kraken/src/RegEx.cpp

#include "RegEx.h"

RegEx::RegEx(std::string inPattern) {
	pattern = inPattern;
	RegExState* current;
	begin = new RegExState(pattern[0]);
	current = begin;
	for (int i = 1; i < pattern.length(); i++) {
		RegExState* next = new RegExState(pattern.at(i));
		current->addNext(next);
		current = next;
	}
}

RegEx::~RegEx() {
	//No cleanup necessary
}

int RegEx::longMatch(std::string stringToMatch) {
	//If the beginning character is wrong, exit immediantly. Otherwise, get all the states we can get from adding the second character to the state where we accepted the first
	if (!begin->characterIs(stringToMatch[0]))
		return -1;
	std::cout << "Matched first character: " << stringToMatch[0] << std::endl;
	int lastMatch = 0;
	currentStates = *(begin->advance(stringToMatch[1]));
	std::vector<RegExState*> nextStates;

	for (int i = 2; i < stringToMatch.size(); i++) {
		//Go through every current state. Check to see if it is goal, if so update last goal.
		//Also, add each state's advance to nextStates
		for (std::vector<RegExState*>::size_type j = 0; j < currentStates.size(); j++) {
			if (currentStates[j]->isGoal()) {
				lastMatch = i-1;
				std::cout << "Hit goal at " << i << " character: " << stringToMatch[i-1] << std::endl;
			} else {
				std::cout << "currentState " << j << ", " << currentStates[j]->toString() << " is not goal" <<std::endl;
			}
			std::vector<RegExState*>* addStates = currentStates[j]->advance(stringToMatch.at(i));
			nextStates.insert(nextStates.end(), addStates->begin(), addStates->end());
			delete addStates;
		}
		//Now, clear our current states and add eaczh one of our addStates if it is not already in current states

		currentStates.clear();
		for (std::vector<RegExState*>::size_type j = 0; j < nextStates.size(); j++) {
			bool inCurrStates = false;
			for (std::vector<RegExState*>::size_type k = 0; k < currentStates.size(); k++) {
				if (nextStates[j] == currentStates[i])
					inCurrStates = true;
			}
			if (!inCurrStates)
				currentStates.push_back(nextStates[j]);
		}
		if (currentStates.size() != 0)
			std::cout << "Matched " << i << " character: " << stringToMatch[i-1] << std::endl;
/*
		std::cout << "Current states are: ";
		for (std::vector<RegExState*>::size_type j = 0; j < currentStates.size(); j++)
			std::cout << currentStates[j]->toString() << " ";
		std::cout << std::endl;
*/
		nextStates.clear();
		//If we can't continue matching, just return our last matched
		if (currentStates.size() == 0)
			break;
	}
	//Check to see if we match on the last character in the string
	for (std::vector<RegExState*>::size_type j = 0; j < currentStates.size(); j++) {
		if (currentStates[j]->isGoal())
			lastMatch = stringToMatch.size()-1;
	}
	return lastMatch;
}

std::string RegEx::getPattern() {
	return pattern;
}

std::string RegEx::toString() {
	return pattern + " -> " + begin->toString();
}