polycomp.hs

data Code = Add | Div

class Compiler a where
    compile :: Code -> (String, String) -> String

instance Compiler Float where
    compile Add (a, b) = show (Unsafe.read a + Unsafe.read b :: Float)
    compile Div (a, b) = show (Unsafe.read a / Unsafe.read b :: Float)

instance Compiler Int where
    compile Add (a, b) = show $ uncurry (+)  $ parseArgs @Int (a, b)
    compile Div (a, b) = show (Unsafe.read a `div` Unsafe.read b :: Int)


parseArgs :: forall x. (Read x) => (String, String) -> (x, x)
parseArgs (a, b) = (Unsafe.read a, Unsafe.read b)

x :: String -> String
x tname = case tname of
    "float" -> compile @Float Add ("1", "2")
    "int" -> compile @Int Add ("1", "2")
    _ -> "Unsupported type"

main :: IO ()
main = putStrLn $ x "float"