Congratulations for arriving at this point. Thus far in the book you’ve learned many of the features that Haskell provides in terms of language and libraries. The notions of functor, monad, and GADT should not be alien to you anymore. You’ve also seen how to design large applications in Haskell and how to manage databases and web applications. And above all, you’ve seen how a strong type system encourages a more systematic way of writing software and helps in reducing time spent in coding and maintenance.
As happens with any other language, a book cannot contain every single use of Haskell. Hackage provides an enormous ...