1 files changed, 23 insertions, 0 deletions
diff --git a/lib/arel/algebra/primitives/ordering.rb b/lib/arel/algebra/primitives/ordering.rb
new file mode 100644
index 0000000000..3efb4c6280
--- /dev/null
+++ b/lib/arel/algebra/primitives/ordering.rb
@@ -0,0 +1,23 @@
+module Arel
+  class Ordering
+    delegate :relation, :to => :attribute
+
+    def bind(relation)
+      self.class.new(attribute.bind(relation))
+    end
+
+    def to_ordering
+      self
+    end
+  end
+
+  class Ascending  < Ordering
+    attributes :attribute
+    deriving :initialize, :==
+  end
+  
+  class Descending < Ordering
+    attributes :attribute
+    deriving :initialize, :==
+  end
+end