Refactoring to Collections

"Refactoring to Collections" is a book and video course that teaches you how to apply functional programming principles to write clean, maintainable PHP. Learn how to use collection pipelines to break down ugly, complex functions into a series of simple transformations, free of loops, complex conditionals, and temporary variables. The first section of the book focuses on teaching you the theory and fundamentals you need to to start applying functional programming principles to your code. You'll learn about the difference between imperative and declarative code, how to use higher order functions to remove duplication, and how to reimplement fundamental operations like map, reduce, and filter from first principles. The second section of the book and the companion screencasts are a deep dive into problem solving with Laravel's Collection library. Through 15 in-depth examples, we walk through everything from beginner to expert level problems, using advanced operations like zip and transpose, and even extending the library with our own custom transformations. (http://adamwathan.me/refactoring-to-collections/) http://adamwathan.me/refactoring-to-c... Contents......Page 3 Imperative Programming......Page 7 Higher Order Functions......Page 9 Noticing Patterns......Page 10 Each......Page 15 Map......Page 17 Map vs. Each......Page 18 Filter......Page 19 Reject......Page 21 Reduce......Page 23 With Great Power......Page 30 Transforming Data......Page 31 Thinking in Steps......Page 33 The Problem with Primitives......Page 35 Arrays as Objects......Page 37 Introducing Collections......Page 38 A Note on Mutability......Page 40 Quacking Like... an Array?......Page 42 ArrayAccess......Page 43 Countable......Page 45 IteratorAggregate......Page 47 The Golden Rule of Collection Programming......Page 49 A Lot of Practice......Page 51 Pricing Lamps and Wallets......Page 52 Replace Conditional with Filter......Page 54 Replace || with Contains......Page 55 Reduce to Sum......Page 56 Replace Nested Loop with FlatMap......Page 58 Plucking for Fun and Profit......Page 61 CSV Surgery 101......Page 62 Everything is Better as a Collection......Page 65 Using a For Loop......Page 67 Breaking It Down......Page 68 Reversing the Collection......Page 69 Mapping with Keys......Page 70 What's Your GitHub Score?......Page 72 Loops and Conditionals......Page 73 Replace Collecting Loop with Pluck......Page 74 Extract Score Conversion with Map......Page 76 Replace Switch with Lookup Table......Page 77 Associative Collections......Page 79 Extracting Helper Functions......Page 82 Encapsulating in a Class......Page 83 Formatting a Pull Request Comment......Page 86 Map and Implode......Page 87 Stealing Mail......Page 88 Replace Nested Check with Contains......Page 90 Contains as a Higher Order Function......Page 91 Choosing a Syntax Handler......Page 94 Looking for a Match......Page 95 Getting the Right Checker......Page 96 Replace Iteration with First......Page 97 Providing a Default......Page 98 The Null Checker......Page 100 Tagging on the Fly......Page 104 Extracting the Loop......Page 105 Normalizing with Map......Page 107 Nitpicking a Pull Request......Page 109 A Fork in the Code......Page 110 Learning from Smalltalk......Page 111 Collection Macros......Page 113 Chainable Conditions......Page 114 Comparing Monthly Revenue......Page 117 Matching on Index......Page 118 Using Zip to Compare......Page 119 Building a Lookup Table......Page 121 PHP's Array Identity Crisis......Page 122 A Reusable Abstraction......Page 123 The toAssoc Macro......Page 124 Mapping to Pairs......Page 125 Transposing Form Input......Page 127 Quick and Dirty......Page 131 Identifying a Need......Page 132 Introducing Transpose......Page 134 Transpose in Practice......Page 136 Ranking a Competition......Page 138 Zipping-in the Ranks......Page 140 Dealing with Ties......Page 141 Grouping by Score......Page 142 Adjusting the Ranks......Page 145 Collapse and Sort......Page 148 Cleaning Up......Page 150 Grouping Operations......Page 153 Breaking the Chain......Page 154 The Pipe Macro......Page 155 Afterword......Page 158 "Refactoring to Collections" is a book and video course that teaches you how to apply functional programming principles to write clean, maintainable PHP.Learn how to use collection pipelines to break down ugly, complex functions into a series of simple transformations, free of loops, complex conditionals, and temporary variables.The first section of the book focuses on teaching you the theory and fundamentals you need to to start applying functional programming principles to your code.You'll learn about the difference between imperative and declarative code, how to use higher order functions to remove duplication, and how to reimplement fundamental operations like map, reduce, and filter from first principles.The second section of the book and the companion screencasts are a deep dive into problem solving with Laravel's Collection library.Through 15 in-depth examples, we walk through everything from beginner to expert level problems, using advanced operations like zip and transpose, and even extending the library with our own custom transformations.[http://adamwathan.me/refactoring-to-c...](http://adamwathan.me/refactoring-to-collections/)