php使用递归实现无限评论回复

/*
        id:回复内容编号
        pid:0 直接回复 大于0追加 （这里存当前回复内容的id）
        vid:回复人的id
        hvid:被回复人的id
        content:回复的内容
        tid:当前的标题Id    
        */
        $cate = array(
        0 => array('id' => 1, 'pid' => 0, 'vid' => 1, 'hvid' => 8, 'content' => '111','tid'=>1),
        1 => array('id' => 2, 'pid' => 0, 'vid' => 2, 'hvid' => 8, 'content' => '222','tid'=>1),
        2 => array('id' => 3, 'pid' => 1, 'vid' => 3, 'hvid' => 2, 'content' => '333','tid'=>1),
        3 => array('id' => 4, 'pid' => 3, 'vid' => 4, 'hvid' => 3, 'content' => '444','tid'=>1),
        4 => array('id' => 5, 'pid' => 2, 'vid' => 5, 'hvid' => 2, 'content' => '555','tid'=>1),
     );

print_r($this->unlimitedForLayer($cate));

//组合一维数组
      public function unlimitedForLevel ($cate, $html = '--', $pid = 0, $level = 0) {
            $arr = array();
            foreach ($cate as $k => $v) {
                if ($v['pid'] == $pid) {
                    $v['level'] = $level + 1;
                    $v['html']  = str_repeat($html, $level);
                    $arr[] = $v;
                    $arr = array_merge($arr, self::unlimitedForLevel($cate, $html, $v['id'], $level + 1));
                }
            }
            return $arr;
        }
        //组合多维数组
         public function unlimitedForLayer ($cate, $name = 'child', $pid = 0) {
            $arr = array();
            foreach ($cate as $v) {
                if ($v['pid'] == $pid) {
                    $v[$name] = self::unlimitedForLayer($cate, $name, $v['id']);
                    $arr[] = $v;
                }
            }
            return $arr;
        }
        //传递一个子分类ID返回所有的父级分类  
        public  function getParents ($cate, $id) {
            $arr = array();
            foreach ($cate as $v) {
                if ($v['id'] == $id) {
                    $arr[] = $v;
                    $arr = array_merge(self::getParents($cate, $v['pid']), $arr); 
                }
            }
            return $arr;
        }
        //传递一个父级分类ID返回所有子分类ID
        public function getChildsId ($cate, $pid) {
            $arr = array();
            foreach ($cate as $v) {
                if ($v['pid'] == $pid) {
                    $arr[] = $v['id'];
                    $arr = array_merge($arr, self::getChildsId($cate, $v['id']));
                }
            }
            return $arr;
        }
        //传递一个父级分类ID返回所有子分类
        public  function getChilds ($cate, $pid) {
            $arr = array();
            foreach ($cate as $v) {
                if ($v['pid'] == $pid) {
                    $arr[] = $v;
                    $arr = array_merge($arr, self::getChilds($cate, $v['id']));
                }
            }
            return $arr;
        }