parseDouble :: Parser Double
parseDouble = do d <- satisfyMany1 isDigit
                 _ <- satisfy (== '.')
                 f <- satisfyMany1 isDigit
                 return (read (d ++ "." ++ f) :: Double)
parseDouble :: Parser Double
parseDouble = do d <- satisfyMany1 isDigit
                 _ <- satisfy (== '.')
                 f <- satisfyMany1 isDigit
                 return (read (d ++ "." ++ f) :: Double)
parseDouble = do d <- satisfyMany1 isDigit
                 _ <- satisfy (== '.')
                 f <- satisfyMany1 isDigit
                 return (read (d ++ "." ++ f) :: Double)