Thanks Kevin, I will try using reduce instead. I would like to know what I'm doing wrong with updating the ref for future reference. Thanks.
On Mon, Nov 24, 2008 at 3:23 PM, Kevin Downey <[EMAIL PROTECTED]> wrote: > > I know you are asking about refs, but you might want to think about > using reduce to walk the line-seq. the nature of reduce lets you have > access to the line-seq, two lines at a time no need for a ref. > > On Mon, Nov 24, 2008 at 2:17 PM, Brian Doyle <[EMAIL PROTECTED]> > wrote: > > I am parsing a file and to compare the current line > > with the previous line of the file. I am using line-seq > > to go thru the file and I thought I would create a > > ref to store the previous line. When I want to update > > the previous line value I can't seem to do it. I've > > never used refs before so I'm sure I'm doing something > > very stupid. > > > > (defstruct line :lat :lon :name) > > > > (defn convert [file] > > (let [prev-line (ref (struct line))] > > (with-open [r (reader file)] > > (doseq [l (line-seq r)] > > (let [ps (split #"," l) > > c-line (struct line (ps 0) (ps 1) (ps 2))] > > (if (not= c-line @pre-line) > > (do ; do stuff here then update pre-line > > (dosync ref-set pre-line (apply struct line (vals > c-line))) > > (println @pre-line)))))))) ; this prints out all nils > > doesn't seem to work > > > > > > > > Sorry if this email is not formatted correctly. Something is wrong with > my > > browser > > currently typing in a textarea. Thanks. > > > > > > > > > > > > > > > -- > The Mafia way is that we pursue larger goals under the guise of > personal relationships. > Fisheye > > > > --~--~---------~--~----~------------~-------~--~----~ 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 To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
