[...]

> I’ll check the doc later today, but it seems this is essentially ready
> for merging, no?

Yes, If you don't mind that I'm still using hash-tables, I think it can
be merged.

> When we merge, would you like to rewrite history and make the whole
> thing appear as a single “perfect” commit, or just merge ‘emacs-ui’ into
> ‘master’?  (I often do the former, but I’m fine with the latter here.)

I don't have a preference here.  I can do a single commit if it is more
appropriate.  Would the following commit message be OK?

--8<---------------cut here---------------start------------->8---
Add Emacs user interface.

* configure.ac (emacsuidir): New variable.
  (AC_CONFIG_FILES): Add 'emacs/guix-init.el', 'emacs/guix-helper.scm'.
* Makefile.am: Include 'emacs.am'.
* emacs.am: New file.
* doc/emacs.texi: New file.
* doc/guix.texi: Include 'emacs.texi'.
* emacs/guix-backend.el: New file.
* emacs/guix-base.el: New file.
* emacs/guix-helper.scm.in: New file.
* emacs/guix-history.el: New file.
* emacs/guix-info.el: New file.
* emacs/guix-init.el.in: New file.
* emacs/guix-list.el: New file.
* emacs/guix-main.scm: New file.
* emacs/guix-utils.el: New file.
* emacs/guix.el: New file.
--8<---------------cut here---------------end--------------->8---