On 12/21/05, Wolfgang Jeltsch
Am Dienstag, 20. Dezember 2005 20:07 schrieb Sebastian Sylvan:
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It's sometimes beneficial to "lie" a bit when starting out. Perhaps say something like "this is a simplified view of things, for all the gory details see chapter 19".
Monadic IO is pretty darn cool, sadly that means that many tutorial authors are tempted to spend pages upon pages explaining exactly why it's cool and how it works, but that is NOT what most people starting out with the language need to read.
I'm still looking for a good *practical* tutorial that I could recommend to newcomers. IO, data types and QuickCheck in the very first chapter, I say! Real program examples from the get go, and go into the theory on why this has been hard in FP before Haskell (or Monadic IO rather) much much later, so as to not scare people away.
I think that there are cases where it's better to start with ordinary functional programming and come to I/O later. In my opinion, an example case would be teaching Haskell at a university.
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! 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!". /S -- Sebastian Sylvan +46(0)736-818655 UIN: 44640862