Re: Footnote line length ratio to current line length

[T. Kurt Bond]

Took a look at the output of Heirloom troff and Plan9 troff in Plan9port
<https://9fans.github.io/plan9port/>, and *they* both have the 11/12
ratio.  In both, the IZ initialization macro does

.if !\\n(FL .nr FL \\n(LLu*11u/12u

And the MC macro (2C just calls MC) sets FL to 11/12 of the width of the
column.

Any idea where I could find the source for earlier versions of the ms
macros?

On Sun, Dec 6, 2020 at 10:49 PM Dorai Sitaram via <groff@gnu.org> wrote:

>  The 5/6 may be a relatively recent consensus based on peer monitoring.
> UTP doesn't mention 5/6, for instance.  It has its own (slightly less)
> strange fraction though: 11/12 (see p. 606). When it came to FL, it was a
> Wild West out there back then, I tell ya.
>
>
> --d
>     On Sunday, November 15, 2020, 06:58:34 AM EST, G. Branden Robinson <
> g.branden.robinson@gmail.com> wrote:
>
>  At 2020-11-13T13:59:27-0500, T. Kurt Bond wrote:
> > Is there any chance of the footnote ratio change I discuss getting in
> > the upcoming groff release?  Should I add it as a bug at
> > savannah.gnu.org?
>
> Probably a good idea.  As you may be aware, I am updating and expanding
> Larry Kollar's ms.ms document with an eye to its inclusion in groff
> 1.23.0.
>
> Due to the way I work, this has involved me learning a lot about ms and
> its history.
>
> > On Thu, Aug 6, 2020 at 11:53 AM T. Kurt Bond <tkurtbond@gmail.com>
> wrote:
> >
> > > groff_ms(7) says that changing the number register FL is effective
> > > at the next footnote.  That seems to be true only for one column
> > > text.
>
> This behavior is worth trying to reproduce in Heirloom Doctools troff.
>
> > > In multicolumn text you have to change the undocumented fn:MCLL
> > > after calling .MC.  fn:MCLL is an alias for the number register
> > > pg@fn-colw, which is set when .MC is called.  (.2C calls .MC to do
> > > the work, so we only have to worry about .MC.)
> > >
> > > Is fn:MCLL intended to be ms internal use only, or is intended to be
> > > available to users?
>
> Definitely internal.  This is clearly documented in the in-progress
> rewrite (alas, it's not committed yet).  I'm attaching it, and let's see
> if I remember to actually do so before sending.
>
> > > I don't like having the line length of the footnotes only 5/6 the
> > > width of the columns: I like them to be the full width of the
> > > current line, whether that is in one column mode or multicolumn
> > > mode.  I'd like to be able to change that default, to avoid having
> > > to change the footnote line length in multicolumn mode using the
> > > undocumented fn:MCLL.
>
> I think the reason for this 5/6 ratio is because that's what AT&T ms did
> in the 1970s, and possibly every ms implementation ever since.
>
> > > I propose adding a string variable, FR (footnote ratio), that
> > > defaults to to 5/6 for compatibility and replaces the uses of the
> > > literal 5/6 for setting footnote line length.  You can set this at
> > > the beginning of your document, or before each .MC or .2C.  For my
> > > use I'd always set it to 1, making the footnote line length the same
> > > as the line length.
> > >
> > > (I think making setting FR effective before the next footnote, like
> > > setting FL in one column mode, would take rewriting par@reset to
> > > recalculate fn:MCLL every time, instead of just after a .MC.)
>
> I'm not entirely sure what to do about this.  How much fidelity to AT&T
> ms behavior do people expect from ms?  I've begun to surmise that the
> answer is "a lot less than they expect from man(7) documents".
>
> Regards,
> Branden
>


-- 
T. Kurt Bond, tkurtbond@gmail.com, https://tkurtbond.github.io