/**
* Concatenates one or more foreach-able object into an Iterator.
* If no objects provided, returns an empty iterator.
* \AppendIterators provided will be deep copied.
* This means changes to \AppendIterator parameters will not be reflected
* in the resulting \Iterator.
* @return \Iterator
*/
public static function concat()
{
$argCount = \func_num_args();
if ($argCount === 0) {
return new \EmptyIterator();
} elseif ($argCount === 1) {
return Iterators::ensureIsIterator(\func_get_args()[0]);
} else {
$retval = new \AppendIterator();
//Workaround for AppendIterator bugs
//https://bugs.php.net/bug.php?id=49104
//https://bugs.php.net/bug.php?id=62212
$retval->append(new \ArrayIterator([0]));
unset($retval->getArrayIterator()[0]);
$recursiveAttach = static function ($iter) use(&$recursiveAttach, $retval) {
foreach ($iter as $concatedIter) {
if ($concatedIter instanceof \AppendIterator) {
$recursiveAttach($concatedIter->getArrayIterator());
} elseif ($concatedIter instanceof \EmptyIterator) {
//Do not add it.
} else {
$retval->append($concatedIter);
}
}
return $retval;
};
return (new \Yasca\Core\FunctionPipe())->wrap(\func_get_args())->pipe([Iterators::_class, 'ensureIsIterator'])->pipe([Iterators::_class, 'select'], [Iterators::_class, 'ensureIsIterator'])->pipe($recursiveAttach)->unwrap();
}
}
public function from($values){
if ($this->iterator === null){
$this->iterator = Iterators::ensureIsIterator($values);
//TODO: More intelligent handling of RecursiveIterators
if ($this->iterator instanceof \RecursiveIterator){
$this->iterator = new \RecursiveIteratorIterator($this->iterator);
}
} else {
throw new IteratorException('Iterator already assigned');
}
return $this;
}