refactoring expressions to a module

4 files changed, 27 insertions, 31 deletions

diff --git a/lib/arel.rb b/lib/arel.rb
index d1c2e44567..989ed12c87 100644
--- a/lib/arel.rb
+++ b/lib/arel.rb
@@ -1,6 +1,7 @@
 require 'arel/crud'
 
 require 'arel/version'
+require 'arel/expressions'
 require 'arel/table'
 require 'arel/attributes'
 require 'arel/compatibility/wheres'
diff --git a/lib/arel/attributes/attribute.rb b/lib/arel/attributes/attribute.rb
index 34c1f45ba6..28493d5cba 100644
--- a/lib/arel/attributes/attribute.rb
+++ b/lib/arel/attributes/attribute.rb
@@ -1,6 +1,8 @@
 module Arel
   module Attributes
     class Attribute < Struct.new :relation, :name, :column
+      include Arel::Expressions
+
       def not_eq other
         Nodes::NotEqual.new self, other
       end
@@ -13,26 +15,6 @@ module Arel
         Nodes::In.new self, other
       end
 
-      def count distinct = false
-        Nodes::Count.new [self], distinct
-      end
-
-      def sum
-        Nodes::Sum.new [self], Nodes::SqlLiteral.new('sum_id')
-      end
-
-      def maximum
-        Nodes::Max.new [self], Nodes::SqlLiteral.new('max_id')
-      end
-
-      def minimum
-        Nodes::Min.new [self], Nodes::SqlLiteral.new('min_id')
-      end
-
-      def average
-        Nodes::Avg.new [self], Nodes::SqlLiteral.new('avg_id')
-      end
-
       def gteq right
         Nodes::GreaterThanOrEqual.new self, right
       end
diff --git a/lib/arel/expressions.rb b/lib/arel/expressions.rb
new file mode 100644
index 0000000000..d1fbfd83d9
--- /dev/null
+++ b/lib/arel/expressions.rb
@@ -0,0 +1,23 @@
+module Arel
+  module Expressions
+    def count distinct = false
+      Nodes::Count.new [self], distinct
+    end
+
+    def sum
+      Nodes::Sum.new [self], Nodes::SqlLiteral.new('sum_id')
+    end
+
+    def maximum
+      Nodes::Max.new [self], Nodes::SqlLiteral.new('max_id')
+    end
+
+    def minimum
+      Nodes::Min.new [self], Nodes::SqlLiteral.new('min_id')
+    end
+
+    def average
+      Nodes::Avg.new [self], Nodes::SqlLiteral.new('avg_id')
+    end
+  end
+end
diff --git a/lib/arel/nodes/sql_literal.rb b/lib/arel/nodes/sql_literal.rb
index 7299fb1d45..e5918620d9 100644
--- a/lib/arel/nodes/sql_literal.rb
+++ b/lib/arel/nodes/sql_literal.rb
@@ -1,17 +1,7 @@
 module Arel
   module Nodes
     class SqlLiteral < String
-      def count distinct = false
-        Count.new [self], distinct
-      end
-
-      def sum
-        Nodes::Sum.new [self], Nodes::SqlLiteral.new('sum_id')
-      end
-
-      def maximum
-        Nodes::Max.new [self], Nodes::SqlLiteral.new('max_id')
-      end
+      include Arel::Expressions
     end
   end
 end