You'll learn how to use Haskell in a variety of practical ways, from short scripts to large and demanding applications. Real World Haskell takes you through the basics of functional programming at a brisk pace, and then helps you increase your understanding of Haskell in real-world issues like I/O, performance, dealing with data, concurrency, and more as you move through each chapter. With this book, you will:Understand the differences between procedural and functional programming Learn the features of Haskell, and how to use it to develop useful programs Interact with filesystems, databases, and network services Write solid code with automated tests, code coverage, and error handling Harness the power of multicore systems via concurrent and parallel programming You'll find plenty of hands-on exercises, along with examples of real Haskell programs that you can modify, compile, and run. Whether or not you've used a functional language before, if you want to understand why Haskell is coming into its own as a practical language in so many major organizations, Real World Haskell is the best place to start.

    Akka uses Actors-independently executing processes that communicate via message passing—as the foundation for fault-tolerant applications where individual actors can fail without crashing everything. Perfect for high-volume applications that need to scale rapidly, Akka is an efficient foundation for event-driven systems that want to scale elastically up and out on demand, both on multi-core processors and across server nodes.Akka in Action is a comprehensive tutorial on building message-oriented systems using Akka. The book takes a hands-on approach, where each new concept is followed by an example that shows you how it works, how to implement the code, and how to (unit) test it. You'll learn to test and deploy an actor system and scale it up and out, showing off Akka's fault tolerance. As you move along, you'll explore a message-oriented event-driven application in Akka. You'll also tackle key issues like how to model immutable messages and domain models, and apply patterns like Event Sourcing, and CQRS. The book concludes with practical advice on how to tune and customize a system built with Akka.

    This is necessary because, in the words of Michael Polanyi, "we can know more than we can tell." Our design choices are not the result of an ineluctable chain of logic; they come from a deeper place, one which is visceral and inarticulate.Polanyi calls this "tacit knowledge", a thing which we only understand as part of something else. When we speak, we do not focus on making sounds, we focus on our words. We understand the muscular act of speech, but would struggle to explain it.To write software, we must learn where to draw boundaries. Good software is built through effective indirection. We seem to have decided that this skill can only be learned through practice; it cannot be taught, except by example. Our decisions may improve with time, but not our ability to explain them. It's true that the study of these questions cannot yield a closed-form solution for judging software design. We can make our software simple, but we cannot do the same to its problem domain, its users, or the physical world. Our tacit knowledge of this environment will always inform our designs.This doesn't mean that we can simply ignore our design process. Polanyi tells us that tacit knowledge only suffices until we fail, and the software industry is awash with failure. Our designs may never be provably correct, but we can give voice to the intuition that shaped them. Our process may always be visceral, but it doesn't have to be inarticulate.And so this book does not offer knowledge, it offers clarity. It is aimed at readers who know Clojure, but struggle to articulate the rationale of their designs to themselves and others. Readers who use other languages, but have a passing familiarity with Clojure, may also find this book useful.

    

    Revised and updated for the Elixir 1.7, Elixir in Action, Second Edition teaches you how to apply Elixir to practical problems associated with scalability, fault tolerance, and high availability. Along the way, you'll develop an appreciation for, and considerable skill in, a functional and concurrent style of programming.

    The authors' enthusiasm for their subject is compelling as they present abstract concepts in a humorous and easy-to-grasp fashion. Together, these books will open new doors of thought to anyone who wants to find out what computing is really about. The Little Schemer introduces computing as an extension of arithmetic and algebra; things that everyone studies in grade school and high school. It introduces programs as recursive functions and briefly discusses the limits of what computers can do. The authors use the programming language Scheme, and interesting foods to illustrate these abstract ideas. The Seasoned Schemer informs the reader about additional dimensions of computing: functions as values, change of state, and exceptional cases. The Little LISPer has been a popular introduction to LISP for many years. It had appeared in French and Japanese. The Little Schemer and The Seasoned Schemer are worthy successors and will prove equally popular as textbooks for Scheme courses as well as companion texts for any complete introductory course in Computer Science.

    This means designing systems as small composable units, expressing constraints and interactions via the type system, and using composition to guide the construction of large systems in a way that maintains the original architectural vision.The book also serves as an introduction to the Cats library. We use abstractions from Cats, and we explain the structure of Cats so you can use it without fear in your own code base. The broad ideas are not specific to Cats, but Cats provides an excellent implementation that is beneficial to learn in its own right.

