I just finished reading Real World Haskell. This was my first book on Haskell, I’ve read only articles and papers before and I believe it was a very good introduction to the language.

The book tries to use real world problems and I feel like it is not very successful as it. The examples focus too much in a tiny feature of the language but don’t show the bigger picture. There are many exercises on parsing, from JSON to binary formats, but nothing that shows you how Haskell deals with abstractions and layers, the bread and butter of what we usually do. I was expecting something more like what Practical Common Lisp does in its examples, with quick examples showing how features behave followed by more complete examples showing how everything fits together.

The description of features, including the type system, is good though. I read the book mostly in the morning train and even without a handy computer I still got a very good understanding of those. I am definitely more comfortable reading a blog about Haskell now.

The introduction to monads wasn’t that great. I can see how the authors try to create the need for monads’ features and then show how to use them but I think that the approach dies in implementation details and forgets about the bigger picture. I believe that this was deliberately made to avoid lengthy and complicated explanations that are present in many articles but I don’t think it gets it right either.

The book is freely available here, full of comments written by the Haskell community. As I said before it may have its problems but is a very good introduction.