The problem is that map returns a lazy seq, and the lazy seq is evaluated outside of the binding by the REPL. If you add a doall inside the binding, it behaves as you expect.
user=> (binding [*v* 2] (doall (map f [1 1 1]))) (3 3 3) Sean On Feb 8, 5:47 am, Alex <alexander.bolodu...@gmail.com> wrote: > Hi, > > I have a question about the scope of "binding" of a var. > > Let's say I have the following var: > > (def *v* 1) > > And I define a function that uses it: > > (defn f [n] (+ *v* n)) > > "binding" behaves as expected, establishing a thread-local binding to > a new value in its scope: > > user=> (binding [*v* 2] (f 1)) > 3 > > But if I pass it to "map", I expected it to pick up the new value, but > it does not. > > user=> (binding [*v* 2] (map f [1 1 1])) > (2 2 2) > > The output should be "(3 3 3)" if I understand it correctly. Where am I wrong? -- 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
