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 ParsingContext(TokenList tokenList,
RegulationList grammar,
LRParsingMap parsingMap,
TokenType2TreeNodeType tokenTypeConvertor)
{
this.StateIdStack = new Stack <int>();
this.StateIdStack.Push(1);
this.TreeStack = new Stack <SyntaxTree>();
this.TokenList = tokenList;
this.Grammar = grammar;
this.ParsingMap = parsingMap;
this.TokenTypeConvertor = tokenTypeConvertor;
}