this is because in order to use ~ to evaluate the fn, you need to use the backtick ` instead of the single quote ' Il giorno 13/lug/2011 00.34, "Paul Meehan" <paulm...@gmail.com> ha scritto: > > Sorry to repoen the discussion, but I got this: > > > => (def alist '(1 ~(fn [x y](+ x y)))) > #'user/alist > > => (apply (second alist) '(1 3)) > > #<CompilerException java.lang.ClassCastException: clojure.lang.Cons cannot be cast to clojure.lang.IFn (NO_SOURCE_FILE:0)> > > > On 07/12/2011 23:13, Benny Tsai wrote: >> >> Nice, yes, that works just as well :) >> >> On Tuesday, July 12, 2011 4:09:09 PM UTC-6, LaPingvino wrote: >>> >>> Didn't try, but shoudn't (def alist `(1 ~(fn [x y] (+ x y)))) be better? Then you don't need the eval :) >>> >>> 2011/7/12 Benny Tsai <benny...@gmail.com> >>>> >>>> alist is missing parens around the fn, so it's really a list of 4 elements like so: >>>> >>>> >>>> (1, fn, [x y], (+ x y)) >>>> >>>> So (second alist) returns just the symbol 'fn. And when you apply a Symbol to a list, the result is the last item in the list (not sure why). >>>> >>>> To do what you want, alist should be defined like this: >>>> >>>> (def alist '(1 (fn [x y] (+ x y)))) >>>> >>>> Also, it seems that the definition of the function needs to be eval'ed first to become an apply-able function. The following returns 4 in my REPL: >>>> >>>> (apply (eval (second alist)) '(1 3)) >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Clojure" group. >>>> To post to this group, send email to clo...@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+u...@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 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 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 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
