private static string GetUniqueString(HashCache cache)
{
LR0Item obj = cache as LR0Item;
return(obj.Dump());
//StringBuilder builder = new StringBuilder();
//builder.Append(obj.Regulation.Left.Nickname);
//builder.Append(" ::= ");
//int count = obj.Regulation.RightPart.Count();
//for (int i = 0; i < count; i++)
//{
// if (i == obj.DotPosition)
// { builder.Append('.'); builder.Append(' '); }
// var item = obj.Regulation.RightNode(i);
// builder.Append(item.Nickname);
// builder.Append(' ');
//}
//if (obj.DotPosition == count)
//{ builder.Append('.'); builder.Append(' '); }
//builder.Append(';');
//return builder.ToString();
}
/// <summary>
///
/// </summary>
/// <param name="lr0Item">group标识</param>
/// <param name="lookAheadNodes">此group下包含的lookAhead结点列表</param>
/// <returns></returns>
public bool TryInsert(LR0Item lr0Item, IEnumerable <TreeNodeType> lookAheadNodes)
{
if (this.regulationDotList.TryInsert(lr0Item))
{
int index = this.regulationDotList.IndexOf(lr0Item);
OrderedCollection <TreeNodeType> list = new OrderedCollection <TreeNodeType>(" ");
foreach (var node in lookAheadNodes)
{
list.TryInsert(node);
}
this.lookAheadCollectionList.Insert(index, list);
this.SetDirty();
return(true);
}
else
{
int index = this.regulationDotList.IndexOf(lr0Item);
bool result = false;
OrderedCollection <TreeNodeType> list = this.lookAheadCollectionList[index];
foreach (var item in lookAheadNodes)
{
result = list.TryInsert(item) || result;
}
//this.SetDirty();// 无论是否插入新的lookAheadNode，都不影响state的hashcode
return(result);
}
}
public LR1Item this[int index]
{
get
{
if (index < 0)
{
throw new ArgumentOutOfRangeException();
}
int current = 0;
for (int i = 0; i < this.regulationDotList.Count; i++)
{
if (index <= current + this.regulationDotList.Count)
{
TreeNodeType node = this.lookAheadCollectionList[i][index - current];
LR0Item item = this.regulationDotList[i];
return(new LR1Item(item.Regulation, item.DotPosition, node));
}
else
{
current += this.regulationDotList.Count;
}
}
throw new ArgumentOutOfRangeException();
}
}
public bool TryInsert(LR1Item item)
{
LR0Item lr0Item = new LR0Item(item.Regulation, item.DotPosition);
if (this.regulationDotList.TryInsert(lr0Item))
{
int index = this.regulationDotList.IndexOf(lr0Item);
var collection = new OrderedCollection <TreeNodeType>(", ");
collection.TryInsert(item.LookAheadNodeType);
this.lookAheadCollectionList.Insert(index, collection);
this.SetDirty();
return(true);
}
else
{
int index = this.regulationDotList.IndexOf(lr0Item);
if (this.lookAheadCollectionList[index].TryInsert(item.LookAheadNodeType))
{
this.SetDirty();
return(true);
}
else
{
return(false);
}
}
}
/// <summary>
/// LR(0)的Closure操作。
/// 补全一个状态。
/// </summary>
/// <param name="list"></param>
/// <param name="state"></param>
/// <returns></returns>
static LR0State Closure(this RegulationList list, LR0State state)
{
Queue <LR0Item> queue = new Queue <LR0Item>();
foreach (var item in state)
{
queue.Enqueue(item);
}
while (queue.Count > 0)
{
LR0Item item = queue.Dequeue();
TreeNodeType node = item.GetNodeNext2Dot();
if (node == null)
{
continue;
}
foreach (var regulation in list)
{
if (regulation.Left == node)
{
var newItem = new LR0Item(regulation, 0);
if (state.TryInsert(newItem))
{
queue.Enqueue(newItem);
}
}
}
}
return(state);
}
public IEnumerator <LR1Item> GetEnumerator()
{
for (int i = 0; i < this.regulationDotList.Count; i++)
{
LR0Item item = this.regulationDotList[i];
foreach (var lookAheadNode in this.lookAheadCollectionList[i])
{
yield return(new LR1Item(item.Regulation, item.DotPosition, lookAheadNode));
}
}
}
/// <summary>
/// LR(0)的Goto操作。
/// 将圆点移到所有LR(0)项中的符号<paramref name="x"/>之后。
/// </summary>
/// <param name="list"></param>
/// <param name="state"></param>
/// <param name="x">一个文法符号，终结点或非终结点。</param>
/// <returns></returns>
static LR0State Goto(this RegulationList list, LR0State state, TreeNodeType x)
{
LR0State toState = new LR0State();
foreach (var item in state)
{
TreeNodeType nextNode = item.GetNodeNext2Dot();
if (nextNode == x)
{
var newItem = new LR0Item(item.Regulation, item.DotPosition + 1);
toState.TryInsert(newItem);
}
}
return(Closure(list, toState));
}
public int IndexOf(LR1Item item)
{
int index = 0;
LR0Item lr0Item = new LR0Item(item.Regulation, item.DotPosition);
int groupIndex = this.regulationDotList.IndexOf(lr0Item);
if (0 <= groupIndex && groupIndex < this.regulationDotList.Count)
