Hi all, I am a very basic user of lilypond - I never did anything more advanced than simple piano pieces with lyrics - but a few weeks ago I found a way to use REPLs to learn Tikz, and I recorded a video about that, that is here...
http://angg.twu.net/eev-tikz.html Its two main ideas can be adapted to Lilypond, and I am going to ask for some help with the second. The first, and main, idea of the video is to use a very simple macro language in which "<<expr>>"s in strings are replaced by the result of evaluating expr in Lua in a certain way. This is trivial to adapt, I just need to change the "<<>>"s by other delimiters. The second idea, that is explained in an exercise at the end of the video - starting here: https://www.youtube.com/watch?v=d7nIzpXcV6c#t=1h27m34s is a way to a) make lualatex run a Lua REPL that is much better than debug.debug(), and b) use that REPL to inspect definitions from the calling lualatex with token.get_meaning, with a wicked trick to inspect the values of pgfkeys. Anyway, let me go back to Lilypond... I know that I can get a Scheme REPL from Lilypond by running this, (top-repl) but I've never been able to use it for anything useful. I _guess_ that competent Scheme users should be able to use that to ask Lilypond what it knows about what it has already processed of the current .ly file... Can anyone give me some examples of how to use the REPL to inspect some interesting variables and data structures? I am hoping to get something like a 5-line demo that I can use as a starting point... Thanks in advance! Eduardo Ochs http://angg.twu.net/eepitch.html
