Hello and happy new year,
I've started this year with playing around with clojure macros and
wrote a macro that
behaves in a way I don't understand:
(defmacro foo
([x] `(list ~x ~x))
([x n] (if (<= n 0)
`(foo ~x)
`(foo ~(foo x)
~(- n 1)))))
(foo :a 0) => (:a :a) ;; What I expected
(foo :a 1) => nil ;; Here I would expect (foo (foo :a) 0) => (foo
(list :a :a) 0) => '((:a :a) (:a :a))
(foo :a 2) => java.lang.NullPointerException
Could someone please explain where my understanding of clojure macros
is flawed ?
Regards
Poul
--~--~---------~--~----~------------~-------~--~----~
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
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
-~----------~----~----~----~------~----~------~--~---
