Function unstable_next

docs/external/js/react.development.js:2691–2716

(eventHandler)

  }

  function unstable_next(eventHandler) {
    var priorityLevel;

    switch (currentPriorityLevel) {
      case ImmediatePriority:
      case UserBlockingPriority:
      case NormalPriority:
        // Shift down to normal priority
        priorityLevel = NormalPriority;
        break;

      default:
        // Anything lower than normal priority should remain at the current level.
        priorityLevel = currentPriorityLevel;
        break;
    }

    var previousPriorityLevel = currentPriorityLevel;
    currentPriorityLevel = priorityLevel;

    try {
      return eventHandler();
    } finally {
      currentPriorityLevel = previousPriorityLevel;
    }
  }

  function unstable_wrapCallback(callback) {
    var parentPriorityLevel = currentPriorityLevel;