attoparsec additions

manyN and manyNtoM

-- | Match a parser at least @N@ times.
manyN :: Int -> Parser a -> Parser [a]
manyN n p
    | n <= 0    = return []
    | otherwise = (++) <$> count n p <*> many p
{-# INLINE manyN #-}

-- | Match a parser at least @N@ times, but no more than @M@ times.
manyNtoM :: Int -> Int -> Parser a -> Parser [a]
manyNtoM n m p
    | n <  0    = return []
    | n >  m    = return []
    | n == m    = count n p
    | n == 0    = do foldr (<|>) (return []) (map (\x -> try $ count x p) (Prelude.reverse [1..m]))
    | otherwise = (++) <$> count n p <*> manyNtoM 0 (m - n) p
{-# INLINE manyNtoM #-}