(def xf (filter keyword?))
Apply to a collection, returning a sequence:
(sequence xf [:a 1 2 :b :c]) ;; => (:a :b :c)
Apply to a collection, reducing the resulting collection with another function:
(transduce xf str [:a 1 2 :b :c]) ;; => ":a:b:c"
Apply to a collection, and...