Would it make sense to, rather than use glissando or something similar, create
a function that takes a syntax similar to the following:
\lineBegin x y
\lineEnd x y
where x is an index so that \lineBegin and \lineEnd may be matched to one
another (even across the entire score), and y is the note event (with the
NoteHead)
that the line is drawn from. As a default, I could make any \lineBegin that
doesn't have a corresponding \lineEnd sets its \lineEnd to the same as
\lineBegin
(so that the length is 0). At the end of the program, a scheme function could
cycle through each set of pairs and draw a dotted line between each pair of
coordinates, possibly with make-stencil rather than usurping a glissando.
Does this seem like it's at all reasonable? Storing a list of pairs and going
back later to draw all the lines?
I'm sure it could do - although I doubt it would be used too much and so even
if such an enhancement were formally requested I think it unlikely it would be
implemented any time soon. There is likely to be someone along here soon who
could tell you how to do this in scheme... (Not something I can do, I'm
afraid).