selectLogic<T> method Null safety

Implementation

static T selectLogic<T>(Object choice, Map<Object, T> cases) {
  // This will work if choice is a string, or if it's e.g. an
  // enum and the map uses the enum values as choices.
  var exact = cases[choice];
  if (exact != null) return exact;
  // If it didn't match exactly, take the toString and
  // take the part after the period. We need to do this
  // because enums print as 'EnumType.enumName' and periods
  // aren't acceptable in ICU select choices.
  var stringChoice = '$choice'.split('.').last;
  var stringMatch = cases[stringChoice];
  if (stringMatch != null) return stringMatch;
  var other = cases['other'];
  if (other == null) {
    throw ArgumentError("The 'other' case must be specified");
  }
  return other;
}