A MODEL FOR VISUALIZING THE EXECUTION OF MODULA-2 PROGRAMS

Abstract

This paper presents the initial work in adapting a model for visualizing program execution of Modula-2 programs that has been successfully used to describe execution of Pascal programs. Languages like Modula-2, which support external modules and their separate compilation, co-routines, and low-level interfaces involve concepts which cannot be readily analyzed and explained using static models. This model looks at execution in terms of source code to avoid some of the complexities which exist at the compiler/assembler level. The model mimics program execution through the introduction of block instances, static and dynamic links, and the binding rule as building blocks. Concepts of scope, parameter passing, information hiding, and quasi-concurrent processes are addressed using the model.