Documentation of lilypond's scheme classes (Pitch, Score etc.)

Question

Where are lilypond's scheme classes (Pitch, Score etc.) documented?

For example the documentation of the scheme-function ly:pitch? says "Is x a smob of class Pitch?".

But there is no link or reference to where the class Pitch is documented.

There is also lilypond's github repository where one can search for the header files, e.g. for pich.hh to see how this class is implemented.

But... is there some kind of documentation for all the classes?

Answer 1

Not really. Lilypond is an open source project, so people will only create documentation if they feel it is necessary. But there is a good technical guide written by Jean Abou-Samra (one of the core devs):

https://extending-lilypond.gitlab.io/

For more detailed questions consider joining the Lilypond mailing lists.