Book review: Functional programming in C#

I have been interested in functional programming for quite some time, experimenting with both F# and Clojure as well as trying out some Scala. But I must admit that I have never really put full focus on it for any longer period, not until I found this book:

Book cover

Functional programming in C# – How to write better C# code is a book by Enrico Buonanno, a CS graduate from Columbia University with over 15 years of experience as a developer, architect, and trainer. It is published by Manning and you can find it at https://www.manning.com/books/functional-programming-in-c-sharp.

What made this book appealing was that it is written for developers who are fluent in C#, a language that I know quite well, meaning I did not have to struggle with both a new language and all the new concepts and ways to think that comes with functional programming. In retrospect this was a really nice way to learn what functional programming is all about.

This book is not for the beginner programmer. It goes into several advanced topics in depth and I would only recommend it to an experienced C# developer who is willing to spend a lot of time and energy on learning about functional concepts such as immutability, functors, monads, partial applicaction, currying and the likes.

With that said, if the above description fits you, I can really recommend that you give this book a try. It describes a lot of concepts and has a lot of sample code and coding excercises. The first eight chapters all ends with a bunch of challenging excercises for the reader and there is also a github repository available that includes the authors own functional library and excercises and solutions from the book. You can find the repository at https://github.com/la-yumba/functional-csharp-code.

The only critique I can give is that I think that it would have been better if the author used the well established language-ext library instead of developing his own. When comparing the two I get impression that the authors library is pretty much a subset of language-ext and does not add anything I don’t get from language-ext.

I feels nice to finally understand what a monad is. My next step on this journey will probably be to take a deep dive in a pure functional language (like Haskell).