The authors, who developed the metaobject protocol andwho were among the group that developed CLOS, introduce this new approach toprogramming language design, describe its evolution and design principles, andpresent a formal specification of a metaobject protocol for CLOS.Kiczales, desRivi?res, and Bobrow show that the "art of metaobject protocol design" lies increating a synthetic combination of object-oriented and reflective techniques thatcan be applied under existing software engineering considerations to yield a newapproach to programming language design that meets a broad set of designcriteria.One of the major benefits of including the metaobject protocol inprogramming languages is that it allows users to adjust the language to better suittheir needs. Metaobject protocols also disprove the adage that adding moreflexibility to a programming language reduces its performance. In presenting theprinciples of metaobject protocols, the authors work with actual code for asimplified implementation of CLOS and its metaobject protocol, providing anopportunity for the reader to gain hands-on experience with the design process. Theyalso include a number of exercises that address important concerns and openissues.Gregor Kiczales and Jim des Rivi?res, are Members of the Research Staff, andDaniel Bobrow is a Research Fellow, in the System Sciences Laboratory at Xerox PaloAlto Research Center.

    It describes 11 interpreters and 2 compilers, including very recent techniques of interpretation and compilation. The book is in two parts. The first starts from a simple evaluation function and enriches it with multiple name spaces, continuations and side-effects with commented variants, while at the same time the language used to define these features is reduced to a simple lambda-calculus. Denotational semantics is then naturally introduced. The second part focuses more on implementation techniques and discusses precompilation for fast interpretation: threaded code or bytecode; compilation towards C. Some extensions are also described such as dynamic evaluation, reflection, macros and objects. This will become the new standard reference for people wanting to know more about the Lisp family of languages: how they work, how they are implemented, what their variants are and why such variants exist. The full code is supplied (and also available over the Net). A large bibliography is given as well as a considerable number of exercises. Thus it may also be used by students to accompany second courses on Lisp or Scheme.

    A LISP "toolkit" in each chapter explains how to use Common LISP programming and debugging tools such as DESCRIBE, INSPECT, TRACE and STEP.

    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.

    The approach is analytic and hands-on. The text uses interpreters, written in Scheme, to express the semantics of many essential language elements in a way that is both clear and directly executable. It also examines some important program analyses. Extensive exercises explore many design and implementation alternatives.

    Beginners will find that its careful explanations and interesting examples make Lisp programming easy to learn. Professional programmers will appreciate its thorough, practical approach.FEATURES:• An up-to-date reference manual for ANSI Common Lisp.• An in-depth look at object-oriented programming. Explains the Common Lisp Object System (CLOS), and also shows how to write your own object-oriented language.• Over 20 substantial examples, including programs for ray-tracing, text generation, pattern-matching, logical inference, generating HTML, sorting and searching, file I/O, compression, and date arithmetic.• Special attention to critical concepts, including prefix syntax, code vs. data, recursion, functional programming, types, implicit pointers, dynamic allocation, closures, macros, class precedence, and generic functions vs. message-passing.• A complete guide to optimization.• The clearest and most thorough explanation of macros in any introductory book.• Examples that illustrate Lisp programming styles, including rapid prototyping, bottom-up programming, object-oriented programming, and embedded languages.• An appendix on debugging, with examples of common errors.

    Clojure's clean, careful design lets you write programs that get right to the essence of a problem, without a lot of clutter and ceremony. Clojure is Lisp reloaded. Clojure has the power inherent in Lisp, but is not constrained by the history of Lisp. Clojure is a functional language. Data structures are immutable, and functions tend to be side-effect free. This makes it easier to write correct programs, and to compose large programs from smaller ones. Clojure is concurrent. Rather than error-prone locking, Clojure provides software transactional memory. Clojure embraces Java. Calling from Clojure to Java is direct, and goes through no translation layer. Clojure is fast. Wherever you need it, you can get the exact same performance that you could get from hand-written Java code. Many other languages offer some of these features, but the combination of them all makes Clojure sparkle. Programming Clojure shows you why these features are so important, and how you can use Clojure to build powerful programs quickly.

