It has been a while since I've read it (as a rusty but not novice haskell programmer), but most of that does actually ring true. I do remember the error messag

It has been a while since I've read it (as a rusty but not novice haskell programmer), but most of that does actually ring true. I do remember the error message now that you mention it! I assume the code was run automatically when the book was compiled. There were a reasonable amount of typos and similar errors I seem to recall now actually, which is either surprising or perhaps revealing given that it was publicly reviewed. That said, I still think it's a good book. I'm not that fussed by having to work through it; that's just how some books are constructed if they're not reference material, particularly when earlier chapters are pre-requisites. I take your point though. As I said it has been a while, but I don't recall being perturbed by the non-idiomatic->idiom transition either. The numerous monad tutorials mentioned in other comments are a great example of how forcing a particular learning path on someone doesn't always work, but by the same token I believe it can be useful to gently show a common path from common naive code to idiom for example. I'd still recommend it anyway, if just for the "real world" approach of the title.