R815 - modelint/shlaer-mellor-metamodel GitHub Wiki
R815 / Mc:Mc-1
Data Flow passes to zero, one or many Data Flow
Data Flow is passed from zero, one or many Data Flow
We pass the value from one Data Flow to another as described in Pass Action.
As we can see in the data flow diagram example, the same Data Flow may be passed more than once in the same Activity.
For example, F15: top floor height is input to the ACTN27 and ACTN29 Pass Actions. During model execution only one of these Pass Actions will activitate, but we still need to account for both possible results.
But for a given Data Flow, it either is or is not the output of a Pass Action. At least that seems to be the case.
In the process of building the repository, I consistently get a duplicate tuple error if I set this as a 1c-Mc-1 association. Not sure why. Everything works if I loosen the constraint to Mc-Mc-1 and leave the output flow id out of the Pass Action identifier. But if you look at the example DFD below, we should be able to establish a unique Pass Action with I2: {Output flow, Activity, Domain}. Odd. So, for now at least, I am keeping the less constrained version until we sort out whether the DB or the model is wrong. - LS 25-11-26
