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  1. OMG Issue

QVT13 — QVTo: Passing DataTypes 'by-reference'

Open Closed All
  • Key: QVT13-33
  • Legacy Issue Number: 19019
  • Status: closed  
  • Source: Model Driven Solutions ( Dr. Edward Willink)
  • Summary:

    Intuitively List and Dict are objects, so if you pass them to a mapping/query/helper as an inout parameter, the object in the caller may be updated by the call.

    This is the behaviour of a Class Instance not a DataType Value.

    Please use the open https://bugs.eclipse.org/bugs/show_bug.cgi?id=420150 to discuss this topic.

  • Reported: QVT 1.1 — Wed, 23 Oct 2013 04:00 GMT
  • Disposition: Resolved — QVT 1.3
  • Disposition Summary:

    List and Dict Class/DataType confusion

    Intuitively List and Dict are objects, so if you pass them to a mapping/query/helper as an inout parameter, the object in the caller may be updated by the call.

    This is the behaviour of a Class Instance not a DataType Value.

    Discussion

    Equally intuitively List (and Dict) are values. Two distinct 'occurrences' may be equal. This is the behavior of a DataType not a Class.

    List and Dict are specified as CollectionType (DataType) derivations so we just need to fix up indications that List and Dict are Classes.

    While clarifying wording, QVT13-120 is merged to remove the prohibition on object creation/update in helpers.

  • Updated: Tue, 29 Mar 2016 15:09 GMT