type families not advertised for 6.8

[Simon Peyton-Jones]

| > Absolutely not; quite the reverse.  It means that some of the *code* for
| type functions happens to be in the 6.8 release --- but that code has bugs.
| It's only in 6.8 for our convenience (to avoid too great a divergence between
| the HEAD and 6.8), but we do not plan to *support* type functions in 6.8.
| Doing that would delay 6.8 by 3 months.
|
| Do you make any difference between associated type synonyms and type
| functions in this respect?

No difference: both are in the 6.8 code base, but we won't support them there.  Both are in the HEAD, and we will support them there.

(Associated data types have the same status -- but the 6.8 code for associated data types is quite a bit solider, so they'll probably work.  No promises though!)

Simon