    If you're new to Elixir, its functional style can seem difficult, but with help from this hands-on introduction, you'll scale the learning curve and discover how enjoyable, powerful, and fun this language can be. Elixir combines the robust functional programming of Erlang with an approach that looks more like Ruby and reaches toward metaprogramming with powerful macro features.Authors Simon St. Laurent and J. David Eisenberg show you how to write simple Elixir programs by teaching you one skill at a time. You’ll learn about pattern matching, recursion, message passing, process-oriented programming, and establishing pathways for data rather than telling it where to go. By the end of your journey, you’ll understand why Elixir is ideal for concurrency and resilience.* Get comfortable with IEx, Elixir's command line interface* Become familiar with Elixir’s basic structures by working with numbers* Discover atoms, pattern matching, and guards: the foundations of your program structure* Delve into the heart of Elixir processing with recursion, strings, lists, and higher-order functions* Create processes, send messages among them, and apply pattern matching to incoming messages* Store and manipulate structured data with Erlang Term * Storage (ETS) and the Mnesia database* Build resilient applications with the Open Telecom Platform (OTP)* Define macros with Elixir's meta-programming tools.

    "

    This book helps you learn the fundamentals of Clojure with examples relating it to the languages you know already, in the domains and topics you work with every day. See how this JVM language can help eliminate unnecessary complexity from your programming practice and open up new options for solving the most challenging problems. Clojure Programming demonstrates the language's flexibility by showing how it can be used for common tasks like web programming and working with databases, up through more demanding applications that require safe, effective concurrency and parallelism, data and statistical analysis, and more. This in-depth look helps tie together the full Clojure development experience, from how to organize your project and an introduction to Clojure build tooling, to a tutorial on how to make the most of Clojure’s REPL during development, and how to deploy your finished application in a cloud environment.Learn how to use Clojure without losing your investment in the Java platform Understand the advantages of Clojure as an efficient Lisp for the JVM See how Clojure is used today in several practical domains Discover how Clojure eliminates the need for many verbose and complicated design patterns Deploy large web applications across tens or hundreds of cloud nodes with Clojure

    Web Development With Clojure shows you how to apply Clojure programming fundamentals to build real-world solutions. You'll develop all the pieces of a full web application in this powerful language. If you already have some familiarity with Clojure, you'll learn how to put it to serious practical use. If you're new to the language, the book provides just enough Clojure to get down to business.You'll learn the full process of web development using Clojure while getting hands-on experience with current tools, libraries, and best practices in the language. You'll develop Clojure apps with both the Light Table and Eclipse development environments. Rather than frameworks, Clojure development builds on rich libraries. You'll acquire expertise in the popular Ring/Compojure stack, and you'll learn to use the Liberator library to quickly develop RESTful services. Plus, you'll find out how to use ClojureScript to work in one language on the client and server sides.Throughout the book, you'll develop key components of web applications, including multiple approaches to database access. You'll create a simple guestbook app and an app to serve resources to users. By the end, you will have developed a rich Picture Gallery web application from conception to packaging and deployment.This book is for anyone interested in taking the next step in web development.Q&A with Dmitri SotnikovWhy did you write Web Development with Clojure?When I started using Clojure, I found that it took a lot of work to find all the pieces needed to put together a working application. There was very little documentation available on how to organize the code, what libraries to use, or how to package the application for deployment. Having gone through the process of figuring out what works, I thought that it would be nice to make it easier for others to get started.What are the advantages of using a functional language?Over the course of my career, I have developed a great appreciation for functional programming. I find that it addresses a number of shortcomings present in the imperative paradigm. For example, in a functional language any changes to the data are created via revisions to the existing data. So they only exist in the local scope. This fact allows us to safely reason about individual parts of the program in isolation, which is critical for writing and supporting large applications.Why use Clojure specifically?Clojure is a simple and pragmatic language that is designed for real-world usage. It combines the productivity of a high-level language with the excellent performance seen in languages like C# or Java. It's also very easy to learn because it allows you to use a small number of concepts to solve a large variety of problems.If I already have a preferred web development platform, what might I get out of this book?If you're using an imperative language, you'll get to see a very different approach to writing code. Even if you're not going to use Clojure as your primary language, the concepts you'll learn will provide you with new ways to approach problems.Is the material in the book accessible to somebody who is not familiar with Clojure?Absolutely. The book targets developers who are already familiar with the basics of web development and are interested in learning Clojure in this context. The book introduces just enough of the language to get you productive and allows you to learn by example.

