Conditional operator in TTreeFormula, (ie "X > 5?

ROOT
1

Hi.

It would be very nice if TTreeFormula and TTree::Draw could support the standard c++ ternary conditional operator.

Although it is easy enough to translate ( X > 5 ? y : z ) into ( ( X > 5 ) * y ) + ( ! ( X > 5 ) * z ) that doesn’t work so well when y and z are strings.

Or perhaps this could be a pair of function in TMath. ie
const char* TMath::IfElseString( Bool_t cond, const char* valTrue, const char* valFalse ).
double TMath::IfElse( Bool_t cond, Double_t valTrue, Double_t valFalse)

Thanks.

2

Hi,

Support for the ternary conditional operator has been added to TFormula and TTreeFormula in revision 30157 of the svn trunk. (30158 for strings).

Cheers,
Philippe.

3

Quite impressive. Espcially since ‘:’ was already used given a meaning in draw and cut expressions.

I assume this will be widely available in the next production ROOT release.

4

Hi,

Yes, it will be part of the next ROOT release (v5.25/02).

Cheers,
Philippe.