PX to REM Sass conversion utility

conversion.scss

// ===================================================
// Rem Conversion
// ===================================================

$pixelBase : 16;

@function parseInt($n) {
  @return $n / ($n * 0 + 1);
}

@function u($values){

  $list: ();

  @each $value in $values {

    // If a 0 or auto just add it to the list
    @if $value == 0 or type-of($value) != "number" {
      $list: append($list, $value);
    }

    // Else split the unit and value
    @else {

      $unit : unit($value);
      $val  : parseInt($value);

      // Convert rem to px if $old-ie is true
      @if ($old-ie) and ($unit == 'rem') {
        $list: append($list, ($val * $pixelBase) + px);
      }

      // Convert px to rem
      @else if($unit == 'px') {
        $list: append($list, ($val / $pixelBase) + rem);
      }

      // Leave rems alone
      @else {
        $list: append($list, $value);
      }

      // Return a warning for unknown units
      @else {
        @warn 'There is no unit conversion for #{$unit}';
      }

    }

  }

  @return $list();

}