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Lexer/RegExs now work on a very basic level. Regular expressions have not been fully implemented, but the structure is there. It creates trivial regexs that only accept a specified sequence, no actual regular expression power.

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This commit is contained in:
Nathan Braswell
2013-07-02 01:47:42 -04:00
parent 94a7739bd9
commit 85da0bf646
10 changed files with 72 additions and 16 deletions
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29
src/RegEx.cpp
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@@ -3,7 +3,7 @@
RegEx::RegEx(std::string inPattern) {
pattern = inPattern;
RegExState* current;
begin = new RegExState(pattern.at(0));
begin = new RegExState(pattern[0]);
current = begin;
for (int i = 1; i < pattern.length(); i++) {
RegExState* next = new RegExState(pattern.at(i));
@@ -17,21 +17,30 @@ RegEx::~RegEx() {
}
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.at(0)));
currentStates = *(begin->advance(stringToMatch[1]));
std::vector<RegExState*> nextStates;
for (int i = 1; i < stringToMatch.size(); i++) {
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())
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;
@@ -42,6 +51,14 @@ int RegEx::longMatch(std::string stringToMatch) {
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)
@@ -58,3 +75,7 @@ int RegEx::longMatch(std::string stringToMatch) {
std::string RegEx::getPattern() {
return pattern;
}
std::string RegEx::toString() {
return pattern + " -> " + begin->toString();
}