... homework ... it is highly unlikely that you will find any help in the list or on stackoverflow.

Quite often students do find homework "help" on stackoverflow. Of course SO will do nothing to discourage that. I'm not saying they should delete homework questions outright, but if they'd want quality, they'd introduce a "homework" tag so that these questions can be avoided more easily by people who would want to use SO to read/write quality answers/questions. But it seems that SO's goal is mostly numbers, that is, users. Actually, viewers for the job ads. And as long as the advertisers are paying ... Anyway, back to Haskell (but not leaving rant mode): the code example in the original question, although being rather short, manages to showcase several features that should be avoided in introductory teaching: numbers, lists, strings, and IO. (*) But, perhaps the instructor had a specific motivation. We can only guess, and that is why the recommended way for getting help with homework is (in that order): pay attention in class, then work on the exercises on your own, then with fellow students, and with the remaining questions, go to your instructor. - J.W. (*) and, recently, we should also avoid tuples https://mail.haskell.org/pipermail/libraries/2016-February/026678.html (I like the "matlab league" characterisation)