If you want to test for not-null, testing for not-null seems like a good
not-empty and not-null are different concepts.
Timothy Marc wrote:
> Hey all,
> what is the beste way to check whether a reference is not null? What i
> want to define is a constraint, that if one end of an binary reference
> is set, the other side has to be set as well.
> Both binary ends have the multiplicity 0 .. 1.
> I have two different approaches:
> 1. context Class1 inv: self.sideA <> null implies self.sideB <> null
> 2. context Class1 inv: self.sideA.notEmpyt() implies self.sideB.notEmpty()
> 3. context Class1 inv: self.sideA->size() = 1 implies self.sideB->size()
> = 1
> What is the best approach?!
> Thanks Timothy