| \begin{lstlisting}[caption=OCL Module for Validating Singletons, label=lst:CaseStudyOcl, language=OCL2] | |
| package Foundation::Core | |
| context Class | |
| def isSingleton : | |
| let isSingleton : Boolean = | |
| self.stereotype->exists(s|s.name = 'singleton') | |
| def getInstanceOperation : | |
| let getInstanceOperation : Operation = | |
| self.feature->select(f|f.oclIsTypeOf(Operation) | |
| and f.name = 'getInstance')->first().oclAsType(Operation) | |
| inv DefinesGetInstanceOperation : | |
| if isSingleton | |
| then getInstanceOperation.isDefined | |
| else true | |
| endif | |
| inv GetInstanceOperationIsStatic : | |
| if isSingleton then | |
| if getInstanceOperation.isDefined | |
| then getInstanceOperation.ownerScope = #classifier | |
| else false | |
| endif | |
| else | |
| true | |
| endif | |
| inv GetOperationReturnsSame : | |
| if isSingleton then | |
| if getInstanceOperation.isDefined then | |
| if getInstanceOperation.returnParameter.isDefined | |
| then getInstanceOperation.returnParameter.type = self | |
| else false | |
| endif | |
| else | |
| false | |
| endif | |
| else | |
| true | |
| endif | |
| context Operation | |
| def returnParameter : | |
| let returnParameter : Parameter = | |
| self.parameter->select(p|p.kind = #return)->first() | |
| endpackage | |
| \end{lstlisting} |