Re: cadenza followed by a MMR is buggy

[Dan Eble]

On Jan 15, 2021, at 06:53, David Kastrup <dak@gnu.org> wrote:
> 
> Werner LEMBERG <wl@gnu.org> writes:
> 
>>> Add issue #3640 to this discussion.  Accidentals, bar numbers, and
>>> (now) multi-measure rests are all impacted by the fact that \bar "|"
>>> does not create a new measure.
>> 
>> Maybe the whole thing is primarily a documentation issue that could be
>> fixed with prominent warnings at appropriate places?
> 
> Maybe \bar "|" could just bump the bar number (and reset bar position)?

If we went that way, I'd generalize it to \bar X when X == 
Timing.defaultBarType.  Regardless, it is likely to be tricky to implement.

Were you thinking of limiting this special effect to the end of a cadenza?

> Can anyone think of a scenario where this would not make sense?

What if the user wants to force a new measure and use a section bar line?  
Would we suggest using \bar "|" \bar "||" to achieve that?  That seems awkward.

Rather than create a new measure, we could try to warn where \bar is used 
suspiciously.  Avoiding false positives is just about as tricky as actually 
creating a new measure.

On the whole, I'm not enthusiastic about adding special cases or new 
interactions to bar lines.  Recently, I've been trying to disentangle things to 
improve the chances of implementing a priority or layering scheme to address 
issue #3688.
— 
Dan