Break Ordering into Ascending/Descending nodes, allow reversal

4 files changed, 48 insertions, 15 deletions

diff --git a/lib/arel/nodes/ascending.rb b/lib/arel/nodes/ascending.rb
new file mode 100644
index 0000000000..bca00a8339
--- /dev/null
+++ b/lib/arel/nodes/ascending.rb
@@ -0,0 +1,23 @@
+module Arel
+  module Nodes
+    class Ascending < Ordering
+
+      def reverse
+        Descending.new(expr)
+      end
+
+      def direction
+        :asc
+      end
+
+      def ascending?
+        true
+      end
+
+      def descending?
+        false
+      end
+
+    end
+  end
+end
diff --git a/lib/arel/nodes/descending.rb b/lib/arel/nodes/descending.rb
new file mode 100644
index 0000000000..d886bdcb5f
--- /dev/null
+++ b/lib/arel/nodes/descending.rb
@@ -0,0 +1,23 @@
+module Arel
+  module Nodes
+    class Descending < Ordering
+
+      def reverse
+        Ascending.new(expr)
+      end
+
+      def direction
+        :desc
+      end
+
+      def ascending?
+        false
+      end
+
+      def descending?
+        true
+      end
+
+    end
+  end
+end
diff --git a/lib/arel/nodes/ordering.rb b/lib/arel/nodes/ordering.rb
index 0a3621cf54..efb4d18ae4 100644
--- a/lib/arel/nodes/ordering.rb
+++ b/lib/arel/nodes/ordering.rb
@@ -1,20 +1,6 @@
 module Arel
   module Nodes
-    class Ordering < Arel::Nodes::Binary
-      alias :expr :left
-      alias :direction :right
-
-      def initialize expr, direction = :asc
-        super
-      end
-
-      def ascending?
-        direction == :asc
-      end
-
-      def descending?
-        direction == :desc
-      end
+    class Ordering < Unary
     end
   end
 end
diff --git a/lib/arel/nodes/unary.rb b/lib/arel/nodes/unary.rb
index 5c4add4792..4688fff623 100644
--- a/lib/arel/nodes/unary.rb
+++ b/lib/arel/nodes/unary.rb
@@ -18,6 +18,7 @@ module Arel
       Not
       Offset
       On
+      Ordering
       Top
       Lock
       DistinctOn