Postprocessor for structured FORTRAN

Abstract

Structured FORTRAN is an extension of FORTRAN language with constructs like DO WHILE, CASE, IF THEN ELSE, etc., that will allow people to write structured programs in FORTRAN. Many preprocessors have been. developed for various versions of structured FORTRAN that will convert programs written in it into regular FORTRAN programs. The resulting programs are then compiled with the regular FORTRAN compiler. This arrangement prohibits teaching structured FORTRAN language to beginning students in computer science because the actual debugging is done on the converted program in regular FORTRAN and then re-converted back to structured FORTRAN. It also poses problems for running experiments comparing programming efforts between a structured FORTRAN language and regular FORTRAN.One solution to these difficulties is to develop a postprocessor. A postprocessor is a processor which will collect the information produced by regular FORTRAN compiler and correlate the information with the program written in structured FORTRAN. This way, by appending a preprocessor and a postprocessor to structured FORTRAN, programmers will not be aware of the intermediate conversion steps that took place during the compilation of their programs. This postprocessor will also eliminate the need of a new structured FORTRAN compiler since the combined function of preprocessor, FORTRAN compiler and postprocessor exactly carries out the functions of a structured FORTRAN compiler.A general design of a postprocessor is described in this paper. Its impact on the existing FORTRAN compiler is kept to a minimum and its communication with the preprocessor is kept simple. The actual implementation will differ for each FORTRAN compiler due to the very fact that compilers are machine dependent. A set of proposed uses of the postprocessor will also be summarized in the paper.