Less restrictive LilyPond identifiers?

[Matthias Kilian]

Hi,

are there any reasons to restrict identifiers in LilyPond to contain only
letters? IMO, it would be nice to at least also allow digits.  That would
make it easier to write large pieces by defining small chuncs of music:

Part1Voice1 = \notes {...}
Part1Voice2 = \notes {...}
...

At least for allowing digits, nothing of the tests, examples and
documentation of LilyPond would be broken, since a quick

$ find . -type f | xargs grep -l '\\[[:alpha:]]\+[[:digit:]]'

only lists some non-ly files.

Allowing _ or - would certainly break existing LilyPond input (for
example, the \fermata_"Cadenza ad lib." in the Mozart example).

If there's no other reason for disallowing digits than to keep
parser/scanner, I could try to write a patch.

Ciao,
        Kili