    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 teaches Clojure from the basics to advanced topics using practical, real-world application examples. Blow through the theory and dive into practical matters like unit-testing and environment set-up, all the way through building a scalable web-application using domain-specific languages, Hadoop, HBase, and RabbitMQ. About the TechnologyClojure is a modern Lisp for the JVM, and it has the strengths you'd expect: first-class functions, macros, support for functional programming, and a Lisp-like, clean programming style. About this BookClojure in Action is a practical guide focused on applying Clojure to practical programming challenges. You'll start with a language tutorial written for readers who already know OOP. Then, you'll dive into the use cases where Clojure really shines: state management, safe concurrency and multicore programming, first-class code generation, and Java interop. In each chapter, you'll first explore the unique characteristics of a problem area and then discover how to tackle them using Clojure. Along the way, you'll explore practical matters like architecture, unit testing, and set-up as you build a scalable web application that includes custom DSLs, Hadoop, HBase, and RabbitMQ. What's InsideA fast-paced Clojure tutorial Creating web services with Clojure Scaling through messaging Creating DSLs with Clojure's macro system Test-driven development with Clojure Distributed programming with Clojure, and moreThis book assumes you're familiar with an OO language like Java, C#, or C++ but requires no background in Lisp or Clojure itself.================================== Table of ContentsPART 1 GETTING STARTED Introduction to Clojure A whirlwind tour Building blocks of Clojure Polymorphism with multimethods Clojure and Java interop State and the concurrent world Evolving Clojure through macros PART 2 GETTING REAL Test-driven development and more Data storage with Clojure Clojure and the web Scaling through messaging Data processing with Clojure More on functional programming Protocols, records, and type More macros and DSLs

    It has become popular in recent years because of its simplicity, conciseness, and clarity. This book teaches functional programming as a way of thinking and problem solving, using Haskell, the most popular purely functional language. Rather than using the conventional (boring) mathematical examples commonly found in other programming language textbooks, the author uses examples drawn from multimedia applications, including graphics, animation, and computer music, thus rewarding the reader with working programs for inherently more interesting applications. Aimed at both beginning and advanced programmers, this tutorial begins with a gentle introduction to functional programming and moves rapidly on to more advanced topics. Details about progamming in Haskell are presented in boxes throughout the text so they can be easily found and referred to.

    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

    The vision behind Clojure is of a radically simple language framework holding together a sophisticated collection of programming features. Learning Clojure involves much more than just learning the mechanics of the language. To really get Clojure you need to understand the ideas underlying this structure of framework and features. You need this book: an accessible introduction to Clojure that focuses on the ideas behind the language as well as the practical details of writing code.

    By reconstructing authentic, complex AI programs using state-of-the-art Common Lisp, the book teaches students and professionals how to build and debug robust practical programs, while demonstrating superior programming style and important AI concepts. The author strongly emphasizes the practical performance issues involved in writing real working programs of significant size. Chapters on troubleshooting and efficiency are included, along with a discussion of the fundamentals of object-oriented programming and a description of the main CLOS functions. This volume is an excellent text for a course on AI programming, a useful supplement for general AI courses and an indispensable reference for the professional programmer.

    Land of Lisp brings the language into the real world, teaching Lisp by showing readers how to write several complete Lisp-based games, including a text adventure, an evolution simulation, and a robot battle. While building these games, readers learn the core concepts of Lisp programming, such as data types, recursion, input/output, object-oriented programming, and macros. And thanks to the power of Lisp, the code is short. Rather than bogging things down with reference information that is easily found online, Land of Lisp focuses on using Lisp for real programming. The book is filled with the author Conrad Barski's famous Lisp cartoons, featuring the Lisp alien and other zany characters.

    Many exercises are presented to help reinforce the lessons learned, and answers to the exercises are given in a new appendix.Most of the remaining chapters are dedicated to the reference material, which describes in detail the standard features of Scheme included in the Revised$^5$ Report on Scheme and the ANSI/IEEE standard for Scheme.Numerous examples are presented throughout the introductory and reference portions of the text, and a unique set of extended example programs and applications, with additional exercises, are presented in the final chapter. Reinforcing the book's utility as a reference text are appendices that present the formal syntax of Scheme, a summary of standard forms and procedures, and a bibliography of Scheme resources.The Scheme Programming Language stands alone as an introduction to and essential reference for Scheme programmers. it is also useful as a supplementary text for any course that uses Scheme.The Scheme Programming Language is illustrated by artist Jean-Pierre Hébert, who writes Scheme programs to extend his ability to create sophisticated works of digital art.R. Kent Dybvig is Professor of Computer Science at Indiana University and principal developer of Chez Scheme.