You're right, it fails when the call to recur should dispatch to another method.
But as long as you are calling the same implementation it does seem to work: *(ns multi-recur)* * * *(defmulti tail-call #(first %&))* * * *(defmethod tail-call :recur [x n]* * (if (zero? n)* * (println x "Made it to" n)* * (recur x (dec n))))* * * *(defmethod tail-call :overflow [x n]* * (if (zero? n)* * (println x "Made it to" n)* * (tail-call x (dec n))))* * * *(tail-call :recur 5000)* *(tail-call :overflow 5000)* I don't know any work arounds for the situation where there dispatch resolves to another method implementation. Juan On Monday, December 17, 2012 2:08:39 PM UTC-3, Jonas wrote: > > recur doesn't work well with multimethods: > > (defmulti foo identity) > > (defmethod foo 1 [n] > (recur (dec n))) > > (defmethod foo 0 [n] > :ok) > > (foo 1) ;; runs forever > > Jonas > > On Monday, December 17, 2012 6:56:34 PM UTC+2, juan.facorro wrote: >> >> What about recur <http://clojure.org/special_forms#recur>? >> >> It's a special form used for tail call optimizations. >> >> Juan >> >> On Monday, December 17, 2012 1:32:31 PM UTC-3, bruce li wrote: >>> >>> Hello, everyone. >>> >>> I'm currently trying to model an automata using multi-method. So in my >>> code, I have something like: >>> >>> (defmethod trans :state >>> [state] >>> ; ....... >>> (trans ......)))) >>> >>> In the last line, the trans will be called with some different state. >>> >>> However, it seems that such call still consumes stack and I quickly come >>> to a stack overflow error when the states are reached multiple times. >>> >>> I'm wondering if there is some ways to optimize the code. >>> >>> Thanks! >>> >> -- 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
