Hello. some questions and suggestions

Duncan Coutts duncan.coutts at worc.ox.ac.uk
Wed Dec 27 20:54:51 EST 2006


On Thu, 2006-12-28 at 01:06 +0000, Ross Paterson wrote:
> On Thu, Dec 28, 2006 at 12:37:07AM +0000, Duncan Coutts wrote:
> > On Wed, 2006-12-27 at 23:22 +0000, Neil Mitchell wrote:
> > > Another advantage of Parsec is that then you'd be able to install a
> > > Hugs package without passing the -98 flag every time. ReadP requires
> > > forall, but Parsec doesn't unless you use the expression parser, which
> > > I doubt Cabal would require.
> > > 
> > > This will also make it easier to do a Yhc port of Cabal.
> > 
> > Actually I fixed that.
> > 
> > The issue was that hugs's version of ReadP needed -98 and Cabal's
> > 'compat' version didn't, so I just changed the ifdefs so that hugs
> > always uses the compat implementation rather than it's own.
> 
> But this means that under Hugs (but not GHC) the parse functions exported
> by Cabal can only be used with Distribution.Compat.ReadP, and can't be
> combined with real ReadP parsers.

Yes, I that's true. Was that a requirement?

We have the same issue for older ghc versions. Perhaps a longer term
solution might be to make hugs's ReadP not need -98. Does it have
something extra compared to the Cabal version that really needs non-H98
extensions?

Duncan



More information about the cabal-devel mailing list