code: function index($count_all = true) {
  		if (!$this->parent) {
  			return -1;
  		} elseif ($count_all) {
  			return $this->parent->findChild($this);
  		} else{
  			$index = -1;
  			//foreach($this->parent->children as &$c) {
  			//	if (!$c->isTextOrComment()) {
  			//		++$index;
  			//	}
  			//	if ($c === $this) {
  			//		return $index;
  			//	}
  			//}
  
  			foreach(array_keys($this->parent->children) as $k) {
  				if (!$this->parent->children[$k]->isTextOrComment()) {
  					++$index;
  				}
  				if ($this->parent->children[$k] === $this) {
  					return $index;
  				}
  			}
  			return -1;
  		}
  	}
docs: Index of node in parent
  @param bool $count_all True to count all tags, false to ignore text and comments
  @return int -1 if not found