Re: \bookpart and variables

[David Kastrup]

Werner LEMBERG <address@hidden> writes:

>> We don't allow assignments inside of music expressions either, and
>> again the reason is not as much that it wouldn't be possible to
>> allow them there, but rather that people would be surprised that
>> "reassigning" a variable inside of music will affect previous uses
>> of it and not be in any conceivable way synchronized with the "flow"
>> of music.
>
> You are correct, of course, but this is not obvious at a first glance.
> Could you add a corollary of our e-mail exchange on this topic to the
> documentation?  Perhaps a section `When does variable expansion
> happen?'...

I'll try keeping it in mind.  In mean time, scores have \header blocks,
and books have \paper blocks, and some information can be put there and
will indeed stay local to those blocks and scores and books.  One can't
usefully _change_ variables there: the meaningful uses are basically as
constants given a value that they keep.

If we find that we are missing tools for organizing scores in a useful
manner, we'll need to think about how we can arrive at semantics that
better reflect what people want to put into their sources while still
working well for the kind of batch parsing we employ (and which will
likely eventually be our road into comparatively reliable MusicXML ex-
and import).

-- 
David Kastrup