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{-# LANGUAGE LexicalNegation #-}
data FreeNum
= FromInteger Integer
| FromRational Rational
| Negate FreeNum
| FreeNum `Subtract` FreeNum
deriving (Show)
instance Num FreeNum where
fromInteger = FromInteger
negate = Negate
(-) = Subtract
instance Fractional FreeNum where
fromRational = FromRational
main = do
print (-123 :: FreeNum)
print (-1.5 :: FreeNum)
print (let x = 5 in -x :: FreeNum)
print (5-1 :: FreeNum) -- unlike NegativeLiterals, we parse it as (5 - 1), not (5 (-1))
print (-0 :: FreeNum)
print (-0.0 :: FreeNum)
print (-0o10 :: FreeNum)
print (-0x10 :: FreeNum)
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