RE: help asked for Calc jump function with empty arguments

Hi Eike,

> > With IFERROR and IFNA these situation should return an empty value to be compatible with Excel.
> AFAIK also Excel does not allow a null argument for IFERROR() second parameter, but I'm not sure, 
> I'd have to check.


Excel replaces an empty argument with an empty value, that is to say, the function description says 
'If value or value_if_error is an empty cell, IFERROR treats it as an empty string value ("").'
and =IFERROR(1/0;) returns an empty cell, not an error message.

> > With IF, the behaviour is described in ODFF1.2.
> Note that there seems to be a typo in the spec, IfFalse is mentioned twice to be considered to be 
> 0, the first (two consecutive ;; case) probably should be IfTrue.

ODFF1.2 syntax is ' IF( Logical Condition [ ; [ Any IfTrue ] [ ; [ Any IfFalse ] ] ] )' and in 
semantics the handling of null arguments is described, but -IF(1;;) return an error in Calc.

> > My question is, where should this behaviour best be put in the code?

> I think the right place would be ScInterpreter::Interpret() at the end where the final result is 
> obtained. There's a check
>     if( pCur->GetOpCode() == ocPush )
> and if not an error is set. An ocMissing here could be propagated through to the ScFormulaResult, 
> then
>     bool isValue( formula::StackVar sv )
> in sc/source/core/tool/formularesult.cxx would need to handle formula::svMissing as well, the 
> ScFormulaResult::GetDouble() already returns 0.0 in such case.

I will try. The problem so far with SCInterpreter::Interpret was that I need to know what the 
function was, as IFERROR and IF have different responses to null arguments (in the case of IF I 
also need to know the values of the first argument as that is to be the result).

> > And as these functions are jump functions, how best to access/modify the stack or FormulaToken?
> Don't ;-)
I won't ;-)

Winfried