Re: Axiom & internal/external GCL (was: Re: [Axiom-developer] Axiom cvs 040624 build error)

[root]

>  - Tim prefers to have a big sources with all included dependencies in
>    order to control the built system;

that's correct. Axiom is a very complex beast (probably over a million
lines in the fully developed system). It is very version dependent for
many subsystems, including GCL. In order to keep the quality of the
system at a high level the system is built and tested with particular
versions of GCL. In fact, a great deal of effort goes into making sure
that it works with the latest version. Axiom periodically takes 
snapshots of the GCL CVS in order to get the latest version. The
snapshots are then modified during the build. 

It is possible, if you have locally modified GCL, to replace the
GCL snapshot version (it is in src/zips) with your local version
but I can't guarantee that Axiom will work. I've tried to fully
document every change for every version of GCL with a complete
explanation so you can understand the what and why. The documentation
is in the various Makefile.pamphlet files (see the Makefile.dvi).

> 
>  - it is possible to build Axiom with an external GCL. In fact, Camm
>    Maguire, lead GCL developer and debian packager of gcl, axiom, maxima
>    and other software, is doing exactly that for the axiom debian
>    package. I don't know however if the machinery has been included in
>    current sources of Axiom.

that's not strictly correct. Axiom will not fully run on an external GCL.
depending on what you are doing it will fail. in particular, axiom adds
special socket handling code to GCL which will be used by the newly added
graph capabilities. further, axiom has special build-time flags (documented
in the top level Makefile) that need to be set to your particular version
of GCL. If you are not using the same version that is included with the
Axiom CVS you need to change these flags and rebuild your local version.

in addition to sockets Axiom is adding code to do machine-level numeric
support. i have a local version (not yet documented, tested, and checked in)
which contains support for BLAS (Basic Linear Algebra Subroutines). These
are built into the GCL image at system build time. Axiom's numerics will
depend on these routines as well as additional routines that are in the
queue to add. There has been some discussion about pushing the numerics
support into GCL as Camm is also the BLAS maintainer. Since Axiom is
currently the only user it is not clear that GCL wants or needs them.

A third package is also in my local version that is going to be added
which requires GCL changes. I've been working with ltk. This is a 
lisp TK toolkit that runs on almost every lisp (except, it seems, GCL).
The current GCL/TK package is broken as far as I can tell. I can get it
to work but it promptly crashes. We're working on a new Axiom GUI to
replace the lost techexplorer and it is being developed using TCL/TK.
Since the current GCL/TK doesn't work and ltk is almost all native
common lisp we're going to use it going forward. Hopefully once it
runs I can convince Camm to support it also but, again, since Axiom is
the only user it is not clear that it is worth adding it to GCL.

so it is unlikely, going forward, that Axiom will run on your installed
version of GCL.

Tim