UML22 — ObjectNode

ObjectNode - modelling of upperBound upperBound is currently an association to ValueSpecification. According to section Semantics, it is either a LiteralInteger or a LiteralNull. The later is used to specify an unbound upper limit. There are two problems with this approach: - one could define a upper bound of "5" which is legal LiteralInteger, but probably not a desired value for the maximum number of tokens allowed in the node - if upperBound had multiplicity "0..1", one would not have to encode the absence of a specific upper bound with a LiteralNull I suggest to model "upperBound" in analogy to "upperBound" from MultiplicityElement (see 7.4.1). - replace upperBound with upperBoundValue as follows: upperBoundValue: LiteralUnlimitedNatural[0..1] and update Figure 187 accordingly - add the following Additional Operation context ObjectNode::upperBound():UnlimitedNatural post: result = if upperBoundValue>isEmpty() then '*' – infinity else upperBoundValue.unlimitedValue() end if - on page 344, replace "The upper bound must be a positive LiteralInteger or a LiteralNull. An upper bound that is a LiteralNull means the upper bound is unlimited." with "An upper bound that is empty means the upper bound is unlimited."

see above