2014-07-09 5:30 GMT+02:00 John Mastro <john.b.mas...@gmail.com>: > Cecil Westerhof <cldwester...@gmail.com> wrote: > > - The book displays all the lines of a look on separate lines. In my > > case it is just one long line. Am I doing something wrong? > > No, you're not doing anything wrong. There's nothing in that data > structure which would inherently cause it to print on multiple lines. > > If you're using Cider, you can enable automatic pretty-printing in the > REPL, which would likely cause it to print on multiple lines. I think > it's M-x cider-repl-toggle-pretty-printing. > > Or you could use a definition of look more like this, which uses println > to print each item on its own line (not sure if you wanted to retain the > parens or not, but both are easily doable). > > (defn look [] > (doseq [d [(describe-location *location* nodes) > (describe-paths *location* edges) > (describe-objects *location* objects *object-locations*)]] > (println d))) >
That certainly looks better. The only problem is that the lines of the different calls are still printed as one. But rewriting to use strings would solve that problem. I just have to finish the book, to see if I can change the lists to strings. > - In Emacs Lisp you can use a function A in the definition of another > > function B before you declared function A. Is it correct that this is > > not possible in Clojure? > > Correct, though you can declare it without defining it, e.g. > (declare function-a). > OK, good to know. > > - Al variables in land of lisp begin and end with an asterisk. As I > > understood it, you only do this for variables that can be changed. So > > I renamed some variables. Did I understand this correctly, or is the > > usage of asterisks for something else? > > The "earmuffs" convention is related to dynamic variables. All global > variables are dynamic in Common Lisp, but that's not the case in > Clojure. You're creating dynamic variables (by using :dynamic metadata > in your defs) but I didn't notice anywhere where you're using this > feature (i.e. no binding or set! forms). Long story short, I would use > earmuffs if the variables are dynamic but not otherwise. > I read a little about it. And no, I do not use dynamic binding. So I probably should use atoms. Is there a convention how to name atoms? > Speaking of global variables, I'd recommend only using def at top level > (it creates global vars regardless of where you use it). Perhaps it > would work to initialize them at top level with a "null value", like > (def something (atom nil)), and then set it later if/when appropriate, > like (reset! something (first whatever)). As a plus, if you use > atoms like this you most likely won't need dynamic variables, even if > you need to start changing global variable values later on. > Yep, I should do that. > Hope that helps, > Certainly. -- Cecil Westerho f -- 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.
