@function __words($string, $args...) {
  $string: __base-to-string($string);
  $result: ();
  $temp: "";
  $lowercase-letters: "abcdefghijklmnopqrstuvwxyz";
  $uppercase-letters: "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890 ";

  @for $index from 1 through str-length($string) {
    $letter: __char-at($string, $index);
    $letter-prev: __char-at($string, $index - 1);
    $letter-next: __char-at($string, $index + 1);

    @if not(str-index($lowercase-letters, $letter)) and not
      (
        str-index($uppercase-letters, $letter-prev) and
          str-index($uppercase-letters, $letter-next)
      )
    {
      @if (str-length($temp) > 0) {
        $result: append($result, $temp);
        $temp: "";
      }

      @if (str-index($uppercase-letters, $letter) and $letter != " ") {
        $temp: $temp + $letter;
      }
    } @else {
      $temp: $temp + $letter;
    }
  }

  @if (str-length($temp) > 0) {
    $result: append($result, $temp);
  }

  @return $result;
}

/// Splits `$string` into a list of its words.
///
///
/// @access public
/// @group String
/// @param {string} $string [''] - The string to inspect.
/// @returns {List} Returns the words of `$string`.
/// @example scss
/// $foo: _words('fred, barney, & pebbles');
/// // => ('fred', 'barney', 'pebbles')

@function _words($args...) {
  @return call(get-function("__words"), $args...);
}