What's the future of the haskellYYYY packages?

Simon Marlow marlowsd at gmail.com
Fri Nov 11 17:33:17 CET 2011

On 11/11/2011 15:06, Bas van Dijk wrote:
> On 11 November 2011 15:09, Henning Thielemann
> <lemming at henning-thielemann.de>  wrote:
>> On Fri, 11 Nov 2011, Bas van Dijk wrote:
>>> I forgot the reason why we need Control.Monad.Instances which exports
>>> orphaned Functor and Monad instances for ((->) r), ((,) a) and (Either
>>> e):
>> Compatibility with Haskell 98's Prelude?
> Thanks I understand.
> What exactly is the future plan of the haskell98 and haskell2010
> packages? I understand that the Haskell' Process[1] now only deals
> with the Haskell language and that the evolution of the core libraries
> is now the responsibility of the Library Submission Process[2]. Does
> this mean we stop making haskellYYYY packages?

I don't think that's true.  Both Haskell 98 and Haskell 2010 specified a 
number of library modules, which are implemented by the packages 
haskell98 and haskell2010 respectively.  If we want to support those 
standards, we have to support their libraries too.

> I think that would be a good thing. Since these packages block
> innovation in certain parts of base (for example: getting rid of some
> orphaned instances in Control.Monad.Instances or designing a new monad
> hierarchy).

They don't necessarily block progress in the base package, they just 
mean that more code has to be copied into haskell98/haskell2010 to 
maintain the original API.

I'm not sure to what extent we want to do this.  So far we've only had 
to copy a few individual functions and fix export lists.  The change to 
Num recently meant that we have diverged from Haskell 98 and Haskell 
2010 in a fairly fundamental way, and to recover compatibility we would 
have to copy a lot of code into haskell98 and haskell2010.  On the other 
hand the change doesn't break very much code, so we could let it slip (I 
think that's what we'll do).

It would be a shame to drop compatibility for Haskell 2010 only two 
years after it was released.  I don't have a good feeling for how 
important this is though - certainly not much code on Hackage is written 
in pure Haskell 98 or Haskell 2010, but what about course materials and 


More information about the Libraries mailing list