QPair<int, double> WorkbookParserPrivate::calculateInfix(int start, QStringList items) {
int i = start;
bool ok;
qreal d, n1, n2;
QStack<qreal> values;
QStack<OperatorBase<qreal>*> operators;
QPair<int, double> result;
// TODO add in errors ie unbalanced brackets wrong number
// of values or operators
// TODO handle cell references and ranges.
while(i < items.size()) {
QString s = items.at(i);
if (s == ")") {
result.first = i + 1;
result.second = values.pop();
return result;
}
if (s == "(") {
i++;
result = calculateInfix(i, items); // Recurse.
i = result.first;
values.push(result.second);
continue;
}
d = s.toDouble(&ok);
if (ok) {
values.insert(i++, d);
continue;
}
// turns constants into their actual value in the list.
ConstantBase *constant = dynamic_cast<ConstantBase*>(pPluginStore->getConstant(s));
if (constant) {
values.insert(i++, constant->value());
continue;
}
IFunction *func = dynamic_cast<IFunction*>(pPluginStore->getFunction(s));
if (func) {
result = calculateInfixFunction(func, i, items); // functioss should return a value.
i = result.first;
values.push(result.second);
continue;
}
OperatorBase<qreal> *op1 = dynamic_cast<OperatorBase<qreal>*>(pPluginStore->getOperator(s));
if (op1) {
if (operators.size() == 0 || operators.top()->level() < op1->level()) {
OperatorBase<qreal> *op2 = operators.pop();
n1 = values.pop();
n2 = values.pop();
d = op2->calculate(n2, n1);
values.push(d);
}
operators.push(op1);
i++;
continue;
}
// TODO string handling
// OperatorBase<QString> *ops1 = dynamic_cast<OperatorBase<QString>*>(pPluginStore->getOperator(s));
// if (op1) {
// // convert numbers to strings if necessary
// }
}
return result;
}
