use Orisai\ObjectMapper\MappedObject;
use Orisai\ObjectMapper\Attributes\Expect\MappedObjectValue;
use Orisai\ObjectMapper\Attributes\Expect\StringValue;

final class UserInput extends MappedObject
{

	/** @StringValue(notEmpty=true) */
	public string $firstName;

	/** @StringValue(notEmpty=true) */
	public string $lastName;

	/** @MappedObjectValue(UserAddressInput::class) */
	public UserAddressInput $address;

}

use Orisai\ObjectMapper\MappedObject;

final class UserAddressInput extends MappedObject
{
	// ...
}

use Orisai\ObjectMapper\Exception\InvalidData;
use Orisai\ObjectMapper\Printers\ErrorVisualPrinter;
use Orisai\ObjectMapper\Printers\TypeToStringConverter;
use Orisai\ObjectMapper\Processing\DefaultProcessor;

$processor = new DefaultProcessor(...);
$errorPrinter = new ErrorVisualPrinter(new TypeToStringConverter());

$data = [
	'firstName' => 'Tony',
	'lastName' => 'Stark',
	'address' => [],
];

try {
	$user = $processor->process($data, UserInput::class);
} catch (InvalidData $exception) {
	$error = $errorPrinter->printError($exception);
	throw new Exception("Validation failed due to following error:\n$error");
}

echo "User name is: {$user->firstName} {$user->lastName}";