# File lib/ruote/exp/fe_filter.rb, line 599
    def block_filter

      return nil if tree.last.empty?

      tree.last.collect { |line|

        next 'or' if line.first == 'or'

        rule = line[1].remap { |(k, v), h|
          if v == nil
            h['field'] = k
          else
            h[k] = v
          end
        }

        rule['field'] ||= line.first

        rule
      }
    end