Attach a debugger to LilyPond

[Urs Liska]

Hi,

a question on the Frescobaldi mailing list got me thinking: is it possible (or 
could it be made possible with reasonable effort) to attach a debugger to a 
LilyPond compilation process?

Probably there would be quite some managing to be done because there's no 
simple relation of code steps like in a programming language, but if the 
LilyPond parser (or the Scheme parser) could be hooked into it would be 
terrific if we could make Frescobaldi step through the input files (or probably 
one would rather want to set a breakpoint, e.g. in a music function and then 
step through that function to better understand what it's doing).

Any estimate on this?
Thanks
Urs