Datahike rule input exception

datahike-rule-input-exception.clj

(require '[datahike.api :as d])

(def schema [{:db/ident       :name
              :db/cardinality :db.cardinality/one
              :db/index       true
              :db/unique      :db.unique/identity
              :db/valueType   :db.type/string}
             {:db/ident       :parents
              :db/cardinality :db.cardinality/many
              :db/valueType   :db.type/ref}
             {:db/ident       :age
              :db/cardinality :db.cardinality/one
              :db/valueType   :db.type/long}])

(def cfg {:store {:backend :mem
                  :id "sandbox"}
          :name "sandbox"
          :keep-history? true
          :schema-flexibility :write
          :attribute-refs? true})

(d/delete-database cfg)
(d/create-database cfg)

(def conn (d/connect cfg))

(d/transact conn {:tx-data schema})

(d/transact conn {:tx-data [{:name "Alice"
                             :age  25}
                            {:name "Bob"
                             :age 30}]})

(d/transact conn {:tx-data [{:name    "Charlie"
                             :age     5
                             :parents [[:name "Alice"]
                                       [:name "Bob"]]}]})



(def rules
  '[[(parent-info ?child ?name ?age)
     [?child :parents ?p]
     [(ground ["Alice" "Bob"]) [?name ...]]
     [?p :name ?name]
     [?p :age ?age]]])

(d/q {:query '{:find [?age ?parent-name]
               :in [$ ?n %]
               :where
               [[?child :name ?n]
                (parent-info ?child ?parent-name ?age)]}
      :args [@conn "Charlie" rules]});; => #{[30 "Bob"] [25 "Alice"]}

(d/q {:query '{:find [?age]
               :in [$ ?n %]
               :where
               [[?child :name ?n]
                (parent-info ?child "Alice" ?age)]}
      :args [@conn "Charlie" rules]});; =>  Unhandled clojure.lang.ExceptionInfo
  ;; Cannot parse binding, expected (bind-scalar | bind-tuple | bind-coll | bind-rel)
  ;; {:error :parser/binding, :form "Alice"}