single property Null safety

SpeechGrammar single

Checks that this iterable has only one element, and returns that element.

Throws a StateError if this is empty or has more than one element.


SpeechGrammar get single {
  int len = this.length;
  if (len == 1) {
    return JS('SpeechGrammar', '#[0]', this);
  if (len == 0) throw new StateError("No elements");
  throw new StateError("More than one element");