coll?

Returns true if x is a collection, false otherwise.

Lists, maps, sets, and vectors are collections.

(coll? [1 2 3])
;;=> true

(coll? '(1 2 3))
;;=> true

(coll? #{1 2 3})
;;=> true

(coll? {:foo 1 :bar 2})
;;=> true

Not collections:

(coll? "foo")
;;=> false

(coll? 123)
;;=> false

(coll? nil)
;;=> false