That is really nasty. :) P.S. Clojure's equivalent of progn is called do.
-Per On Tue, Apr 20, 2010 at 1:43 AM, Kevin Livingston <kevinlivingston.pub...@gmail.com> wrote: > SO as a complete hack to get file and line number metadata I > implemented this macro, my file of rules is now just loaded with load- > file and the rules that are define in it with RULE have the > appropriate file and line associated with them. This is compete abuse > of DEF and maybe the compiler (although it's not too dissimilar from > very valid approaches in common lisp), but is this creating any > ridiculous side effects that I should be aware of? is using the same > symbol to def to over and over and over again bad? register rule is > what takes care of putting the rule that was constructed where I need > it to be. > > in common lisp I would use a progn here I used a let with no bindings, > is there a better way in clojure? > > > > (defmacro RULE > "macro for creating an registering a rule" > [& params] > ;; is there a way to do this without the let? this is progn? > `(let [] > ;;def is used as a hack to get file name and line number metadata > ;; arguably instead of using a repeated symbol, rules could be > ;; def'ed to their own name, except that would create a lot of > vars > ;; which likely are never needed and would waste memory? > (def r# (verify-name (struct-map rule ~...@params))) > ;; gets the metatdata from the var, but changes :name to rule's > name > (let [reg-r# (with-meta r# (assoc (meta (var r#)) :name (:name > r#)))] > (register-rule reg-r#) > reg-r#))) > > > > > On Apr 17, 10:48 am, Per Vognsen <per.vogn...@gmail.com> wrote: >> On Sat, Apr 17, 2010 at 2:29 AM, Kevin Livingston >> >> <kevinlivingston.pub...@gmail.com> wrote: >> > I have an application that will read in a large number of structures >> > from a file. those structures will be used throughout the application >> > to produce additional data etc. since they are "user" configurable, >> > it would be nice to know where they come from should one of them start >> > misbehaving. the type of metadata the compiler associates with >> > function definitions etc. would be very valuable. if I'm reading my >> > structures in with (read) is there anyway to get it to attach filename >> > and line-number etc. metadata? >> >> The reader doesn't do that but you can easily do it yourself if you >> only want to annotate top-level values. >> >> Thinking about this made me realize that it would be nice if the >> reader reentered itself (as it does in LispReader's >> readDelimitedList() and a few other contexts) through a var so it >> could be rebound by a programmer. Then you could inject your own line >> number annotation into the reader which would apply not only to >> top-level values (e.g. a vector literal) but also its subvalues (e.g. >> the elements of the vector literal). >> >> -Per >> >> -- >> 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 >> athttp://groups.google.com/group/clojure?hl=en > > -- > 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 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
