From 95a69d9007860c722632931120c47a2467f51cb5 Mon Sep 17 00:00:00 2001
From: Marcel Otto <marcelotto@gmx.de>
Date: Sun, 11 Oct 2020 01:07:53 +0200
Subject: [PATCH] Add Enumerable protocol implementation for RDF.PropertyMap

---
 lib/rdf/property_map.ex         |  9 +++++++++
 test/unit/property_map_test.exs | 26 +++++++++++++++++++++++---
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/lib/rdf/property_map.ex b/lib/rdf/property_map.ex
index 27cfcd4..3cbd6e4 100644
--- a/lib/rdf/property_map.ex
+++ b/lib/rdf/property_map.ex
@@ -143,6 +143,15 @@ defmodule RDF.PropertyMap do
     end
   end
 
+  defimpl Enumerable do
+    alias RDF.PropertyMap
+    def reduce(%PropertyMap{iris: iris}, acc, fun), do: Enumerable.reduce(iris, acc, fun)
+
+    def member?(%PropertyMap{iris: iris}, mapping), do: Enumerable.member?(iris, mapping)
+    def count(%PropertyMap{iris: iris}), do: Enumerable.count(iris)
+    def slice(_property_map), do: {:error, __MODULE__}
+  end
+
   defimpl Inspect do
     import Inspect.Algebra
 
diff --git a/test/unit/property_map_test.exs b/test/unit/property_map_test.exs
index ae28b31..ae6dc35 100644
--- a/test/unit/property_map_test.exs
+++ b/test/unit/property_map_test.exs
@@ -171,9 +171,6 @@ defmodule RDF.PropertyMapTest do
              PropertyMap.new(Baz: EX.Baz)
   end
 
-  describe "expand_description/2" do
-  end
-
   describe "Access behaviour" do
     test "fetch/2" do
       assert @example_property_map[:foo] == ~I<http://example.com/test/foo>
@@ -197,4 +194,27 @@ defmodule RDF.PropertyMapTest do
                {~I<http://example.com/test/foo>, PropertyMap.delete(@example_property_map, :foo)}
     end
   end
+
+  describe "Enumerable protocol" do
+    test "Enum.count" do
+      assert Enum.count(PropertyMap.new()) == 0
+      assert Enum.count(@example_property_map) == 3
+    end
+
+    test "Enum.member?" do
+      assert Enum.member?(@example_property_map, {:foo, ~I<http://example.com/test/foo>})
+      assert Enum.member?(@example_property_map, {:bar, ~I<http://example.com/test/bar>})
+      assert Enum.member?(@example_property_map, {:Baz, RDF.iri(EX.Baz)})
+      refute Enum.member?(@example_property_map, {:bar, ~I<http://example.com/test/foo>})
+    end
+
+    test "Enum.reduce" do
+      assert Enum.reduce(@example_property_map, [], fn mapping, acc -> [mapping | acc] end) ==
+               [
+                 {:foo, ~I<http://example.com/test/foo>},
+                 {:bar, ~I<http://example.com/test/bar>},
+                 {:Baz, RDF.iri(EX.Baz)}
+               ]
+    end
+  end
 end