/**
* This method computes the nth factorial number.
*
* @access public
* @static
* @param IInteger\Type $n the operand
* @return IInteger\Type the result
*/
public static function factorial(IInteger\Type $n) : IInteger\Type
{
return IInteger\Module::eq($n, IInteger\Type::zero())->unbox() ? IInteger\Type::one() : IInteger\Module::multiply($n, IInteger\Module::factorial(IInteger\Module::decrement($n)));
}
/**
* This method tests the "multiply" method.
*
* @dataProvider data_multiply
*/
public function test_multiply(array $provided, array $expected)
{
$p0 = IInteger\Module::multiply(IInteger\Type::box($provided[0]), IInteger\Type::box($provided[1]));
$e0 = $expected[0];
$this->assertInstanceOf('\\Saber\\Data\\IInteger\\Type', $p0);
$this->assertSame($e0, $p0->unbox());
}
