On Tue, 2020-08-04 at 08:21 -0600, Carl Sorensen wrote: > > > On Tue, Aug 4, 2020 at 7:00 AM David Sumbler <da...@aeolia.co.uk> > wrote: > > My latest Lilypond project had been compiling satisfactorily. But > > at a > > certain point it began throwing out the following message: > > > > %%%%% > > Preprocessing graphical > > objects.../usr/local/lilypond/usr/share/lilypond/current/ly/engrave > > r- > > init.ly:836:5: In procedure ly:stencil-extent in expression > > (ly:stencil-extent (ly:note-head::print g) X): > > This particular line is trying to find the X-extent (horizontal > extent) of the note-head you are printing. > > X and Y are defined as Scheme constants for the X (horizontal) and Y > (vertical) directions. > > One feature of Scheme is that you can redefine anything. So you > redefined X and it caused problems. > > A general rule for lilypond is to avoid any variable names that are > all uppercase. In addition to X and Y, LEFT, CENTER, RIGHT, UP, and > DOWN are all defined Scheme constants, and if you redefine them it > will cause problems. > > HTH, > > Carl
Thank you for that clear explanation. I knew it must be something like that, but couldn't guess what X was. I had started off with lower-case Roman numerals, but that gives a problem with 100 and 500, which are also note-names. I suppose the best solution is probably to use upper case C and D (and M, probably), and lower case i, v, x and l, so that 1,444 would be MCDxliv. That doesn't look too bad, and should keep me, Lilypond and Scheme all happy. David
