Re: A work-in-progress guide to extending LilyPond

[Thomas Morley]

Am Sa., 10. Apr. 2021 um 16:47 Uhr schrieb Jean Abou Samra <jean@abou-samra.fr>:

> Just a question: you say
>
>    In music-functions, when calling a variable
>    containing music .$ is preferable, because
>    otherwise a subsequent call of the same
>    variable will not see the original.
>
> Is that not due to the copy $ makes? Do you
> have an example?

See the different behaviour of:

foo = #(define-music-function (mus)(ly:music?) #{ \transpose c c' #mus #mus #})
\foo { b1 }

buzz = #(define-music-function (mus)(ly:music?) #{ \transpose c c' $mus $mus #})
\buzz { b1 }

Speaking only for me I mostly want to keep the unchanged original
around, thus $mus.
(or (ly:music-deep-copy mus), more typing, though)

>
> > Best,
> >    Harm
> > Hi again,
> >
> > I cloned the repo, but I've no clue how to get it compiled.
> > First I had to install missing sphinx-stuff, then I tried
> > make html
> > and got:
> > $ make html
> > Running Sphinx v1.8.5
> > Adding copy buttons to code blocks...
> > building [mo]: targets for 0 po files that are out of date
> > building [html]: targets for 7 source files that are out of date
> > updating environment: 7 added, 0 changed, 0 removed
> > reading sources... [100%] translation
> >
> > Sphinx error:
> > master file /home/hermann/extending-lilypond/contents.rst not found
> > make: *** [Makefile:20: html] Error 2
> >
> > Any hint?
> >
> > Cheers,
> >    Harm
>
>
>
> Now to the build failure: you are using a
> very outdated version of Sphinx, I have 3.5.3
> over here. The "contents.rst" file has been
> since renamed to "index.rst". Try updating?
> Note that, as is common practice in Python
> projects, the repository contains a file
> called requirements.txt, which lists the
> package requirements with pinned versions.
> This means that you can just do
>
> python3 -m pip install --user --requirement requirements.txt
>
> (it's safest to uninstall first).
>
> Best,
> Jean

Well, I first tried to get the sphinx-stuf from my distribution.
Ubuntu-20.04 is not that ancient...

Anyway, I followed your advice and now it compiles with:
$ SPHINXBUILD=/home/hermann/.local/bin/sphinx-build make html

I'll  check for your recent changes soon.

Thanks,
  Harm