[Haskell-cafe] newtype deriving Alternative

[Martijn van Steenbergen]

Hello café,

I've never written an Alternative instance for a newtype yet that 
doesn't look like this:

> instance Alternative T where
>   empty = T empty
>   T x <|> T y = T (x <|> y)

Why does newtype deriving not work for Alternative? (It works fine for 
Monoid.)

Thanks,

Martijn.