@function str-replace($string, $search, $replace: '') {
  $index: str-index($string, $search);

  @if $index {
    $start: str-slice($string, 1, $index - 1);
    $end: str-replace(str-slice($string, $index + str-length($search)), $search, $replace);

    @return $start + $replace + $end;
  }

  @return $string;
}

@function str-fr($selector, $name, $i: '') {
  @return str-replace(str-replace($selector, '<name>', $name), '<i>', $i);
}

@function str-fe($selector, $name, $noProc, $i: '') {
  @if $noProc {
    @return str-fr($selector, $name, $i);
  }

  @return join(str-fr($selector, '', $i), str-fr($selector, $name, $i), $separator: comma);
}