The Object Constraint Language (OCL) is a central component in modeling and transformation languages such as the Unified Modeling Language (UML), the Meta Object Facility (MOF), and Query View Transformation (QVT). OCL is standardized as a strict functional language. In this article, we propose a lazy evaluation strategy for OCL. We argue that a lazy evaluation semantics is beneficial in some m...

The Object Constraint Language (OCL) is a specification language which could be used for describing constraints on object-oriented models and other modelling artifacts. OCL is a part of the Unified Modelling Language (UML) which is the de facto standard for objectoriented analysis and design. OCL is designed to be used by software engineers and modellers and requires only modest mathematical tr...

Business rules are often speci ed only implicitly by applications to express user-de ned constraints. OCL provides the chance to explicitly and automatically deal with business rules when building object-oriented applications. We investigate how OCL constraints can be handled in database applications as one of the most important kind of business applications. Based on our OCL toolset prototype ...

Checking the correctness of UML/OCL models is a crucial task in the design of complex software and hardware systems. As a consequence, several approaches have been presented which address this problem. Methods based on satisfiability (SAT) solvers have been shown to be very promising in this domain. Here, the actual verification task is encoded as an equivalent bit-vector instance to be solved ...

At its origins, OCL was conceived as a strict semantics for undefinedness, with the exception of the logical connectives of type Boolean that constitute a three-valued propositional logic. Recent versions of the OCL standard added a second exception element, which, similar to the null references in programming languages, is given a non-strict semantics. In this paper, we report on our results i...

OCL is used to add rigour to UML/MOF models, and in particular can be used to express behavioural details (e.g., operation preand postconditions, class invariants) of such models. The applicability and utility of OCL can be assessed by applying it to realistic applications and by investigating its capabilities both in terms of language characteristics and tool support. With this in mind, in thi...

UML/OCL is perceived as the de-facto standard for specifying object-oriented models in general and data models in particular. Since recently, all data types of UML/OCL comprise two different exception elements: invalid (“bottom” in semantics terminology) and null (for “non-existing element”). This has far-reaching consequences on both the logical and algebraic properties of OCL expressions as w...

Precise modeling is essential to the success of the OMG’s Model Driven Architecture initiative. At the modeling level (M1) OCL allows for the precision needed to write executable models. Can OCL be extended to become a full high-level executable language with side-effects? At the meta-level (M2), queries, views and transformations are subjects that will be vital to the success of the OMG’s Mode...

OCL 2.0 is the newest version of the OMG’s constraint language to accompany their suit of Object Oriented modelling languages. The use of OCL as an accompanying constraint and query language to modelling with these languages is essential. As tools are built to support the modelling languages, it is also necessary to implement the OCL. This paper reports our experience of implementing OCL based ...

The “Object Constraint Language” (OCL) offers a formal notation for constraining model elements in UML diagrams. OCL consists of a navigational expression language which, for instance, can be used to state invariants and preand post-conditions in class diagrams. We discuss some problems in ensuring non-local, navigating OCL class invariants, as for bidirectional associations, in programming lan...