/**
* Reduces the supplied monetary object into a single
* Money object of the supplied currency.
*
* @param \Dough\Money\MoneyInterface $source
* @param string|null $toCurrency
*
* @return Money
*
* @throws \Dough\Exception\InvalidCurrencyException when a supplied currency is
* unknown.
*/
public function reduce(MoneyInterface $source, $toCurrency = null)
{
if (null === $toCurrency) {
$toCurrency = $this->getBaseCurrency();
}
$this->checkCurrencies($toCurrency);
return $source->reduce($this, $toCurrency);
}
/**
* Reduces the supplied monetary object into a single
* Money object.
*
* @param \Dough\Money\MoneyInterface $source
*
* @return \Dough\Money\Money
*/
public function reduce(MoneyInterface $source)
{
return $source->reduce($this);
}
/**
* Subtracts the subtrahend from the money object.
*
* The subtrahend should be passed in as a positive value.
*
* @param MoneyInterface $subtrahend
* @return Sum
*/
public function subtract(MoneyInterface $subtrahend)
{
return $this->plus($subtrahend->times(-1));
}