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  1. OMG Issue

OCL25 — OCL 2.3 7.5.3 Missing Association End name problems

  • Key: OCL25-48
  • Legacy Issue Number: 16161
  • Status: open  
  • Source: Model Driven Solutions ( Ed Willink)
  • Summary:

    The 'clarified' text in OCL 2.3 for missing association ends, is still unclear.

    Problem 1: if multiple association ends acquire the same name, what happens? Suggest: they all acquire the same name and the resulting lookup up finds multiple names which should be diagnosed as an ambiguity and consequently a semantic error.

    Problem 2: if a missing association end is recursive, a class acquires a property with the same name as the class. Consequently invocation of e.g X.allInstances() for class X may encounter an ambiguity while resolving X. Is it self.X or global X? Suggest: auto-generated missing names may only be invoked via a navigation operator.

    Problem 3: does a derived association end get a resolution for a missing name? if OCL is used to define a number of helper properties that all return the same type, then provision of the missing 'opposites' results in unhelpful clutter at best. Suggest: missing names are not provided for derived association ends.

  • Reported: OCL 2.1 — Tue, 26 Apr 2011 04:00 GMT
  • Updated: Thu, 8 Oct 2015 14:11 GMT