Breakable figured bass extender lines

[liang seng]

Hi, I'm using Lilypond to type out some music with figured basses and I came 
up with a unique situation. Is it possible to use a breakable extender line 
over several bars when the break would correspond to a rest in the bass line 
music? Consider the following example:

\version "2.7.17"
\relative {
<<
\context Voice {
\clef bass
f,4 r f r f r f r }
\context FiguredBass \figuremode {  \set useBassFigureExtenders = ##t
<6>4 r <6> r <6> r <6> r } >> }

As you can see, all the notes "f" have the same figure. However, is it 
possible to substitute all the figures "6" except the first one with 
extender lines? This is used to mean that the instrument that is playing the 
realized figured bass plays the same chords all the way. The catch is the 
extender line cannot be continuos since it will not make sense as when there 
are rests, the instrument does not play. Therefore, the extender line 
"break" whenever it encounters a rest. In a way, it can be described that 
the all "6" except the first are relaced by dashes.
I'm highlighting this because there are some scores whose figured bass is 
typed this way.
Thanks

example.pdf
Description: Adobe PDF document