ALF 1.0 FTF Avatar
  1. OMG Issue

ALF_ — AssignmentExpression as a data value update

  • Key: ALF_-68
  • Legacy Issue Number: 17516
  • Status: closed  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    Subject: AssignmentExpression as a data value update

    Subclause: 13.2.2 AssignmentExpression,

    · An assignment expression should only be allowed to be a data value update if its left hand side is a feature reference whose primary expression is a local name or parameter name.

    · The derivation of the assignment for an assignment expression needs to account for the cases of a data value update and an indexed left hand side.

  • Reported: ALF 1.0b2 — Thu, 19 Jul 2012 04:00 GMT
  • Disposition: Resolved — ALF 1.0
  • Disposition Summary:

    The deriviation of isDataValueUpdate is such that it is true only in the case mentioned in the first bullet. However, nothing currently prevents assignment to an attribute of a data type where the primary expression of the feature reference is not a local name or parameter. Such an assignment will not be mapped correctly, because it will not be considered a data value update and, so, the updated data value will be lost. Therefore, this case should be disallowed.
    In the case of a data value update for an indexed left-hand side, the multiplicity of the new assignment should not be that of the left-hand side (which will be 1) but, rather, should be * (since only a sequence can be indexed).

  • Updated: Fri, 6 Mar 2015 21:49 GMT