php、golang无限分类

<?php 
$categories = array(
    array('id'=>1,'name'=>'电脑','pid'=>0),
    array('id'=>2,'name'=>'手机','pid'=>0),
    array('id'=>3,'name'=>'笔记本','pid'=>1),
    array('id'=>4,'name'=>'台式机','pid'=>1),
    array('id'=>5,'name'=>'智能机','pid'=>2), 
    array('id'=>6,'name'=>'功能机','pid'=>2), 
    array('id'=>7,'name'=>'超级本','pid'=>3),
    array('id'=>8,'name'=>'游戏本','pid'=>3),
);

echo "<pre>";
$tree = getDataTree($categories);
print_r($tree);

function getDataTree($rows, $id='id',$pid = 'pid',$child = 'child',$root=0) {
    $tree = array();
    if(is_array($rows)){
        $array = array();
        foreach ($rows as $key=>$item){
            $rows[$key]['level'] = 0;
            $rows[$key]['str'] = '';
            $array[$item[$id]] = &$rows[$key];
        }

        foreach($rows as $key=>$item){
            $parentId = $item[$pid];
            if($root == $parentId){
                $tree[] = &$rows[$key];
            }else{
                if(isset($array[$parentId])){
                    $parent = &$array[$parentId];
                    $rows[$key]['level'] = $array[$parentId]['level']+1;
                    $rows[$key]['str'] = str_repeat("--",$rows[$key]['level']);
                    $parent[$child][] = &$rows[$key];
                }
            }
        }

    }

    return $tree;
}


// 递归
function getTree($data, $parent_id = 0,$level=0)
{
    $tree = array();
    foreach ($data as $k => $v) {
        if ($v["pid"] == $parent_id) {
            unset($data[$k]);
            $v["level"] = $level;
            if (!empty($data)) {
                $children = getTree($data, $v["id"],$v['level']+1);
                if (!empty($children)) {
                    $v["child"] = $children;
                }
            }
            $tree[] = $v;
        }
    }
    return $tree;
}

// model/articleCategory.go
package model

type TreeList struct {
    ID       int
    ParentID int
    Name     string
    //Level    int
    Children []TreeList
}

func GetMenu(menuList []model.TreeList,pid int) []model.TreeList {
    var treeList  []model.TreeList
    for _, v := range menuList {
        if v.ParentID == pid {
            child := GetMenu(menuList,v.ID)
            node := model.TreeList {
                ID: v.ID,
                Name: v.Name,
                ParentID: v.ParentID,
                Children:child,
            }

            //strings.Repeat(s,2)
            treeList = append(treeList, node)
        }
    }
    return treeList
}