People, I have a question about usage of `show' in the GHCi dialogue system. I introduce my user class DShow, trying to improve the class Show of Haskell-98. For example, I program --------------------------- class DShow a where dShow :: ShowOptions -> a -> String ... main = let listOfListPairs = [ ([1,2,3], [] ), ([4,5,6], [7] ), ([9,8,0], [0,0,0]) ] :: [ ([Int], [Int]) ] opts = ShowOptions {verbosity = 2, listSepator = ", \n\n", fieldSeparator = ", \n"} in putStr (dShow opts listOfListPairs) --------------------------- Then, the command ./Main outputs ----------------------- [([1, 2, 3], []), ([4, 5, 6], [7]), ([9, 8, 0], [0, 0, 0])] ----------------------- This way of the output format control by dShow and ShowOptions is my goal. But the command
main
in the ghci interpreter outputs something like this: "[([1, 2, 3), []),\n\n([4, 5, 6), [7]),\n\n([9, 8, 0],\n\n[0, 0, 0])]" How can the user force ghci to output the same output format as in the case of ./Main (how to interprete '\n') ? 1. If we give to the interpreter the line
listOfListPairs
, then the ghci dialogue system does interprete the NewLine characters on output as needed -- only for the value of (show listOfListPairs). And I need it for the value of (dShow opts listOfListPairs). Is there any way to substitute a user function instead of `show' in the ghci output? (and dShow has additional argument ...). 2. Which function outputs a string in the ghci dialogue system? Can the user make this function to interprete the NewLine character in the argument string? Thank you in advance for your explanation. ----------------- Serge Mechveliani mechvel@botik.ru