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@mvolkmann
Created January 6, 2018 16:41
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instance LogType (IO a) where
logn' arr = do
-- Call putStr on all the elements in arr.
mapM_ putStr arr -- functions that end in _ ignore their result
-- Output a newline.
putStrLn ""
-- The "do" block must return something.
return undefined
instance (Show a, LogType r) => LogType (a -> r) where
logn' arr x = logn' (arr ++ [show x] ++ [" "])
logn :: (LogType t) => t -- Why doesn't () work in place of the last t?
logn = logn' []
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