core: Graph.new, .add and .put accept Descriptions as data to be added

Graph.put with a list of Descriptions remains to be done

lib/rdf/graph.ex

@@ -23,7 +23,7 @@ defmodule RDF.Graph do
   @doc """
   Creates an unnamed `RDF.Graph` with an initial triple.
   """
-  def new(triple = {_, _, _}),
+  def new({_, _, _} = triple),
     do: new |> add(triple)
 
   @doc """
@@ -32,6 +32,12 @@ defmodule RDF.Graph do
   def new(triples) when is_list(triples),
     do: new |> add(triples)
 
+  @doc """
+  Creates an unnamed `RDF.Graph` with an `RDF.Description`.
+  """
+  def new(%RDF.Description{} = description),
+    do: new |> add(description)
+
   @doc """
   Creates an empty named `RDF.Graph`.
   """
@@ -50,6 +56,12 @@ defmodule RDF.Graph do
   def new(name, triples) when is_list(triples),
     do: new(name) |> add(triples)
 
+  @doc """
+  Creates a named `RDF.Graph` with an `RDF.Description`.
+  """
+  def new(name, %RDF.Description{} = description),
+    do: new(name) |> add(description)
+
   @doc """
   Creates an unnamed `RDF.Graph` with initial triples.
   """
@@ -99,6 +111,15 @@ defmodule RDF.Graph do
     end
   end
 
+  def add(%RDF.Graph{name: name, descriptions: descriptions},
+          %Description{subject: subject} = description) do
+    description = if existing_description = descriptions[subject],
+      do:   Description.add(existing_description, description),
+      else: description
+    %RDF.Graph{name: name,
+               descriptions: Map.put(descriptions, subject, description)}
+  end
+
 
   @doc """
   Puts statements to a `RDF.Graph`, overwriting all statements with the same subject and predicate.
@@ -136,6 +157,15 @@ defmodule RDF.Graph do
   def put(graph = %RDF.Graph{}, {subject, predicate, object}),
     do: put(graph, subject, predicate, object)
 
+  def put(%RDF.Graph{name: name, descriptions: descriptions},
+          %Description{subject: subject} = description) do
+    description = if existing_description = descriptions[subject],
+      do:   Description.put(existing_description, description),
+      else: description
+    %RDF.Graph{name: name,
+               descriptions: Map.put(descriptions, subject, description)}
+  end
+
   def put(graph = %RDF.Graph{}, statements) when is_map(statements) do
     Enum.reduce statements, graph, fn ({subject, predications}, graph) ->
       put(graph, subject, predications)

test/unit/graph_test.exs

@@ -87,6 +87,18 @@ defmodule RDF.GraphTest do
       assert graph_includes_statement?(g, {EX.Subject, EX.predicate, EX.Object1})
       assert graph_includes_statement?(g, {EX.Subject, EX.predicate, EX.Object2})
     end
+
+    test "creating a named graph with an initial description" do
+      g = Graph.new(EX.GraphName, Description.new({EX.Subject, EX.predicate, EX.Object}))
+      assert named_graph?(g, uri(EX.GraphName))
+      assert graph_includes_statement?(g, {EX.Subject, EX.predicate, EX.Object})
+    end
+
+    test "creating an unnamed graph with an initial description" do
+      g = Graph.new(Description.new({EX.Subject, EX.predicate, EX.Object}))
+      assert unnamed_graph?(g)
+      assert graph_includes_statement?(g, {EX.Subject, EX.predicate, EX.Object})
+    end
   end
 
   describe "adding triples" do
@@ -123,6 +135,31 @@ defmodule RDF.GraphTest do
       assert graph_includes_statement?(g, {EX.Subject3, EX.predicate3, EX.Object3})
     end
 
