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Actually parses LR(0) grammers and sentences\! Only two problems is very inefficint gotoTable() and actionTable(), and it REJECTS the sentence after completing the Goal->Sentence(*) production. However, need to go to bed now. Does practially work though\! Yay\!

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This commit is contained in:
Nathan Braswell
2013-05-29 20:43:35 -04:00
parent 315dc55409
commit 69713ffe1a
8 changed files with 96 additions and 21 deletions
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49
src/Parser.cpp
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@@ -150,18 +150,57 @@ std::string Parser::stateSetToString() {
}
int Parser::gotoTable(int state, Symbol* token) {
return 0;
std::vector<ParseRule*> allInState = *(stateSets[state]->getTotal());
ParseRule* currentRule;
for (std::vector<ParseRule*>::size_type i = 0; i < allInState.size(); i++) {
currentRule = allInState[i];
if (*(currentRule->getAtNextIndex()) == *token) {
ParseRule* advancedCurrent = currentRule->clone();
advancedCurrent->advancePointer();
for (std::vector<State*>::size_type j = 0; j < stateSets.size(); j++) {
for (std::vector<ParseRule*>::size_type k = 0; k < stateSets[j]->basis.size(); k++ ) {
if ( *(stateSets[j]->basis[k]) == *advancedCurrent)
return(j);
}
}
}
}
return(-1);
}
ParseAction* Parser::actionTable(int state, Symbol* token) {
return NULL;
std::vector<ParseRule*>* allStateRules = stateSets[state]->getTotal();
ParseRule* currentRule;
for (std::vector<ParseRule*>::size_type i = 0; i < allStateRules->size(); i++) {
currentRule = (*allStateRules)[i];
//If the current rule in the state is completed, then do a reduce action
if (currentRule->isAtEnd()) {
if (*currentRule == *(stateSets[0]->basis[0]))
return new ParseAction(ParseAction::ACCEPT);
return new ParseAction(ParseAction::REDUCE, currentRule);
}
//If the current rule in the state is not completed, see if it has the next correct token
std::cout << currentRule->getAtNextIndex()->toString() << " comp to " << token->toString() << std::endl;
if ( *(currentRule->getAtNextIndex()) == *token){
//If it does have the correct next token, then find the state that has this rule advanced as basis, that is the state we shift to
//Goes to n^2 here, really need that table
ParseRule* advancedCurrent = currentRule->clone();
advancedCurrent->advancePointer();
for (std::vector<State*>::size_type j = 0; j < stateSets.size(); j++) {
for (std::vector<ParseRule*>::size_type k = 0; k < stateSets[j]->basis.size(); k++ ) {
if ( *(stateSets[j]->basis[k]) == *advancedCurrent)
return new ParseAction(ParseAction::SHIFT, j);
}
}
}
}
return new ParseAction(ParseAction::REJECT);
}
void Parser::parseInput(std::string inputString) {
StringReader inputReader;
inputReader.setString(inputString);
Symbol* token = new Symbol(reader.word(), false);
Symbol* token = new Symbol(inputReader.word(), true);
ParseAction* action;
stateStack.push(0);
@@ -184,7 +223,7 @@ void Parser::parseInput(std::string inputString) {
}
case ParseAction::SHIFT:
symbolStack.push(token);
token = new Symbol(inputReader.word(), false);
token = new Symbol(inputReader.word(), true);
stateStack.push(action->shiftState);
std::cout << "Shift " << symbolStack.top()->toString() << std::endl;
break;