Functional Programming Simplified

Summary Functional Programming in Scala is a serious tutorial for programmers looking to learn FP and apply it to the everyday business of coding. The book guides readers from basic techniques to advanced topics in a logical, concise, and clear progression. In it, you'll find concrete examples and exercises that open up the world of functional programming. Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications. About the Technology Functional programming (FP) is a style of software development emphasizing functions that don't depend on program state. Functional code is easier to test and reuse, simpler to parallelize, and less prone to bugs than other code. Scala is an emerging JVM language that offers strong support for FP. Its familiar syntax and transparent interoperability with Java make Scala a great place to start learning FP. About the Book Functional Programming in Scala is a serious tutorial for programmers looking to learn FP and apply it to their everyday work. The book guides readers from basic techniques to advanced topics in a logical, concise, and clear progression. In it, you'll find concrete examples and exercises that open up the world of functional programming. This book assumes no prior experience with functional programming. Some prior exposure to Scala or Java is helpful. What's Inside Functional programming concepts The whys and hows of FP How to write multicore programs Exercises and checks for understanding About the Authors Paul Chiusano and Rúnar Bjarnason are recognized experts in functional programming with Scala and are core contributors to the Scalaz library. Table of Contents PART 1 INTRODUCTION TO FUNCTIONAL PROGRAMMING What is functional programming? Getting started with functional programming in Scala Functional data structures Handling errors without exceptions Strictness and laziness Purely functional state PART 2 FUNCTIONAL DESIGN AND COMBINATOR LIBRARIES Purely functional parallelism Property-based testing Parser combinators PART 3 COMMON STRUCTURES IN FUNCTIONAL DESIGN Monoids Monads Applicative and traversable functors PART 4 EFFECTS AND I/O External effects and I/O Local effects and mutable state Stream processing and incremental I/O

Save time and trouble building object-oriented, functional, and concurrent applications with Scala. The latest edition of this comprehensive cookbook is packed with more than 250 ready-to-use recipes and 1,000 code examples to help you solve the most common problems when working with Scala 3 and its popular libraries. Scala changes the way you think about programming--and that's a good thing. Whether you're working on web, big data, or distributed applications, this cookbook provides recipes based on real-world scenarios for both experienced Scala developers and programmers just learning to use this JVM language. Author Alvin Alexander includes practical solutions from his experience using Scala for component-based, highly scalable applications that support concurrency and distribution. Recipes cover: Strings, numbers, and control structures Classes, methods, objects, traits, packaging, and imports Functional programming techniques Scala's wealth of collections classes and methods Building and publishing Scala applications with sbt Actors and concurrency with Scala Future and Akka Typed Popular libraries, including Spark, Scala.js, Play Framework, and GraalVM Types, such as variance, givens, intersections, and unions Best practices, including pattern matching, modules, and functional error handling

If you've had trouble trying to learn Functional Programming (FP), you're not alone. In this book, Alvin Alexander -- author of the Scala Cookbook and former teacher of Java and Object-Oriented Programming (OOP) classes -- writes about his own problems in trying to understand FP, and how he finally conquered it. What he originally learned is that experienced FP developers are driven by two goals: to use only immutable values, and write only pure functions. What he later learned is that they have these goals as the result of another larger goal: they want all of their code to look and work just like algebra. While that sounds simple, it turns out that these goals require them to use many advanced Scala features -- which they often use all at the same time. As a result, their code can look completely foreign to novice FP developers. As Mr. Alexander writes, "When you first see their code it's easy to ask, 'Why would anyone write code like this?'" Mr. Alexander answers that "Why?" question by explaining the benefits of writing pure functional code. Once you understand those benefits -- your motivation for learning FP -- he shares five rules for programming in the book: All fields must be immutable ('val' fields). All functions must be pure functions. Null values are not allowed. Whenever you use an 'if' you must also use an 'else'. You won't create OOP classes that encapsulate data and behavior; instead you'll design data structures using Scala 'case' classes, and write pure functions that operate on those data structures. In the book you'll see how those five, simple rules naturally lead you to write pure, functional code that reads like algebra. He also shares one more Golden Rule for learning: Always ask "Why"? Lessons in the book include: How and why to write only pure functions Why pure function signatures are much more important than OOP method signatures Why recursion is a natural tool for functional programming, and how to write recursive algorithms Because the Scala 'for' expression is so important to FP, dozens of pages explain the details of how it works In the end you'll see that monads aren't that difficult because they're a natural extension of the Five Rules The book finishes with lessons on FP data modeling, and two main approaches for organizing your pure functions As Mr. Alexander writes, "In this book I take the time to explain all of the concepts that are used to write FP code in Scala. As I learned from my own experience, once you understand the Five Rules and the small concepts, you can understand Scala/FP." Please note that because of the limits on how large a printed book can be, the paperback version does not include all of the chapters that are in the Kindle eBook. The following lessons are not in the paperback version: Grandma's Cookies (a story about pure functions) The ScalaCheck lessons The Type Classes lessons The appendices Because those lessons didn' fit in the print version, they have been made freely available online. (Alvin Alexander (alvinalexander.com) wrote the popular Scala Cookbook for O'Reilly, and also self-published two other books, How I Sold My Business: A Personal Diary, and A Survival Guide for New Consultants.)

