[looping in groff list]

At 2022-08-11T10:34:50-0400, Dan Cross wrote:
> On Thu, Aug 11, 2022 at 8:13 AM <arnold@skeeve.com> wrote:
> > Dan Cross <crossd@gmail.com> wrote:
> > > I wrote to Brian, who works part-time at Google, and pitched the
> > > idea to him, and he extended pic to generate SVG, though it wasn't
> > > clear to what sources he was modifying, exactly. Then the pandemic
> > > hit, and I ended up leaving Google, so I don't think it went
> > > beyond that, but IIRC he said that coercing pic to generate SVG
> > > wasn't particularly difficult.
> >
> > I'm sure he'd have been messing with his own sources. These days
> > it'd be best to tr to get new features into GNU pic (IMHO, of
> > course).
> 
> Oh surely. I just don't know what sources those would be, exactly;
> presumably some derivative he's been shepherded all these years? I
> wonder what it is....

Per Kernighan's _Unix: A History and a Memoir_ (2020), it seems likely
that it was simply groff.

"Camera-ready copy for this book was produced by the author in Times
Roman and Helvetica, using groff, ghostscript, and other open source
Unix tools." (copyright page)

Further, figure 5.4 in that work was "created with Pic" (p. 95).

GNU pic is already parameterized in the output format it produces,
supporting four variants: "tpic" (`-c` option), "tex" (`-t`), "fig"
(`-f`), and "troff".  "fig" support has been #defined out for years and
may never have been completed.

SVG output, perhaps behind an `-s` flag, would be extremely helpful
toward simplifying groff's HTML output story.  (The other barrier is
tbl's production of HTML tables, Savannah #60052.[1])

Regards,
Branden

[1] https://savannah.gnu.org/bugs/?60052