public SyntaxTree Parse(TokenList tokenList)
{
LRParsingMap parsingMap = GetParsingMap();
RegulationList grammar = GetGrammar();
//TODO:这个convertor以后是可以配置的。
var tokenTypeConvertor = new TokenType2TreeNodeType();
var context = new ParsingContext(tokenList, grammar, parsingMap, tokenTypeConvertor);
while (context.CurrentTokenIndex < context.TokenList.Count + 1)
{
PrintParsingProgress(context);
TreeNodeType nodeType = context.CurrentNodeType();
int stateId = context.StateIdStack.Peek();
LRParsingAction action = parsingMap.GetAction(stateId, nodeType);
int currentTokenIndex = action.Execute(context);
context.CurrentTokenIndex = currentTokenIndex;
}
PrintLastState(context);
if (context.TreeStack.Count > 0)
{
return(context.TreeStack.Peek());
}
else
{
return(new SyntaxTree());
}
}
public override int Execute(ParsingContext context)
{
Regulation regulation = context.Grammar[RegulationId - 1];
var newNode = new SyntaxTree();
int tokenCount = 0;
int count = regulation.RightPart.Count();
for (int i = 0; i < count; i++)
{
var item = context.TreeStack.Pop();
context.StateIdStack.Pop();//只弹出，不再使用。
newNode.Children.Insert(0, item);
item.Parent = newNode;
tokenCount += item.MappedTokenLength;
if (i == 0)
{
newNode.MappedTokenStartIndex = item.MappedTokenStartIndex;
}
}
newNode.MappedTokenLength = tokenCount;
newNode.MappedTotalTokenList = context.TokenList;
newNode.NodeType = regulation.Left;
context.TreeStack.Push(newNode);
int stateId = context.StateIdStack.Peek();
LRParsingAction gotoAction = context.ParsingMap.GetAction(stateId, regulation.Left);
gotoAction.Execute(context);
return(context.CurrentTokenIndex);
}
private void PrintParsingProgress(ParsingContext context)
{
#if DEBUG
if (!print)
{
return;
} // 调试时快速取消print
Debug.WriteLine("=======================");
{
Debug.WriteLine("Current Stack:");
Debug.Write(" ");
var stateIdArray = context.StateIdStack.ToArray();
var treeArray = context.TreeStack.ToArray();
for (int i = stateIdArray.Length - 1; i > 0; i--)
{
Debug.Write(stateIdArray[i]);
Debug.Write('['); Debug.Write(treeArray[i - 1].NodeType.Nickname); Debug.Write(']');
}
Debug.Write(stateIdArray[0]); Debug.Write(' ');
Debug.WriteLine("");
}
{
Debug.WriteLine("Current token list:");
Debug.Write(" ");
for (int i = context.CurrentTokenIndex; i < context.TokenList.Count; i++)
{
Debug.Write(context.TokenList[i].TokenType.Content); Debug.Write(' ');
}
Debug.WriteLine("");
}
{
Debug.WriteLine("Next action:");
TreeNodeType nodeType = context.CurrentNodeType();
int stateId = context.StateIdStack.Peek();
LRParsingAction action = context.ParsingMap.GetAction(stateId, nodeType);
Debug.Write(" "); Debug.WriteLine(action);
}
{
Debug.WriteLine("Current syntax tree:");
SyntaxTree virtualParent = new SyntaxTree();
virtualParent.NodeType = new TreeNodeType("VirtualParent", "", "Virtual Parent");
var treeArray = context.TreeStack.ToArray();
for (int i = treeArray.Length - 1; i >= 0; i--)
{
virtualParent.Children.Add(treeArray[i]);
treeArray[i].Parent = virtualParent;
}
Debug.WriteLine(virtualParent);
foreach (var item in context.TreeStack)
{
item.Parent = null;
}
}
Debug.WriteLine("=======================");
#endif
}
private void PrintLastState(ParsingContext context)
{
#if DEBUG
if (!print)
{
return;
} // 调试时快速取消print
Debug.WriteLine("=======================");
Debug.WriteLine("***********************");
{
Debug.WriteLine("Last Stack:");
Debug.Write(" ");
var stateIdArray = context.StateIdStack.ToArray();
var treeArray = context.TreeStack.ToArray();
for (int i = stateIdArray.Length - 1; i > 0; i--)
{
Debug.Write(stateIdArray[i]);
Debug.Write('['); Debug.Write(treeArray[i - 1].NodeType.Nickname); Debug.Write(']');
}
Debug.Write(stateIdArray[0]); Debug.Write(' ');
Debug.WriteLine("");
}
{
Debug.WriteLine("Last token list:");
Debug.Write(" ");
for (int i = context.CurrentTokenIndex; i < context.TokenList.Count; i++)
{
Debug.Write(context.TokenList[i].TokenType.Content); Debug.Write(' ');
}
Debug.WriteLine("");
}
{
Debug.WriteLine("Last action:");
TreeNodeType nodeType = context.CurrentNodeType();
int stateId = context.StateIdStack.Peek();
LRParsingAction action = context.ParsingMap.GetAction(stateId, nodeType);
Debug.Write(" "); Debug.WriteLine(action);
}
{
Debug.WriteLine("Last syntax tree:");
Debug.WriteLine(context.TreeStack.Peek());
foreach (var item in context.TreeStack)
{
item.Parent = null;
}
}
Debug.WriteLine("***********************");
Debug.WriteLine("=======================");
#endif
}