Haskell 98: Enum Class

Simon Peyton-Jones simonpj@microsoft.com
Thu, 25 Oct 2001 06:30:06 -0700

| In addition, I suggest that, since it is widely agreed that=20
| the instances of Enum for Float and Double are highly=20
| unsatisfactory, the report should give these instances the=20
| same status as n+k patterns have (in 1.4 of the recent=20
| revision).  In particular, their use should be "discouraged",=20
| and there=20
| should be a warning that the instances may be "altered or=20
| removed in Haskell 2".
| It might clear the ground somewhat for Haskell 2 if there=20
| were a new section containing a list of deprecated features;=20
| we can probably think of some other things which should go in=20
| there.  In addition to what's said for n+k patterns, I=20
| suggest the standard explicitly encourage (but not oblige)=20
| conforming compilers to issue warnings when deprecated=20
| features are used.

The Revised Haskell 98 report is suppposed to be in
conclusion mode.  An attempt to decide what features are
deprecated would open up a big new debate.  One could
instead list features which are controversial --- that would
be easier.  Whether it would actually be worth the work of
getting consensus on such a list is not clear to me. =20