The plan is to cover the major techniques used to write serious, real-world Haskell code, so that programmers can just get to work in the language. By the end of the book readers should be able to write real libraries and applications in Haskell, and be able to:
design data structures
know how to write, and when to use, monads and monad transformers
use Haskell’s concurrency and parallelism abstractions
be able to write parsers for custom formats in Parsec.
be able to do IO and binary IO of all forms
be able to bind Haskell to foreign functions in C
be able to do database, network and gui programming
know how to do exception and error handling in Haskell
have a good knowledge of the core libraries
be able to use the type system to track and prevent errors
take advantage of tools like QuickCheck, Cabal and Haddock
understand advanced parts of the language, such as GADTs and MPTCs.
That is, you should be able to just write Haskell!
The existing handful of books about Haskell are all aimed at teaching programming to early undergraduate audiences, so they are ill-suited to people who already know how to code. And while there’s a huge body of introductory material available on the web, you have to be both tremendously motivated and skilled to find the “good stuff” and apply it to your own learning needs.
The time has come for the advanced, practical Haskell book.
Here’s the proposed chapter outline:
Why functional programming? Why Haskell?
Getting started: compiler, interpreter, values, simple functions, and types
Syntax, type system basics, type class basics
Write a real library: the rope data structure, cabal, building projects
Typeclasses and their use
Bringing it all together: file name matching and regular expressions
All about I/O
I/O case study: a DSL for searching the filesystem
Code case study: barcode recognition
Testing the Haskell way: QuickCheck
Handling binary files and formats
Designing and using data structures
Monads
Monad case study: refactoring the filesystem seacher
Monad transformers
Using parsec: parsing a bioinformatics format
Interfacing with C: the FFI
Error handling
Haskell for systems programming
Talking to databases: Data.Typeable
Web client programming: client/server networking
GUI programming: gtk2hs
Data mining and web applications
Basics of concurrent and parallel Haskell
Advanced concurrent and parallel programming
Concurrency case study: a lockless database with STM
Performance and efficiency: profiling
Advanced Haskell: MPTCs, TH, strong typing, GADTs
Appendices
We’re seeking technical reviewers from both inside and outside the Haskell community, to help review and improve the content, with the intent that this text will become the standard reference for those seeking to learn serious Haskell. If you’d like to be a reviewer, please drop us a line at book-review-interest@realworldhaskell.org, and let us know a little about your background and areas of interest.
Finally, a very exciting aspect of this project is that O’Reilly has agreed to publish chapters online, under a Creative Commons License! We’ll be publishing chapters incrementally, and seeking feedback from our reviewers and readers as we go.
