CoutStatementNode * ParserClass::CoutStatement() {
Match(COUT_TOKEN);
Match(INSERTION_TOKEN);
CoutStatementNode *csn = new CoutStatementNode();
ExpressionNode *expression = Expression();
csn->AddExpression(expression);
while (true) {
TokenType tt = mScanner->PeekNextToken().GetTokenType();
if (tt == INSERTION_TOKEN) {
Match(INSERTION_TOKEN);
TokenClass next = mScanner->PeekNextToken();
if (next.GetTokenType() == ENDL_TOKEN) {
Match(ENDL_TOKEN);
csn->AddExpression(NULL);
}
else {
ExpressionNode *nextExpression = Expression();
csn->AddExpression(nextExpression);
}
}
else {
if (tt == ENDL_TOKEN) {
Match(ENDL_TOKEN);
csn->AddExpression(NULL);
}
Match(SEMICOLON_TOKEN);
break;
}
}
return csn;
}
IntegerNode * ParserClass::Integer() {
TokenClass tc = Match(INTEGER_TOKEN);
string s = tc.GetLexeme();
const char *c = s.c_str();
IntegerNode *i = new IntegerNode(atoi(c));
return i;
}
TokenClass ParserClass::Match(TokenType expectedType) {
TokenClass currToken = mScanner->GetNextToken();
if (currToken.GetTokenType() != expectedType) {
cerr << "Error in ParserClass::Match. " << endl;
cerr << "Recieved token type " << currToken.GetTokenTypeName() << endl;
exit(1);
}
MSG("Sucessfully matched Token Type: " <<
currentToken.GetTokenTypeName() << ". Lexeme: \"" <<
currentToken.GetLexeme() << "\"");
return currToken;
}
// Verify that the next token in the input file is of the same type
// that the parser expects.
TokenClass ParserClass::Match(TokenType expectedType)
{
TokenClass currentToken = this->mScanner->GetNextToken();
if (currentToken.GetTokenType() != expectedType)
{
std::cerr << "Error in ParserClass::Match. " << std::endl;
std::cerr << "Expected token type " <<
TokenClass::GetTokenTypeName(expectedType) <<
", but got type " << currentToken.GetTokenTypeName() <<
std::endl;
exit(1);
}
MSG("\tSuccessfully matched Token Type: " << currentToken.GetTokenTypeName() << ". Lexeme: \"" <<
currentToken.GetLexeme() << "\"");
return currentToken; // the one we just processed
}
int main(int argc, char* argv[])
{
ScannerClass scanner;
TokenClass token = scanner.getToken();
while(token.type != EOF_T && token.type != EMPTY_T)//Check for EOF and error
{
token.display();
token = scanner.getToken();
}
if(token.type == EMPTY_T)//If there is an error
cout<<"Compilation error at line "<<scanner.getCurrentLine()<<". ";
cout<<token.lexeme<<endl;
scanner.printStateTable();
scanner.close();
cin.get();
return (0);
}
StatementNode * ParserClass::Statement() {
TokenClass nextToken = mScanner->PeekNextToken();
TokenType tt = nextToken.GetTokenType();
if (tt == INT_TOKEN) {
return DeclarationStatement();
}
else if (tt == IDENTIFIER_TOKEN) {
return AssignmentStatement();
}
else if (tt == COUT_TOKEN) {
return CoutStatement();
}
else if (tt == LCURLY_TOKEN) {
return Block();
}
else if (tt == IF_TOKEN) {
return IfStatement();
}
else if (tt == DO_TOKEN) {
return DoWhile();
}
return NULL;
}
IdentifierNode * ParserClass::Identifier() {
TokenClass token = Match(IDENTIFIER_TOKEN);
IdentifierNode *in = new IdentifierNode(token.GetLexeme(), mSymbolTable);
return in;
}
IntegerNode * ParserClass::Integer()
{
TokenClass token = this->Match(INTEGER_TOKEN);
IntegerNode * in = new IntegerNode(std::atoi(token.GetLexeme().c_str()));
return in;
}