Class System current status

[Manuel M T Chakravarty]

Stephanie Weirich:
> Simon Peyton-Jones wrote:
> > My suggestion is this:
> >
> > * Specify MPTCs in the main language
> >
> > * Specify FDs in an Appendix (with some reasonably conservative
> > 	interpretation of FDs). 
> >
> > * A Haskell' implementation should implement the Appendix, and
> > 	programmers can write programs against it.  But
> > 	we are advertising specifically that we aren't sure, one way
> > 	or the other, whether FDs will stay in the language for ever
> >
> >   
> Simon,
> 
> Why is an Appendix is better than just a footnote in the Standard that 
> says "we aren't sure, one way or the other, whether FDs will stay in the 
> language for ever."  Why do we need this extra structure?

IMHO the right thing is to decouple finalising an FD/AT appendix from
finalising the main body of Haskell'.  This is clearly more easily
realised when the delayed material is out-of-line.

Manuel