A non-recursive and stack overflow safe fibonacci function in PHP

finonacci.php

<?php

function fib() {
	list($x, $y) = [0, 1];
	while(1) {
		yield $y;
		list($x, $y) = [$y, $x + $y];
	}
}

$generator = fib();
$i = 0;
while($i++ < 10) {
	echo $generator->send(null) . "\n";
}