    It combines the nice features of a scripting language with the powerful features of a production environment—features like persistent data structures and clean multithreading that you'll need for industrial-strength application development.The Joy of Clojure goes beyond just syntax to show you how to write fluent and idiomatic Clojure code. You'll learn a functional approach to programming and will master Lisp techniques that make Clojure so elegant and efficient. The book gives you easy access to hard soft ware areas like concurrency, interoperability, and performance. And it shows you how great it can be to think about problems the Clojure way. Purchase of the print book comes with an offer of a free PDF, ePub, and Kindle eBook from Manning. Also available is all code from the book. What's InsideThe what and why of ClojureHow to work with macrosHow to do elegant application designFunctional programming idiomsWritten for programmers coming to Clojure from another programming background—no prior experience with Clojure or Lisp is required.

    At long last you'll be united with the programming language you've been longing for: Clojure!As a Lisp-style functional programming language, Clojure lets you write robust and elegant code, and because it runs on the Java Virtual Machine, you can take advantage of the vast Java ecosystem. Clojure for the Brave and True offers a "dessert-first" approach: you'll start playing with real programs immediately, as you steadily acclimate to the abstract but powerful features of Lisp and functional programming. Inside you'll find an offbeat, practical guide to Clojure, filled with quirky sample programs that catch cheese thieves and track glittery vampires.Learn how to: Wield Clojure's core functions Use Emacs for Clojure development Write macros to modify Clojure itself Use Clojure's tools to simplify concurrency and parallel programmingClojure for the Brave and True assumes no prior experience with Clojure, the Java Virtual Machine, or functional programming. Are you ready, brave reader, to meet your true destiny? Grab your best pair of parentheses—you're about to embark on an epic journey into the world of Clojure!

    However, data structures for these languages do not always translate well to functional languages such as Standard ML, Haskell, or Scheme. This book describes data structures from the point of view of functional languages, with examples, and presents design techniques that allow programmers to develop their own functional data structures. The author includes both classical data structures, such as red-black trees and binomial queues, and a host of new data structures developed exclusively for functional languages. All source code is given in Standard ML and Haskell, and most of the programs are easily adaptable to other functional languages. This handy reference for professional programmers working with functional languages can also be used as a tutorial or for self-study.

    With metaprogramming, you can produce elegant, clean, and beautiful programs. Once the domain of expert Rubyists, metaprogramming is now accessible to programmers of all levels. This thoroughly revised and updated second edition of the bestselling Metaprogramming Ruby explains metaprogramming in a down-to-earth style and arms you with a practical toolbox that will help you write your best Ruby code ever.Dig under the surface and explore Ruby's most advanced feature: a collection of techniques and tricks known as metaprogramming. In this book, you'll learn metaprogramming as an essential component of Ruby and discover the deep, non-obvious details of the language. Once you understand the tenets of Ruby, including the object model, scopes, and singleton classes, you're on your way to applying metaprogramming both in your daily work assignments and in your fun, after-hours projects.Metaprogramming Ruby, Second Edition makes mastering the language enjoyable. The book is packed with: Pragmatic examples of metaprogramming in action, many of which come straight from real-life gems such as Rails.Programming challenges that let you experiment and play with some of the most out-there metaprogramming concepts.Metaprogramming spells--33 practical recipes and idioms that you can study and apply right now, to write code that is sure to impress.This completely revised new edition covers the new features in Ruby 2.0 and 2.1, and contains code from the latest Ruby libraries, including Rails 4. Most examples are new, from the wild, with more recent libraries. And the book reflects current ideas of when and how much metaprogramming you should use.Whether you're a Ruby apprentice on the path to mastering the language or a Ruby wiz in search of new tips, this book is for you.What You Need: Ruby 2.x, Ruby 1.9, or a recent version of JRuby.