HH\Lib\Keyset\filter
Requires the Hack Standard Library to be installed.
Facebook Engineer?
This function is available as Keyset\filter() in Facebook's www repository.
Returns a new keyset containing only the values for which the given predicate
returns true
namespace HH\Lib\Keyset;
function filter<Tv as arraykey>(
Traversable<Tv> $traversable,
?(function(Tv): bool) $value_predicate = NULL,
): keyset<Tv>;
The default predicate is casting the value to boolean.
To remove null values in a typechecker-visible way, see Keyset\filter_nulls().
Time complexity: O(n * p), where p is the complexity of $value_predicate
Space complexity: O(n)
Parameters
Traversable<Tv> $traversable?(function(Tv): bool) $value_predicate = NULL
Returns
keyset<Tv>