MyWord.hs

{-# LANGUAGE GeneralisedNewtypeDeriving #-}

import System.Exit

newtype MyWord = MyWord Word deriving(Enum,Eq,Integral,Num,Ord,Real)

myInt :: MyWord -> Int
myInt = fromIntegral
{-# INLINE myInt #-}

fromMyWord :: Num a => MyWord -> a
fromMyWord (MyWord w) = fromIntegral w
{-# INLINE fromMyWord #-}

myInt2 :: MyWord -> Int
myInt2 = fromMyWord

int :: Word -> Int
int = fromIntegral

fib :: Integral a => a -> a
fib 0 = 0
fib 1 = 1
fib n = fib (n-1) + fib (n-2)

main = exitWith $ ExitFailure $ myInt (fib 10) + myInt2 (fib 10) + int (fib 10)