mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  1. TResult? messageView(
    1. UMessageViewReplyToMessageView value
    )?,
  2. TResult? deletedMessageView(
    1. UMessageViewReplyToDeletedMessageView value
    )?,
  3. TResult? messageBeforeUserJoinedGroupView(
    1. UMessageViewReplyToMessageBeforeUserJoinedGroupView value
    )?,
  4. TResult? unknown(
    1. UMessageViewReplyToUnknown 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( UMessageViewReplyToMessageView value)?  messageView,TResult? Function( UMessageViewReplyToDeletedMessageView value)?  deletedMessageView,TResult? Function( UMessageViewReplyToMessageBeforeUserJoinedGroupView value)?  messageBeforeUserJoinedGroupView,TResult? Function( UMessageViewReplyToUnknown value)?  unknown,}){
final _that = this;
switch (_that) {
case UMessageViewReplyToMessageView() when messageView != null:
return messageView(_that);case UMessageViewReplyToDeletedMessageView() when deletedMessageView != null:
return deletedMessageView(_that);case UMessageViewReplyToMessageBeforeUserJoinedGroupView() when messageBeforeUserJoinedGroupView != null:
return messageBeforeUserJoinedGroupView(_that);case UMessageViewReplyToUnknown() when unknown != null:
return unknown(_that);case _:
  return null;

}
}