Returns a MutableSet containing the values of the current MutableSet up to but not including the first value that produces false when passed to the specified callback

public function takeWhile(
  (function(Tv):bool) $fn,
): MutableSet<Tv>;

The returned MutableSet will always be a proper subset of the current MutableSet.


  • (function(Tv):bool) $fn - The callback that is used to determine the stopping condition.

Return Values