Causing Entities - New Language Feature

[MartinLoeper]

I recognised that we need a language feature for the causing entities. We cannot assume that a rule consistent of A -> B -> C has either B nor A as causing entity for C. The user may decide on his own whether to choose A or B.

We observe this in BPArchitectureModelLookup#lookUpEntryLevelSystemCallsWithParameterOfTypes which is written in KAMP-DSL as follows:

rule lookUpEntryLevelSystemCallsWithParameterOfTypes:
    pcm::DataType <- pcm::OperationSignature[returnType__OperationSignature] <- pcm::EntryLevelSystemCall[operationSignature__EntryLevelSystemCall];

In this rule, the author chose to select DataType as causing entity.

[MartinLoeper]

I suggest, we add a causing entities marker (*) after the lookup which is targeted.

A -> B* -> C

[MartinLoeper]

We must ensure via validation that:

• there is at most one marker per rule
• the marker does not target the affected elements (as it does not make sense that affected elements are affected because of themselves)

[MartinLoeper]

I suggest, we set the causing entities marker onto the marked elements or the next-to-last lookup. This will be taken into account if no marker was explicitly set.

[MartinLoeper]

We do not need to restrict the positions for the markers! Multiple markers add all elements in the subsequent lookup into the set of causing entities.

A causing entity marker on the last lookup rule instructs the engine to put all elements inside the causing entity set which share a common marked element.