Originally posted by: SystemAdmin

Hi everybody!

Is it possible in OPL to late initialize a dexpr? Quick example: in most of the programming languages, you can easily write

int a; 
// declaration 
//[...] a = 1; 
// initialization

Even if I think it's possible in OPL to do it for constants (albeit the initialization has to be within an "execute" block), I couldn't find any way to do it for dexprs. I'm asking because I'd like to write sets of dexprs which encode equality systems:

dexpr 

int x = y - 1; 
// compile-time error: y is not declared yet dexpr 

int y = 3 - x;

in place of declaring x and y as variables, and putting the equalities in the "subject to" block. Unfortunately, the former syntax leads to an error because y dexpr is used before is declared, and I can't find any way to declare x without initializing it at the same time. Indeed a syntax like

dexpr 

int x; 
// declaration of x dexpr 

int y = 3 - x; 
// no compile-time error here, because x is already declared x = y - 1; 
// initialization of x

does not work.

Any ideas?

Regards,
Stefano
#DecisionOptimization
#OPLusingCPLEXOptimizer