+    test "a Description" do
+      g = Graph.add(graph, Description.new(EX.Subject1, [
+        {EX.predicate1, EX.Object1},
+        {EX.predicate2, EX.Object2},
+      ]))
+      assert graph_includes_statement?(g, {EX.Subject1, EX.predicate1, EX.Object1})
+      assert graph_includes_statement?(g, {EX.Subject1, EX.predicate2, EX.Object2})
+
+      g = Graph.add(g, Description.new({EX.Subject1, EX.predicate3, EX.Object3}))
+      assert graph_includes_statement?(g, {EX.Subject1, EX.predicate1, EX.Object1})
+      assert graph_includes_statement?(g, {EX.Subject1, EX.predicate2, EX.Object2})
+      assert graph_includes_statement?(g, {EX.Subject1, EX.predicate3, EX.Object3})
+    end
+
+    test "a list of Descriptions" do
+      g = Graph.add(graph, [
+        Description.new({EX.Subject1, EX.predicate1, EX.Object1}),
+        Description.new({EX.Subject2, EX.predicate2, EX.Object2}),
+        Description.new({EX.Subject1, EX.predicate3, EX.Object3})
+      ])
+      assert graph_includes_statement?(g, {EX.Subject1, EX.predicate1, EX.Object1})
+      assert graph_includes_statement?(g, {EX.Subject2, EX.predicate2, EX.Object2})
+      assert graph_includes_statement?(g, {EX.Subject1, EX.predicate3, EX.Object3})
+    end
+
     test "duplicates are ignored" do
       g = Graph.add(graph, {EX.Subject, EX.predicate, EX.Object})
       assert Graph.add(g, {EX.Subject, EX.predicate, EX.Object}) == g
@@ -138,7 +175,8 @@ defmodule RDF.GraphTest do
     end
   end
 
-  test "putting triples" do
+  describe "putting triples" do
+    test "a list of triples" do
       g = Graph.new([{EX.S1, EX.P1, EX.O1}, {EX.S2, EX.P2, EX.O2}])
         |> RDF.Graph.put([{EX.S1, EX.P2, EX.O3}, {EX.S1, EX.P2, bnode(:foo)},
                           {EX.S2, EX.P2, EX.O3}, {EX.S2, EX.P2, EX.O4}])
@@ -151,6 +189,34 @@ defmodule RDF.GraphTest do
         assert graph_includes_statement?(g, {EX.S2, EX.P2, EX.O4})
     end
 
+    test "a Description" do
+      g = Graph.new([{EX.S1, EX.P1, EX.O1}, {EX.S2, EX.P2, EX.O2}, {EX.S1, EX.P3, EX.O3}])
+        |> RDF.Graph.put(Description.new(EX.S1, [{EX.P3, EX.O4}, {EX.P2, bnode(:foo)}]))
+
+      assert Graph.triple_count(g) == 4
+      assert graph_includes_statement?(g, {EX.S1, EX.P1, EX.O1})
+      assert graph_includes_statement?(g, {EX.S1, EX.P3, EX.O4})
+      assert graph_includes_statement?(g, {EX.S1, EX.P2, bnode(:foo)})
+      assert graph_includes_statement?(g, {EX.S2, EX.P2, EX.O2})
+    end
+
+    @tag skip: "TODO: Requires Graph.put with a list to differentiate a list of statements and a list of Descriptions. Do we want to support mixed lists also?"
+    test "a list of Descriptions" do
+      g = Graph.new([{EX.S1, EX.P1, EX.O1}, {EX.S2, EX.P2, EX.O2}])
+        |> RDF.Graph.put([
+            Description.new(EX.S1, [{EX.P2, EX.O3}, {EX.P2, bnode(:foo)}]),
+            Description.new(EX.S2, [{EX.P2, EX.O3}, {EX.P2, EX.O4}])
+           ])
+
+        assert Graph.triple_count(g) == 5
+        assert graph_includes_statement?(g, {EX.S1, EX.P1, EX.O1})
+        assert graph_includes_statement?(g, {EX.S1, EX.P2, EX.O3})
+        assert graph_includes_statement?(g, {EX.S1, EX.P2, bnode(:foo)})
+        assert graph_includes_statement?(g, {EX.S2, EX.P2, EX.O3})
+        assert graph_includes_statement?(g, {EX.S2, EX.P2, EX.O4})
+    end
+  end
+
   test "subject_count" do
     g = Graph.add(graph, [
       {EX.Subject1, EX.predicate1, EX.Object1},