Datomic rule to find schema attributes whose name matches a prefix

gistfile1.clj

;; The Datomic schema is made up of Datomic data, so you manipulate it
;; with ordinary queries and transactions -- and with ordinary code
;; in Java or Clojure.

;; query rule that finds attributes in schema whose names start with ?prefix
;; note the Java interop call to .startsWith
;; you could create a similar rule for namespace prefixes
(def rules '[[[attr-starts-with ?prefix ?attr]
              [?e :db/valueType]
              [?e :db/ident ?attr]
              [(name ?attr) ?name]
              [(.startsWith ^String ?name ?prefix)]]])


;; in-memory example database
(use '[datomic.api :only (db q) :as d])
(def uri "datomic:mem://test")
(d/create-database uri)
(def conn (d/connect uri))

;; what attributes have names starting with "t"?
(q '[:find ?a
     :in $ % ?prefix
     :where (attr-starts-with ?prefix ?a)]
   (db conn)
   rules
   "t")