Domain-specific language modelling with UML profiles by decoupling abstract and concrete syntaxes

UML profiling presents some acknowledged deficiencies, among which the lack of expressiveness of the profiled notations, together with the high coupling between abstract and concrete syntaxes outstand. These deficiencies may cause distress among UML-profile modellers, who are often forced to extend from unsuitable metaclasses for mere notational reasons, or even to model domain-specific languages from scratch just to avoid the UML-profiling limitations. In order to palliate this situation, this article presents an extension of the UML profile metamodel to support arbitrarily-complex notational extensions by decoupling the UML abstract and concrete syntax. Instead of defining yet another metamodel for UML-notational profiling, notational extensions are modelled with DI, i.e., the UML notation metamodel for diagram interchange, keeping in this way the extension within the standard. Profiled UML notations are rendered with DI by defining the graphical properties involved, the domain-specific constraints applied to DI, and the rendering routines associated. Decoupling abstract and concrete syntax in UML profiles increases the notation expressiveness while decreasing the abstract-syntax complexity.