Casting variables in the ruby{} filter

Note that the mutate{} filter contains a convert{} operation, which is very useful.

If you find yourself in ruby for another purpose, you might want to cast the variables while your there.  Here are some examples:

      ruby {
        code => "
          begin
            event['foo'] = event['foo'].to_f
            event['bar'] = event['bar'].to_i
          rescue Exception;
            event['ruby_exception'] = 'cast'
          end
        "
      }