data Apple = Apple { color :: String , diameter :: Int , weight :: Double } instance Eq Apple where (Apple c d w) == (Apple c' d' w') = c == c' && d == d' && w == w' main = do let apple1 = Apple "red" 1 2.5 let apple2 = Apple "green" 2 3.2 putStr "apple1 == apple2 : " print $ apple1 == apple2 let apple3 = Apple "red" 1 2.5 putStr "apple1 == apple3 : " print $ apple1 == apple3