In this paper we propose an exception logic { formalizing reasoning about exceptions. We use this logic to defend two claims. First, we argue that default logic { formalizing reasoning about default assumptions { is an extension of exception logic. A deconstruction argument shows that reasoning about exceptions is one of the rst principles of reasoning about default assumptions. Second, we argu...

Exception handling in Ada has a number of well-known problems. It allows for the propagation of unhandled and anonymous exceptions, it is error-prone and it is inappropriate for some language features including tasking and tagged types. Ada programs with exceptions are difficult to understand, develop, modify or analyse, and the exception handling features can be misused in a number of ways. In...

Given a disjunctive normal form (DNF) expression φ and a set A of vectors satisfying the expression, called the set of exceptions, we would like to update φ to get a new DNF which is false on A, and otherwise is equivalent to φ. Is there an algorithm with running time polynomial in the number of variables, the size of the original formula and the number of exceptions, which produces an updated ...

Existing methods for dealing with knowledge updates differ greatly depending on the underlying knowledge representation formalism. When Classical Logic is used, updates are typically performed by manipulating the knowledge base on the model-theoretic level. On the opposite side of the spectrum stand the semantics for updating Answer-Set Programs that need to rely on rule syntax. Yet, a unifying...

Most modern programming languages rely on exceptions for dealing with errors. Although exception handling was a significant improvement over other mechanisms like checking return codes, it’s far from perfect. In fact, it can be argued that this mechanism is seriously flawed. In this paper we argue that exception handling should be automatically done at the runtime/operating system level. The mo...

This paper presents a classification framework for workflow exception handling in the form of patterns. This framework is independent of specific modelling approaches or technologies and as such provides an objective means of delineating the exception-handling capabilities of specific workflow systems. It is subsequently used to assess the level of exceptions support provided by eight commercia...

Exceptions are a powerful feature for the propagation and handling of failure of operations. Naive use of exceptions however introduces subtle complexity into a system due to the nonlocal nature of throwing an exception. This paper presents a pattern language of eleven Java idioms which serve as a framework for using exceptions. The patterns help to balance the forces that the overall complexit...

In this paper we extend the concept of exception spaces as defined by Cost and Salzberg (Cost and Salzberg, 1993), in the context of exemplar-based reasoning. Cost et al. defined exception spaces based on the goodness, in terms of performance, of an exemplar. While this is straightforward when using exemplars for classification problems, such a definition does not exist for regression problems....

Architecture-based development environments are becoming an effective solution towards the construction of robust distributed systems. Through the abstract description of complex software systems configurations in terms of the interconnection of software elements at the interface level, software reuse and evolution get promoted. In addition, as shown by research results from the software archit...

Exceptions are a painful reality for most companies. Missing customer information, improperly coded order fields, incorrectly allocated inventory, and data mismatches between customer and billing systems are just a few examples of exceptions that can happen in the typical course of business. When these exceptions divert business transactions from the normal process path, the results are often l...