Re: [Groff] underlining

[Ralph Corderoy]

Hi Peter,

> Have a look at om.tmac, the macro definition '.de ul*ps'.

http://git.savannah.gnu.org/cgit/groff.git/tree/contrib/mom/om.tmac#n175
OK, so it takes the normal grops definitions, e.g.

    /Q{moveto show}bind def

and replaces them with its own,

    /Q { moveto X show Y } def

where X saves the current place on the page and Y draws a line from
there to the new, post-show, place.  (Q can't bind the definition since
X and Y switch definitions between doing nothing and drawing the line.)

One thought, if grops grows some more definitions, it might hit X as
it's currently up to T.  Perhaps grops should declare a prefix it won't
use that's available for the user?

Cheers, Ralph.