Deprecating haskell98 module aliases

[Christian Maeder]

Gwern Branwen schrieb:
> See http://hackage.haskell.org/trac/hackage/ticket/640
> 
> It seems to me that a warning on using the 'haskell98' package
> wouldn't be a bad thing; those modules have since been split apart in
> better modules, the names are ever more unfamiliar, etc.
> 
> But Duncan thinks it merits discussion.

The modules in haskell98 are just wrapper modules providing their
functions under different module names in order to support the (old)
currently documented haskell98 standard from Dec. 2002 (also used in
many teaching books).
http://www.haskell.org/onlinelibrary/

This documentation lists even modules that are not part of current ghc
installations like:
module PreludeList, module PreludeText, module PreludeIO

I don't miss these modules and I think we should eventually get rid of
haskell98 as a *core* package of ghc (and the haskell-platform).

Before omitting the haskell98 package we should warn about it!

Whoever still wants to use the haskell98 package may install it via
cabal (or use his/her own wrapper module(s)).

I would at least warn about a haskell98 dependency in .cabal files.
Maybe even a warning for every non-hierarchical module import should be
issued.

Cheers Christian