text: import { operate } from '../util/lift';
  import { noop } from '../util/noop';
  import { OperatorSubscriber } from './OperatorSubscriber';
  export function sample(notifier) {
      return operate(function (source, subscriber) {
          var hasValue = false;
          var lastValue = null;
          source.subscribe(new OperatorSubscriber(subscriber, function (value) {
              hasValue = true;
              lastValue = value;
          }));
          var emit = function () {
              if (hasValue) {
                  hasValue = false;
                  var value = lastValue;
                  lastValue = null;
                  subscriber.next(value);
              }
          };
          notifier.subscribe(new OperatorSubscriber(subscriber, emit, noop));
      });
  }
  //# sourceMappingURL=sample.js.map