/// <summary>
/// 计算actionTable，产生下一步的ItemSet
/// </summary>
private void CalcAction()
{
foreach (Item project in this.items)
{
if (project.Type == ProjectType.Convention)
{
BuildConvertionAction(project); //规约项
}
else
{
BuildGotoAction(project); //移进项
}
}
//检查生产的GotoAction所指的项目是否存在
foreach (var GotoActionItem in actionTable.Where(c => c.Value.GetType() == typeof(GotoAction)))
{
GotoAction gotoAction = (GotoAction)GotoActionItem.Value;
bool exist = false;
foreach (ItemSet itemSet in this.family.AllItemSet)
{
if (gotoAction.ItemSet.IsSameWith(itemSet))// 已经存在，直接指向已有的项目
{
gotoAction.ItemSet = itemSet;
exist = true;
break;
}
}
if (!exist) //将转移后的ItemSet注册到family中，family将会调用CaluClosure计算闭包
{
this.family.Register(gotoAction.ItemSet);
}
}
}
public void Analyze()
{
Item firstItem = new Item()
{
Rule = grammer.GrammerRuleSet[0],
DotPosition = 0,
IsCore = true,
FowardSearch = new List <VertexTerminator>()
{
VertexTerminator.End
}
};
ItemSet firstItemSet = new ItemSet();
firstItemSet.AddItem(firstItem);
ItemFamily itemFamily = new ItemFamily(grammer);
itemFamily.FirstItemSet = firstItemSet;
itemFamily.Register(firstItemSet);
Queue <ItemSet> queue = new Queue <ItemSet>();
queue.Enqueue(firstItemSet);
int maxIndex = 0;
while (queue.Count > 0)
{
ItemSet currentItemSet = queue.Dequeue();
foreach (var actionItem in currentItemSet.ActionTable)
{
var v = actionItem.Key;
var action = actionItem.Value;
if (action.GetType() == typeof(GotoAction))
{
GotoAction gotoAction = (GotoAction)action;
if (gotoAction.ItemSet.Index > maxIndex)
{
queue.Enqueue(gotoAction.ItemSet);
}
maxIndex = Math.Max(maxIndex, gotoAction.ItemSet.Index);
}
}
}
this.ItemFamily = itemFamily;
}
private void BuildGotoAction(Item project)
{
GotoAction action = new GotoAction(); //移进
Vertex vert = project.AfterDot(0);
Item proAfterShift = project.Shift();
proAfterShift.IsCore = true;
if (actionTable.ContainsKey(vert))
{
if (actionTable[vert].IsConflicWith(action))
{
throw new Exception(String.Format("在 {0} 遇到 {1} 产生冲突：{2} 和 {3}", this, vert, actionTable[vert], action));
}
action = (GotoAction)actionTable[vert];
action.ItemSet.items.Add(proAfterShift);
}
else
{
action.ItemSet = new ItemSet();
action.ItemSet.items.Add(proAfterShift);
this.actionTable.Add(vert, action);
}
}