    # File lib/compass/sass_extensions/functions/constants.rb, line 11
        def opposite_position(position)
          position = unless position.is_a?(Sass::Script::List)
            Sass::Script::List.new([position], :space)
          else
            Sass::Script::List.new(position.value.dup, position.separator)
          end
          position.value.map! do |pos|
            if pos.is_a? Sass::Script::String
              opposite = case pos.value
              when "top" then "bottom"
              when "bottom" then "top"
              when "left" then "right"
              when "right" then "left"
              when "center" then "center"
              else
                Compass::Util.compass_warn("Cannot determine the opposite position of: #{pos}")
                pos.value
              end
              Sass::Script::String.new(opposite)
            elsif pos.is_a? Sass::Script::Number
              if pos.numerator_units == ["%"] && pos.denominator_units == []
                Sass::Script::Number.new(100-pos.value, ["%"])
              else
                Compass::Util.compass_warn("Cannot determine the opposite position of: #{pos}")
                pos
              end
            else
              Compass::Util.compass_warn("Cannot determine the opposite position of: #{pos}")
              pos
            end
          end
          if position.value.size == 1
            position.value.first
          else
            position
          end
        end