (if (nil? (-> this .cdr)) > 1 > (inc (.count cdr)))) > > ;; Can't implement nth here, since it's not a member of the interface > ;(nth > ;[this n] > ;(if (zero? n) > ;(-> this .car) > ;(.nth cdr (dec n)))) > ) > -- 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
