/**
 * set the start and end direction based on
 * $direction variable
 */
setDirection(state)
  if ($direction == 'ltr')
    return state == 'start' ? left : right

  return state == 'start' ? right : left

multiple(value, times)
  if ($cssVar == true)
    return 'calc(%s * %s)' % (value times)

  return value * times

_calc()
  if ($cssVar == true)
    return arguments[1]
  return convert(arguments)
  

unitRes(min, max)
  'calc( %spx + (%s - %s) * (100vw - %s) / %s )' % (min max min $responsiveMin $responsiveRatio)