Write Yourself a Scheme in 48 Hours
From the webpage:
Most Haskell tutorials on the web seem to take a language-reference-manual approach to teaching. They show you the syntax of the language, a few language constructs, and then have you construct a few simple functions at the interactive prompt. The “hard stuff” of how to write a functioning, useful program is left to the end, or sometimes omitted entirely.
This tutorial takes a different tack. You’ll start off with command-line arguments and parsing, and progress to writing a fully-functional Scheme interpreter that implements a good-sized subset of R5RS Scheme. Along the way, you’ll learn Haskell’s I/O, mutable state, dynamic typing, error handling, and parsing features. By the time you finish, you should be fairly fluent in both Haskell and Scheme.
Functional programming is gaining ground. Are you?