empty

(empty coll)

clojure.core/empty: an empty collection of the same kind as coll. A vector, map or set answers a fresh empty one; a sorted map or set answers an empty one under the same comparator; each carries coll's metadata. A string, nil and any value that is no collection answer nil; a record signals (Can't create empty: ...). As a value a one-argument function.

Deviation: a list, a lazy seq and a seq answer nil, where the oracle answers () (the empty-as-nil position of rest and next), so they carry no metadata; a map entry answers [] where the oracle answers nil.