Chaur Wu

Microsoft’s Dynamic Language Runtime (DLR) is a platform for running dynamic languages such as Ruby and Python on an equal footing with compiled languages such as C#. Furthermore, the runtime is the foundation for many useful software design and architecture techniques you can apply as you develop your . NET applications. Pro DLR in . NET 4 introduces you to the DLR, showing how you can use it to write software that combines dynamic and static languages, letting you choose the right tool for the job. You will learn the core DLR components such as LINQ expressions, call sites, binders, and dynamic objects—and how they work together to achieve language interoperability. You’ll see how to mix and match objects and functions from compiled and dynamic languages, so you can write code in the language of your choice while taking advantage of libraries written in other languages. And you'll discover how the various languages interoperate behind the scenes. With the basics out of the way, the book then details the various ways you can leverage the DLR in the design and architecture of your software applications. You’ll learn about runtime code generation, which lets you avoid much of the boilerplate code typical in layered business applications. You’ll see practical examples of using the DLR to build domain-specific languages, and you’ll learn how the DLR helps enable aspect-oriented programming.

This book is not a treatment of the theory of design patterns. We show design patterns applied in real-world architectural scenarios so that you can see them in action and see the benefits that they bring. It explains why it's worth spending time building design patterns into your applications, even though this may seem at odds with Rapid Application Development. After a fast-paced introduction to design patterns, the core of this book consists of three case studies, which show how design patterns are applied in each of the main tiers of an application: the data, business, and presentation layers. These case studies flesh out the reader's understanding of design patterns, and show how they can be employed in real scenarios that will be instantly recognizable to all VB . NET programmers. The book also shows how design patterns can be used in conjunction with . NET Remoting, so that they can be applied not just within individual tiers, but across them as well. Since many VB . NET programmers may not be completely familiar with UML, we also provide a UML primer as an appendix.