New extension in GHC: newtype deriving clause

[Lennart Augustsson]

John Hughes wrote:

> Simon PJ and I have come up with an extension to newtype deriving clauses
> which is intended to make it easier to make types abstract.
>
> The new extension allows you to derive these instances, just by adding the
> classes to the deriving clause of the newtype declaration.

I like this, and I suggested it about 10 years ago. :-)
(And we have it in BlueSpec.)

    -- Lennart