X11 libraries

[Simon Marlow]

=20
> I'm in the process of moving the X11 libraries over from hslibs into
> fptools/libraries and thought I'd better check I'm doing it the
> approved way before I commit.
>=20
> At present, I'm modelling my infrastructure (Makefiles, directory
> structure, etc) on the HOpenGL infrastructure so, naturally, I'm
> putting it in fptools/libraries/X11 and have the following modules:
>=20
>   module X11   -- reexports  X11.Types and X11.Xlib
>   module X11.StdDIS
>   module X11.Types
>   module X11.Xlib
>=20
> The X11 module lives in fptools/libraries/X11.hs.
> The X11 library is only built if GhcLibsWithX11 is set.
>=20
> The X11 library is covered by the same license as GHC, Hugs, etc.
>=20
>=20
> 1) Is this the right place to put X11 in the directory tree or should
>    I put it under libraries/base or some other existing directory?

fptools/libraries/X11 is fine.  This will mean that X11 becomes a
separate package in GHC-speak, but that's what we want.

> 2) Is this the right place to put the X11 module in the hierarchial
>    namespace?

According to the current hierarchy document[1] we have these libraries
under Graphics.X11.Xlib.  Perhaps these names would be correct:
 =20
    Graphics.X11.Xlib
    Graphics.X11.Xlib.Types
    Graphics.X11.X1ib.StdDIS

The reason for separating Xlib into its own hierarchy is that there are
other APIs under X11 (Xt, Xaw, Xmu).  We could follow the convention of
having the parent export the children though, and have Graphics.X11
export the contents of Graphics.X11.Xlib.

> I'm hoping to get round to moving the Win32 and HGL libraries over
> pretty soon as well so whatever answer you give should apply to them
> too.

Win32 is currently listed as being under System.Win32.  However, since
we've just put Dotnet at the top of the hierarchy, and Win32 contains a
range of both systems and graphics stuff, I'd be happy for it to be at
the top of the hierarchy too.  HGL is assigned Graphics.HGL, which seems
like the right thing.

> ps The makefiles seem to be entirely for GHC usage but we will want to
>    build X11 and Win32 for Hugs and NHC as well.  Since we already
>    have makefiles and other scripts for doing this (Hugs only at
>    present), the easy way to do this would be to copy over the
>    existing scripts and completely ignore the fptools Makefile
>    infrastructure - but it would perhaps be nicer if we could easily
>    exploit the existing infrastructure.

Not sure what you mean here.  Can't you use the existing mechanisms that
Hugs uses to get access to the rest of the libraries?  That way we can
have fptools Makefiles too, and the X11 lib will build for GHC.

The NHC folks seem to be using their own Makefiles, called
Makefile.nhc98.

>  (This applies to all the
>    existing stuff in fptools/libraries/base too - the Hugs distro
>    contains stuff to compile all the files that contain ffi code but
>    this largely replicates the instructions from the fptools
>    makefile.)

> pps Should I continue the unsavoury practice of committing GreenCard
>    generated code to the repository?  (Currently done for Win32, I'd
>    do it for Xlib too for the sake of consistency.)

I think the reason for this was that we could avoid a greencard
dependency in a GHC build.  I'm agnostic really, since we probably won't
be including X11 in the default GHC build (see previous discussions
about why we want to tighten up the set of libraries that GHC is shipped
with).

Cheers,
	Simon

[1] fptools/libraries/doc/lib-hierarchy.html, and
    http://www.haskell.org/~simonmar/lib-hierarchy.html