ExprAST *Parser::parsePrimary ()
{
// At the top level, we have to have either an identifier of some kind,
// a number, or an open paren. We might also have a unary minus sign, handle
// that specially right here.
switch (currentToken)
{
case TOKEN_IDENTIFIER_FUNCTION:
return parseFunctionIdentifierExpr ();
case TOKEN_IDENTIFIER_CONSTANT:
return parseConstantIdentifierExpr ();
case TOKEN_IDENTIFIER_VARIABLE:
return parseVariableIdentifierExpr ();
case TOKEN_NUMBER:
return parseNumberExpr ();
case TOKEN_PAREN_OPEN:
return parseOpenParenExpr ();
case TOKEN_OPERATOR:
if (strToken == "-")
return parseUnaryMinusExpr ();
// Fall through for any other operator
default:
error (boost::format ("Expecting an expression, got %1% instead!") %
formatToken ());
return NULL;
}
}
int main(int argc, char * argv[]) {
TokenType ttype;
source = stdin;
listing = stdout;
struct stack_t *scannerStack = newStack(); //track tags
int relevant = 0; //track if current tag section is relevant to print -- 0 is relevant, > 0 is irrelevant, < 0 is no tags
while((ttype=getToken()) != ENDFILE) {
/* if open tag, push onto stack */
if(ttype == 1) {
push(scannerStack, formatToken(ttype, tokenString));
if(relevant > 0) relevant++; //increment relevant flag for any tag inside irrelevant tag
else if(!compareToken(top(scannerStack))) relevant++; //increment relevant flag on irrelevant tag
}
/* if close tag, check top of stack for matching open tag */
if(ttype == 2) {
/* if close tag does not match top of stack, report error */
if(top(scannerStack) == NULL || strcmp(top(scannerStack), formatToken(ttype, tokenString))) {
if(relevant == 0) printf("-- Error: CLOSE-TAG </%s> with no matching open tag at top of stack at line %d\n", formatToken(ttype, tokenString), lineno);
continue;
}
/* if close tag matches top of stack, pop */
else {
pop(scannerStack);
/* decrement relevant tag on pop if greater than 0 */
if(relevant > 0) {
relevant--;
continue;
}
}
}
/* print tokens if relevant and tag is on stack */
if(relevant == 0 && top(scannerStack) != NULL) printToken(ttype, tokenString);
}
/* print off remaining tags in stack as errors */
while(top(scannerStack)) {
printf("-- Error: OPEN-TAG <%s> with no closing tag left over in stack\n", top(scannerStack));
pop(scannerStack);
}
destroyStack(&scannerStack);
return 0;
}
ExprAST *Parser::parseBinOpRHS (int exprPrecedence, ExprAST *LHS)
{
while (1)
{
// This should be either an operator, a close-paren, comma,
// or the end of the formula.
if (currentToken != TOKEN_OPERATOR &&
currentToken != TOKEN_PAREN_CLOSE &&
currentToken != TOKEN_COMMA &&
currentToken != TOKEN_END)
{
error (boost::format ("Attempting to parse the RHS of a binary operator, "
"and got %1%!") % formatToken ());
return NULL;
}
// Get the precedence
int tokenPrecedence = -1;
for (int i = 0 ; i < NUM_OPERATORS ; i++)
{
if (strToken == operators[i].name)
{
tokenPrecedence = operators[i].precedence;
break;
}
}
// We're done if we run into an equivalent or lower-precedence binary
// operator (or, notably, something that's not an operator at all, like
// the end of the formula)
if (tokenPrecedence < exprPrecedence)
return LHS;
// Pull off the operator
std::string binOp = strToken;
getNextToken ();
// Parse the primary after the operator
ExprAST *RHS = parsePrimary ();
if (!RHS)
return NULL;
// We've now parsed a full binary operator pair, "A op B". If the next
// thing is a binary operator (which it should be, or it should be
// nothing at all), we need to see whether we want "(A op B) op2 ..." or
// "A op (B op2 ...)" by precedence rules. Look ahead:
int nextPrecedence = -1;
for (int i = 0 ; i < NUM_OPERATORS ; i++)
{
if (strToken == operators[i].name)
{
nextPrecedence = operators[i].precedence;
break;
}
}
if (tokenPrecedence < nextPrecedence)
{
// Next precedence is greater, we want "A op (B op2 ...)". Do that by
// parsing B op2 ... into a new RHS.
