Instances for data types

[Benjamin Franksen]

On Friday 30 April 2004 21:09, S. Alexander Jacobson wrote:
> And (going slightly OT) as long we are are
> simplifying instance declarations, how about
> making it easier to specialize them?  
> ...
> I'd like to
> declare default implementations e.g.
>
>    instance Property BasicProp a where
>
> And then only if I have a more interesting type
> do:
>
>    instance Property BasicProp CoolType where
>
> And only define the functions that are different
> from the default behavior for (Propry BasicProp a)

AFAIK, with overlapping and undecidable instances enabled (via compiler 
switch) this is already possible in GHC.

Ben