inside-out programming

gistfile1.clj

user> (zero? 1)
false
user> (zero? 0)
true
user> [0 1 2 0 3]
[0 1 2 0 3]
user> (filter zero? [0 1 2 0 3])
(0 0)
user> (count (filter zero? [0 1 2 0 3]))
2
user> (#(count (filter zero? %)) [0 1 2 0 3])
2
user> (defn count-zero[coll]
        (count (filter zero? coll)))
#'user/count-zero
user> (count-zero [0 1 2 0 3])
2