HH\Lib\Keyset\flatten
Returns a new keyset formed by joining the values within the given Traversables into a keyset
namespace HH\Lib\Keyset;
function flatten<Tv as arraykey>(
Traversable<Container<Tv>> $traversables,
): keyset<Tv>;
For a fixed number of Traversables, see Keyset\union().
Time complexity: O(n), where n is the combined size of all the
$traversables
Space complexity: O(n), where n is the combined size of all the
$traversables
Parameters
Traversable<Container<Tv>>$traversables
Returns
keyset<Tv>
Examples
$example_set = vec[keyset[1,2,3,4,5],keyset[98, 99]];
$result = Keyset\flatten($example_set);
print_r($result);
//result: keyset[1,2,3,4,5,98,99]
$example_set = vec[vec[1,2,3,4,5,5,5,5]];
$result = Keyset\flatten($example_set);
print_r($result);
//result: keyset[1,2,3,4,5]
$example_set = vec[];
$result = Keyset\flatten($example_set);
print_r($result);
//result: keyset[]