DATA-ORIENTED EXCEPTION HANDLING

Exception handling mechanisms were added to programming languages to segregate normal algorithmic processing from error processing. However, handlers, which are typically associated with exceptions through programs' control features, clutter source text when features are nested or when different objects require different responses to exceptions. We describe a method for associating handlers with data objects in declarations that better segregates algorithmic and error processing. We call our notation data-oriented exception handling to distinguish it from more conventional, control-oriented mechanisms. Empirical studies of Ada programs indicate that conventional exception handling mechanisms are more complex than necessary and that data-oriented exception handling can be used to produce programs that are smaller, better structured, and easier to understand and modify.