Simple generator in PHP

simple_generator.php

<?php

declare(strict_types=1);

function simpleGenerator() {
  echo "The generator begins\n"; 

  for ($i = 0; $i < 3; ++$i) {
    yield $i;
    echo "Yielded $i\n";
  }

  echo "The generator ends\n"; 
}

// foreach (simpleGenerator() as $v){}

$generator = simpleGenerator();

// while ($generator->valid()) {
//     echo "Received {$generator->current()}\n";
//     $generator->next();
// }

echo "Received {$generator->current()}\n";
$generator->next();

echo "Received {$generator->current()}\n";
$generator->next();

echo "Received {$generator->current()}\n";
$generator->next();

/*
Output:

The generator begins
Received 0
Yielded 0
Received 1
Yielded 1
Received 2
Yielded 2
The generator ends
*/