@function __trunc($string, $options: null, $guard: null, $omission: null, $length: null, $separator: null) {
    @if ($guard and __is-iteratee-call($string, $options, $guard)) {
        $options: null;
    }

    $length: __either($length, __const('DEFAULT_TRUNC_LENGTH'));
    $omission: __either($omission, __const('DEFAULT_TRUNC_OMISSION'));
    $separator: __either($separator, null);

    @if $options != null {
        @if (__is-map($options)) {
            $separator: if(
                map-has-key($options, 'separator'),
                __get($options, 'separator'),
                $separator);
            $length: if(
                map-has-key($options, 'length'),
                __get($options, 'length'),
                $length);
            $omission: if(
                map-has-key($options, 'omission'),
                __base-to-string(__get($options, 'omission')),
                $omission);
        } @else {
            $length: __parse-int($options);
        }
    }

    $string: __base-to-string($string);

    @if ($length >= str-length($string)) {
        @return $string;
    }

    $end: $length - str-length($omission);

    @if ($end < 1) {
        @return $omission;
    }

    $result: str-slice($string, 0, $end);

    @if ($separator == null) {
        @return $result + $omission;
    }

    @if (__string-index-of($string, $separator, $end) != $end) {
        $index: __string-last-index-of($result, $separator);

        @if ($index > -1) {
            $result: str-slice($result, 0, $index - 1);
        }
    }

    @return $result + $omission;
}


/// Truncates `$string` if it is longer than the given maximum string length.
/// The last characters of the truncated string are replaced with the omission
/// string which defaults to "...".
///
///
/// @access public
/// @group String
/// @param {string} $string [''] - The string to truncate.
/// @param {Map|number} $options [null] - The options object or maximum string length.
/// @param {number} $length [30] - The maximum string length.
/// @param {string} $omission ['...'] - The string to indicate text is omitted.
/// @param {string} $separator [null] - The separator pattern to truncate to.
/// @returns {string} Returns the truncated string.
/// @example scss
/// $foo: _trunc('hi-diddly-ho there, neighborino');
/// // => 'hi-diddly-ho there, neighbo...'
/// 
/// $foo: _trunc('hi-diddly-ho there, neighborino', 24);
/// // => 'hi-diddly-ho there, n...'
/// 
/// $foo: _trunc('hi-diddly-ho there, neighborino',
///   $length: 24,
///   $separator: ' '
/// );
/// // => 'hi-diddly-ho there,...'
///
/// $foo: _trunc('hi-diddly-ho there, neighborino', 
///   $omission: ' (...)'
/// );
/// // => 'hi-diddly-ho there, neig (...)'

@function _trunc($string, $options: null, $guard: null, $omission: null, $length: null, $separator: null) {
    @return call(get-function('__trunc'), $string, $options, $guard, $omission, $length, $separator);
}