(seq-union)
(seq-union s1)
(seq-union s1 s2)
(seq-union s1 s2 & sets)
A union that preserves order.
Source
(defn seq-union
"A union that preserves order."
([] '())
([s1] s1)
([s1 s2] (concat s1 (remove (set s1) s2)))
([s1 s2 & sets] (reduce seq-union (list* s1 s2 sets))))