Rails(TM) AntiPatterns identifies these widespread Rails code and design problems, explains why they're bad and why they happen--and shows exactly what to do instead.The book is organized into concise, modular chapters--each outlines a single common AntiPattern and offers detailed, cookbook-style code solutions that were previously difficult or impossible to find. Leading Rails developers Chad Pytel and Tammer Saleh also offer specific guidance for refactoring existing bad code or design to reflect sound object-oriented principles and established Rails best practices. With their help, developers, architects, and testers can dramatically improve new and existing applications, avoid future problems, and establish superior Rails coding standards throughout their organizations.This book will help you understand, avoid, and solve problems withModel layer code, from general object-oriented programming violations to complex SQL and excessive redundancy Domain modeling, including schema and database issues such as normalization and serialization View layer tools and conventions Controller-layer code, including RESTful code Service-related APIs, including timeouts, exceptions, backgrounding, and response codes Third-party code, including plug-ins and gems Testing, from test suites to test-driven development processes Scaling and deployment Database issues, including migrations and validations System design for "graceful degradation" in the real world

    Try out more than 1,000 commands to find and get software, monitor system health and security, and access network resources. Then, apply the skills you learn from this book to use and administer desktops and servers running Ubuntu, Debian, and KNOPPIX or any other Linux distribution.

    Generics and the greatly expanded collection libraries have tremendously increased the power of Java 5 and Java 6. But they have also confused many developers who haven't known how to take advantage of these new features.Java Generics and Collections covers everything from the most basic uses of generics to the strangest corner cases. It teaches you everything you need to know about the collections libraries, so you'll always know which collection is appropriate for any given task, and how to use it.Topics covered include:• Fundamentals of generics: type parameters and generic methods• Other new features: boxing and unboxing, foreach loops, varargs• Subtyping and wildcards• Evolution not revolution: generic libraries with legacy clients and generic clients with legacy libraries• Generics and reflection• Design patterns for generics• Sets, Queues, Lists, Maps, and their implementations• Concurrent programming and thread safety with collections• Performance implications of different collectionsGenerics and the new collection libraries they inspired take Java to a new level. If you want to take your software development practice to a new level, this book is essential reading.Philip Wadler is Professor of Theoretical Computer Science at the University of Edinburgh, where his research focuses on the design of programming languages. He is a co-designer of GJ, work that became the basis for generics in Sun's Java 5.0.Maurice Naftalin is Technical Director at Morningside Light Ltd., a software consultancy in the United Kingdom. He has most recently served as an architect and mentor at NSB Retail Systems plc, and as the leader of the client development team of a major UK government social service system."A brilliant exposition of generics. By far the best book on the topic, it provides a crystal clear tutorial that starts with the basics and ends leaving the reader with a deep understanding of both the use and design of generics." Gilad Bracha, Java Generics Lead, Sun Microsystems

    I also love the sense of humor. It's very good at disarming the fear. And it's gorgeous. I'll be recommending this book highly." --Tom Igoe, author of Physical Computing and Making Things TalkWant to learn the fundamentals of electronics in a fun, hands-on way? With Make: Electronics, you'll start working on real projects as soon as you crack open the book. Explore all of the key components and essential principles through a series of fascinating experiments. You'll build the circuits first, then learn the theory behind them!Build working devices, from simple to complex You'll start with the basics and then move on to more complicated projects. Go from switching circuits to integrated circuits, and from simple alarms to programmable microcontrollers. Step-by-step instructions and more than 500 full-color photographs and illustrations will help you use -- and understand -- electronics concepts and techniques.Discover by breaking things: experiment with components and learn from failureSet up a tricked-out project space: make a work area at home, equipped with the tools and parts you'll needLearn about key electronic components and their functions within a circuitCreate an intrusion alarm, holiday lights, wearable electronic jewelry, audio processors, a reflex tester, and a combination lockBuild an autonomous robot cart that can sense its environment and avoid obstaclesGet clear, easy-to-understand explanations of what you're doing and why

    This guide also illustrates how to handle input and output, make programs perform repetitive tasks, manipulate data, hide information, use functions and build flexible, easily modifiable programs.

    We are living in an age where data comes in abundance, and thanks to the self-learning algorithms from the field of machine learning, we can turn this data into knowledge. Automated speech recognition on our smart phones, web search engines, e-mail spam filters, the recommendation systems of our favorite movie streaming services – machine learning makes it all possible.Thanks to the many powerful open-source libraries that have been developed in recent years, machine learning is now right at our fingertips. Python provides the perfect environment to build machine learning systems productively.This book will teach you the fundamentals of machine learning and how to utilize these in real-world applications using Python. Step-by-step, you will expand your skill set with the best practices for transforming raw data into useful information, developing learning algorithms efficiently, and evaluating results.You will discover the different problem categories that machine learning can solve and explore how to classify objects, predict continuous outcomes with regression analysis, and find hidden structures in data via clustering. You will build your own machine learning system for sentiment analysis and finally, learn how to embed your model into a web app to share with the world

