Milestone reached: hyperlinked mdoc(7) documents in PDF

[G. Branden Robinson]

Hi folks,

Following up my earlier announcement regarding man(7),[1], I'm pleased
to report that we have a functioning PDF hyperlink story for the mdoc
package.

* The Mt macro hyperlinks email addresses.
* The Lk macro hyperlinks general URLs.
* The Xr macro produces "man:foo(1)"-style hyperlinks.

I've also refactored groff's "an.tmac" file sufficiently that the macro
redefinitions that Deri contributed as part of the "doc/GMPfront.t"
file[2] are no longer necessary.

The new GMPfront.t is smaller and more obviously performative of the
straightforward business of formatting a cover page, so that other
projects that want to collect their man pages into a PDF can use it as a
model without being baffled by macro appendments and quadruply-escaped
expressions.  Even better, because we are no longer appending to macros,
the input line numbers are not made inaccurate in the event of
diagnostic messages.[3]

Thus, if you build groff Git HEAD from source, the generated
groff-man-pages.pdf is now internally linked between not only all the
man(7) format pages, but the mdoc(7) one as well.

A copy is available at the usual Dropbox, of course.

https://www.dropbox.com/sh/17ftu3z31couf07/AAC_9kq0ZA-Ra2ZhmZFWlLuva?dl=0

As a further demonstration, and as a gift (bone?) to mdoc(7) mavens, I'm
attaching a PDF of all the mandoc(1) man pages, along with the 2-line
shell script I used to produce it.

I welcome feedback, as always.  And bug reports.

Regards,
Branden

P.S. Alex, you might want to consider simplifying your cover page
     similarly once you bring your copy of groff up to date.

https://git.savannah.gnu.org/cgit/groff.git/tree/doc/GMPfront.t.in

[1] https://lists.gnu.org/archive/html/groff/2024-01/msg00125.html

[2] ...now generated from "doc/GMPfront.t.in" at build time, so that the
    cover page can include the groff version number without requiring
    manual maintenance.

[3] This is a long-standing deficiency of GNU troff.  Would take some
    doing to solve, I think; the whole concept of a line number could no
    longer be expressed as an integer, but would instead require a
    structured object of some kind.  Possibly a recursively structured
    object at that, since `am` requests could occur inside portions of
    macros that were themselves populated by `am`...

mandoc-groffed.pdf
Description: Adobe PDF document

mandoc-groffication.sh
Description: Text document

signature.asc
Description: PGP signature