Abstract

Procedural programming languages usually do not support side_effect free functions but merely a form of function procedures. We argue that functions should be free of (non_local) side_effects, if they are considered as abstraction mechanism for expressions. While it is easy to statically detect side_effects in functions that do not dynamically allocate variables, this is no longer the case for functions that do create new data structures. After giving a classification of different levels of side_effects, we describe a simple and efficient method that allows for their dynamic detection while retaining assignments, i.e., without referring to a pure functional implementation. The method has been implemented for an experimental subset of Oberon. 3 1 Introduction Procedural programming languages usually provide two different concepts for specifying computation, namely expressions and statements. In a first step, we consider only expressions that do not call functions, and only sta...

Citations