mapOrNull<TResult extends Object?> method

@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>({ TResult? getItem(ReadOperation<T> value)?, TResult? getItems(ReadListOperation<T> value)?, TResult? getByIds(ReadByIdsOperation<T> value)?, TResult? setItem(WriteOperation<T> value)?, TResult? setItems(WriteListOperation<T> value)?, TResult? delete(DeleteOperation<T> 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( ReadOperation<T> value)?  getItem,TResult? Function( ReadListOperation<T> value)?  getItems,TResult? Function( ReadByIdsOperation<T> value)?  getByIds,TResult? Function( WriteOperation<T> value)?  setItem,TResult? Function( WriteListOperation<T> value)?  setItems,TResult? Function( DeleteOperation<T> value)?  delete,}){
final _that = this;
switch (_that) {
case ReadOperation() when getItem != null:
return getItem(_that);case ReadListOperation() when getItems != null:
return getItems(_that);case ReadByIdsOperation() when getByIds != null:
return getByIds(_that);case WriteOperation() when setItem != null:
return setItem(_that);case WriteListOperation() when setItems != null:
return setItems(_that);case DeleteOperation() when delete != null:
return delete(_that);case _:
  return null;

}
}