Online PHP editor | refs for VG4TN

<?php if (!function_exists('interface_exists')) { die('PHP version too old'); } $throwables = listThrowableClasses(); $throwablesPerParent = splitInParents($throwables); printTree($throwablesPerParent); if (count($throwablesPerParent) !== 0) { die('ERROR!!!'); } function listThrowableClasses() { $result = []; $throwableExists = interface_exists('Throwable'); if ($throwableExists) { foreach (get_declared_classes() as $cn) { $implements = class_implements($cn); if (isset($implements['Throwable'])) { $result[] = $cn; } } } if (!$throwableExists || empty($result)) { foreach (get_declared_classes() as $cn) { if ($cn === 'Exception' || is_subclass_of($cn, 'Exception')) { $result[] = $cn; } } } return $result; } function splitInParents($classes) { $result = []; foreach ($classes as $cn) { $parent = (string) get_parent_class($cn); if (isset($result[$parent])) { $result[$parent][] = $cn; } else { $result[$parent] = [$cn]; } } return $result; } function printTree(&$tree) { if (!isset($tree[''])) { die('No root classes!!!'); } printLeaves($tree, '', 0); } function printLeaves(&$tree, $parent, $level) { if (isset($tree[$parent])) { $leaves = $tree[$parent]; unset($tree[$parent]); natcasesort($leaves); $leaves = array_values($leaves); $count = count($leaves); for ($i = 0; $i < $count; ++$i) { $leaf = $leaves[$i]; echo str_repeat(' ', $level), $leaf, "\n"; printLeaves($tree, $leaf, $level + 1); } } }