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

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

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


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