sequenceList method

Option<List<T>> sequenceList()

Turns an Iterable<Option<T>> into an Option<List<T>>. If all elements are Some, it returns a Some<List<T>>. If any element is a None, it returns None.

Implementation

Option<List<T>> sequenceList() {
  final buffer = <T>[];
  for (final e in this) {
    if (e.isNone()) return const None();
    buffer.add(e.unwrap());
  }
  return Some(buffer);
}