One important thing to be aware of that I should have mentioned when suggesting the adjacency list solution is the rationale for using that representation. When you put atoms in the nodes of your data structure, it's no longer an immutable data structure and you lose the usage patterns that clojure provides for other idiomatic data. For example if you call update or assoc you get a new data structure back that shares the same mutable atoms under the unmodified keys, which means that any modifications are reflected in all the other contexts the data is used. Of course you could (and probably should) also use defensive copying, but then you need some method of handling the cycles when copying ... in the big picture it's much simpler to use the adjacency list format which preserves the usage style we are used to with other clojure data.
On Mon, Jul 24, 2017 at 7:12 AM Rob Nikander <rob.nikan...@gmail.com> wrote: > I think in my case here the easiest thing will be to remove the cycles, > but still I'd like to understand a couple things... > > > On Sunday, July 23, 2017 at 10:12:46 PM UTC-4, Didier wrote: >> >> I'm not sure I can fully help without you explaining more what you're >> doing. It sounds like you've got a collection or container type which has >> an implementation of print that loops over its elements, and calls print on >> them. So if you have a cycle, the print will go on forever until memory >> runs out. >> > > My container type (the tree node) is simply the standard clojure map. > > If you're using a standard type, you might be able to limit *print-level* >> <https://clojuredocs.org/clojure.core/*print-level*>. Most Clojure >> collections will limit how deep they print based on the value of this >> global dynamic Var. >> > > Okay, *print-level* works but it looks like I have to call print myself. I > can't rely on the REPL to print it. > > (binding [*print-level* 2] (println (find-route "/reports"))) ; okay > > Why does `alter-var-root` here seem to succeed, but have no effect? > > (alter-var-root #'*print-level* (constantly 2)) > => 2 > *print-level* > => nil > (find-route "/reports") > stack overflow > > > > -- > 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.
