From cd5636528fd880edb41c817a8a4f03b98da360dd Mon Sep 17 00:00:00 2001
From: Marcel Otto <marcelotto@gmx.de>
Date: Tue, 6 Jun 2017 23:35:46 +0200
Subject: [PATCH] core: RDF.Dataset.add, .put and .new support another dataset
 as input

---
 lib/rdf/dataset.ex         | 22 ++++++++++++++++++++++
 test/unit/dataset_test.exs | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/lib/rdf/dataset.ex b/lib/rdf/dataset.ex
index 2f7f2da..a59ac66 100644
--- a/lib/rdf/dataset.ex
+++ b/lib/rdf/dataset.ex
@@ -44,6 +44,11 @@ defmodule RDF.Dataset do
   def new(%RDF.Graph{} = graph),
     do: new() |> add(graph, graph.name)
 
+  @doc """
+  Creates an unnamed `RDF.Dataset` from another `RDF.Dataset`.
+  """
+  def new(%RDF.Dataset{graphs: graphs}),
+    do: %RDF.Dataset{graphs: graphs}
 
   @doc """
   Creates an empty named `RDF.Dataset`.
@@ -75,6 +80,11 @@ defmodule RDF.Dataset do
   def new(name, %RDF.Graph{} = graph),
     do: new(name) |> add(graph, graph.name)
 
+  @doc """
+  Creates a named `RDF.Dataset` from another `RDF.Dataset`.
+  """
+  def new(name, %RDF.Dataset{graphs: graphs}),
+    do: %RDF.Dataset{new(name) | graphs: graphs}
 
 
   @doc """
@@ -135,6 +145,12 @@ defmodule RDF.Dataset do
     end
   end
 
+  def add(%RDF.Dataset{} = dataset, %RDF.Dataset{} = other_dataset, _) do
+    Enum.reduce graphs(other_dataset), dataset, fn (graph, dataset) ->
+      add(dataset, graph)
+    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.
@@ -228,6 +244,12 @@ defmodule RDF.Dataset do
     end
   end
 
+  def put(%RDF.Dataset{} = dataset, %RDF.Dataset{} = other_dataset, _) do
+    Enum.reduce graphs(other_dataset), dataset, fn (graph, dataset) ->
+      put(dataset, graph)
+    end
+  end 
+
   def put(%RDF.Dataset{} = dataset, statements, graph_context)
         when is_map(statements) do
     with graph_context = convert_graph_name(graph_context) do
diff --git a/test/unit/dataset_test.exs b/test/unit/dataset_test.exs
index c3169ae..b320798 100644
--- a/test/unit/dataset_test.exs
+++ b/test/unit/dataset_test.exs
@@ -257,6 +257,44 @@ defmodule RDF.DatasetTest do
       assert dataset_includes_statement?(ds, {EX.Subject1, EX.predicate2, EX.Object3, EX.Graph})
     end
 
+    test "an unnamed Dataset" do
+      ds = Dataset.add(dataset(), Dataset.new([
+        {EX.Subject1, EX.predicate1, EX.Object1},
+        {EX.Subject1, EX.predicate2, EX.Object2},
+      ]))
+      assert ds.name == nil
+      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, Dataset.new({EX.Subject1, EX.predicate2, EX.Object3}))
+      ds = Dataset.add(ds, Dataset.new({EX.Subject1, EX.predicate2, EX.Object3, EX.Graph}))
+      assert ds.name == nil
+      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 named Dataset" do
+      ds = Dataset.add(named_dataset(), Dataset.new(EX.DS1, [
+        {EX.Subject1, EX.predicate1, EX.Object1},
+        {EX.Subject1, EX.predicate2, EX.Object2},
+      ]))
+      assert ds.name == uri(EX.DatasetName)
+      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, Dataset.new(EX.DS2, {EX.Subject1, EX.predicate2, EX.Object3}))
+      ds = Dataset.add(ds, Dataset.new(EX.DS2, {EX.Subject1, EX.predicate2, EX.Object3, EX.Graph}))
+      assert ds.name == uri(EX.DatasetName)
+      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
       ds = Dataset.add(dataset(), [
         Description.new({EX.Subject1, EX.predicate1, EX.Object1}),