@function __string-split($string, $delimiter: "", $guard: null, $args...) {
  @if $guard and __is-iteratee-call($string, $delimiter, $guard) {
    $delimiter: "";
  }

  $string: __to-string($string);

  @if not $delimiter or str-length($delimiter) == 0 or $delimiter == "" {
    @return __to-list($string);
  }

  $delimiter-index: str-index($string, $delimiter);

  @if not $delimiter-index {
    @return append((), $string);
  }

  @return join(
    str-slice($string, 1, $delimiter-index - 1),
    __string-split(
      str-slice($string, $delimiter-index + str-length($delimiter)),
      $delimiter
    )
  );
}

/// Splits a string from indexes of `$delimiter` to a list.
///
/// @access public
/// @group String
/// @param {String} $string - String to split.
/// @param {String} $delimiter [null] - Characters to use for separating the `$string`.
/// @returns {List} Returns list of substrings from split `$string`.
/// @example scss
/// $foo: _split('a--b--c--d--e', '--');
/// // => 'a' 'b' 'c' 'd' 'e'

@function _split($args...) {
  @return call(get-function("__string-split"), $args...);
}