[gentoo-science] sage-on-gento/gap-on-gentoo

[François Bissey]

Hi all,

It occurred to me a few months ago, that the sage-on-gentoo overlay
was also the place to get a recent `gap`. The version in the main tree
is 4.4.12 and in the sage-on-gentoo overlay we have some 4.7.x and 
4.8.x. However while functional and sufficient to work with sage,
gap from the overlay stinks. And then there is the issue of gap packages.

Unlike R, gap doesn’t have a nice package installer and you cannot
just drop them in a user space (that I know off).
Also package’s documentation is messy and expected inside the 
package. The format seems to be html, new style doc, or tex, old
style doc. So often we have both in separate folder.

I also discovered there is something called `gac` to precompile
packages that hasn’t been exposed by the current ebuild. And a 
good thing too since it is fairly broken. But looking at it explains a
lot about the requirement of keeping gap’s object files around I was
told about.

So later today I will merge a new gap branch which will include a clean
up of files that we don’t want. Expose gac, offer an archive instead of
object files for gac to use, and a first batch of gap packages in a new
dev-gap category. Anyone wanting to know why I want a new category,
there are a lots of packages at 
http://www.gap-system.org/Packages/packages.html 
and a new category will eft any possible ambiguity. 
I am concentrating on packages standardly used in sage but I’ll take 
request and certainly PR for new packages.

If there are any gap users or specialists I’ll take your opinions
seriously.

Cheers,
François