rank property
What's the rank of this card? Note that we use a shift on the number value; that's why the numbers are important. Note that jokers do not have rank or suit.
Implementation
Rank? get rank {
if (index < Card.LowAceOfClubs.index || index > Card.AceOfSpades.index) {
return null;
}
return Rank.values[index >> 2];
}