Explore the world of lightning fast Clojure apps with asynchronous channels, logic, reactive programming, and more About This Book Discover Clojure's features and advantages and use them in your existing projects Explore lesser-known and more advanced features, constructs, and methodologies such as asynchronous channels, actors, logic programming, and reactive programming Measure and monitor performance, and understand optimization techniques Who This Book Is For If you're looking to learn more about its core libraries and delve into the Clojure language in detail, then this book is ideal for you. Prior knowledge of the Clojure language is required. What You Will Learn Understand tools for the Clojure world and how they relate to Java tools and standards (such as Maven) Write simple multicore programs using Clojure's core concepts, such as atoms, agents, and refs Get to grips with Clojure's concurrency and state-management primitives in depth Analyze latency using the Criterium library Avoid reflection and boxing with type hints Maximize the impact of parallelization, functional composition, and process transformation by composing reducers and transducers Modify and add features to the Clojure language using macros Test your code with unit tests, specs, and type checks to write testable code Troubleshoot and style your Clojure code to make it more maintainable In Detail Clojure is a general-purpose language from the Lisp family with an emphasis on functional programming. It has some interesting concepts and features such as immutability, gradual typing, thread-safe concurrency primitives, and macro-based metaprogramming, which makes it a great choice to create modern, performant, and scalable applications. This learning path aims at unleashing the true potential of the Clojure language so you can use it in your projects. It begins with installing and setting up the Clojure environment before moving on to explore the language in depth. You'll get acquainted with its various features such as functional programming, concurrency, reducers, transducers, core.async and core.logic, and so on with a great level of detail. Moving on, you'll also learn how to enhance performance using Java interoperability and JVM-specific features from Clojure; you'll even master language features such as asynchronous channels, actors, logic programming, reactive programming, metaprogramming, and so on. This learning path combines some of the best that Packt has to offer in one complete, curated package. It includes content from the following Packt products: Clojure for Java Developers by Eduardo Diaz Clojure High Performance Programming, Second Edition by Shantanu Kumar Mastering Clojure by Akhil Wali Style and approach This is an easy-to-follow, step-by-step guide to start writing Clojure programs, making use of all of its varied features and advantages.

Become an expert at writing fast and high performant code in Clojure 1.7.0 About This Book Enhance code performance by using appropriate Clojure features Improve the efficiency of applications and plan their deployment A hands-on guide to designing Clojure programs to get the best performance Who This Book Is For This book is intended for intermediate Clojure developers who are looking to get a good grip on achieving optimum performance. Having a basic knowledge of Java would be helpful. What You Will Learn Identify performance issues in Clojure programs using different profiling tools Master techniques to achieve numerical performance in Clojure Use Criterium library to measure latency of Clojure expressions Exploit Java features in Clojure code to enhance performance Avoid reflection and boxing with type hints Understand Clojure's concurrency and state-management primitives in depth Measure and monitor performance, and understand optimization techniques In Detail Clojure treats code as data and has a macro system. It focuses on programming with immutable values and explicit progression-of-time constructs, which are intended to facilitate the development of more robust programs, particularly multithreaded ones. It is built with performance, pragmatism, and simplicity in mind. Like most general purpose languages, various Clojure features have different performance characteristics that one should know in order to write high performance code. This book shows you how to evaluate the performance implications of various Clojure abstractions, discover their underpinnings, and apply the right approach for optimum performance in real-world programs. It starts by helping you classify various use cases and the need for them with respect to performance and analysis of various performance aspects. You will also learn the performance vocabulary that experts use throughout the world and discover various Clojure data structures, abstractions, and their performance characteristics. Further, the book will guide you through enhancing performance by using Java interoperability and JVM-specific features from Clojure. It also highlights the importance of using the right concurrent data structure and Java concurrency abstractions. This book also sheds light on performance metrics for measuring, how to measure, and how to visualize and monitor the collected data. At the end of the book, you will learn to run a performance profiler, identify bottlenecks, tune performance, and refactor code to get a better performance. Style and approach An easy-to-follow guide full of real-world examples and self-sufficient code snippets that will help you get your hands dirty with high performance programming with Clojure.

