private static void RecurGetStatesInternal <T>(IRegexFSMState <T> startState, HashSet <IRegexFSMState <T> > states)
{
if (states.Add(startState))
{
foreach (var transition in startState.Transitions.Where(transition => transition.Target != null))
{
RegexFSMUtility.RecurGetStatesInternal(transition.Target, states);
}
}
}
/// <summary>
/// 递归获取指定起始状态开始能达到的所有状态的集合。
/// </summary>
/// <param name="startState">指定的起始状态。</param>
/// <returns>指定起始状态开始能达到的所有状态的集合。</returns>
/// <exception cref="ArgumentNullException"><paramref name="startState"/> 的值为 null 。</exception>
public static IEnumerable <IRegexFSMState <T> > RecurGetStates <T>(this IRegexFSMState <T> startState)
{
if (startState == null)
{
throw new ArgumentNullException(nameof(startState));
}
HashSet <IRegexFSMState <T> > states = new HashSet <IRegexFSMState <T> >();
RegexFSMUtility.RecurGetStatesInternal(startState, states);
return(states);
}