Springer Books on Professional Computing – serie

Much of the material in this book comes from what I've learned as I've traveled around the country conducting seminars about working profitably in the automated office. During the first few months of those seminars, there was a question I was asked more often than any other single question. I wa~ asked the question so often that I gave it a nickname. I called it my "What The Devil" question. Often in different words, usually at the morning break in the seminar, and almost always with an effort not to offend or embarrass, I was asked, "What the devil is a psychologist doing conducting seminars about computer systems?" I'm not asked "What the Devil" questions much anymore. Those familiar with office automation have come to realize that human factors chiefly determine whether a computer system will be a success or an expensive failure. So many computer systems have not gained acceptance by is employees because the planners didn't use good psychological sense. That especially true as the computers move from the Engineering Department into the executive suites and the role of computers changes from just producing paper into also assisting in managerial decision making. One human factor I've learned is that people would much rather skip around in a book than read it from front cover to back cover directly. It's true whether the book is a user manual for office equipment or a volume on computer systems for decision makers.

This book describes the programming language Modula-2. It is written for people who know the Pascal language and who wish to learn Modula-2 in terms of their knowledge of Pascal. The text is divided into three parts. Part 1 introduces concepts unique to Modula-2 and thus new to Pascal programmers. Part 2 describes differences from Pascal. Part 3 defines modules which provide basic programming facilities. The appendices include a glossary and syntax diagrams. Please note that this book does not offer a complete description of the Modula-2 language; it is intended to complement Niklaus Wirth's definitive book Programming in Modula-2 (Springer-Verlag, 1983). Some readers will recognize this book as being based upon the Volition Systems Modula-2 User's Manual. Enough has changed to merit its reappearance in this more dignified form: existing material has been reorganized to improve clarity; new material has been added to improve content. This book was written with the ASE text editor. The text was produced in camera-ready form on the Scenic LaserTezt composition system. I wish to thank the following people and organizations for their contributions to the development of this book: Volition Systems, for giving me the opportunity to write about Modula-2; Jim Merritt, for reviewing an early draft; the Institut far Informatik, ETH Zarich, for publishing a series of informative technical papers on Modula-2; and finally, all the pioneer users of Volition Systems Modula-2, for their patience and foresight and support.

Ada® in Practice started lifeas a case studies report, the result of work per­ formed under government contract at SofTech, Inc. as part of an effort to identify and resolve issues related to Ada usage. Although that report has now evolved into a book intended for a more general audience, its objectives are largely unchanged. Asbefore,the primary goal is to promote effective use of Ada, both in general programming and design practice and in embedded computer systems specifically. Many features of Ada will be new to pro­ grammers and designers familiar with other languages; the program examples presented in the case studies are intended to serve as guidelines for proper usage of such features while pointing out common misconceptions and programming errors. In addition, we hope that this book as a whole will highlight the advan­ tages of using Ada at all stages of a program's life cycle, from problem analysis through testing and maintenance. However, it does not purport to hold all the answers to questions ofAda application;areas that would benefit from further investigation or more definitive guidelines are also suggested.

The earth, viewed through the window of an airplane, shows a regularity and reptition of features, for example, hills, valleys, rivers, lakes, and forests. Nevertheless, there is great local variation; Vermont does not look like Utah. Similarly, if we rise above the details of a few programming languages, we can discern features that are common to many languages. This is the programming language landscape; the main features include variables, types, control structures, and input/output. Again, there is local variation; Pascal does not look like Basic. This work is a broad and comprehensive discussion of the principal features of the major programming languages. A Study of Concepts The text surveys the landscape of programming languages and its features. Each chapter concentrates on a single language concept. A simple model of the feature, expressed as a mini-language, is presented. This allows us to study an issue in depth and relative isolation. Each chapter concludes with a discussion of the way in which the concept is incorporated into some well-known languages. This permits a reasonably complete coverage of language issues.

A small program is presented to motivate the concerns for programmer productivity and program quality that are the central issues of this set of essays. The example is one which demonstrates the performance aspect of programming. In order to achieve program quality, where a program is understood and known to be correct, we need a primary program description. This primary program description not only describes the program but is also used to generate the program. The method of applying primary program descriptions to produce programs is called metaprogramming and is described in Chapter 3. In the later chapters, we show how the method can be analyzed from an economic point of view to address the issues of productivity as well. 1 Introduction In thinking about programming over the last decade, I have concluded that very little is known about the process of programming or the engineering of software [1]. The consequence of having very little established truth to use as a basis for thinking about programming is that almost every conclusion must be reasoned out from first principles. Also, you cannot rely solely on textbooks but must use experimentation and direct observation to gain some experience with which to proceed.

Well suited to medium-scale general purpose computing, the Unix time­ sharing operating system is deservedly popular with academic institutions, research laboratories, and commercial establishments alike. Its user com­ munity, until recently a brotherhood of experienced computer profes­ sionals, it now attracting many people concerned with computer appli­ cations rather than the computer systems themselves. This book is intended for that new audience, people who have never encountered the Unix system before but who do have some acquaintance with computing. While helping beginning users get started is the primary aim of this book, it is also intended to serve as a handy reference subsequently. However, it is not designed to replace the definitive Unix system docu­ mentation. Unix operating systems now installed in computing centers, offices, and personal computers come in three related but distinct breeds: Seventh Edition Unix, Berkeley 4.2 BSD, and System V. These differ from each other in details, even though their family resemblance is strong. This book emphasizes System V, while paying heed to its two popular cousins. It also includes a few facilities in wide use, but not included in the normal system releases. Individual details, of course, must be found in the manuals supplied with each system.