function diff()

in src/vec/select.php [27:45]

• 19 lines of code
• 5 McCabe index (conditional complexity)

function diff<Tv1 as arraykey, Tv2 as arraykey>(
  Traversable<Tv1> $first,
  Traversable<Tv2> $second,
  Container<Tv2> ...$rest
)[]: vec<Tv1> {
  if (!$first) {
    return vec[];
  }
  if (!$second && !$rest) {
    return cast_clear_legacy_array_mark($first);
  }
  $union = !$rest
    ? keyset($second)
    : Keyset\union($second, ...$rest);
  return filter(
    $first,
    ($value) ==> !C\contains_key($union, $value),
  );
}