Re: Understanding symbol-list? variable names

[Simon Albrecht]

On 09.06.2018 01:51, Aaron Hill wrote:
> By the by, I noticed a little inconsistency with the support for 
> commas within symbol lists.
>
> %%%%
>   \version "2.19.81"
>   foo,bar = { c'4 }
>   {
>     \foo.bar % works
>     \foo,bar % error: syntax error, unexpected ','
>   }
> %%%%
>
> I would have expected the original assignment to fail, but the parser 
> at that point seems fine with the comma as an alternative to a period 
> for defining a symbol list.  However, then, at the point of 
> referencing the variable, the parser is not able to form a symbol list 
> in the same manner. 

I’d be fine with that. There are two ways that symbol (or key?) lists 
are used: in a hierarchically vertical or horizontal way.
Referencing an alist value as in
\foo.bar
definitely falls into the ‘vertical’ category, while
\tagGroup score,part,vocal-score
is definitely in the ‘horizontal’ category.
The comma-separated syntax is only intended for ‘horizontal’ uses, IIUC.

Best, Simon