R1006 - modelint/shlaer-mellor-metamodel GitHub Wiki

R1006 / 1:Mc

Read Action reads attributes of instance in exactly one Single Instance Flow

Single Instance Flow provides instance to be read by zero, one or many Read Action

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Since a Read Action only operates on a single instance, it takes a Single Instance Flow as its input. This provides the instance whose Attribute(s) will be read by the Read Action. If no instance is provided, an tuple will be generated which will may trigger an error downstream if not checked.

A Single Instance Flow can flow into many different actions and might not feed a Read Action at all.