Book Image

Metaprogramming in C#

By : Einar Ingebrigtsen
Book Image

Metaprogramming in C#

By: Einar Ingebrigtsen

Overview of this book

Metaprogramming is an advanced technique that helps developers to automate repetitive tasks, generate scalable code, and enhance productivity in software development. Metaprogramming in C# is a comprehensive guide that will help you reap the full potential of metaprogramming in .NET runtime. You’ll start by learning about the .NET runtime environment and how you can use it to become a more productive developer. You'll learn how to infer types using reflection, use attributes, and create dynamic proxies. You’ll also explore the use of expressions to create and execute code and how to take advantage of Dynamic Language Runtime. But that's not all! You’ll also learn to go beyond inheritance and use method signature conventions to create easily maintainable code. Finally, you’ll dive into the world of compiler magic with Roslyn, where you'll discover how to use Roslyn to generate code, perform static code analysis, and write your own compiler extensions. By the end of this book, you’ll have a deep understanding of metaprogramming concepts and how to apply them to your C# code. You’ll be able to think about types, use attributes and expressions to generate code, and apply crosscutting concerns to improve code quality.
Table of Contents (25 chapters)
1
Part 1:Why Metaprogramming?
5
Part 2:Leveraging the Runtime
12
Part 3:Increasing Productivity, Consistency, and Quality
18
Part 4:Compiler Magic Using Roslyn

Creating expressions as delegates and executing them

We can think of expressions as methods or functions we can call. They might have parameters or not and they might return results or not. We can represent the expressions as either Action or Func. Both are delegate types found in the System namespace. Action represents a parameter-less action that can, if you need to, return results. While Func represents a function that has one or more parameters and can return a result. Both of these delegate types can take generic parameters representing the input parameter types and the result type.

Delegates are basically just representations of methods. They define a callable signature. We can invoke delegates as methods directly.

With expressions, we can turn them into a callable expression. This is done through Expression.Lambda(). Let’s build on the property assign expression we had earlier:

var parameter = Expression.Parameter(typeof(MyType));
var property = typeof(MyType...