/**
* This method compares the specified object with the current object for order.
*
* @access public
* @static
* @param IHashSet\Type $xs the left operand
* @param IHashSet\Type $ys the object to be compared
* @return ITrit\Type whether the current object is less than,
* equal to, or greater than the specified
* object
*/
public static function compare(IHashSet\Type $xs, IHashSet\Type $ys) : ITrit\Type
{
$x_length = $xs->__size();
$y_length = $ys->__size();
if ($x_length == $y_length) {
$xi = IHashSet\Module::iterator($xs);
foreach ($xi as $x) {
if (!$ys->__hasItem($x)) {
return ITrit\Type::make(strcmp((string) serialize($xs), (string) serialize($ys)));
// order is not "stable"
}
}
return ITrit\Type::zero();
} else {
if ($x_length < $y_length) {
return ITrit\Type::negative();
} else {
// ($x_length > $y_length)
return ITrit\Type::positive();
}
}
}
/**
* This method returns the size of the collection.
*
* @access public
* @final
* @return int the size of the collection
*/
public final function count() : int
{
return $this->xs->__size();
}
