Re: Alternate (scheme) text spanner ignores spacers

[Rutger Hofman]

I tested with multiple spanners. It threw me an error on line 77: s is 
an unbound variable. I don't grasp your code, but if I replace '(cdr s)' 
with 'f' in that line, it works fine with overlapping spanners.

Thanks very much!

Rutger

On 10/07/2016 04:47 PM, David Nalesnik wrote:
> Hi again,
>
> On Fri, Oct 7, 2016 at 9:11 AM, David Nalesnik <address@hidden> wrote:
> > Hi Rutger,
> >
> > On Fri, Oct 7, 2016 at 2:30 AM, Rutger Hofman <address@hidden> wrote:
> > > Hello list,
> > >
> > > David Nalesnik wrote a scheme TextSpanner that honours the spanner-id
> > > predicate. This is really, really great: I no longer have to create new
> > > Voices for overlapping TextSpanners. But it has a feature/bug that is really
> > > unwelcome: if the \stopTextSpan is after a spacer note (maybe by using David
> > > Kastrup's now famous \after), this spacing is ignored. The right-bound text
> > > appears immediately after the 'true' note.
> > >
> > > Two observations:
> > >  - the standard TextSpanner behaves correctly
> > >  - the TextSpanner in scheme, which David N. used as an example, also has
> > > the feature/bug
> > >
> > > Alternate text spanner:
> > > https://lists.gnu.org/archive/html/lilypond-devel/2015-10/msg00042.html
> > >
> > > Attached a minimal example of correct/buggy behaviour, and, for ease of
> > > reference, David N.'s implementation.
> > >
> > > I would dearly love to see this fixed, but I have no idea where to look.
> >
> > This engraver is based on the regression test
> > 'scheme-text-spanner.ly', which suffers from the same limitation.
> > I'll see what I can figure out.
>
> The problem happens because of a missing check as to whether the
> spanner we are building has a left/right bound.  The attached should
> work, though would you mind testing it on an example that has multiple
> spanners?
>
> Best,
> David
>
> P.S. The checks are also missing in the regression test.  I need to
> get back into contributing, so I will attempt to bring the regression
> test more in line with the C++ original in
> lily/text-spanner-engraver.cc