Cunningham Ward - Pragmatic Programmer, The: From Journeyman to Master

As a reviewer I got an early opportunity to read the book you are holding. It was great, even in draft form. Dave Thomas and Andy Hunt have something to say, and they know how to say it. I saw what they were doing and I knew it would work. I asked to write this foreword so that I could explain why.

Simply put, this book tells you how to program in a way that you can follow. You wouldn't think that that would be a hard thing to do, but it is. Why? For one thing, not all programming books are written by programmers. Many are compiled by language designers, or the journalists who work with them to promote their creations. Those books tell you how to talk in a programming languagewhich is certainly important, but that is only a small part of what a programmer does.

What does a programmer do besides talk in programming language? Well, that is a deeper issue. Most programmers would have trouble explaining what they do. Programming is a job filled with details, and keeping track of those details requires focus. Hours drift by and the code appears. You look up and there are all of those statements. If you don't think carefully, you might think that programming is just typing statements in a programming language. You would be wrong, of course, but you wouldn't be able to tell by looking around the programming section of the bookstore.

In The Pragmatic Programmer Dave and Andy tell us how to program in a way that we can follow. How did they get so smart? Aren't they just as focused on details as other programmers? The answer is that they paid attention to what they were doing while they were doing itand then they tried to do it better.

Imagine that you are sitting in a meeting. Maybe you are thinking that the meeting could go on forever and that you would rather be programming. Dave and Andy would be thinking about why they were having the meeting, and wondering if there is something else they could do that would take the place of the meeting, and deciding if that something could be automated so that the work of the meeting just happens in the future. Then they would do it.

That is just the way Dave and Andy think. That meeting wasn't something keeping them from programming. It was programming. And it was programming that could be improved. I know they think this way because it is tip number two: Think About Your Work.

So imagine that these guys are thinking this way for a few years. Pretty soon they would have a collection of solutions. Now imagine them using their solutions in their work for a few more years, and discarding the ones that are too hard or don't always produce results. Well, that approach just about defines pragmatic. Now imagine them taking a year or two more to write their solutions down. You might think, That information would be a gold mine. And you would be right.

The authors tell us how they program. And they tell us in a way that we can follow. But there is more to this second statement than you might think. Let me explain.

The authors have been careful to avoid proposing a theory of software development. This is fortunate, because if they had they would be obliged to warp each chapter to defend their theory. Such warping is the tradition in, say, the physical sciences, where theories eventually become laws or are quietly discarded. Programming on the other hand has few (if any) laws. So programming advice shaped around wanna-be laws may sound good in writing, but it fails to satisfy in practice. This is what goes wrong with so many methodology books.

I've studied this problem for a dozen years and found the most promise in a device called a pattern language. In short, a pattern is a solution, and a pattern language is a system of solutions that reinforce each other. A whole community has formed around the search for these systems.

This book is more than a collection of tips. It is a pattern language in sheep's clothing. I say that because each tip is drawn from experience, told as concrete advice, and related to others to form a system. These are the characteristics that allow us to learn and follow a pattern language. They work the same way here.

You can follow the advice in this book because it is concrete. You won't find vague abstractions. Dave and Andy write directly for you, as if each tip was a vital strategy for energizing your programming career. They make it simple, they tell a story, they use a light touch, and then they follow that up with answers to questions that will come up when you try.

And there is more. After you read ten or fifteen tips you will begin to see an extra dimension to the work. We sometimes call it QWAN, short for the quality without a name. The book has a philosophy that will ooze into your consciousness and mix with your own. It doesn't preach. It just tells what works. But in the telling more comes through. That's the beauty of the book: It embodies its philosophy, and it does so unpretentiously.

So here it is: an easy to readand usebook about the whole practice of programming. I've gone on and on about why it works. You probably only care that it does work. It does. You will see.

Ward Cunningham

What distinguishes Pragmatic Programmers? We feel it's an attitude, a style, a philosophy of approaching problems and their solutions. They think beyond the immediate problem, always trying to place it in its larger context, always trying to be aware of the bigger picture. After all, without this larger context, how can you be pragmatic? How can you make intelligent compromises and informed decisions?

Another key to their success is that they take responsibility for everything they do, which we discuss in The Cat Ate My Source Code. Being responsible, Pragmatic Programmers won't sit idly by and watch their projects fall apart through neglect. In Software Entropy, we tell you how to keep your projects pristine.

Most people find change difficult to accept, sometimes for good reasons, sometimes because of plain old inertia. In Stone Soup and Boiled Frogs, we look at a strategy for instigating change and (in the interests of balance) present the cautionary tale of an amphibian that ignored the dangers of gradual change.

One of the benefits of understanding the context in which you work is that it becomes easier to know just how good your software has to be. Sometimes near-perfection is the only option, but often there are trade-offs involved. We explore this in Good-Enough Software.

Of course, you need to have a broad base of knowledge and experience to pull all of this off. Learning is a continuous and ongoing process. In Your Knowledge Portfolio, we discuss some strategies for keeping the momentum up.

Finally, none of us works in a vacuum. We all spend a large amount of time interacting with others. Communicate! lists ways we can do this better.

Pragmatic programming stems from a philosophy of pragmatic thinking. This chapter sets the basis for that philosophy.

There are certain tips and tricks that apply at all levels of software development, ideas that are almost axiomatic, and processes that are virtually universal. However, these approaches are rarely documented as such; you'll mostly find them written down as odd sentences in discussions of design, project management, or coding.

In this chapter we'll bring these ideas and processes together. The first two sections, The Evils of Duplication and Orthogonality, are closely related. The first warns you not to duplicate knowledge throughout your systems, the second not to split any one piece of knowledge across multiple system components.

As the pace of change increases, it becomes harder and harder to keep our applications relevant. In