/**
* Construct a new Reduce Collector giving the reduce function.
*
* @param callable|BiFunction $fn Reduce function.
*
* @throws \InvalidArgumentException If function is not callable or BiFunction
*/
public function __construct($fn)
{
parent::__construct();
if ($fn instanceof BiFunction) {
$this->func = $fn;
} else {
if (is_callable($fn)) {
$this->callable = $fn;
} else {
throw new \InvalidArgumentException('Parameter must be callable or BiFunction.');
}
}
}
/**
* Instanciate a new MinCollector using specific comparator function.
* If comparator function is not set, use default comparator.
*
* @param callable|Comparator $cmp Comparator method / object.
*
* @throws \InvalidArgumentException If parameter is not callable or instance of Comparator.
*/
public function __construct($cmp = null)
{
parent::__construct();
if ($cmp === null) {
$this->callable = function ($o1, $o2) {
if ($o1 == $o2) {
return 0;
}
return $o1 < $o2 ? -1 : 1;
};
} else {
if ($cmp instanceof Comparator) {
$this->comparator = $cmp;
} else {
if (is_callable($cmp)) {
$this->callable = $cmp;
} else {
throw new \InvalidArgumentException('Parameter must be callable or Comparator.');
}
}
}
}