The beginner parts were _a_ gap, but they weren't the only gap. In fact, none of the existing books really went very far beyond Monad, with only RWH covering monad transformers.

So, part of the appeal of the book isn't just that we cover beginner topics better, we cover _everything_ from beginner to intermediate/advanced that you're likely to apply in order to, say, make a web application. And in fact, we use a micro web framework in Haskell to demonstrate stuff in the later chapters.

It may not seem like it, because chapters like "data structures" actually cover - profiling time, profiling memory, containers, benchmarking, constant applicative forms, avoiding memory leaks, etc.

We'll be updating the site to explain what each chapter covers in more detail soon.

I've spent a couple years teaching Haskell and haven't found LYAH to set anyone up for success in Haskell. They usually hit a brick wall because they don't have either the foundation or intermediate idioms to really get anywhere. So there's usually a 45-days-in-the-desert period after LYAH where they have to muck through tens or hundreds of blog posts to plug all the gaps.

I talk about this here: http://bitemyapp.com/posts/2014-12-31-functional-education.h...

Suffice to say, I would've happily written a much smaller, shorter book - but this was needed.