Try this: user=> (def a) #'user/a user=> (bound? (var a)) false user=> (def a nil) #'user/a user=> (bound? (var a)) true
Sean On Mon, Apr 29, 2013 at 8:32 AM, AtKaaZ <atk...@gmail.com> wrote: > How do you guys handle the cases when the var is unbound? I mean > specifically in the cases where you just test if the var is nil. > > => (def a) > #'clojurewerkz.titanium.graph-test/a > > => a > #<Unbound Unbound: #'clojurewerkz.titanium.graph-test/a> > > => (nil? a) > false > > => (bound? a) > ClassCastException clojure.lang.Var$Unbound cannot be cast to > clojure.lang.Var clojure.core/bound?/fn--4837 (core.clj:4954) > > => (bound? #'a) > false > > ok imagine the following sample :)) > > => (defn decorate [input] > (when (not (nil? input)) (str "prefix:" input ":suffix"))) > #'clojurewerkz.titanium.graph-test/decorate > > => (decorate "1") > "prefix:1:suffix" > > => (decorate a) > "prefix:Unbound: #'clojurewerkz.titanium.graph-test/a:suffix" > > so... fix? > but more importantly does anyone need to add checks for is-the-var-bound in > their code where they checked for nil ? > > -- > -- > 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/groups/opt_out. > > -- Sean A Corfield -- (904) 302-SEAN An Architect's View -- http://corfield.org/ World Singles, LLC. -- http://worldsingles.com/ "Perfection is the enemy of the good." -- Gustave Flaubert, French realist novelist (1821-1880) -- -- 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/groups/opt_out.
