*/ public $trace = []; /** @var list> */ private $returns; /** @var int */ private $returnsPos; /** * @param list> $returns */ public function __construct(array $returns = []) { $this->returns = $returns; $this->returnsPos = 0; } public function beforeTraverse(array $nodes): ?array { return $this->traceEvent('beforeTraverse', $nodes); } public function enterNode(Node $node) { return $this->traceEvent('enterNode', $node); } public function leaveNode(Node $node) { return $this->traceEvent('leaveNode', $node); } public function afterTraverse(array $nodes): ?array { return $this->traceEvent('afterTraverse', $nodes); } /** * @param Node|Node[] $param * @return mixed */ private function traceEvent(string $method, $param) { $this->trace[] = [$method, $param]; if ($this->returnsPos < count($this->returns)) { $currentReturn = $this->returns[$this->returnsPos]; if ($currentReturn[0] === $method && $currentReturn[1] === $param) { $this->returnsPos++; return $currentReturn[2]; } } return null; } public function __destruct() { if ($this->returnsPos !== count($this->returns)) { throw new Exception('Expected event did not occur'); } } }