Selector Namespace


You can add methods to existing class globally now.
But global changes are evil.

Selector namespace is a feature to encapsulate changes in certain scope.

   $a = "4"
   namespace foo # syntax may change
     class String
       def to_i
         0
       end
     end
     p $a.to_i   # => 0, in this namespace
   end # of namespace
   p $a.to_i     # => 4