Damn you! This was my “learn me a Haskell project”!
Don’t learn Haskell through projects, that rarely works for people, even those that know an ML already. Learning the idioms becomes a lot easier with exercises that have minimal distracting details.
Use my guide, do the exercises. IRC channel on Freenode at #haskell-beginners if you need somebody to talk to, about 150 users in there most days.