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Changed Parser to be a virtual base class, inherited by LALRParser

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Nathan Braswell
2013-07-30 01:42:51 -04:00
parent 733fe1c08d
commit 3fba45591b
6 changed files with 128 additions and 79 deletions
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62
src/Parser.cpp
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@@ -310,67 +310,7 @@ std::string Parser::tableToString() {
return table.toString();
}
NodeTree<Symbol*>* Parser::parseInput(std::string inputString) {
lexer.setInput(inputString);
Symbol* token = lexer.next();
std::vector<ParseAction*>* actionList;
ParseAction* action;
stateStack.push(0);
symbolStack.push(new Symbol("INVALID", false));
while (true) {
std::cout << "In state: " << intToString(stateStack.top()) << std::endl;
actionList = table.get(stateStack.top(), token);
action = (*(actionList))[actionList->size()-1];
//std::cout << "Doing ParseAction: " << action->toString() << std::endl;
switch (action->action) {
case ParseAction::REDUCE:
{
std::cout << "Reduce by " << action->reduceRule->toString() << std::endl;
int rightSideLength = action->reduceRule->getRightSide().size();
//Keep track of symbols popped for parse tree
std::vector<Symbol*> poppedSymbols;
for (int i = 0; i < rightSideLength; i++) {
poppedSymbols.push_back(symbolStack.top());
stateStack.pop();
symbolStack.pop();
}
std::reverse(poppedSymbols.begin(), poppedSymbols.end()); //To put in order
//Assign the new tree to the new Symbol
Symbol* newSymbol = action->reduceRule->getLeftSide()->clone();
newSymbol->setSubTree(reduceTreeCombine(newSymbol, poppedSymbols));
symbolStack.push(newSymbol);
std::cout << "top of state is " << intToString(stateStack.top()) << " symbolStack top is " << symbolStack.top()->toString() << std::endl;
actionList = table.get(stateStack.top(), symbolStack.top());
action = (*(actionList))[actionList->size()-1];
stateStack.push(action->shiftState);
//std::cout << "Reduced, now condition is" << std::endl;
//std::cout << "top of state is " << intToString(stateStack.top()) << " symbolStack top is " << symbolStack.top()->toString() << std::endl;
break;
}
case ParseAction::SHIFT:
std::cout << "Shift " << token->toString() << std::endl;
symbolStack.push(token);
token = lexer.next();
stateStack.push(action->shiftState);
break;
case ParseAction::ACCEPT:
std::cout << "ACCEPTED!" << std::endl;
return(symbolStack.top()->getSubTree());
break;
case ParseAction::REJECT:
std::cout << "REJECTED!" << std::endl;
std::cout << "REJECTED Symbol was " << token->toString() << std::endl;
return(NULL);
break;
}
}
}
//parseInput is now pure virtual
NodeTree<Symbol*>* Parser::reduceTreeCombine(Symbol* newSymbol, std::vector<Symbol*> &symbols) {
NodeTree<Symbol*>* newTree = new NodeTree<Symbol*>(newSymbol->getName(), newSymbol);