Beautiful Code [3]
Time and again since that summer, I have heard people bemoan the fact that our profession doesn't teach students to see this. Architects are taught to look at buildings, and com-posers study one another's scores, but programmers—they look at each other's work only when there's a bug to fix; even then, they try to look at as little as possible. We tell students to use sensible variable names, introduce them to some basic design patterns, and then wonder why so much of what they write is so ugly.
This book is our attempt to fix this. In May 2006, I asked some well-known (and not so well-known) software designers to dissect and discuss the most beautiful piece of code they knew. As this book shows, they have found beauty in many different places. For some, it lives in the small details of elegantly crafted software. Others find beauty in the big picture—in how a program's structure allows it to evolve gracefully over time, or in the techniques used to build it.
Wherever they find it, I am grateful to our contributors for taking time to give us a tour. I hope that you enjoy reading this book as much as Andy and I have enjoyed editing it, and that it inspires you to create something beautiful, too.
Preface
Beautiful code was conceived by greg wilson in 2006 as a way to elicit insights from leading software developers and computer scientists. Together, he and his co-editor, Andy Oram, approached experts with diverse backgrounds from all over the world. They received a flood of responses, partly because royalties from the book are being donated to Amnesty International. The results of the project appear in this volume.
As wide-ranging as this book is, it represents just a small fraction of what is happening in this most exciting of fields. Thousand of other projects, equally interesting and educational, are being moved forward every day by other programmers whom we did not contact. Furthermore, many excellent practitioners who were asked for chapters do not appear in this book because they were too busy at the time, preferred not to contribute to Amnesty International, or had conflicting obligations. To benefit from the insights of all these people, we hope to do further books along similar lines in the future.
How This Book Is Organized
Chapter 1, A Regular Expression Matcher, by Brian Kernighan, shows how deep insight into a language and a problem can lead to a concise and elegant solution.
Chapter 2, Subversion's Delta Editor: Interface As Ontology, by Karl Fogel, starts with a well-chosen abstraction and demonstrates its unifying effects on the system's further development.
Chapter 3, The Most Beautiful Code I Never Wrote, by Jon Bentley, suggests how to measure a procedure without actually executing it.
Chapter 4, Finding Things, by Tim Bray, draws together many strands in Computer Science in an exploration of a problem that is fundamental to many computing tasks.
Chapter 5, Correct, Beautiful, Fast (in That Order): Lessons from Designing XML Verifiers, by Elliotte Rusty Harold, reconciles the often conflicting goals of thoroughness and good performance.
Chapter 6, Framework for Integrated Test: Beauty Through Fragility, by Michael Feathers, presents an example that breaks the rules and achieves its own elegant solution.
Chapter 7, Beautiful Tests, by Alberto Savoia, shows how a broad, creative approach to testing can not only eliminate bugs but turn you into a better programmer.
Chapter 8, On-the-Fly Code Generation for Image Processing, by Charles Petzold, drops down a level to improve performance while maintaining portability.
Chapter 9, Top Down Operator Precedence, by Douglas Crockford, revives an almost forgotten parsing technique and shows its new relevance to the popular JavaScript