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 (see http://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 -- 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
