static function rotate($a, $cmp, $from, $mid, $to)
{
$n = null;
if ($from === $mid || $mid === $to) {
return;
}
$n = haxe_ds_ArraySort::gcd($to - $from, $mid - $from);
while ($n-- !== 0) {
$val = $a[$from + $n];
$shift = $mid - $from;
$p1 = $from + $n;
$p2 = $from + $n + $shift;
while ($p2 !== $from + $n) {
$a[$p1] = $a[$p2];
$p1 = $p2;
if ($to - $p2 > $shift) {
$p2 += $shift;
} else {
$p2 = $from + ($shift - ($to - $p2));
}
}
$a[$p1] = $val;
unset($val, $shift, $p2, $p1);
}
}
