whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>({
  1. TResult? eligible()?,
  2. TResult? refused(
    1. String clause
    )?,
})

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()?  eligible,TResult? Function( String clause)?  refused,}) {final _that = this;
switch (_that) {
case MountEligible() when eligible != null:
return eligible();case MountRefused() when refused != null:
return refused(_that.clause);case _:
  return null;

}
}