Hi Stuart fantastic - it is starting to make sense now. One follow on question.
Presumably this only applies to functions? If I replace (defn foo [] "hello") with (def foo "hello") I don't get the same results. Is this because functions are handled differently? many thanks (again) Dave On Apr 23, 2:48 am, Stuart Campbell <stu...@harto.org> wrote: > Hi Dave, > > If you write > > (run-jetty routes ...) > > then the current value of "routes" is looked-up and passed to run-jetty. > You won't see any change if you subsequently redefine "routes", because the > original definition is what was passed to run-jetty. > > On the other hand, > > (run-jetty #'routes ...) > > passes a var (seehttp://clojure.org/vars) to run-jetty. Now whenever > run-jetty invokes your handler function, the currently-bound value of > "routes" is invoked. > > Here's a simplified example: > > user> (defn foo [] "hello") > #'user/foo > user> (def a foo) > #'user/a > user> (def b #'foo) > #'user/b > user> (defn foo [] "goodbye") > #'user/foo > user> (a) > "hello" > user> (b) > "goodbye" > > Cheers, > Stuart > > On 23 April 2012 06:01, David Simmons <shortlypor...@gmail.com> wrote: > > > > > Hi > > > I'm new to Clojure but very keen to learn. I'm following Web > > Development with Clojure (http://www.vijaykiran.com/2012/01/11/web- > > application-development-with-clojure-part-1/) and came across the > > following code: > > > (run-jetty #'routes {:port (or port 8080) :join? false})) > > > I know that #'routes is the same as (var routes) and that it is > > passing the "object" rather than the actual value BUT I don't > > understand why this is used. Specifically if I replace #'route with > > route the code works fine. I've read somewhere this is something to do > > with autoloading changes to code when developing for the web. Does > > anyone have a simple explanaition for #' and why it is used here. If > > you have some simple clojure code to illustrate its use I'd be really > > grateful. > > > many thanks in advance for any help. > > > Dave > > > -- > > 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- Hide quoted text - > > - Show quoted text - -- 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
