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  1. OMG Issue

UML25 — LiteralNull semantics

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  • Key: UML25-266
  • Legacy Issue Number: 17820
  • Status: closed  
  • Source: Model Driven Solutions ( Dr. Edward Willink)
  • Summary:

    This makes no sense to me. The absence of a value is modeled by the absence of a value, particularly given that UML provides no CollectionTypes to model the multiplicity of values.If the upper bound is one, then LiteralNull could possibly be an alternative to a Literal'NotNull', but it isn't an empty set. If the upper bound is greater than one, how are any of the values really represented in UML?If LiteralNull is to be an optional value, it should derive from LiteralBoolean, LiteralReal. etc.

    Suggest delete LiteralNull or redefine it solely for use as the '0' of a [0..1] multiplicity.
  • Reported: UML 2.4.1 — Wed, 26 Sep 2012 04:00 GMT
  • Disposition: Resolved — UML 2.5
  • Disposition Summary:

    Merged with 9700
  • Updated: Fri, 6 Mar 2015 20:59 GMT