whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  1. TResult? $default(
    1. bool? prioritizeIPv6,
    2. int? tryDelayMs,
    3. int? interleave,
    4. int? maxConcurrentTry,
    )?
)

A variant of when that fallback to returning null

It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return null;
}

Implementation

@optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  TResult? Function(bool? prioritizeIPv6, int? tryDelayMs, int? interleave,
          int? maxConcurrentTry)?
      $default,
) {
  final _that = this;
  switch (_that) {
    case _HappyEyeballsConfig() when $default != null:
      return $default(_that.prioritizeIPv6, _that.tryDelayMs,
          _that.interleave, _that.maxConcurrentTry);
    case _:
      return null;
  }
}