In fact, the way that count works on ISeqs is rather roundabout -- it only works because all implementations of ISeq in clojure.jar also happen to implement java.util.List, so count calls Collection.size(). In theory, some user-provided ISeq which didn't implement List would not respond to count.
It's probably a good idea for interop reasons to have seqs implement the java collection types, but I don't feel too happy about clojure code which uses the java Collection interface on seqs. Phil On 13 May 2013 15:48, Meikel Brandmeyer (kotarak) <m...@kotka.de> wrote: > Hi, > > Am Montag, 13. Mai 2013 16:16:57 UTC+2 schrieb Sean Corfield: >> >> >> So you think (count (map inc [1 2 3])) should be illegal? >> >> (I'm just trying to understand your logic here) >> > > In the hardcore version, yes. In the practical version, probably not. I > never had to call count on a seq. (Various versions of partition-by or split > being a notable exception.) (Still a promised O(1) count would be nice for > reasoning as we have it for contains?. What is clojure.lang.Counted good for > anyway?) > > Meikel > > -- > -- > 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/groups/opt_out. > > -- -- 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/groups/opt_out.
