sequenceSet method
Turns an Iterable<Option<T>> into an Option<Set<T>>.
If all elements are Some, it returns a Some<Set<T>>. If any element
is a None, it returns None.
Implementation
Option<Set<T>> sequenceSet() {
final buffer = <T>{};
for (final e in this) {
switch (e) {
case Some(value: final v):
buffer.add(v);
case None():
return const None();
}
}
return Some(buffer);
}