An Automatic Programming System SPACE with Highly Visualized and Abstract Program Specification

摘要

In this paper, it is stated that visualization and abstraction of program specifications can be highly integrated on the basis of decision tables and condition expressions. In order to demonstrate this idea, we developed an automatic programming system called SPACE: Specification Acquisition and Compiling Engine. SPACE is designed to ease the production of business data processing program. SPACE has functions both to support the creation of visual program specifications and to generate COBOL programs according to the input program specifications. To visualize program specification, SPACE design windows are comprised of two diagrams and four tables in a format similar to the conventional detailed design sheets. To represent module functions, in particular, a visualized computation model called a decision table is used. All the possible execution states of a module are represented by combining the state function called condition expressions. The condition expressions represent the typical file processing patterns in very familiar form to actual business application designer. They do not simply give function values; each of them carries out implicit attached procedures according to the characteristic I/O control logic for business data processing. Hence users can describe program specifications concisely by designating merely the condition expression instead of the detailed I/O control logic. This paper uses sample descriptions of stock control problems to explain how visualization of computation and abstraction of algorithm can be integrated and formalized on a basis of a decision table and a condition expression. Also the paper describes how to generate programs from visual specifications.