GHC and Haskell 98

[Bas van Dijk]

On 17 June 2011 16:47, Simon Peyton-Jones <simonpj at microsoft.com> wrote:
> So:    Under Plan A, some Hackage packages will become un-compilable,
>       and will require source code changes to fix them.  I do not have
>        any idea how many Hackage packages would fail in this way.

Of the 372 direct reverse dependencies of haskell98:

http://bifunctor.homelinux.net/~roel/cgi-bin/hackage-scripts/revdeps/haskell98-1.1.0.1#direct

there are 344 which also depend on base (See http://hpaste.org/47933
for calculating the intersection).

Am I correct that a package which depends on both base and haskell98
will always fail to build when the Prelude is also exported from
haskell98? (Unless of course the package uses the PackageImports
extension)

I don't know how many of these 344 packages use PackageImports or have
upper bounds on their haskell98 dependency (I guess not many). So I
guess many of these 344 will break.

Still I'm in favour of plan A since it's simple and discourages mixing
haskell98 with more modern modules.

Regards,

Bas