Distributed across servers, difficult to test, and resistant to modification--modern software is complex. Grokking Simplicity is a friendly, practical guide that will change the way you approach software design and development. It introduces a unique approach to functional programming that explains why certain features of software are prone to complexity, and teaches you the functional techniques you can use to simplify these systems so that they''re easier to test and debug. Available in PDF (ePub, kindle, and liveBook formats coming soon). about the technology Even experienced developers struggle with software systems that sprawl across distributed servers and APIs, are filled with redundant code, and are difficult to reliably test and modify. Adopting ways of thinking derived from functional programming can help you design and refactor your codebase in ways that reduce complexity, rather than encouraging it. Grokking Simplicity lays out how to use functional programming in a professional environment to write a codebase that''s easier to test and reuse, has fewer bugs, and is better at handling the asynchronous nature of distributed systems. about the book In Grokking Simplicity, you''ll learn techniques and, more importantly, a mindset that will help you tackle common problems that arise when software gets complex. Veteran functional programmer Eric Normand guides you to a crystal-clear understanding of why certain features of modern software are so prone to complexity and introduces you to the functional techniques you can use to simplify these systems so that they''re easier to read, test, and debug. Through hands-on examples, exercises, and numerous self-assessments, you''ll learn to organize your code for maximum reusability and internalize methods to keep unwanted complexity out of your codebase. Regardless of the language you''re using, the ways of thinking in this book will help recognize problematic code and tame even the most complex software. what''s inside Apply functional programming principles to reduce codebase complexity Work with data transformation pipelines for code that''s easier to test and reuse Tools for modeling time to simplify asynchrony 60 exercises and 100 questions to test your knowledge about the reader For experienced programmers. Examples are in JavaScript. about the author Eric Normand has been a functional programmer since 2001 and has been teaching functional programming online and in person since 2007. Visit LispCast.com to see more of his credentials.

In his latest book, Alvin Alexander, author of the Scala Cookbook and Functional Programming, Simplified, brings you a quick, simple introduction to the Scala programming language. In under 250 fast-paced pages, Mr. Alexander demonstrates that Scala is a beautiful, modern, expressive programming language. The book is broken down into 55 short lessons to help you learn one topic at a time, and also help you easily find what you need. Lessons include: - An introduction to Scala's two types of variables, `val` and `var`- Scala control structures, including powerful `for` expressions and `match` expressions- An overview of Scala collections classes and methods- Coverage of object-oriented programming (OOP), including features of Scala classes and methods- An introduction to functional programming (FP), including pure functions, using functions as variables, case classes, match expressions, functional error handling, and more- How to program in a modular style with traits- How to build Scala projects with SBT- How to write TDD and BDD unit tests with ScalaTest- Programming concurrency with Akka actors and Scala futures To help get you started with Scala as fast as possible, the book shares many source code examples, including several open source Github projects that you can run immediately. All examples in the book have been written with the latest Scala release (version 2.12), and represent 2018's "best practices" for Scala programming.

Create robust and maintainable Java applications using the functional style of programming About This Book Explore how you can blend object-oriented and functional programming styles in Java Use lambda expressions to write flexible and succinct code A tutorial that strengthens your fundamentals in functional programming techniques to enhance your applications Who This Book Is For If you are a Java developer with object-oriented experience and want to use a functional programming approach in your applications, then this book is for you. All you need to get started is familiarity with basic Java object-oriented programming concepts. What You Will Learn Use lambda expressions to simplyfy code Use function composition to achieve code fluency Apply streams to simply implementations and achieve parallelism Incorporate recursion to support an application's functionality Provide more robust implementations using Optionals Implement design patterns with less code Refactor object-oriented code to create a functional solution Use debugging and testing techniques specific to functional programs In Detail Functional programming is an increasingly popular technology that allows you to simplify many tasks that are often cumbersome and awkward using an object-oriented approach. It is important to understand this approach and know how and when to apply it. Functional programming requires a different mindset, but once mastered it can be very rewarding. This book simplifies the learning process as a problem is described followed by its implementation using an object-oriented approach and then a solution is provided using appropriate functional programming techniques. Writing succinct and maintainable code is facilitated by many functional programming techniques including lambda expressions and streams. In this book, you will see numerous examples of how these techniques can be applied starting with an introduction to lambda expressions. Next, you will see how they can replace older approaches and be combined to achieve surprisingly elegant solutions to problems. This is followed by the investigation of related concepts such as the Optional class and monads, which offer an additional approach to handle problems. Design patterns have been instrumental in solving common problems. You will learn how these are enhanced with functional techniques. To transition from an object-oriented approach to a functional one, it is useful to have IDE support. IDE tools to refactor, debug, and test functional programs are demonstrated through the chapters. The end of the book brings together many of these functional programming techniques to create a more comprehensive application. You will find this book a very useful resource to learn and apply functional programming techniques in Java. Style and approach In this tutorial, each chapter starts with an introduction to the terms and concepts covered in that chapter. It quickly progresses to contrast an object-oriented approach with a functional approach using numerous code examples.

How can you overcome JavaScript language oddities and unsafe features? With this book, you’ll learn how to create code that’s beautiful, safe, and simple to understand and test by using JavaScript’s functional programming support. Author Michael Fogus shows you how to apply functional-style concepts with Underscore.js, a JavaScript library that facilitates functional programming techniques. Sample code is available on GitHub at https://github.com/funjs/book-source. Fogus helps you think in a functional way to help you minimize complexity in the programs you build. If you’re a JavaScript programmer hoping to learn functional programming techniques, or a functional programmer looking to learn JavaScript, this book is the ideal introduction. Use applicative programming techniques with first-class functions Understand how and why you might leverage variable scoping and closures Delve into higher-order functions—and learn how they take other functions as arguments for maximum advantage Explore ways to compose new functions from existing functions Get around JavaScript’s limitations for using recursive functions Reduce, hide, or eliminate the footprint of state change in your programs Practice flow-based programming with chains and functional pipelines Discover how to code without using classes