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module CC.Pretty where
class Pretty a where
{-# MINIMAL pretty | prettyPrec #-}
pretty :: a -> String
pretty = prettyPrec (-1)
-- | Higher precedence binds tighter.
-- Parentheses are required if the printed element has lower precedence
-- than the Int argument.
prettyPrec :: Int -> a -> String
prettyPrec _ = pretty
instance Pretty Int where
pretty = show
-- Useful if you want the Pretty instance to be equal to the Show instance.
newtype PrettyShow a = PrettyShow a
deriving (Show)
instance Show a => Pretty (PrettyShow a) where
pretty (PrettyShow x) = show x
pprint :: Pretty a => a -> IO ()
pprint = putStrLn . pretty
precParens :: Int -> Int -> String -> String
precParens environ self s
| self < environ = "(" ++ s ++ ")"
| otherwise = s
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