mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  1. TResult? newMessageArrived(
    1. MessengerExternalEventNewMessageArrived value
    )?,
})

A variant of map that fallback to returning null.

It is equivalent to doing:

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

Implementation

@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>({TResult? Function( MessengerExternalEventNewMessageArrived value)?  newMessageArrived,}){
final _that = this;
switch (_that) {
case MessengerExternalEventNewMessageArrived() when newMessageArrived != null:
return newMessageArrived(_that);case _:
  return null;

}
}