datomic.clj

(declare complete-mask)

(deftype CompleteMask [spec]
  clojure.lang.IPersistentMap
  (assoc [_ k v]
    (throw (ex-info "Mask function not implemented." {:name "assoc"})))
  (assocEx [_ k v]
    (throw (ex-info "Mask function not implemented." {:name "assocEx"})))
  (without [_ k]
    (throw (ex-info "Mask function not implemented." {:name "without"})))
  clojure.lang.Associative
  (containsKey [_ k]
    (not-empty (filter #(= (:name %) k) (:items spec))))
  (entryAt [_ k]
    (let [{iname :name
           [_ typ] :type
           :as item} (first (filter #(= (:name %) k) (:items spec)))
           is-nested (= :rec (recursiveness item))]
      (MapEntry. k (if is-nested (complete-mask (get-spec typ)) true))))
  clojure.lang.ILookup
  (valAt [t k] (.val (.entryAt t k)))
  (valAt [t k default] (let [v (.val (.entryAt t k))] (if v v default))))

(defn complete-mask [spec]
  "Builds a mask-map of the given spec for consumption by
  build-transactions. Recurs down specs to add everything in
  time."
  (CompleteMask. spec))