gistfile1.clj

(use 'clojure.core.typed) 

;; I would like to only allow {:a 1} {:b 2} or {:a 1, :b 2}

(def-alias A '{:a '1})
(def-alias B '{:b '2})

;; naive version would be to use a Union
(ann foo [(U A B) -> (Value 1)])
(defn foo [x] 1)


;; but this type checks :(
(cf (foo {:b 2 :a nil}))

;; I could create HMaps with all the possible k/v possible (and using :optional) for these
;; but I guess there is a better way (short of using macros).