RHS = parseBinOpRHS (tokenPrecedence + 1, RHS);
if (RHS == NULL)
return NULL;
}
// Next precedence is lower, we want "(A op B) op2 ...", so make a new LHS
LHS = new BinaryExprAST (binOp, LHS, RHS);
// And loop back to the beginning
}
}
QString DateTime::formatDateTime(const QString &rFormat) const
{
if (rFormat.isEmpty())
return QString();
if (!isValid())
return QString();
const QLatin1Char null('0');
const QLatin1Char quote('\'');
const QString tokens = QLatin1String("\'dMyhHmszAPapw");
const bool am_pm = hasAMPM(rFormat);
QString result;
QString token;
QChar expected = null;
QChar c;
int i;
for (i = 0; i < rFormat.length(); i++)
{
c = rFormat.at(i);
// Handle literal text
if (expected == quote)
{
if (c == quote)
{
Q_ASSERT_X(i > 0, "DateTime::toString()", "Found quote with status quote at i = 0");
if (i > 0 && rFormat.at(i - 1) == quote)
// Second of two quotes
result += quote;
expected = null;
}
else
// Next literal character
result += c;
}
else if (c == expected)
{
// Extend token
token += c;
}
else
{
// Close last token
result += formatToken(token, am_pm);
token.clear();
expected = null;
// Test for valid character
if (tokens.indexOf(c) >= 0)
{
if (c == QLatin1Char('a'))
expected = QLatin1Char('p');
else if (c == QLatin1Char('A'))
expected = QLatin1Char('P');
else if (c.toLower() == QLatin1Char('p'))
expected = null;
else
expected = c;
if (c != quote)
token += c;
} else
result += c;
}
}
result += formatToken(token, am_pm);
return result;
}
QString DateTime::formatToken(const QString &rToken, bool am_pm) const
{
if (rToken.isEmpty())
return QString();
const QChar c = rToken.at(0);
QString result;
int used = 0;
// Qt data format strings
if (rToken.startsWith(QLatin1String("dddd")))
{
result = QDate::longDayName(date().dayOfWeek());
used = 4;
}
else if (rToken.startsWith(QLatin1String("ddd")))
{
result = QDate::shortDayName(date().dayOfWeek());
used = 3;
}
else if (rToken.startsWith(QLatin1String("dd")))
{
result = QString::number(date().day()).rightJustified(2, QLatin1Char('0'), true);
used = 2;
}
else if (c == QLatin1Char('d'))
{
result = QString::number(date().day());
used = 1;
}
else if (rToken.startsWith(QLatin1String("MMMM")))
{
result = QDate::longMonthName(date().month());
used = 4;
}
else if (rToken.startsWith(QLatin1String("MMM")))
{
result = QDate::shortMonthName(date().month());
used = 3;
}
else if (rToken.startsWith(QLatin1String("MM")))
{
result = QString::number(date().month()).rightJustified(2, QLatin1Char('0'), true);
used = 2;
}
else if (c == QLatin1Char('M'))
{
result = QString::number(date().month());
used = 1;
}
else if (rToken.startsWith(QLatin1String("yyyy")))
{
result = QString::number(date().year());
used = 4;
}
else if (rToken.startsWith(QLatin1String("yy")))
{
result = QString::number(date().year() % 100).rightJustified(2, QLatin1Char('0'), true);
used = 2;
}
// Qt time format strings
else if (rToken.startsWith(QLatin1String("hh")) || rToken.startsWith(QLatin1String("HH")))
{
int hour = time().hour();
if (am_pm && c == QLatin1Char('h') && hour > 12)
hour -= 12;
result = QString::number(hour).rightJustified(2, QLatin1Char('0'), true);
used = 2;
}
else if (c == QLatin1Char('h') || c == QLatin1Char('H'))
{
int hour = time().hour();
if (am_pm && c == QLatin1Char('h') && hour > 12)
hour -= 12;
result = QString::number(hour);
used = 2;
}
else if (rToken.startsWith(QLatin1String("mm")))
{
result = QString::number(time().minute()).rightJustified(2, QLatin1Char('0'), true);
used = 2;
}
else if (c == (QLatin1Char('m')))
{
result = QString::number(time().minute());
used = 1;
}
else if (rToken.startsWith(QLatin1String("ss")))
{
result = QString::number(time().second()).rightJustified(2, QLatin1Char('0'), true);
used = 2;
}
else if (c == QLatin1Char('s'))
{
result = QString::number(time().second());
used = 1;
}
else if (rToken.startsWith(QLatin1String("zzz")))
{
result = QString::number(time().msec()).rightJustified(3, QLatin1Char('0'), true);
used = 3;
}
else if (c == QLatin1Char('z'))
{
result = QString::number(time().msec());
used = 1;
}
else if (c.toLower() == QLatin1Char('a'))
{
bool is_lower = c == QLatin1Char('a');
if (time().hour() < 12)
result = QLatin1String("AM");
else
result = QLatin1String("PM");
if (is_lower)
result = result.toLower();
if (rToken.size() > 1 &&
((is_lower && rToken.at(1) == QLatin1Char('p')) ||
(!is_lower && rToken.at(1) == QLatin1Char('P')))
)
used = 2;
else
used = 1;
}
// Extension for week number
else if (rToken.startsWith(QLatin1String("ww")))
{
result = QString::number(date().weekNumber()).rightJustified(2, QLatin1Char('0'), true);
used = 2;
}
else if (c == QLatin1Char('w'))
{
result = QString::number(date().weekNumber());
used = 1;
}
if (used)
return result + formatToken(rToken.mid(used), am_pm);
else
return result;
}