Untested, but maybe this: (def- parse-date [date-str] (when-not (blank? date-str) (let [date-str (trim date-str)] (take 1 (filter identity (map #(try (.parse % date-str) (catch ParseException e nil)) [full-date-format date-format-wo-tz short-date-format-wo- tz]))))))
WARNING: SimpleDateFormat is not thread-safe, so it's probably a bad idea to stick one in a shared context like def. On Jul 29, 10:35 pm, abhinav sarkar <abhinav.sar...@gmail.com> wrote: > Hi, > I am just starting to learn Clojure by writing a small library. I came > across a situation in which I have to parse a String for getting a Date. Now > the string can be in one of the three formats. So I wrote this functions to > parse it: > > (def #^{:private true :tag SimpleDateFormat} full-date-format > (doto (SimpleDateFormat. "EEE, dd MMMM yyyy HH:mm:ss +0000") > (.setTimeZone (TimeZone/getTimeZone "GMT")))) > > (def #^{:private true :tag SimpleDateFormat} date-format-wo-tz > (doto (SimpleDateFormat. "EEE, dd MMMM yyyy HH:mm:ss") > (.setTimeZone (TimeZone/getTimeZone "GMT")))) > > (def #^{:private true :tag SimpleDateFormat} short-date-format-wo-tz > (doto (SimpleDateFormat. "dd MMM yyyy, HH:mm") > (.setTimeZone (TimeZone/getTimeZone "GMT")))) > > (defn- parse-date [date-str] > (if (some #(% date-str) [nil? blank?]) > nil > (let [clean-date-str (trim date-str)] > (try > (.parse full-date-format clean-date-str) > (catch java.text.ParseException e > (try > (.parse date-format-wo-tz clean-date-str) > (catch java.text.ParseException e > (.parse short-date-format-wo-tz clean-date-str)))))))) > > I can't help but think that there must be a better way to do the same > without so many nested try catch blocks. If this were Java, I could have > looped over all the date formats and used an explicit return in the try > block and continue in catch block. I don't understand how to do explicit > return in Clojure. > > Also as the number of formats grows, I'll have to add more nested try catch > blocks. Please suggest a cleaner way to do this. > > Regards, > Abhinav -- 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