Re: Creating books with Scheme

[Nicolas Sceaux]

Le 29 août 09 à 14:28, Reinhold Kainhofer a écrit :

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Am Montag, 17. August 2009 12:05:23 schrieb Nicolas Sceaux:
> > Le 17 août 09 à 09:23, Nicolas Sceaux a écrit :
> > > If you look at the definition of `bookpart-score-handler' in my
> > > file, you see that the book-part argument is not used. Instead,
> > > all scores are added to the toplevel-scores parser variable (even
> > > though they are not really toplevel, it does not matter).
> > > The `toplevel-bookpart-handler' then uses this variable to actually
> > > add the scores to the bookpart. This function is called by the  
> > > parser
> > > when a \bookpart block is closed, so at this point the bookpart  
> > > object
> > > is known.
> > >
> > > You can change the book-score-handler and toplevel-book-handler to
> > > act the same way.
> >
> > Here is a short example showing how that may be done.
>
> Thanks a lot, but I just realized that if you use several bookparts,  
> the
> \header section of the bookparts get ignored. Also, you cannot mix  
> explicitly
> written scores with computer-generated scores...

After playing for a while with handlers, it seems that properly mixing
programmaticaly-generated scores and explicit scores requires some  
tweaks
in the parser. The hacks exposed earlier cannot deal with all various  
cases.

Proposition:

At the beginning of a \book (or \bookpart) block, the parser sets a
eg. $book (or $bookpart) parser variable, and unset it at the end of the
block.

Then, scores can be programmatically added this way:

(define (add-score parser score)
   (cond ((ly:parser-lookup parser '$bookpart)
          (bookpart-score-handler (ly:parser-lookup parser  
'$bookpart) score))
         ((ly:parser-lookup parser '$book)
          (book-score-handler (ly:parser-lookup parser '$book) score))
         (else
          (toplevel-score-handler parser score))))

Nicolas