Re: Variable names

[Hans Aberg]

On 13 May 2011, at 16:05, Carl Sorensen wrote:

>>>> I have tried to find some description of the valid syntax of LilyPond
>>>> variables and haven't found any. I would like to use variable names with
>>>> numbers and possibly with underscores - is it somehow possible?
>>> 
>>> Unfortunately, no.
>> 
>> I'm just curious... Do you know how much work would it take to change
>> it? Like, some work, a lot of work, tons of work or rewriting whole
>> Lily?
> 
> 
> It would introduce a bunch of shift/reduce conflicts in the parser, as I
> understand it.
> 
> http://article.gmane.org/gmane.comp.gnu.lilypond.devel/16481

Normally, one would try changing the lexer, in which case the work is minimal. 
Since a number can follow directly as another token after a letter-identifier, 
extending identifiers with numbers would force one entering a space after an 
identifier followed by a number. That is, not upwards compatible.

But one can seek for other solutions. One I have used is admitting arbitrary 
identifier names within single quotes '...'. Such a solution is practical when 
calling Guile names, and does not affect the parser at all, as it is just 
another form of an identifier.

Hans