The difference between String[] and Object[] is that a member of the former doesn't need a checked cast to String, but the latter does need one. In the code under consideration, however, nothing specific to String is used, so even in the Java code you can freely replace String[] with Object[] and everything still works.
If, on the other hand, you needed to invoke say *substring*, you'd see a small penalty due to the checked cast operation. On Tuesday, February 19, 2013 5:52:31 PM UTC+1, Andy Fingerhut wrote: > > ^objects is a Clojure synonym for ^"[Ljava.lang.Object;". Note that there > are such synonyms for only a few Java types, not everything, e.g. there is > no ^strings. > > What you are hinting is that a1 and a2 are Java arrays of objects. I > think this might speed up (aget a1 i) expressions, since it is known that > a1 is an array of objects, but I'm not sure about that. I believe "under > the hood" in the JVM all arrays of Objects are treated the same, regardless > of whether those Objects are String, Integer, java.awt.Color, etc. > > Andy > > On Feb 19, 2013, at 8:46 AM, Geo wrote: > > One thing I don't get is that switching the type hints from > > [#^"[Ljava.lang.String;" a1 #^"[Ljava.lang.String;" a2] > > to [^objects a1 ^objects a2] didn't seem to have any negative impact on > performance. Can anyone explain why hinting ^objects is just as good as > specifying that it's an array of Strings? What are you hinting with > ^objects that Clojure doesn't already know? > > -- -- 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.
