我需要编写一个简单的脚本来加载来自多个文件的数据并以某种方式合并它.但是,鉴于文件可能非常庞大,我想部分加载数据.为此,我决定使用yield.根据示例,我发现我可以使用以下构造用于单个发电机：

$generator = $someClass->load(); //load method uses yield so IT returns generator object
foreach($generator as $i) {
  // do something
}

但是如果我想一次使用两台发电机呢？

$generatorA = $someClass1->load(); //load method uses yield so it returns generator object
$generatorB = $someClass2->load(); //load method uses yield so it returns generator object
foreach($generatorA as $i) {
  // how can I access to resultSet From generatorB here?
}

$aAndB = new ApPEndIterator();
$aAndB->append($generatorA);
$aAndB->append($generatorB);

foreach ($aAndB as $i) {
    ...

$both = new Multipleiterator();
$both->attachIterator($generatorA);
$both->attachIterator($generatorB);

foreach ($both as list($valueA,$valueB)) {
    ...