Removed naga/nil from graph data

Author: Paula Gearon

src/naga/data.clj

@@ -22,7 +22,7 @@
  [k (into {} (map #(apply vector (rest %)) vs))]))
  (into {}))
  node-list (loop [nl [] n node]
- (if (= :naga/nil n)
+ (if-not n
  nl
  (let [{f :naga/first r :naga/rest} (listmap n)]
  (recur (conj nl f) r))))]
@@ -44,11 +44,10 @@
  (let [id (store/new-node *current-storage*)
  [value-id triples] (value-triples v)
  [next-id next-triples] (list-triples vs)]
- [id (concat [[id (store/data-property *current-storage* value-id) value-id]
-  [id :naga/rest next-id]]
+ [id (concat [[id (store/data-property *current-storage* value-id) value-id]]
+ (when next-id [[id :naga/rest next-id]])
  triples
- next-triples)])
- [:naga/nil nil]))
+ next-triples)])))
 
 (defmethod value-triples List
  [vlist]
@@ -59,7 +58,7 @@
 
 (defmethod value-triples Map [v] (map->triples v))
 
-(defmethod value-triples nil [v] [:naga/nil nil])
+(defmethod value-triples nil [v] nil)
 
 (defmethod value-triples :default [v] [v nil])
 
@@ -69,7 +68,7 @@
  and builds triples around it"
  [entity-id :- s/Any
  [property value] :- [s/Keyword s/Any]]
- (let [[value-id value-data] (value-triples value)]
+ (if-let [[value-id value-data] (value-triples value)]
  (cons [entity-id property value-id] value-data)))
 
 
@@ -128,8 +127,7 @@
  "Return all the property/value pairs for a given entity in the store."
  [store :- Storage
  entity :- s/Any]
- (if-not (= entity :naga/nil)
- (store/resolve-pattern store [entity '?p '?o])))
+ (store/resolve-pattern store [entity '?p '?o]))
 
 
 (s/defn check-structure :- (s/maybe [[s/Keyword s/Any]])
@@ -161,8 +159,9 @@
  ;; convert the data to a map
  (let [st (into {} pairs)]
  ;; if the properties indicate a list, then process it
- (if-let [remaining (:naga/rest st)]
- (let [first-prop-elt (get-data st)
+ (when (:naga/first st)
+ (let [remaining (:naga/rest st)
+ first-prop-elt (get-data st)
  [_ first-elt] (recurse-node store first-prop-elt)]
  (assert first-elt)
  ;; recursively build the list

test/naga/test_data.clj

@@ -35,7 +35,6 @@
  [:test/n2 :naga/first 42]
  [:test/n2 :naga/rest :test/n3]
  [:test/n3 :naga/first 54]
- [:test/n3 :naga/rest :naga/nil]
  [:test/n2 :naga/contains 42]
  [:test/n2 :naga/contains 54]] m3))
  (is (= [[:test/n1 :db/ident :test/n1]
@@ -52,9 +51,7 @@
  [:test/n4 :naga/rest :test/n6]
  [:test/n5 :a 2]
  [:test/n6 :naga/first :test/n7]
- [:test/n6 :naga/rest :naga/nil]
  [:test/n7 :naga/first "nested"]
- [:test/n7 :naga/rest :naga/nil]
  [:test/n7 :naga/contains "nested"]
  [:test/n2 :naga/contains :test/n3]
  [:test/n2 :naga/contains :test/n5]
@@ -83,7 +80,6 @@
  [:test/n2 :naga/first 42]
  [:test/n2 :naga/rest :test/n3]
  [:test/n3 :naga/first 54]
- [:test/n3 :naga/rest :naga/nil]
  [:test/n2 :naga/contains 42]
  [:test/n2 :naga/contains 54]] m3))
  (is (= [[:test/n1 :db/ident :test/n1] 
@@ -100,9 +96,7 @@
  [:test/n4 :naga/rest :test/n6]
  [:test/n5 :a 2]
  [:test/n6 :naga/first :test/n7]
- [:test/n6 :naga/rest :naga/nil]
  [:test/n7 :naga/first "nested"]
- [:test/n7 :naga/rest :naga/nil]
  [:test/n7 :naga/contains "nested"]
  [:test/n2 :naga/contains :test/n3]
  [:test/n2 :naga/contains :test/n5]