At first glance this is surprising to me and I'm sure I would be tripped up by this at least a few times before I finally learned my lesson.
On Mon, Oct 5, 2009 at 5:23 PM, MarkSwanson <mark.swanson...@gmail.com> wrote: > > To expand on Meikel's nice explanation: > (to see if I understand correctly) > > 1. (defn baz ...) > > 2. (binding [foo bar] (baz [1 2 3])) - dynamically binds foo and > creates a lazy-seq response to the baz fn. Because map is lazy the [1 > 2 3] sequence is actually not read by anything within the binding > dynamic scope. The binding value simply isn't used as there isn't any > code that takes any values out of the lazy map. > > 3. After (binding ...) is finished it will return the last expr > evaluated - which was (baz [1 2 3]) _and_ it puts foo back to 42. > > 4. The repl now wants to print (baz [1 2 3]) so it takes the values > out of the lazy map (while foo = 42). > > I wonder if this concept will be thought of as a source of problems in > the future. Or, maybe this is just one of those fundamental Clojure > concepts you just have to learn and once you do you find you don't get > bit by it. > > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
