Re: variables in \book { }

[Graham King]

On Wed, 2016-02-17 at 10:58 +0100, David Kastrup wrote:
> Graham King <address@hidden> writes:
>
> > Thanks Ben, 
> > that will be useful once I've found a solution to the immediate problem:
> > defining and using a variable within \book{} or \bookpart{} or
> > \book[part]{ \score { }}
> >
> >         \version "2.19.35"
> >         \book {
> >           music = \relative { c' d e f }
> >           \score {
> >             \music
> >           }
> >         }
>
> Shrug.  As I stated already, there is no book-local scope where such
> variables could be defined.  So there is no solution to what you
> identify as your problem.
>
> > (In case you were suggesting that I use \bookpart{} within
> > book-titling.ily, I've tried that too and it throws a lot of
> > "unrecognised string" errors.)
>
> The problem with the repeated use of "I've tried that" is that nobody
> can really guess just _what_ exactly you have tried with what error
> messages as the result.  And nobody can try reproducing or debugging or
> diagnosing the problem since there is no code to work with.
David,
my apologies.  You've underestimated my ignorance: I didn't realise that "The \book block does not really have a scope of its own..." implied that there is no solution.  I'm sorry to have cost you your time and frustration.

For what it's worth, here is how I now understand my error:
>       music = \relative { c' d e f }
>       \score {
>         \music
>       }
works just fine.  When the Learning Manual (at section 3.1.1) says: "If you haven't explicitly added [a \book block], LilyPond wraps your entire input code in a \book block implicitly." it does _not_ mean that the above code is equivalent to:
>       \book {
>         music = \relative { c' d e f }
>         \score {
>          \music
>         }
>       }
but rather:
>       music = \relative { c' d e f }
>       \book {
>         \score {
>           \music
>         }
>       }
So, for my immediate problem, I'll bite the bullet and create a namespace in which I can define all 12 instances of the various variables involved, and put the definitions outside the \book { ... }.  If that doesn't work, I'll just stitch some PDF's together without further troubling the list.