An Algorithm for Structuring Programs

Abstract

Structured programming emphasizes programming language constructs such as while loops, until loops, and if then else statements. Properly used, these constructs make occurrences of loops and branching of control obvious. They are preferable to goto statements, which tend to obscure the flow of control [DDH,DIJ]. This paper describes an algorithm which transforms a flowgraph into a program written using repeat (do forever) and if then else statements. The goal of the algorithm is to produce readable programs, rather than to avoid the use of goto statements entirely. goto statements are generated when there is no better way to describe the flow of control.