Exemplo n.º 1
0
 /// <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);
         }
     }
 }
Exemplo n.º 2
0
        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;
        }
Exemplo n.º 3
0
        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);
            }
        }