{
for (int i = 0; i < groupIndex; i++)
{
index += this.lookAheadCollectionList[i].Count;
}
index += this.lookAheadCollectionList[groupIndex].IndexOf(item.LookAheadNodeType);
}
else
{
index = -1;
}
return(index);
}
public bool Contains(LR1Item item)
{
LR0Item lr0Item = new LR0Item(item.Regulation, item.DotPosition);
int groupIndex = this.regulationDotList.IndexOf(lr0Item);
if (0 <= groupIndex && groupIndex < this.regulationDotList.Count)
{
int index = this.lookAheadCollectionList[groupIndex].IndexOf(item.LookAheadNodeType);
if (0 <= index && index < this.lookAheadCollectionList[groupIndex].Count)
{
return(true);
}
else
{
return(false);
}
}
else
{
return(false);
}
}
/// <summary>
/// 用SLR分析法计算分析表
/// </summary>
/// <param name="grammar"></param>
/// <returns></returns>
public static void GetSLRParsingMap(this RegulationList grammar,
out LRParsingMap map,
out LR0StateCollection stateCollection,
out LR0EdgeCollection edgeCollection, TextWriter writer)
{
// 给文法添加一个辅助的开始产生式 S' -> S $
// 如何添加一个外来的结点类型？用Enum是无法做到的。
var decoratedS = new TreeNodeType("__S2", "S'", "<S'>");
var decoratedEnd = TreeNodeType.endOfTokenListNode;
var decoratedRegulation = new Regulation(
decoratedS, grammar[0].Left, decoratedEnd);
var decoratedGrammar = new RegulationList(decoratedRegulation);
decoratedGrammar.AddRange(grammar);
// 初始化T为{ Closure(S' -> S $) }
var firstItem = new LR0Item(decoratedGrammar[0], 0);
var firstState = new LR0State(firstItem);
firstState = decoratedGrammar.Closure(firstState);
stateCollection = new LR0StateCollection(firstState);
edgeCollection = new LR0EdgeCollection(stateCollection);
var queue = new Queue <LR0State>();
queue.Enqueue(firstState);
int lastOutputLength = 0;
int stateListCount = 1;
int queueCount = 1;
while (queue.Count > 0)
{
LR0State fromState = queue.Dequeue(); queueCount--;
int itemIndex = 0;
int itemCount = fromState.Count();
foreach (var item in fromState)
{
{
TextWriter currentWriter = Console.Out;
if (Console.Out != writer)
{
Console.SetOut(writer);
}
for (int i = 0; i < lastOutputLength; i++)
{
Console.Write('\u0008');
}
string output = string.Format("Calculating SLR State List: {0} <-- {1}, working on {2}/{3} ...",
stateListCount, queueCount, 1 + itemIndex++, itemCount);
Console.Write(output);
lastOutputLength = output.Length;
Console.SetOut(currentWriter);
}
TreeNodeType x = item.GetNodeNext2Dot();
if (x == null || x == decoratedEnd)
{
continue;
}
LR0State toState = decoratedGrammar.Goto(fromState, x);
if (stateCollection.TryInsert(toState))
{
queue.Enqueue(toState);
stateListCount++;
queueCount++;
var edge = new LR0Edge(fromState, x, toState);
edgeCollection.TryInsert(edge);
}
else
{
int index = stateCollection.IndexOf(toState);
toState = stateCollection[index];
var edge = new LR0Edge(fromState, x, toState);
edgeCollection.TryInsert(edge);
}
}
}
{
TextWriter currentWriter = Console.Out;
if (Console.Out != writer)
{
Console.SetOut(writer);
}
Console.WriteLine();
Console.SetOut(currentWriter);
}
map = new LRParsingMap();
foreach (var edge in edgeCollection)
{
if (edge.X.IsLeave)
{
int stateId = edge.From.ParsingMapIndex + 1; //stateCollection.IndexOf(edge.From) + 1
int gotoStateId = edge.To.ParsingMapIndex + 1; //stateCollection.IndexOf(edge.To) + 1
map.SetAction(stateId, edge.X, new LR1ShiftInAction(gotoStateId));
}
else
{
int stateId = edge.From.ParsingMapIndex + 1; //stateCollection.IndexOf(edge.From) + 1
int gotoStateId = edge.To.ParsingMapIndex + 1; //stateCollection.IndexOf(edge.To) + 1
map.SetAction(stateId, edge.X, new LR1GotoAction(gotoStateId));
}
}
var endItem = new LR0Item(decoratedRegulation, 1);
FOLLOWCollection followCollection;
decoratedGrammar.GetFollowCollection(out followCollection);
foreach (var state in stateCollection)
{
if (state.Contains(endItem))
{
int stateId = state.ParsingMapIndex + 1;//stateCollection.IndexOf(state) + 1
map.SetAction(stateId, decoratedEnd, new LR1AceptAction());
}
foreach (var lr0Item in state)
{
if (lr0Item.GetNodeNext2Dot() == null)
{
FOLLOW follow = FindFollow(followCollection, lr0Item.Regulation.Left);
foreach (var value in follow.Values)
{
int stateId = state.ParsingMapIndex + 1;// stateCollection.IndexOf(state) + 1;
int reductionId = decoratedGrammar.IndexOf(lr0Item.Regulation);
var action = new LR1ReducitonAction(reductionId);
map.SetAction(stateId, value, action);
}
}
}
}
}
