Hi all,
Since LilyPond uses Guile, you should look up Scheme details in the
Guile documentation.
https://www.gnu.org/software/guile/manual/html_node/index.html
... or, since the latest stable version is still on Guilev2 as far as I
know, one might use
https://www.gnu.org/software/guile/docs/docs-2.2/guile-ref/
For serious programming work in LilyPond, there's no way around perusing
the official Guile manual now and then (something which I myself
realised much too late). But before that, there's two additional
resources that, while currently unmaintained, are too valuable to let
them slide into oblivion:
- Our late friend Urs Liska wrote a significant portion of a
user-friendly Scheme introduction with a view towards LilyPond:
https://scheme-book.readthedocs.io/en/latest/
- Jean Abou Samra has written a guide to Extending LilyPond that also
covers Scheme, but then also goes intro great detail about finer points
of advanced LilyPond work (like writing custom engravers, etc.)
https://extending-lilypond.gitlab.io/en/index.html
Both resources also contain nice explanations on the subject of Scheme
symbols.
Lukas
