Год выпуска: 2011 Автор: Lars Wortel Издательство: LAP Lambert Academic Publishing Страниц: 92 ISBN: 9783846514825
Описание
In programming practice, side effects are a well-known phenomenon. However, a formal definition of side effects is missing. Intuitively, a side effect of a propositional statement is a change in state of a program or model other than the effect (or change in state) it was initially executed for. In this book, I will check this intuition and I will give a formal definition of side effects. I will do so by modifying a system for modelling program instructions and program states, Quantified Dynamic Logic (QDL), to a system called Dynamic Logic with Assignments as Formulas (DLAf), which in contrast to QDL allows assignments in formulas and makes use of short-circuit evaluation. I will show the underlying logic in those formulas to be a variant of short-circuit logic called repetition-proof short-circuit logic. Using that, I can give the definition and even a classification of side effects. The definition and the classification of side effects outlined in this book not only open doors to...
