private function update_current_iterator()
{
$this->current_iterator = $this->chain->valid() ? Crankshaft::ToIterator($this->chain->current()) : null;
if ($this->current_iterator !== null) {
$this->current_iterator->rewind();
}
}
public function setup()
{
$this->seen = Crankshaft::Set();
$this->inner_iterator->rewind();
}
public function __construct($traversable, $map_fn)
{
Crankshaft::AssertCallable($map_fn);
parent::__construct($traversable);
$this->map_fn = $map_fn;
}
/**
* Internal: Used to implement max() and min().
*/
private function optimal($is_better_fn, $key_fn = null)
{
Crankshaft::AssertCallable($is_better_fn);
if ($key_fn === null) {
$key_fn = 'Thumbtack\\Crankshaft\\Crankshaft::Identity';
} else {
Crankshaft::AssertCallable($key_fn);
}
$initializing = true;
$result = null;
$best_key = null;
foreach ($this as $value) {
$key = call_user_func($key_fn, $value);
if ($initializing) {
$initializing = false;
$current_value_is_better = true;
} else {
$current_value_is_better = call_user_func($is_better_fn, $best_key, $key);
}
if ($current_value_is_better) {
$result = $value;
$best_key = $key;
}
}
if ($initializing) {
throw new EmptyIterableError('Cannot take the max or min of an empty iterable.');
}
return $result;
}
public function __construct(\Iterator $iterator, $filter_fn)
{
Crankshaft::AssertCallable($filter_fn);
parent::__construct($iterator);
$this->filter_fn = $filter_fn;
}