Explore the Java Virtual Machine with modern programming languages About This Book This guide provides in-depth coverage of the Java Virtual Machine and its features Filled with practical examples, this book will help you understand the core concepts of Java, Scala, Clojure, Kotlin, and Groovy Work with various programming paradigms and gain knowledge about imperative, object-oriented and functional programming Who This Book Is For This book is meant for programmers who are interested in the Java Virtual Machine (JVM) and want to learn more about the most popular programming languages that can be used for JVM development. Basic practical knowledge of a modern programming language that supports object-oriented programming (JavaScript, Python, C#, VB.NET, and C++) is assumed. What You Will Learn Gain practical information about the Java Virtual Machine Understand the popular JVM languages and the Java Class Library Get to know about various programming paradigms such as imperative, object-oriented, and functional Work with common JVM tools such as Eclipse IDE, Gradle, and Maven Explore frameworks such as SparkJava, Vert.x, Akka and JavaFX Boost your knowledge about dialects of other well-known programming languages that run on the JVM, including JavaScript, Python, and Ruby In Detail Anyone who knows software development knows about the Java Virtual Machine. The Java Virtual Machine is responsible for interpreting Java byte code and translating it into actions. In the beginning, Java was the only programming language used for the JVM. But increasing complexity of the language and the remarkable performance of the JVM created an opening for a new generation of programming languages. If you want to build a strong foundation with the Java Virtual Machine and get started with popular modern programming languages, then this book is for you. The book will begin with a general introduction of the JVM and its features, which are common to the JVM languages, helping you get abreast with its concepts. It will then dive into explaining languages such as Java, Scala, Clojure, Kotlin, and Groovy and will show how to work with each language, their features, use cases, and pros and cons. By writing example projects in those languages and focusing on each language's strong points, it will help you find the programming language that is most appropriate for your particular needs. By the end of the book, you will have written multiple programs that run on the Java Virtual Machine and know about the differences between the various languages. Style and approach This practical, example-filled guide will help you get started with the JVM and some of its most popular languages.

Drowning in unnecessary complexity, unmanaged state, and tangles of spaghetti code? In the best tradition of Lisp, Clojure gets out of your way so you can focus on expressing simple solutions to hard problems. Clojure cuts through complexity by providing a set of composable tools--immutable data, functions, macros, and the interactive REPL. Written by members of the Clojure core team, this book is the essential, definitive guide to Clojure. This new edition includes information on all the newest features of Clojure, such as transducers and specs. Clojure joins the flexibility and agility of Lisp with the reach, stability, and performance of Java. Combine Clojure's tools for maximum effectiveness as you work with immutable data, functional programming, and safe concurrency to write programs that solve real-world problems. Start by reading and understanding Clojure syntax and see how Clojure is evaluated. From there, find out about the sequence abstraction, which combines immutable collections with functional programming to create truly reusable data transformation code. Clojure is a functional language; learn how to write programs in a functional style, and when and how to use recursion to your advantage. Discover Clojure's unique approach to state and identity, techniques for polymorphism and open systems using multimethods and protocols, and how to leverage Clojure's metaprogramming capabilities via macros. Finally, put all the pieces together in a real program. New to this edition is coverage of Clojure's spec library, one of the most interesting new features of Clojure for describing both data and functions. You can use Clojure spec to validate data, destructure data, explain invalid data, and generate large numbers of tests to verify the correctness of your code. With this book, you'll learn how to think in Clojure, and how to take advantage of its combined strengths to build powerful programs quickly. What You Need: Java 6 or higher Clojure 1.9

If you are a Clojure developer who is interested in using Reactive Programming to build asynchronous and concurrent applications, this book is for you. Knowledge of Clojure and Leiningen is required. Basic understanding of ClojureScript will be helpful for the web chapters, although it is not strictly necessary.

