core: add statements of a Graph to a Dataset

lib/rdf/dataset.ex

@@ -65,6 +65,12 @@ defmodule RDF.Dataset do
 
   @doc """
   Adds triples and quads to a `RDF.Dataset`.
+
+  The optional third argument `graph_context` defaulting to `nil` for the default
+  graph, specifies the graph to which the statements are added.
+
+  Note: This also applies when adding a named graph. Its name is ignored over
+  `graph_context` and its default value.
   """
   def add(dataset, statements, graph_context \\ nil)
 
@@ -103,6 +109,17 @@ defmodule RDF.Dataset do
     end
   end
 
+  def add(%RDF.Dataset{name: name, graphs: graphs}, %Graph{} = graph,
+          graph_context) do
+    with graph_context = Quad.convert_graph_context(graph_context) do
+      %RDF.Dataset{name: name,
+        graphs:
+          Map.update(graphs, graph_context, Graph.new(graph_context, graph), fn current ->
+            current |> Graph.add(graph)
+          end)
+      }
+    end
+  end
 
   @doc """
   Adds statements to a `RDF.Dataset` and overwrites all existing statements with the same subjects and predicates in the specified graph context.

test/unit/dataset_test.exs

@@ -172,23 +172,63 @@ defmodule RDF.DatasetTest do
       assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object2})
 
       ds = Dataset.add(ds, Description.new({EX.Subject1, EX.predicate3, EX.Object3}), EX.Graph)
+      assert Enum.count(ds) == 3
       assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate1, EX.Object1})
       assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object2})
       assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate3, EX.Object3, EX.Graph})
     end
 
-    @tag skip: "TODO"
     test "an unnamed Graph" do
-      ds = Dataset.add(dataset(), Graph.new(%{EX.Subject1 => [
+      ds = Dataset.add(dataset(), Graph.new([
-        {EX.predicate1, EX.Object1},
+        {EX.Subject1, EX.predicate1, EX.Object1},
-        {EX.predicate2, EX.Object2},
+        {EX.Subject1, EX.predicate2, EX.Object2},
-      ]}))
+      ]))
+      assert unnamed_graph?(Dataset.default_graph(ds))
       assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate1, EX.Object1})
       assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object2})
+
+      ds = Dataset.add(ds, Graph.new({EX.Subject1, EX.predicate2, EX.Object3}))
+      assert unnamed_graph?(Dataset.default_graph(ds))
+      assert Enum.count(ds) == 3
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate1, EX.Object1})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object2})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object3})
+
+      ds = Dataset.add(ds, Graph.new({EX.Subject1, EX.predicate2, EX.Object3}), EX.Graph)
+      assert unnamed_graph?(Dataset.default_graph(ds))
+      assert named_graph?(Dataset.graph(ds, EX.Graph), uri(EX.Graph))
+      assert Enum.count(ds) == 4
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate1, EX.Object1})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object2})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object3})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object3, EX.Graph})
     end
 
-    @tag skip: "TODO"
     test "a named Graph" do
+      ds = Dataset.add(dataset(), Graph.new(EX.Graph1, [
+        {EX.Subject1, EX.predicate1, EX.Object1},
+        {EX.Subject1, EX.predicate2, EX.Object2},
+      ]))
+      refute Dataset.graph(ds, EX.Graph1)
+      assert unnamed_graph?(Dataset.default_graph(ds))
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate1, EX.Object1})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object2})
+
+      ds = Dataset.add(ds, Graph.new(EX.Graph2, {EX.Subject1, EX.predicate2, EX.Object3}))
+      refute Dataset.graph(ds, EX.Graph2)
+      assert unnamed_graph?(Dataset.default_graph(ds))
+      assert Enum.count(ds) == 3
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate1, EX.Object1})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object2})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object3})
+
+      ds = Dataset.add(ds, Graph.new(EX.Graph3, {EX.Subject1, EX.predicate2, EX.Object3}), EX.Graph)
+      assert named_graph?(Dataset.graph(ds, EX.Graph), uri(EX.Graph))
+      assert Enum.count(ds) == 4
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate1, EX.Object1})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object2})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object3})
+      assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object3, EX.Graph})
     end
 
     test "a list of Descriptions" do