set

(set coll)

Answers the set of the elements of coll: a list, vector, map (its entry vectors) or set dedupes into a fresh equal table with each member stored under itself; set of nil is the empty set. Members compare by =, so equal vectors dedupe.

As a value a one-argument lambda.

Deviation: a repeated set-literal element is refused by spelling at read time, but equal members arriving at run time dedupe silently.