FLOW : a programming environment using diagrams

Abstract

A graphical language is developed as a generalization of the structured flowcharts proposed by Nessi and Shneiderman. This language can be used in the specification of procedures, procedure interfaces and data structures. A software production support environment is then developed using this language which is capable of producing systems in FORTRAN IV, COBOL and Pascal. The environment integrates new and existing tools and facilitates and encourages the design, coding and testing of well-structured systems using the methodology of stepwise refinement. A central component of the environment is a software production data base which holds the programme source as well as control information pertaining to the state of development of the system and interfaces of the various programme modules being created within the system. A helpful syntax directed editor for the graphical language is used to update the data base. Programme specifications are extracted from the data base by a number post-processors which produce target code for the required high level languages as well as system documentation. Some of the practical experience gained over a three year period is described and suggestions for the extension of the current environment and topics for future research are presented.