[Haskell-cafe] Inheritance constraints

[MigMit]

On 7 Jun 2012, at 20:55, Gábor Lehel wrote:
> 
> If I'm understanding you correctly, this is similar to something I
> recently filed as a feature request:
> 
> http://hackage.haskell.org/trac/ghc/ticket/5927

Yes, that seems to be it. Now I know I'm not alone.

> In the meantime it's possible to emulate it to a limited extent with
> the Sub type from the constraints package:
> 
> http://hackage.haskell.org/packages/archive/constraints/0.3/doc/html/Data-Constraint.html#g:3

Good. Seems to be enough for me.

> Out of curiosity, do you have any specific use case in mind?

It's something like Data types à la carte, but instead of a "sum" of all possible operations I try to use a class.