Thanks James. So the repl behaves differently from some compiled code - good to know!
I don't yet know about the "safe" issues "read-eval". This came with the little template built by lein. But I'll read up on it. On Saturday, October 8, 2016 at 10:11:29 PM UTC-4, James Reeves wrote: > > > > On 9 October 2016 at 03:00, Phil Virgo <pwv...@gmail.com <javascript:>> > wrote: > >> WHY? >> >> The following prints 1/n 2/n 3/n fine in the repl >> >> (for [f [1 2 3]] (println f)) >> >> But does nothing in this lein project (the "Hello World???" does print) >> >> (ns slide.core >> (:gen-class)) >> >> (defn -main >> [& args] >> ;; work around dangerous default behaviour in Clojure >> (alter-var-root #'*read-eval* (constantly false)) >> (for [f [1 2 3]] (println f)) >> (println "Hello, World??")) >> > > The "for" macro is lazy. It only evaluates the items in the list when it's > consumed. You want the "doseq" macro instead, which is used for > side-effects. > > Incidentally, setting *read-eval* to false doesn't make clojure.core/read > safe. You should always consider clojure.core/read to be unsafe for use > with data from sources you don't control. Instead use something like > clojure.edn/read, which is designed to be safe. > > - James > -- 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.
