adding unary node

9 files changed, 26 insertions, 29 deletions

diff --git a/lib/arel/nodes.rb b/lib/arel/nodes.rb
index 95dcc0480e..c454152d0d 100644
--- a/lib/arel/nodes.rb
+++ b/lib/arel/nodes.rb
@@ -1,4 +1,5 @@
 require 'arel/nodes/node'
+require 'arel/nodes/unary'
 require 'arel/nodes/binary'
 require 'arel/nodes/equality'
 require 'arel/nodes/between'
diff --git a/lib/arel/nodes/group.rb b/lib/arel/nodes/group.rb
index 57a7c579da..a7fa6f170d 100644
--- a/lib/arel/nodes/group.rb
+++ b/lib/arel/nodes/group.rb
@@ -1,11 +1,6 @@
 module Arel
   module Nodes
-    class Group
-      attr_accessor :expr
-
-      def initialize expr
-        @expr = expr
-      end
+    class Group < Arel::Nodes::Unary
     end
   end
 end
diff --git a/lib/arel/nodes/grouping.rb b/lib/arel/nodes/grouping.rb
index d52671f169..18adeae97f 100644
--- a/lib/arel/nodes/grouping.rb
+++ b/lib/arel/nodes/grouping.rb
@@ -1,11 +1,6 @@
 module Arel
   module Nodes
-    class Grouping < Arel::Nodes::Node
-      attr_accessor :expr
-
-      def initialize expression
-        @expr = expression
-      end
+    class Grouping < Arel::Nodes::Unary
     end
   end
 end
diff --git a/lib/arel/nodes/having.rb b/lib/arel/nodes/having.rb
index 1944a84391..6972c58dda 100644
--- a/lib/arel/nodes/having.rb
+++ b/lib/arel/nodes/having.rb
@@ -1,11 +1,6 @@
 module Arel
   module Nodes
-    class Having
-      attr_accessor :expr
-
-      def initialize expr
-        @expr = expr
-      end
+    class Having < Arel::Nodes::Unary
     end
   end
 end
diff --git a/lib/arel/nodes/offset.rb b/lib/arel/nodes/offset.rb
index baa4068d93..d93e46aa1f 100644
--- a/lib/arel/nodes/offset.rb
+++ b/lib/arel/nodes/offset.rb
@@ -1,11 +1,7 @@
 module Arel
   module Nodes
-    class Offset
-      attr_accessor :value
-
-      def initialize value
-        @value = value
-      end
+    class Offset < Arel::Nodes::Unary
+      alias :value :expr
     end
   end
 end
diff --git a/lib/arel/nodes/ordering.rb b/lib/arel/nodes/ordering.rb
index d395c8631d..0a3621cf54 100644
--- a/lib/arel/nodes/ordering.rb
+++ b/lib/arel/nodes/ordering.rb
@@ -1,10 +1,11 @@
 module Arel
   module Nodes
-    class Ordering < Arel::Nodes::Node
-      attr_accessor :expr, :direction
+    class Ordering < Arel::Nodes::Binary
+      alias :expr :left
+      alias :direction :right
 
-      def initialize expression, direction = :asc
-        @expr, @direction = expression, direction
+      def initialize expr, direction = :asc
+        super
       end
 
       def ascending?
diff --git a/lib/arel/nodes/unary.rb b/lib/arel/nodes/unary.rb
new file mode 100644
index 0000000000..edda89e1f0
--- /dev/null
+++ b/lib/arel/nodes/unary.rb
@@ -0,0 +1,11 @@
+module Arel
+  module Nodes
+    class Unary < Arel::Nodes::Node
+      attr_accessor :expr
+
+      def initialize expr
+        @expr = expr
+      end
+    end
+  end
+end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index ae90c0c4b6..abec5317ca 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -97,7 +97,7 @@ module Arel
       end
 
       def visit_Arel_Nodes_Offset o
-        "OFFSET #{visit o.value}"
+        "OFFSET #{visit o.expr}"
       end
 
       # FIXME: this does nothing on SQLLite3, but should do things on other
diff --git a/test/visitors/test_depth_first.rb b/test/visitors/test_depth_first.rb
index 32778f7d4b..8d637c7d75 100644
--- a/test/visitors/test_depth_first.rb
+++ b/test/visitors/test_depth_first.rb
@@ -130,6 +130,9 @@ module Arel
         @visitor.accept stmt
         assert_equal [:a, :b, stmt.columns, :c, stmt], @collector.calls
       end
+
+      def test_offset
+      end
     end
   end
 end