Re: Scheme function returning \book

[Lukas-Fabian Moser]

> > \version "2.19.82"
> >
> > test = #(define-scheme-function (suffix) (string?)  #{
> >    \book {
> >      \bookOutputSuffix #suffix
> >      \score {
> >        d4
> >      }
> >    }
> > #} )
> >
> > \test "surname"
> >
> > (still) causes a "Bad expression type" error.
> Ah, well.  Turns out that copying the code for \xxx here where \xxx was
> a book identifier was not really a good idea before anybody figures out
> and defines the difference between a book and a bookpart.  Currently it
> is not viable to distinguish them.
>
> \book { \test "surname" }
>
> could conceivably just close its eyes and say "ok, let's treat it as a
> book rather than a bookpart" but doesn't.  Does anybody have an idea
> what is supposed to distinguish a book from a bookpart outside of actual
>
> \book {
>    \bookpart { ... } }
>
> usage?

I suspect that I do not understand the question correctly; at least I 
certainly do not understand the technicalities involved.

For me, as a user, the point is just that a book generates a stand-alone 
file whose filename can be defined indepentently of everything else. 
(Also, I noticed that whereas bookparts can have their own \paper 
blocks, it seems that the generated pdf has one paper size for all which 
is filled to varying degrees?)

But am I right in thinking that your question pertains to inherent 
structural properties of the generated expressions so they can be 
distinguished to be of one type or the other in an internal 
representation that does not sport a label 'book'?