function get_the_category_list( $separator = '', $parents = '', $post_id = false ) {
  global $wp_rewrite;

  if ( ! is_object_in_taxonomy( get_post_type( $post_id ), 'category' ) ) {
    
/** This filter is documented in wp-includes/category-template.php */
    return apply_filters( 'the_category', '', $separator, $parents );
  }

  
/**
 * Filters the categories before building the category list.
 *
 * @since 4.4.0
 *
 * @param WP_Term[] $categories An array of the post's categories.
 * @param int|false $post_id    ID of the post to retrieve categories for.
 *                              When `false`, defaults to the current post in the loop.
 */
  $categories = apply_filters( 'the_category_list', get_the_category( $post_id ), $post_id );

  if ( empty( $categories ) ) {
    
/** This filter is documented in wp-includes/category-template.php */
    return apply_filters( 'the_category', __( 'Uncategorized' ), $separator, $parents );
  }

  $rel = ( is_object( $wp_rewrite ) && $wp_rewrite->using_permalinks() ) ? 'rel="category tag"' : 'rel="category"';

  $thelist = '';
  if ( '' === $separator ) {
    $thelist .= '<ul class="post-categories">';
    foreach ( $categories as $category ) {
      $thelist .= "\n\t<li>";
      switch ( strtolower( $parents ) ) {
        case 'multiple':
          if ( $category->parent ) {
            $thelist .= get_category_parents( $category->parent, true, $separator );
          }
          $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name . '</a></li>';
          break;
        case 'single':
          $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '"  ' . $rel . '>';
          if ( $category->parent ) {
            $thelist .= get_category_parents( $category->parent, false, $separator );
          }
          $thelist .= $category->name . '</a></li>';
          break;
        case '':
        default:
          $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name . '</a></li>';
      }
    }
    $thelist .= '</ul>';
  } else {
    $i = 0;
    foreach ( $categories as $category ) {
      if ( 0 < $i ) {
        $thelist .= $separator;
      }
      switch ( strtolower( $parents ) ) {
        case 'multiple':
          if ( $category->parent ) {
            $thelist .= get_category_parents( $category->parent, true, $separator );
          }
          $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name . '</a>';
          break;
        case 'single':
          $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>';
          if ( $category->parent ) {
            $thelist .= get_category_parents( $category->parent, false, $separator );
          }
          $thelist .= "$category->name</a>";
          break;
        case '':
        default:
          $thelist .= '<a href="' . esc_url( get_category_link( $category->term_id ) ) . '" ' . $rel . '>' . $category->name . '</a>';
      }
      ++$i;
    }
  }

  
/**
 * Filters the category or list of categories.
 *
 * @since 1.2.0
 *
 * @param string $thelist   List of categories for the current post.
 * @param string $separator Separator used between the categories.
 * @param string $parents   How to display the category parents. Accepts 'multiple',
 *                          'single', or empty.
 */
  return apply_filters( 'the_category', $thelist, $separator, $parents );
}