    Led by a SQL Server expert, you’ll learn the concepts behind T-SQL querying and programming, and then apply your knowledge with exercises in each chapter. Once you understand the logic behind T-SQL, you’ll quickly learn how to write effective code—whether you’re a programmer or database administrator.Discover how to:Work with programming practices unique to T-SQLCreate database tables and define data integrityQuery multiple tables using joins and subqueriesSimplify code and improve maintainability with table expressionsImplement insert, update, delete, and merge data modification strategiesTackle advanced techniques such as window functions, pivoting and grouping setsControl data consistency using isolation levels, and mitigate deadlocks and blockingTake T-SQL to the next level with programmable objects

    The time you spend context switching between your editor and your consoles eats away at your productivity. Take control of your environment with tmux, a terminal multiplexer that you can tailor to your workflow. With this updated second edition for tmux 2.3, you'll customize, script, and leverage tmux's unique abilities to craft a productive terminal environment that lets you keep your fingers on your keyboard's home row.You have a database console, web server, test runner, and text editor running at the same time, but switching between them and trying to find what you need takes up valuable time and breaks your concentration. By using tmux 2.3, you can improve your productivity and regain your focus. This book will show you how.This second edition includes many features requested by readers, including how to integrate plugins into your workflow, how to integrate tmux with Vim for seamless navigation - oh, and how to use tmux on Windows 10.Use tmux to manage multiple terminal sessions in a single window using only your keyboard. Manage and run programs side by side in panes, and create the perfect development environment with custom scripts so that when you're ready to work, your programs are waiting for you. Manipulate text with tmux's copy and paste buffers, so you can move text around freely between applications. Discover how easy it is to use tmux to collaborate remotely with others, and explore more advanced usage as you manage multiple tmux sessions, add custom scripts into the tmux status line, and integrate tmux with your system.Whether you're an application developer or a system administrator, you'll find many useful tricks and techniques to help you take control of your terminal.

    Why do we recognize patterns? Is there such a thing as positive stress? Are we genetically programmed to be in conflict with each other? Those are just some of the 150 questions that the world's best scientific minds answer with elegant simplicity.With contributions from Jared Diamond, Richard Dawkins, Nassim Taleb, Brian Eno, Steven Pinker, and more, everything is explained in fun, uncomplicated terms that make the most complex concepts easy to comprehend.

    The book details the major subsystems and features of the Linux kernel, including its design, implementation, and interfaces. It covers the Linux kernel with both a practical and theoretical eye, which should appeal to readers with a variety of interests and needs. The author, a core kernel developer, shares valuable knowledge and experience on the 2.6 Linux kernel. Specific topics covered include process management, scheduling, time management and timers, the system call interface, memory addressing, memory management, the page cache, the VFS, kernel synchronization, portability concerns, and debugging techniques. This book covers the most interesting features of the Linux 2.6 kernel, including the CFS scheduler, preemptive kernel, block I/O layer, and I/O schedulers. The third edition of Linux Kernel Development includes new and updated material throughout the book:An all-new chapter on kernel data structuresDetails on interrupt handlers and bottom halvesExtended coverage of virtual memory and memory allocationTips on debugging the Linux kernelIn-depth coverage of kernel synchronization and lockingUseful insight into submitting kernel patches and working with the Linux kernel community

    It's a beautifully written tutorial that begins with the basic steps to get your first Ruby program up and running and goes on to explore sophisticated topics like callable objects, reflection, and threading. Whether the topic is simple or tough, the book's easy-to-follow examples and explanations will give you immediate confidence as you build your Ruby programming skills.The Well-Grounded Rubyist is a thoroughly revised and updated edition of the best-selling Ruby for Rails. In this new book, expert author David A. Black moves beyond Rails and presents a broader view of Ruby. It covers Ruby 1.9, and keeps the same sharp focus and clear writing that made Ruby for Rails stand out.Starting with the basics, The Well-Grounded Rubyist explains Ruby objects and their interactions from the ground up. In the middle chapters, the book turns to an examination of Ruby's built-in, core classes, showing the reader how to manipulate strings, numbers, arrays, ranges, hashes, sets, and more. Regular expressions get attention, as do file and other I/O operations.Along the way, the reader is introduced to numerous tools included in the standard Ruby distribution--tools like the task manager Rake and the interactive Ruby console-based interpreter Irb--that facilitate Ruby development and make it an integrated and pleasant experience.The book encompasses advanced topics, like the design of Ruby's class and module system, and the use of Ruby threads, taking even the new Rubyist deep into the language and giving every reader the foundations necessary to use, explore, and enjoy this unusually popular and versatile language.It's no wonder one reader commented: "The technical depth is just right to not distract beginners, yet detailed enough for more advanced readers."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.

    It introduces the use of classes; shows how to write ADTs that maximize the perfomance of C++ in creating reusable code; and provides coverage of all important OO functions, including inheritance, polymorphism and encapsulation.