As Mike points out, it does seem that MapEntry is considered a collection and is designed to emulate a vector so that you don't really have to worry about whether you have a MapEntry or a two-element vector (and as he points out, in ClojureScript there really is no distinction between a MapEntry and a vector).
With that in mind, I would agree that MapEntry's lack of implementation for empty is most likely an oversight, and ideally should behave as if it were a vector. On Sat, Jul 19, 2014 at 11:46 AM, Mike Fikes <mikefi...@me.com> wrote: > MapEntry is a collection: > > (coll? (clojure.lang.MapEntry. "a" 1)) > > ;=> true > > > (ancestors (class (clojure.lang.MapEntry. "a" 1))) > > ;=> (a set that includes clojure.lang.IPersistentCollection) > > > The docstring for empty implies it would return an empty MapEntry. But > perhaps since MapEntry is a special collection type that must have a size > exactly equal to 2, empty must return nil. > > > Perhaps ClojureScript will one day introduce a MapEntry type and behave > the same way as Clojure (ClojureScript currently returns a > PersistentVector). > > -- > 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. > -- 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.