Table Of Content

Deremu Peco s Co essence O Compucunc r THE ESSENCE OF THE ESSENCE OF COMPUTING SERIES Published titles The Essence of Program Design The Essence of Discrete Mathematics The Essence of Logic The Essence of Programming Using C++ Forthcoming titles The Essence of Artificial intelligence The Essence of Databases The Essence of Human-Computer Interaction The Essence of Z The Essence of Compilers LHe ESSENCE OTF PROGRAM DESIGN Douglas Bell lan Morrey and John Pugh Ut Prentice Hall LONDON NEWYORK TORONTO SYDNEY TOKYO SINGAPORE MADRID MEXICOCITY MUNICH PARIS First published 1997 by Prentice Hall Europe — Campus 400, Maylands Avenue Hemel Hempstead UK Hertfordshire, HP2 7EZ A division of Simon & Schuster International Group~ © Prentice Hall 1997 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form, or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission, in writing, from the publisher. Typeset in 10/12 pt Times by Photoprint, Torquay Printed and bound in Great Britain by Hartnolls Limited, Bodmin, Cornwall Library of Congress Cataloging-in-Publication Data Available from the publisher British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 0-13-367806-7 lel eos 4:5 01 00 99 98 97 This book is for our children: Alice, Tom, Beth, Chloe and Gareth. 4 They made the effort worthwhile. . = - * " Serema Users’. Copy - SCé Contents Foreword x Acknowledgements Xll Preface Xili 1 Introduction 1 1.1 What is design? 1 1.2. Why do program design? 2 1.3. A variety of methods 3 1.4 The range of application areas DS 1.5 Assessing methods 4 1.6 Summary 6 2 Structured programming 7 2.1 Introduction 7 2.2 Arguments against goto 8 2.3 Arguments in favour of goto 12 2.4 Selecting control structures 14 2.5 What is structured programming? 16 2.6 Summary 19 29 Exercises 19 2.8 References and further reading 2) 3 Functional decomposition 22 3.1. Introduction De 3.2 An example — a video game 98 3.3. More about the method Da 3.4 What about data? 28 3.5 Alternative solutions 28 3.6 The place of functional decomposition 29 3.7 Discussion 30 3.8 Summary SZ 3.9 Exercises 32 3.10 References and further reading ou, viii CONTENTS 4 The Michael Jackson program design method Introduction A simple example Processing input files Physical and logical structures Processing several input and output streams Serial file processing and correspondence Structure clashes . Discussion and evaluation Summary Exercises 4.11 References and further reading 5 Data flow design Introduction An analogy First examples A second example Rationale for the method Another example — monitoring a plant Discussion and evaluation Summary Exercises onl References and further reading 6 Object-oriented design Introduction OOP concepts Objects and encapsulation Polymorphism and dynamic binding Classes Inheritance and subclassing Class libraries Summary of OOP concepts Introduction to OO design CRC design Refining a design Designing is programming and programming is designing OO design methodologies Discussion and evaluation Summary Exercises References and further reading