Thanks a lot James. It seems I completely missed the order of let and doseq.
On Sun, Apr 5, 2015 at 1:12 PM, James Reeves <ja...@booleanknot.com> wrote: > Dereferencing an atom will give you the value of the atom at the time you > dereferenced it. So at the start of the doseq loop, you deref the atom and > get back an immutable vector of values. It's the same as writing: > > (let [data @a-data] > (doseq [element data] > ...)) > > You dereference first, and then you iterate over that fixed sequence. The > value of "a-data" might change, but the dereferenced "data" does not. > > - James > > On 5 April 2015 at 18:00, Shahrdad Shadab <shahrd...@gmail.com> wrote: > >> Hi folks >> >> It may seem silly question but why when I doseq over a vector that is >> wrapped in an atom and change the vector using swap! while I am inside >> doseq, the doseq sets to the beginning of the vector intermittently: >> >> >> (def a-data (atom [15 9 8 1 4 11 7 12 13 14 5 3 16 2 10 6])) >> >> (defn switch-two-elements [the-vector] ... ) ;; swaping two elements in >> given vector >> >> (doseq [element @a-data] >> (println @a-data) (println element) >> (swap! a-data switch-two-elements)) >> >> [15 9 8 1 4 11 7 12 13 14 5 3 16 2 10 6] >> 15 >> >> [1 9 8 15 4 11 7 12 13 14 5 3 16 2 10 6] >> 9 >> >> [1 4 8 15 9 11 7 12 13 14 5 3 16 2 10 6] >> 8 >> >> [1 4 5 15 9 11 7 12 13 14 8 3 16 2 10 6] >> 1 ==> I expect this to be 15 >> >> I suspect the reason would be the same as the one behind not changing a >> collection in java while iterating over it. >> >> I appreciate any insight on this. >> >> Thanks a lot >> Best regards >> >> >> >> >> -- >> Software Architect & Computer Scientist >> >> -- >> 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 unsubscribe from this group and stop receiving emails from it, send an >> email to clojure+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > > -- > 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 unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- Software Architect & Computer Scientist -- 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 unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
