Alistair Bayley wrote:
OTOH, if you want to do anything useful with any language you have to learn to do IO (and simple IO is tackled early in most languages), and therefore you must deal with Monads. I often wish that Haskell books and tutorials would introduce IO earlier; it is often near the end, in the "advanced" topics (after you've been dazzled/saturated by the magic you can do with list functions and comprehensions, and how easy it is to create abstract datatypes, and write parsers, etc...).
I agree with this. And for what it's worth, in my textbook "The Haskell School of Expression" (http://haskell.org/soe), I introduce IO on page 37, Chapter 3 (out of 350 pages and 24 chapters). This is even before I talk about polymorphism and higher-order functions! I talk about "actions" and "sequencing", and I use the do syntax, but I do not mention monads at all. Monads are introduced on page 251, Chapter 18. -Paul Hudak