EXPLOITING PERSISTENT LINKAGE IN SOFTWARE ENGINEERING ENVIRONMENTS

Persistent programming systems are designed to provide technology for the construction and maintenance of large, long-lived object-based app lication systems. Many successful prototypes have been constructed and a large body of application building experience is emerging. Three co mmon attributes of persistent systems are persistent linkage, strong t yping, and the referential integrity of data. Persistent linkage allow s persistent objects to be included in the binding process. Strong typ ing guarantees that objects are only manipulated in a manner consisten t with their type system descriptions. Referential integrity ensures t hat once a link (reference) to an object is established, its identity is unique and it persists over time. As a consequence no object can be deleted while another refers to it. Here we examine some of the advan tages of providing software engineering environments within a persiste nt object system with strong typing and referential integrity. It is s hown how the integration of system specifications, programs, configura tion management tools and documentation all within a single persistent environment leads to powerful new techniques. This new power is achie ved by sharing structured persistent data across the hitherto enclosin g boundaries of system components.