Re: Manipulating instrument names and staff group names

[Jean Abou Samra]

Le 03/11/2021 à 22:16, Lukas-Fabian Moser a écrit :
> Hi,
>
> > Well, I would say it depends on what you intend to
> > do. Help out in implementing this particular feature?
> > The StaffCollection ancestor to StaffGroup might be
> > a good first contribution. For completeness you could
> > also add the intermediate type StaffMonoid.
>
> I already have this ready in a branch, along with some cleanup of 
> ly/engraver-init.ly (but didn't feel much of a hurry to create a merge 
> request).

Now I see why you asked about context definitions on the devel list.

> But I'm at a bit of a loss about your notion of a StaffMonoid. All 
> sorts of math puns aside (a CommutativeStaffRing of nonzero 
> characteristic especially for engraving _Le Spec de la Rose_ by 
> Berlioz) - what do you mean by a StaffMonoid?

There is absolutely nothing besides the math pun. It was too tempting 
given that I know both Kieren and yourself have some background in that.


> To be clear: I have a StaffCollection such that the definition of 
> StaffGroup boils down to
>
> \context {
>   \StaffCollection
>   \name "StaffGroup"
>
>   \consists "Span_bar_engraver"
>   \consists "Span_bar_stub_engraver"
>   \consists "System_start_delimiter_engraver"
>
>   systemStartDelimiter = #'SystemStartBracket
>
>   %% The default for DynamicText.extra-spacing-width causes dynamics to
>   %% be placed across span bars, so switch it off:
>   \override DynamicText.extra-spacing-width = ##f
> }
>
> (and I still wasn't sure if the Span_arpeggio_engraver should be in 
> StaffCollection or rather in StaffGroup).


I would put Span_arpeggio_engraver in StaffCollection. It makes sense 
for something intended at logically grouping staves, and doesn't harm 
after all: as long as the user does not \set 
StaffCollection.connectArpeggios, it has no effect.

Also, don't forget \alias StaffCollection in the definition of 
StaffGroup so users can write commands as \set StaffCollection.whatever 
= ... or \override StaffCollection.Whatever.whatnot = ... and have them 
work in all contexts that group staves.

> So StaffMonoid, if it's not meant as a joke, should be some subset of 
> this?
>
> > https://gitlab.com/lilypond/lilypond/-/issues?scope=all&state=opened&label_name[]=Doc 
> >
> >
> > Now if what you want is really coding, there are
> > heaps of open issues waiting for you. Here are a
> > few that I believe (NB no warranty) would be feasible
> > for a power user with some minimal understanding of
> > Scheme:
>
> Wow, this is very valuable. Thanks much for this list!

You are welcome. It's one of the cases where one can say: I hope it will 
not stay valuable too long.

> PS. And also thanks for the comments on the Instrument_name_engraver; 
> I'm afraid I won't have time before the weekend to really think about 
> your comments.

There is no rush at all.

Best,
Jean