/**
 * @template-covariant TStatic of A
 */
abstract class A
{
    /**
     * @return TStatic
     */
    abstract public function returnStatic(): object;
}

/**
 * @template-covariant TStatic of B
 * @extends A<TStatic>
 */
abstract class B extends A
{
}

enum A
{
    case X;
}

var_dump(spl_object_id(new stdClass())); // int(1)
var_dump(spl_object_id(A::X)); // int(1)
var_dump(spl_object_id(new stdClass())); // int(2)

$code = 'enum Mega {';
for ($i = 0; $i < 60_000; ++$i) {
    $code .= "case C{$i};";
}
$code .= '}';
eval($code);
unset($code);

var_dump(memory_get_usage() / 1024 / 1024); // 14.9

for ($i = 0; $i < 60_000; ++$i) {
    constant("Mega::C{$i}");
}

var_dump(memory_get_usage() / 1024 / 1024); // 13.1 😳

final readonly class Importer
{
  private const BATCH_SIZE = 10_000;

  public function __construct(private Connection $connection) {}

  public function import(): void
  {
    foreach ($this->parseBatched() as $batch) {
      $sqlValues = '';
      $values = [];

      foreach ($batch as $value) {
        $sqlValues .= ($sqlValues === '' ? '' : ',') . '(?)';
        $values[] = $value;
      }

      $this->connection->execute(
        'insert into data (val) values ' . $sqlValues,
        $values,
      );
    }
  }

  private function parseBatched(): Generator
  {
    $parsed = new NoRewindIterator($this->parse());

    while ($parsed->valid()) {
      yield new LimitIterator($parsed, limit: self::BATCH_SIZE);
    }
  }

  private function parse(): Generator
  {
    // ...
  }
}

$csv = <<<'CSV'
    data://text/csv,PHP Version,2022-01,2022-07,2023-01,2023-07
    8.0,23.9%,20.6%,16.2%,12.3%
    8.1,9.1%,24.5%,38.8%,39.3%
    8.2,0.0%,0.0%,4.7%,17.2%
    CSV;
$expected = [...];

$parsed = parseCSVFile($csv);

self::assertSame($expected, $parsed);