text: # -*- coding: utf-8 -*-
  
  class JsonApiFormatter(object):
  
      def __call__(self, field, operator):
          ret = 'filter[{}]'.format(field)
          if operator:
              ret += '[{}]'.format(operator)
          return ret
  
  class DelimiterFormatter(object):
  
      def __init__(self, delimiter):
          self.delimiter = delimiter
  
      def __call__(self, field, operator):
          parts = [field]
          if operator:
              parts.append(operator)
          return self.delimiter.join(parts)
  
  underscore_formatter = DelimiterFormatter('__')
  