explicitComparator<T> function
Returns an explicit Comparator based on an iterable
of elements.
Implementation
Comparator<T> explicitComparator<T>(Iterable<T> iterable) {
final ranks = <T, int>{};
for (final element in iterable.indexed()) {
ranks[element.value] = element.index;
}
return (a, b) => _rank(ranks, a) - _rank(ranks, b);
}