Please don't deprecate Haskell 98 modules.

Gwern Branwen gwern0 at
Thu Mar 11 10:37:45 EST 2010

On Thu, Mar 11, 2010 at 10:00 AM, Yitzchak Gale <gale at> wrote:
> John Meacham wrote:
>> Please don't deprecate these modules.
>> It is actively contributing to bitrot to deprecate a perfectly useful
>> and well defined API.
> I think "deprecate" is just the wrong word. Gwern is not
> saying that we should remove haskell98 from Hackage,
> nor remove the -98 flag from Hugs, nor build a special
> case into compilers that make modules not compile if
> they use Haskell 98 syntax.
> As I understand it, the problem he is trying to solve is the
> following:
> Haskell code today uses hierarchical module names almost
> universally. This has been the case for years. Yet a huge number
> of packages on Hackage directly or indirectly depend on the
> the haskell98 module, whose sole purpose is to allow the old
> non-hierarchical module names from pre-addendum Haskell 98.
> Gwern is just trying to think of a way to remove all of those
> spurious dependencies. I agree that this cleanup would be
> a good idea. The only question is, how do we best go about it?
> Or have I misunderstood?
> Thanks,
> Yitz

Seems reasonable. Besides asking for a warning in Cabal (the logical
place, since GHC is too low-level and doesn't handle
module/package-level stuff), Neil has already mentioned that hlint
will warn about haskell98 module names, and I have been sending in
patches removing haskell98 deps - the fewer users of haskell98 there
are, the less the cost of adding such a warning. With a three-pronged
approach, the pain should be as minimal as possible.


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