ENCOMPASS: A SAGA BASED ENVIRONMENT FOR THE COMPOSITION OF PROGRAMS AND SPECIFICATIONS.

ENCOMPASS is an example integrated software engineering environment being constructed by the SAGA project. ENCOMPASS supports the specification, design, and construction of efficient, validated, and verified programs in a modular programming language. We present the development paradigm, schema of software configurations, and hierarchical library structure used by ENCOMPASS. We illustrate these with an example of software development. In ENCOMPASS, a development proceeds through the phases planning, requirements definition, validation, refinement, and system integration. The refinement phase may be decomposed into a number of steps, each consisting of a design transformation and its verification. The components in a software system are modeled as entities which have relationships between them. An entity may have different versions and different views of the same project are allowed. The simple entities supported by ENCOMPASS may be combined into modules which may be collected into projects. ENCOMPASS supports multiple programmers and projects using a hierarchical library system containing a workspace for each programmer; a project library for each project, and a global library common to all projects. A prototype implementation of ENCOMPASS is being constructed on the Unix operating system using an existing revision control system.