Automating the Transformational Development of Software. Volume 1

摘要

This report proposes a new model of software development by transformation. It provides a formal basis for automating and documenting the software development process. The current manual transformation model has two major problems: long sequences of low-level transformations are required to move from formal specification to implementation, and the problem-solving used to reach an implementation is not recorded. Left implicit (and undocumented) are the goals and methods that lead to transformation applications, and the criteria used to select one transformation over another. The new model, as incorporated in a system called Glitter, explicitly represents transformation goals, methods, and selection criteria. Glitter achieves a user-supplied goal by carrying out the problem-solving required to generate an appropriate sequence of transformation applications. For example, the user asks Glitter to eliminate a data structure that would be expensive to store or a function costly to compute. Glitter achieves this by locating all references to the offending construct and devising an appropriate substitution for each. Glitter was able to automatically generate 90 percent of the planning and transformation steps in the examples studied. This report is published in two volumes. Volume 1 contains the text of the report; Volume 2 is a set of seven appendices relating to and illustrating the text in Volume 1.