Sebastian Sylvan wrote:
Well, I certainly disagree there. I'm not advocating going into a full-blown explanation of monads, just enough to actually be able to write a real stand-alone program after the first chapter. They only need to know that do-notation is for sequencing computations, and (<-) is for binding a name to the result of a computation. That's it!
As a newbie... I agree that a newbie should be able to write this fairly early on: main = do x <- getLine() putStrLn ("The answer is " ++ show(fib(read(x)))) Now, you just said "do-notation is for sequencing computations". Would it be fair to say that do-blocks are imperative blocks in an otherwise functional program?
You could spend the next ten chapters with coding examples that are not very IO-heavy, and lead with a good example of doing as much as possible in the pure world (as well as pointing out every now and then whenever a particularly good "IO-separtion" was achieved - to emphasize that it's good practice).
When someone who has programmed before learns Haskell and gets the impression that IO is beeing left for later because it's "hard" they might think "bah, what a rubbish language, IO in Visual Basic isn't hard at all!".
I would agree with both paragraphs. Show basic IO and show that there's no need for complex IO because all the logic should be functional. Cheers, Daniel. -- /\/`) http://oooauthors.org /\/_/ http://opendocumentfellowship.org /\/_/ \/_/ I am not over-weight, I am under-tall. /