infinite_tree.php
<?php
public static function infiniteTree($data,$parent_index='parent_id',$data_index='id',$child_name='child'){
$items = [];
foreach ($data as $d){
$items[$d[$data_index]] = $d;
if(!isset($d[$parent_index]) || !isset($d[$data_index]) || isset($d[$child_name])){
return false;
}
}
$tree = [];$n=0;
foreach($items as $item){
if(isset($items[$item[$parent_index]])){
$items[$item[$parent_index]][$child_name][] = &$items[$item[$data_index]];
}else{
$tree[$n++] = &$items[$item[$data_index]];
}
}
return $tree;
}