Preloading seq.el

[Stefan Kangas <stefan@marxist.se>]

Hi,

I'm working on some things in help.el, and it would be very nice to be
able to use a function in seq.el to simplify my code.  Alas, seq.el is
not preloaded.

Could we preload seq.el?

Previous discussion here:
https://lists.gnu.org/archive/html/emacs-devel/2016-07/msg00852.html

In the previous discussion someone said that we would be punishing
users that do not use it if we preloaded it.  It's not clear to me how
this would punish users.  On the contrary, if it was preloaded, more
powerful abstractions would make it easier to maintain Emacs and free
time for developers by not forcing us to reinvent wheels.  This would
improve Emacs and help all users.

Another argument was that seq.el is not used that much.  This is not
surprising, since it's not preloaded.  It's therefore hard to use in
some places of Emacs.  If it was preloaded, it would presumably see
more use.

Stefan Monnier also pointed out that seq.el depends on cl-lib, and
that to preload seq, we would need to preload cl-lib.  This seems to
be due to a single use of the  cl-subseq function in cl-extra.el.  If
this is a show stopper, perhaps we could see if we can get rid of that
single use.

Best regards,
Stefan Kangas