On 26 May 2014 16:31, Timothy Baldridge <tbaldri...@gmail.com> wrote: > All functions are eventually created via fn*. If you look for the source > code of fn it's a macro that emits a call to fn*. It's done this way so that > things like destructuring can be defined in clojure.core (and in Clojure) > instead of in Compiler.java (and in java).
Ah, thanks, that makes sense. But I think I asked the wrong question :-) What I really wanted to know was why clojure.java.jdbc needs fn* in this macro rather than a simple fn, and why it needs the :once tag. I found the answer here: http://clj-me.cgrand.net/2013/09/11/macros-closures-and-unexpected-object-retention/ Ray. > On Mon, May 26, 2014 at 9:08 AM, Ray Miller <r...@1729.org.uk> wrote: >> >> I was looking at the source for clojure.java.jdbc, and came across the >> following macro: >> >> (defmacro with-db-transaction >> [binding & body] >> `(db-transaction* ~(second binding) >> (^{:once true} fn* [~(first binding)] ~@body) >> ~@(rest (rest binding)))) >> >> I understand all of that apart from fn*, which I can't find any >> documentation for. Can anyone enlighten me? >> >> Also, why is the :once tag needed? >> >> Ray. >> >> -- >> 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. > > > > > -- > “One of the main causes of the fall of the Roman Empire was that–lacking > zero–they had no way to indicate successful termination of their C > programs.” > (Robert Firth) > > -- > 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.
