Function unstable_runWithPriority

docs/external/js/react.development.js:2668–2689

(priorityLevel, eventHandler)

  }

  function unstable_runWithPriority(priorityLevel, eventHandler) {
    switch (priorityLevel) {
      case ImmediatePriority:
      case UserBlockingPriority:
      case NormalPriority:
      case LowPriority:
      case IdlePriority:
        break;

      default:
        priorityLevel = NormalPriority;
    }

    var previousPriorityLevel = currentPriorityLevel;
    currentPriorityLevel = priorityLevel;

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

  function unstable_next(eventHandler) {
    var priorityLevel;