generators

function getLines($file) {
    $f = fopen($file, 'r');
    if (!$f) throw new Exception();
    while ($line = fgets($f, 1024)) {
        yield strlen($line);
    }
    var_dump($f);
    fclose($f);
    var_dump($f);
}

function getLines_res($f) {
    if (!$f) throw new Exception();
    while ($line = fgets($f, 1024)) {
        yield strlen($line);
    }
}

function getLines_try($file) {
    $f = fopen($file, 'r');
    if (!$f) throw new Exception();
    try {
      while ($line = fgets($f, 1024)) {
        yield strlen($line);
      }
    } catch (Exception $e) {
      var_dump($f);
      fclose($f);
      var_dump($f);
    }
    var_dump($f);
    fclose($f);
    var_dump($f);
}



echo "<pre>";
@Timer::start();
foreach(getLines('xml.xml') as $k => $item){
    echo $k.': '.$item."\n";
    if($k>5){
        echo "break\n";
        break;
    }
}
echo 'Time: '.@Timer::get();

echo PHP_EOL.PHP_EOL;

@Timer::start();
$f = fopen('xml.xml', 'r');
foreach(getLines_res($f) as $k => $item){
    echo $k.': '.$item."\n";
    if($k>5){
        echo "break\n";
    fclose($f);
        break;
    }
}
echo 'Time: '.@Timer::get();


echo PHP_EOL.PHP_EOL;

@Timer::start();
$gen = getLines_try('xml.xml');
foreach($gen as $k => $item){
    echo $k.': '.$item."\n";
    if($k>5){
        echo "break\n";
    $gen->throw(new Exception('break and close!'));
        break;
    }
}
echo 'Time: '.@Timer::get();

echo "</pre>";