Please don't deprecate Haskell 98 modules.

Aaron Denney wnoise at
Fri Mar 12 17:43:17 EST 2010

On 2010-03-11, 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.

It is precisely the right word -- in the context of computer standards
it means discouraging use due to new ways of accomplishing the same
thing, while still allowing it.  Doing any of those things you mentioned
would not be deprecation, but breaking.

> As I understand it, the problem he is trying to solve is the
> following:

I don't see why it's a problem, frankly.

> Haskell code today uses hierarchical module names almost
> universally. This has been the case for years.

Check and check.

> 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.

In other words, to _implement the standard_.  Some people do
code to the standard as much as practicable, because that portion
is then guaranteed to work, leaving only uncertainties about the
portions that aren't Haskell 98.  If you want to instead throw their
code on a treadmill of evolving "what works as of GHC-HEAD", then you
have to be the maintainer.

> 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?

I don't see how it's a _useful_ cleanup, or that the dependencies
are truly spurious.

Aaron Denney

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