Integrating editline with ghc

[Judah Jacobson]

On Jan 17, 2008 1:19 AM, Christian Maeder <Christian.Maeder at dfki.de> wrote:
> Judah Jacobson wrote:
> > - System.Console.Editline.Readline contains the readline APIs provided
> > by the editline library (mostly a cut/paste of
> > System.Console.Readline).
>
> I would like to see a restructuring of the old readline
> package:
>
> 1. a _new_ readline package that only contains the interface that can be
> implemented using libeditline _or_ libreadline. If this package is call
> "readline" (with a new version number) most libraries i.e. like Shellac
> would not need modifications.
>
> 2. Two further packages for extension of editline and those functions of
> readline that are not part of "1". Maybe call these packages
> editline-ext and readline-ext

A problem with the above proposal: the readline-ext package would
depend not just on the readline package, but on an instance of the
readline package that was built against libreadline specifically.  I
don't think that we can enforce that constraint; and even if we could,
on a machine with both editline and readline installed it would get
confusing pretty quickly.

I think it will be much simpler if we keep the readline and editline
packages as they are now, and possibly add a third readline-compat
package which can use either one as a dependency.  Then any project
(including GHC) can choose which of those packages to use, based on
API requirements and/or license issues.

Best,
-Judah