[luatex] First question: Retrieve *family* name of a font / the three main families

[Werner LEMBERG]

> Of course, but that's beside the point as of course you *can* use
> any font in LilyPond.  But there are no finer options such as
> detailed implicit selection of font weights, optical sizes (although
> it does so for notation font!), openType features.

The last one is not correct.  It *can* select openType features (since
July 2017).

To summarize: LilyPond is using the pango library for selecting
fonts.  What's needed is a `converter' for font names from pango to
luatex and vice versa.

Blaming lilypond is actually barking the wrong tree.  Pango itself
uses the fontconfig library to extract font properties, and it would
be a very useful thing if luatex could understand and handle
fontconfig data in general.  There are certainly far more programs
that link to pango than programs that use luatex for text
formatting...

> But even worse, there's really no useful paragraph formatting.
> Paragraphs are as ugly as when you disable hyphenation in
> LibreOffice.

This was the reason that in the beginning of development LilyPond used
LaTeX as the typsetting backend (and it produced a DVI file, BTW).
However, this was not a working solution for various reason, thus the
change from LaTeX to pango.

I think that LilyPond should not become a `lilyTeX' program.  Let's
LilyPond do what it can best, namely typesetting music, and
typesetting of larger text blocks should be done by specialized
programs like luatex.  As a consequence, there exists the `lyluatex'
package as an interface between the two worlds, and thus is it is
important to make the font name `conversion' as smooth as possible.


    Werner