private static boolean isSingleArgSum(Ptg token) {
if (token instanceof AttrPtg) {
AttrPtg attrPtg = (AttrPtg) token;
return attrPtg.isSum();
}
return false;
}
// visibility raised for testing
/* package */ ValueEval evaluateFormula(OperationEvaluationContext ec, Ptg[] ptgs) {
Stack<ValueEval> stack = new Stack<ValueEval>();
for (int i = 0, iSize = ptgs.length; i < iSize; i++) {
// since we don't know how to handle these yet :(
Ptg ptg = ptgs[i];
if (ptg instanceof AttrPtg) {
AttrPtg attrPtg = (AttrPtg) ptg;
if (attrPtg.isSum()) {
// Excel prefers to encode 'SUM()' as a tAttr token, but this evaluator
// expects the equivalent function token
byte nArgs = 1; // tAttrSum always has 1 parameter
ptg = new FuncVarPtg("SUM", nArgs);
}
}
if (ptg instanceof ControlPtg) {
// skip Parentheses, Attr, etc
continue;
}
if (ptg instanceof MemFuncPtg) {
// can ignore, rest of tokens for this expression are in OK RPN order
continue;
}
if (ptg instanceof MemErrPtg) {
continue;
}
ValueEval opResult;
if (ptg instanceof OperationPtg) {
OperationPtg optg = (OperationPtg) ptg;
if (optg instanceof UnionPtg) {
continue;
}
OperationEval operation = OperationEvaluatorFactory.create(optg);
int numops = operation.getNumberOfOperands();
ValueEval[] ops = new ValueEval[numops];
// storing the ops in reverse order since they are popping
for (int j = numops - 1; j >= 0; j--) {
ValueEval p = stack.pop();
ops[j] = p;
}
// logDebug("invoke " + operation + " (nAgs=" + numops + ")");
opResult = operation.evaluate(ops, ec);
if (opResult == MissingArgEval.instance) {
opResult = BlankEval.INSTANCE;
}
} else {
opResult = getEvalForPtg(ptg, ec);
}
if (opResult == null) {
throw new RuntimeException("Evaluation result must not be null");
}
// logDebug("push " + opResult);
stack.push(opResult);
}
ValueEval value = stack.pop();
if (!stack.isEmpty()) {
throw new IllegalStateException("evaluation stack not empty");
}
value = dereferenceValue(value, ec.getRowIndex(), ec.getColumnIndex());
if (value == BlankEval.INSTANCE) {
// Note Excel behaviour here. A blank final final value is converted to zero.
return NumberEval.ZERO;
// Formulas _never_ evaluate to blank. If a formula appears to have evaluated to
// blank, the actual value is empty string. This can be verified with ISBLANK().
}
return value;
}