Explore the world of lightning fast Clojure apps with asynchronous channels, logic, reactive programming, and moreAbout This Book- Discover Clojure's features and advantages and use them in your existing projects- Explore lesser-known and more advanced features, constructs, and methodologies such as asynchronous channels, actors, logic programming, and reactive programming- Measure and monitor performance, and understand optimization techniquesWho This Book Is ForIf you're looking to learn more about its core libraries and delve into the Clojure language in detail, then this book is ideal for you. Prior knowledge of the Clojure language is required.What You Will Learn- Understand tools for the Clojure world and how they relate to Java tools and standards (such as Maven)- Write simple multicore programs using Clojure's core concepts, such as atoms, agents, and refs- Get to grips with Clojure's concurrency and state-management primitives in depth- Analyze latency using the Criterium library- Avoid reflection and boxing with type hints- Maximize the impact of parallelization, functional composition, and process transformation by composing reducers and transducers- Modify and add features to the Clojure language using macros- Test your code with unit tests, specs, and type checks to write testable code- Troubleshoot and style your Clojure code to make it more maintainableIn DetailClojure is a general-purpose language from the Lisp family with an emphasis on functional programming. It has some interesting concepts and features such as immutability, gradual typing, thread-safe concurrency primitives, and macro-based metaprogramming, which makes it a great choice to create modern, performant, and scalable applications.This learning path aims at unleashing the true potential of the Clojure language so you can use it in your projects. It begins with installing and setting up the Clojure environment before moving on to explore the language in depth. You'll get acquainted with its various features such as functional programming, concurrency, reducers, transducers, core.async and core.logic, and so on with a great level of detail.Moving on, you'll also learn how to enhance performance using Java interoperability and JVM-specific features from Clojure; you'll even master language features such as asynchronous channels, actors, logic programming, reactive programming, metaprogramming, and so on.This learning path combines some of the best that Packt has to offer in one complete, curated package. It includes content from the following Packt products:- Clojure for Java Developers by Eduardo Diaz- Clojure High Performance Programming, Second Edition by Shantanu Kumar- Mastering Clojure by Akhil WaliStyle and approachThis is an easy-to-follow, step-by-step guide to start writing Clojure programs, making use of all of its varied features and advantages.

Statistics, big data, and machine learning for Clojure programmers About This Book Write code using Clojure to harness the power of your data Discover the libraries and frameworks that will help you succeed A practical guide to understanding how the Clojure programming language can be used to derive insights from data Who This Book Is For This book is aimed at developers who are already productive in Clojure but who are overwhelmed by the breadth and depth of understanding required to be effective in the field of data science. Whether you're tasked with delivering a specific analytics project or simply suspect that you could be deriving more value from your data, this book will inspire you with the opportunities–and inform you of the risks–that exist in data of all shapes and sizes. What You Will Learn Perform hypothesis testing and understand feature selection and statistical significance to interpret your results with confidence Implement the core machine learning techniques of regression, classification, clustering and recommendation Understand the importance of the value of simple statistics and distributions in exploratory data analysis Scale algorithms to web-sized datasets efficiently using distributed programming models on Hadoop and Spark Apply suitable analytic approaches for text, graph, and time series data Interpret the terminology that you will encounter in technical papers Import libraries from other JVM languages such as Java and Scala Communicate your findings clearly and convincingly to nontechnical colleagues In Detail The term “data science” has been widely used to define this new profession that is expected to interpret vast datasets and translate them to improved decision-making and performance. Clojure is a powerful language that combines the interactivity of a scripting language with the speed of a compiled language. Together with its rich ecosystem of native libraries and an extremely simple and consistent functional approach to data manipulation, which maps closely to mathematical formula, it is an ideal, practical, and flexible language to meet a data scientist's diverse needs. Taking you on a journey from simple summary statistics to sophisticated machine learning algorithms, this book shows how the Clojure programming language can be used to derive insights from data. Data scientists often forge a novel path, and you'll see how to make use of Clojure's Java interoperability capabilities to access libraries such as Mahout and Mllib for which Clojure wrappers don't yet exist. Even seasoned Clojure developers will develop a deeper appreciation for their language's flexibility! You'll learn how to apply statistical thinking to your own data and use Clojure to explore, analyze, and visualize it in a technically and statistically robust way. You can also use Incanter for local data processing and ClojureScript to present interactive visualisations and understand how distributed platforms such as Hadoop sand Spark's MapReduce and GraphX's BSP solve the challenges of data analysis at scale, and how to explain algorithms using those programming models. Above all, by following the explanations in this book, you'll learn not just how to be effective using the current state-of-the-art methods in data science, but why such methods work so that you can continue to be productive as the field evolves into the future. Style and approach This is a practical guide to data science that teaches theory by example through the libraries and frameworks accessible from the Clojure programming language.

