Reflections on the Object Constraint Language

The object Constraint Language (OCL), which forms part of the UML set of modelling notations, is a precise, textual language for expressing constraints that cannot be shown diagrammatically in UML. This paper reflects on a number of aspects of the syntax and semantics of the OCL, and makes proposals for clarification or extension. Specifically, the paper suggests that: the concept of flattening collections of collections is unnecessary, state models should be connectable to class models, defining object creation should be made more convenient, OCL should be based on a 2-valued logic, set subtraction should be covered more fully, and a "let" feature should be introduced.

• Type: Conference
• Year: 1998
• Where: UML
• Authors: Ali Hamie, Franco Civello, John Howse, Stuart Kent, Richard Mitchell
• Keywords: Natural Language Processing, Object Constraint Language, Textual Language, UML 1998, UML Set