[cvs-nhc98] Matching instances of Num

[Malcolm Wallace]

Sven Panne <Sven.Panne at aedion.de> writes:

> bar :: Blah -> Bool
> bar 0 = False
> bar _ = True
> ------------------------------------------------
> Fail: What? matchAltIf at 15:9
> ------------------------------------------------

Fixed (I think).  It didn't matter whether Blah was a data or a
newtype; we got the same crash.

> I'm not sure if the error is in FixSyntax.fsExp' or Case.matchAltIf
> itself because I don't know enough about nhc98's dictionary handling
> and pattern matching. Help required... :-}

It was in fsExp.  It shouldn't have been flattening out dictionaries
in patterns (only in expressions).

Regards,
    Malcolm