Access the power of bare-metal systems programming with Scala Native, an ahead-of-time Scala compiler. Without the baggage of legacy frameworks and virtual machines, Scala Native lets you re-imagine how your programs interact with your operating system. Compile Scala code down to native machine instructions; seamlessly invoke operating system APIs for low-level networking and IO; control pointers, arrays, and other memory management techniques for extreme performance; and enjoy instant start-up times. Skip the JVM and improve your code performance by getting close to the metal. Developers generally build systems on top of the work of those who came before, accumulating layer upon layer of abstraction. Scala Native provides a rare opportunity to remove layers. Without the JVM, Scala Native uses POSIX and ANSI C APIs to build concise, expressive programs that run unusually close to bare metal. Scala Native compiles Scala code down to native machine instructions instead of JVM bytecode. It starts up fast, without the sluggish warm-up phase that's common for just-in-time compilers. Scala Native programs can seamlessly invoke operating system APIs for low-level networking and IO. And Scala Native lets you control pointers, arrays, and other memory layout types for extreme performance. Write practical, bare-metal code with Scala Native, step by step. Understand the foundations of systems programming, including pointers, arrays, strings, and memory management. Use the UNIX socket API to write network client and server programs without the sort of frameworks higher-level languages rely on. Put all the pieces together to design and implement a modern, asynchronous microservice-style HTTP framework from scratch. Take advantage of Scala Native's clean, modern syntax to write lean, high-performance code without the JVM. What You Need: A modern Windows, Mac OS, or Linux system capable of running Docker. All code examples in the book are designed to run on a portable Docker-based build environment that runs anywhere. If you don't have Docker yet, see the Appendix for instructions on how to get it.

Transition smoothly from Java to the most widely used functional JVM-based language – Clojure About This Book Write apps for the multithreaded world with Clojure's flavor of functional programming Discover Clojure's features and advantages and use them in your existing projects The book is designed so that you'll be able put to use your existing skills and software knowledge to become a more effective Clojure developer Who This Book Is For This book is intended for Java developers, who are looking for a way to expand their skills and understand new paradigms of programming. Whether you know a little bit about functional languages, or you are just getting started, this book will get you up and running with how to use your existing skills in Clojure and functional programming. What You Will Learn Understand the tools for the Clojure world and how they relate to Java tools and standards (like Maven) Learn about immutable data structures, and what makes them feasible for everyday programming Write simple multi-core programs using Clojure's core concepts, like atoms, agents and refs Understand that in Clojure, code is data, and how to take advantage of that fact by generating and manipulating code with macros Learn how Clojure interacts with Java, how the class loaders work and how to use Clojure from Java or the other way around Discover a new, more flexible meaning of polymorphism and understand that OOP is not the only way to get it In Detail We have reached a point where machines are not getting much faster, software projects need to be delivered quickly, and high quality in software is more demanding as ever. We need to explore new ways of writing software that helps achieve those goals. Clojure offers a new possibility of writing high quality, multi-core software faster than ever, without having to leave your current platform. Clojure for Java developers aims at unleashing the true potential of the Clojure language to use it in your projects. The book begins with the installation and setup of the Clojure environment before moving on to explore the language in-depth. Get acquainted with its various features such as functional programming, concurrency, etc. with the help of example projects. Additionally, you will also, learn how the tooling works, and how it interacts with the Java environment. By the end of this book, you will have a firm grip on Clojure and its features, and use them effectively to write more robust programs. Style and approach An easy to follow, step-by-step, guide on how to start writing Clojure programs making use of all of its varied features and advantages. As this is a new language, certain new concepts are supported with theoretical section followed by simple projects to help you gain a better understanding and practice of how Clojure works.

