American Queen

Messy code is a nuisance. “Tidying” code, to make it more readable, requires breaking it up into manageable sections. In this practical guide, author Kent Beck, creator of Extreme Programming and pioneer of software patterns, suggests when and where you might apply tidyings to improve your code while keeping the overall structure of the system in mind. Instead of trying to master tidying all at once, this book lets you try out a few examples that make sense for your problem. If you have a big function containing many lines of code, you’ll learn how to logically divide it into smaller chunks. Along the way, you’ll learn the theory behind software design: coupling, cohesion, discounted cash flows, and optionality. This book helps you:• Understand the basic theory of how software design works and the forces that act on it• Explore the difference between changes to a system’s behavior and changes to its structure• Improve your programming experience by sometimes tidying first and sometimes tidying after• Learn how to make large changes in small, safe steps• Approach software design as an exercise in human relationships Kent Beck, creator of Extreme Programming, is a pioneer of software patterns, coauthor of JUnit, rediscoverer of Test-Driven Development, and observer of 3X: Explore/Expand/ Extract. Alphabetically, he’s the first signatory of the Agile Manifesto. Kent lives in San Francisco, California, and he is Chief Scientist at Mechanical Orchard, teaching skills to help geeks feel safe in the world. Cover 1 Copyright 6 Table of Contents 9 Foreword 13 Preface 15 What Is Tidy First? 15 Audience 16 What You Will Learn 16 Structure of the Book 17 Why “Empirical” Software Design? 17 How I Came to Write Tidy First? 18 O’Reilly Online Learning 20 How to Contact Us 20 Acknowledgments 21 Introduction 23 Part I. Tidyings 25 Chapter 1. Guard Clauses 27 Chapter 2. Dead Code 29 Chapter 3. Normalize Symmetries 31 Chapter 4. New Interface, Old Implementation 33 Chapter 5. Reading Order 35 Chapter 6. Cohesion Order 37 Chapter 7. Move Declaration and Initialization Together 39 Chapter 8. Explaining Variables 41 Chapter 9. Explaining Constants 43 Chapter 10. Explicit Parameters 45 Chapter 11. Chunk Statements 47 Chapter 12. Extract Helper 49 Chapter 13. One Pile 51 Chapter 14. Explaining Comments 53 Chapter 15. Delete Redundant Comments 55 Part II. Managing 57 Chapter 16. Separate Tidying 59 Chapter 17. Chaining 63 Conclusion 65 Chapter 18. Batch Sizes 67 Chapter 19. Rhythm 71 Chapter 20. Getting Untangled 73 Chapter 21. First, After, Later, Never 75 Never 75 Later 75 After 77 First 77 Summary 78 Part III. Theory 79 Chapter 22. Beneficially Relating Elements 81 Elements 81 Relating 82 Beneficially 82 Beneficially Relating Elements 82 Chapter 23. Structure and Behavior 85 Chapter 24. Economics: Time Value and Optionality 89 Chapter 25. A Dollar Today > A Dollar Tomorrow 91 Chapter 26. Options 93 Chapter 27. Options Versus Cash Flows 97 Chapter 28. Reversible Structure Changes 99 Chapter 29. Coupling 101 Chapter 30. Constantine’s Equivalence 105 Chapter 31. Coupling Versus Decoupling 109 Chapter 32. Cohesion 113 Chapter 33. Conclusion 115 Appendix. Annotated Reading List and References 117 Index 121 About the Author 124 Colophon 124 Tidying up messy software is a must. And that means breaking up the code to make it more readable, and using guard clauses and helping functions to make it understandable. In this practical guide, author Kent Beck, creator of Extreme Programming and pioneer of software patterns, suggests when and where you might apply tidyings in your code.Instead of trying to master tidying all at once, this book lets you try out a few examples that make sense for your problem. If you have a big function containing many lines of code, you'll learn how to logically divide it into smaller chunks. Along the way, you'll learn the theory behind software design: coupling, cohesion, discounted cash flows, and optionality.