* Support for bitwise operations as infix operators. Tests included.

*** Individual commit messages included below ***
* Preliminary support for bitwise operations as infix operators.  Tests to follow.

* Added bitwise xor, shift left and shift right operators

* Fixed the BitwiseOr class so it uses the :| operator instead of :&
* All the methods for the bitwise operators in the Arel::Math module now wrap them up in Arel::Nodes::Grouping so the operation becomes isolated like addition and subtraction
* Preliminary set of tests for the new operators

* Updated README with examples of bitwise operations

* Added a new UnaryOperation class which is a riff on the InfixOperation class
* Added tests for UnaryOperation (inspired by InfixOperation tests)
* Added the bitwise not (~) operator as a UnaryOperation
* Added tests for the bitwise not operator

* Added documentation for the bitwise not operator

* Updated gemspec using `rake arel.gemspec`

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 598bf2d984..80bea56ce6 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -801,6 +801,11 @@ module Arel
       alias :visit_Arel_Nodes_Multiplication :visit_Arel_Nodes_InfixOperation
       alias :visit_Arel_Nodes_Division       :visit_Arel_Nodes_InfixOperation
 
+      def visit_Arel_Nodes_UnaryOperation o, collector
+        collector << " #{o.operator} "
+        visit o.expr, collector
+      end
+
       def visit_Array o, collector
         inject_join o, collector, ", "
       end