MOF 2.4 RTF Avatar
  1. OMG Issue

MOF24 — MOF 2.0 9.1 Confusing instance superclass statement

  • Key: MOF24-68
  • Legacy Issue Number: 15272
  • Status: closed  
  • Source: Model Driven Solutions ( Ed Willink)
  • Summary:

    The statement in clause 9.1 semantics

    "Class Element is the superclass of all model elements in MOF, and is the
    superclass of all instances of MOF model elements."

    is confusing since instances do not normally have superclasses.

    The statement could be interpreted to mean that every class always has
    Element as a superclass including user-defined classes. But this would then
    make it impossible to model lightweight application classes supporting
    solely the required functionality.

    Surely it is every M2 (and M3 and ...) class that has Element as a
    superclass?

    At M1 the superclasses are as modelled by the user.

    This is significant for OCL since OCL inserts at least OclAny as the top
    type at M1 in order to support some reflective behaviour. If Element really
    is an M1 superclass, then OCL should align. If Element is not an M1
    superclass, OCL should provide its reflection in OclAny.

  • Reported: MOF 2.0 — Wed, 2 Jun 2010 04:00 GMT
  • Disposition: Resolved — MOF 2.4
  • Disposition Summary:

    closed no change

  • Updated: Mon, 20 Apr 2015 17:34 GMT