Bernie Pope
Of course, [unsafeShow] won't be able to print functions in any helpful way, unless we attach source code information to functions as well (which may be worth doing anyway?).
It might not be able to print the function's definition, but perhaps its type?
One thing to watch out for is cycles in data structures. You may not want to try to detect them, but at least you should be lazy in generating the printable representation of values.
For debugging output, I find I often limit output to avoid this. For instance, I defined this helper function for XML parser debugging: showSome :: [Tag] -> String showSome a@(_:_:_:_:_:_:_) = (init . show . take 5 $ a)++" ... ]" showSome a = show a with a typical error call: then error ("Couldn't find tag '"++show tag++"' in\n"++showSome list) Come to think of it, ghci's print-bind-result functionality could benefit from something like that... I also think it would be nice if unsafeShow could be available also in compiled code, not just ghci - e.g. sometimes you might want a mere user to run your application with debugging turned on. -k -- If I haven't seen further, it is by standing in the footprints of giants