25 recipes to deeply understand and implement advanced algorithms in Clojure About This Book Explore various advanced algorithms and learn how they are used to address many real-world computing challenges Construct elegant solutions using impressive techniques including zippers, parsing, and pattern matching Solve complex problems by adopting innovative approaches such as logic or asynchronous programming In Detail Data-structures and algorithms often cross your path when you compress files, compile programs, access databases, or simply use your favourite text editor. Understanding and implementing them can be daunting. Curious learners and industrial developers can find these complex, especially if they focus on the detailed implementation of these data structures. Clojure is a highly pragmatic and expressive language with efficient and easy data manipulation capabilities. As such, it is great for implementing these algorithms. By abstracting away a great share of the unnecessary complexity resulting from implementation, Clojure and its contrib libraries will help you address various algorithmic challenges, making your data exploration both profitable and enjoyable. Through 25 recipes, you'll explore advanced algorithms and data-structures, well served by a sound Clojure implementation. This book opens with an exploration of alternative uses of the array data-structure, covering LZ77 compression, drawing fractals using Pascal's triangles, simulating a multi-threaded program execution, and implementing a call-stack winding and un-winding operations. The book elaborates on linked lists, showing you how to construct doubly linked ones, speed up search times over the elements of such structures, use a linked-list as the foundation of a shift-reduce parser, and implement an immutable linked-list using skew binary numbers representation. After that, the tree data-structure is explored, focusing on building self-balancing Splay Trees, designing a B-Tree backing-up an efficient key-value data-store, constructing an undo capable Rope, and showing how Tries can make for an auto-completing facility. Next, some optimization and machine learning techniques are discussed, namely for building a co-occurrence-based recommendation engine, using branch-and-bound to optimize integral cost and profit problems, using Dijkstra's algorithm to determine optimal paths and summarizing texts using the LexRank algorithm. Particular attention is given to logic programming, you will learn to use this to discover interesting relations between social website data, by designing a simple type inferencer for a mini Java-like language, and by building a simple checkers game engine. Asynchronous programming will be addressed and you will design a concurrent web-crawler, an interactive HTML5 game, and an online taxi booking platform. Finally, you'll explore advanced cases for higher order functions in Clojure while implementing a recursive descent parser using efficient mutual resucrsion, devising a mini resusable firewall simulator thanks to Clojure 1.7 new tansducers feature or building a simple unification engine with the help of Continuation Passing Style. What You Will Learn Explore alternative uses of classical data-structures like arrays and linked-lists Discover advanced types of tree data-structures Explore advanced machine learning and optimization techniques Utilise powerful Clojure libraries, such as Instaparse for parsing, core.match for pattern matching, clojure.zip for zippers, and clojure.matrix for matrix operations Learn logic programming through the usage of the library core.logic Master asynchronous programming using the core.async library See the transducers in action while resolving real-world use-cases Who This Book Is For If you are an experienced Clojure developer, longing to take your knowledge to the next level by discovering and using advanced algorithms and seeing how they can be applied to real-world problems, then this book is for you. Style and approach This book consists of a set of step-by-step recipes, each demonstrating the material covered in action so it is put in context. When necessary, pointers to further resources are provided.