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

src/LALRParser.cpp

@@ -0,0 +1,70 @@
+#include "LALRParser.h"
+
+LALRParser::LALRParser() {
+	//Nothing to do in this version
+}
+LALRParser::~LALRParser() {
+	//Nothing to do in this version
+}
+
+NodeTree<Symbol*>* LALRParser::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;
+		}
+	}
+}