265     function children($idx=-1)  argument
267         if ($idx===-1)
271         if (isset($this->children[$idx])) return $this->children[$idx];
303         $idx = 0;
305         while ($idx<$count && $this!==$this->parent->children[$idx])
307             ++$idx;
309         if (++$idx>=$count)
313         return $this->parent->children[$idx];
320         $idx = 0;
322         while ($idx<$count && $this!==$this->parent->children[$idx])
323             ++$idx;
324         if (--$idx<0) return null;
325         return $this->parent->children[$idx];
502     function find($selector, $idx=null, $lowercase=false)  argument
546         if (is_null($idx)) return $found;
547         else if ($idx<0) $idx = count($found) + $idx;
548         return (isset($found[$idx])) ? $found[$idx] : null;
948     function getElementsById($id, $idx=null) {return $this->find("#$id", $idx);}  argument
950     function getElementsByTagName($name, $idx=null) {return $this->find($name, $idx);}  argument
952     function childNodes($idx=-1) {return $this->children($idx);}  argument
1111     function find($selector, $idx=null, $lowercase=false)  argument
1113         return $this->root->find($selector, $idx, $lowercase);
1626             $idx = ($remove_tag) ? 0 : 1;
1627             $this->noise[$key] = $matches[$i][$idx][0];
1628 …$this->doc = substr_replace($this->doc, $key, $matches[$i][$idx][1], strlen($matches[$i][$idx][0])…
1709     function childNodes($idx=-1) {return $this->root->childNodes($idx);}  argument
1715     function getElementsById($id, $idx=null) {return $this->find("#$id", $idx);}  argument
1717     function getElementsByTagName($name, $idx=-1) {return $this->find($name, $idx);}  argument