An Interface-Based Ada Programming Support Environment

Programming Support Environments (PSEs) have recently been the focus o f much research directed at producing new methods for developing software mor e efficiently and reliably. The traditional approach to developing PSEs has been t o create a number of novel tools, and then integrate the tools together by adding a common database and modifying the interfaces between the tools until they ca n work together. Recently, however, it has been recognized that the interface s between the tools and the rest of the environment are critical, and perhaps mor e important, than the tools themselves. To be useful in solving the larger problem s currently associated with software, a PSE must be able to adapt and provide ne w capabilities, and be available to a relatively large number of users on a variety o f machines. The goal of this research was to determine whether PSEs based on abstrac t interfaces provide enhanced portability and extensibility over traditionally designed environments. To accomplish this goal, a prototype interface-based PS E was developed and then compared against traditional environments to determin e which had better portability and extensibility. First, an interface model was developed to define exactly what types of interface assumptions must be specified to define an appropriate abstract interface. Next, a prototype APSE based on that interface model was designed, specified, and implemented. Finally, this pro-totype APSE was measured against traditionally designed environments using ori-ginal environment portability and extensibility metrics. I. Introductio n The software crisis, characterized by late, unreliable, unmaintainable, and expensive softwar