/*
 * Check if current selector is for a pseudo element
 */
is-pseudoelement() {
  return match(':(before|after)', selector());
}

/*
 * Wrapper for `calc()` with `s` support
 *
 * Examples:
 *   scalc('100% + %s', $var)
 */
scalc(expression, args...) {
  return unquote('calc(' + (expression % args) + ')');
}