For https://stackoverflow.com/questions/44605314/clojure-spec-coll-of-alternative-types

specing_oddly_shaped_data.clj

(require '[clojure.spec.alpha :as s])

(s/def ::coord nat-int?)
(s/def ::x ::coord)
(s/def ::y ::coord)
(s/def ::xy (s/keys :req-un [::x ::y]))
(s/def ::point (s/map-of #{:point} ::xy))
(s/def ::username (s/and string? seq))
(s/def ::user (s/map-of #{:user} ::username))

(s/def ::vector-entry (s/or :point ::point :user ::user))
(s/def ::my-vector (s/coll-of ::vector-entry :kind vector))

(s/valid? ::point {:point {:x 0 :y 0}})
(s/valid? ::my-vector [{:point {:x 0 :y 0}}])
(s/valid? ::my-vector [{:point {:x 0 :y 0}} {:user "joe"}])