Benjamin L. Russell wrote:
Wow, that's very general. So you want to divide hanoi into a main function, a helper function, and a display function.
I tried it out, and got this far so far:
[...]
hanoi_shower :: Show a => [(a, a)] -> String hanoi_shower [(a, b)] = "Move " ++ show a ++ " to " ++ show b ++ "."
That's exactly what I was thinking about, but your hanoi_shower only handles list of exactly one action, but you have to handle longer lists, too. This could be done with explicit recursion hanoi_shower [] = ... hanoi_shower ((a, b) : moves) = ... or (preferably) with map hanoi_shower moves = unlines (map show_move moves) where show_move (a, b) = ... Note the use of unlines again. I decided to use where to introduce a local binding to avoid cluttering the top-level scope with function names. Tillmann