Add equal?/2 on RDF.Description, RDF.Graph and RDF.Dataset

CHANGELOG.md

@@ -1,4 +1,4 @@
-# Change Log
+# Changelog
 
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/) and
@@ -11,9 +11,10 @@ This project adheres to [Semantic Versioning](http://semver.org/) and
 
 - `RDF.PrefixMap`
 - prefix management of `RDF.Graph`s:
-	- the structure now has `prefixes` field with an optional `RDF.PrefixMap`
+	- the structure now has a `prefixes` field with an optional `RDF.PrefixMap`
 	- new functions `add_prefixes/2`, `delete_prefixes/2` and `clear_prefixes/1` 
 - configurable `RDF.default_prefixes`
+- `RDF.Description.equal?/2`, `RDF.Graph.equal?/2` and `RDF.Dataset.equal?/2` 
 
 
 ### Changed

lib/rdf/dataset.ex

@@ -779,6 +779,21 @@ defmodule RDF.Dataset do
   end
 
 
+  @doc """
+  Checks if two `RDF.Dataset`s are equal.
+
+  Two `RDF.Dataset`s are considered to be equal if they contain the same triples
+  and have the same name.
+  """
+  def equal?(dataset1, dataset2)
+
+  def equal?(%RDF.Dataset{} = dataset1, %RDF.Dataset{} = dataset2) do
+    dataset1 == dataset2
+  end
+
+  def equal?(_, _), do: false
+
+
   defimpl Enumerable do
     def member?(dataset, statement), do: {:ok, RDF.Dataset.include?(dataset, statement)}
     def count(dataset),              do: {:ok, RDF.Dataset.statement_count(dataset)}

lib/rdf/description.ex

@@ -617,6 +617,20 @@ defmodule RDF.Description do
   end
 
 
+  @doc """
+  Checks if two `RDF.Description`s are equal.
+
+  Two `RDF.Description`s are considered to be equal if they contain the same triples.
+  """
+  def equal?(description1, description2)
+
+  def equal?(%RDF.Description{} = description1, %RDF.Description{} = description2) do
+    description1 == description2
+  end
+
+  def equal?(_, _), do: false
+
+
   defimpl Enumerable do
     def member?(desc, triple), do: {:ok, RDF.Description.include?(desc, triple)}
     def count(desc),           do: {:ok, RDF.Description.count(desc)}

lib/rdf/graph.ex

@@ -683,6 +683,21 @@ defmodule RDF.Graph do
   end
 
 
+  @doc """
+  Checks if two `RDF.Graph`s are equal.
+
+  Two `RDF.Graph`s are considered to be equal if they contain the same triples
+  and have the same name. The prefixes of the graph are irrelevant for equality.
+  """
+  def equal?(graph1, graph2)
+
+  def equal?(%RDF.Graph{} = graph1, %RDF.Graph{} = graph2) do
+    clear_prefixes(graph1) == clear_prefixes(graph2)
+  end
+
+  def equal?(_, _), do: false
+
+
   @doc """
   Adds `prefixes` to the given `graph`.
 

test/acceptance/turtle_w3c_test.exs

@@ -53,12 +53,12 @@ defmodule RDF.Turtle.W3C.Test do
 
        test TestSuite.test_title(test_case), %{test_case: test_case} do
          with base = to_string(TestSuite.test_input_file(test_case)) do
-           assert (TestSuite.test_input_file_path(test_case, "Turtle")
-                   |> Turtle.read_file!(base: base)
-                   |> RDF.Graph.clear_prefixes()
-                  ) ==
-                  (TestSuite.test_result_file_path(test_case, "Turtle")
-                   |> NTriples.read_file!)
+           assert RDF.Graph.equal?(
+                    (TestSuite.test_input_file_path(test_case, "Turtle")
+                     |> Turtle.read_file!(base: base)),
+                    (TestSuite.test_result_file_path(test_case, "Turtle")
+                     |> NTriples.read_file!)
+                  )
          end
        end
      end)

test/unit/dataset_test.exs

@@ -739,6 +739,17 @@ defmodule RDF.DatasetTest do
   end
 
 
+  test "equal/2" do
+    assert Dataset.new({EX.S, EX.p, EX.O}) |> Dataset.equal?(Dataset.new({EX.S, EX.p, EX.O}))
+    assert Dataset.new({EX.S, EX.p, EX.O}, name: EX.Dataset1)
+           |> Dataset.equal?(Dataset.new({EX.S, EX.p, EX.O}, name: EX.Dataset1))
+
+    refute Dataset.new({EX.S, EX.p, EX.O}) |> Dataset.equal?(Dataset.new({EX.S, EX.p, EX.O2}))
+    refute Dataset.new({EX.S, EX.p, EX.O}, name: EX.Dataset1)
+           |> Dataset.equal?(Dataset.new({EX.S, EX.p, EX.O}, name: EX.Dataset2))
+  end
+
+
   describe "Enumerable protocol" do
     test "Enum.count" do
       assert Enum.count(Dataset.new(name: EX.foo)) == 0

test/unit/description_test.exs

@@ -358,6 +358,11 @@ defmodule RDF.DescriptionTest do
              %{p: ["Foo"]}
   end
 
+  test "equal/2" do
+    assert Description.new({EX.S, EX.p, EX.O}) |> Description.equal?(Description.new({EX.S, EX.p, EX.O}))
+    refute Description.new({EX.S, EX.p, EX.O}) |> Description.equal?(Description.new({EX.S, EX.p, EX.O2}))
+  end
+
   describe "Enumerable protocol" do
     test "Enum.count" do
       assert Enum.count(Description.new EX.foo) == 0

test/unit/graph_test.exs

@@ -462,6 +462,20 @@ defmodule RDF.GraphTest do
              }
   end
 
+
+  test "equal/2" do
+    assert Graph.new({EX.S, EX.p, EX.O}) |> Graph.equal?(Graph.new({EX.S, EX.p, EX.O}))
+    assert Graph.new({EX.S, EX.p, EX.O}, name: EX.Graph1)
+           |> Graph.equal?(Graph.new({EX.S, EX.p, EX.O}, name: EX.Graph1))
+    assert Graph.new({EX.S, EX.p, EX.O}, prefixes: %{ex: EX})
+           |> Graph.equal?(Graph.new({EX.S, EX.p, EX.O}, prefixes: %{xsd: XSD}))
+
+    refute Graph.new({EX.S, EX.p, EX.O}) |> Graph.equal?(Graph.new({EX.S, EX.p, EX.O2}))
+    refute Graph.new({EX.S, EX.p, EX.O}, name: EX.Graph1)
+           |> Graph.equal?(Graph.new({EX.S, EX.p, EX.O}, name: EX.Graph2))
+  end
+
+
   describe "add_prefixes/2" do
     test "when prefixes already exist" do
       graph = Graph.new(prefixes: %{xsd: XSD}) |> Graph.add_prefixes(ex: EX)