[Haskell-cafe] Functor instance derived from Monad

[Frantisek Farka]

On Wed, 19 Feb 2014 16:38:17 -0500
Brandon Allbery <allbery.b at gmail.com> wrote:

> On Wed, Feb 19, 2014 at 5:25 PM, Frantisek Farka <frantisek at farka.eu>
> wrote:
> 
> There is not, because the need for UndecidableInstances there is
> warning you that this is perilous.

Yes, I am aware of that. It's not the case I want to use this actual
code. I am rather interested in its impact on typeclass hierarchy 
compared to AMP and Default Superclass instances

> 
> I thought some of the discussion behind the AMP touched on why this
> was not considered as a solution?
> 

Could you elaborate on that? Although I gave it fair amount of googling
I did not find out anything. Was it on some mailing list? 

Thanks a lot

Cheers 

FF