[Haskell-cafe] ATs vs FDs

[Andrew Coppin]

Andrew Coppin wrote:
> Ivan Lazar Miljenovic wrote:
>> If so, how does this not solve the issue?
>>
>> ,----
>> | class NextOneUpAT v where
>> |   type Next v
>> |   ...
>> | | instance NextOneUpAT Vector3 where
>> |   type Next Vector3 = Vector4
>> |   ...
>> `----
>>   
>
> Can I use that to go both up and down? Would the types be unambiguous? 
> I guess I'll have to go try it out...

Actually, this seems to work just fine as-is. (Famous last words...)