Re: Detecting first and last pages of a score

[David Kastrup]

Leah Velleman <address@hidden> writes:

> Well, although my knowledge of the internals is quite limited, it looks to
> me like there is precedent for this, involving page headers. As you say, a
> score can be placed multiple times. And each time it is placed, it can be
> interrupted at different points by page headers. I could see this being
> quite tricky -- but there is apparently a mechanism that lets it happen.
>
> At the moment when Lilypond stops placing systems on the page in order to
> insert one of those page headers, could it not be given access to the
> information "this is partway through a score, and here is the title from
> the header block of that score"?

LilyPond does not have something akin to TeX's "output routine",
user-accessible code that gets called at the time an output page wants
to get assembled.  Instead it calls hardcoded C++ code that does stuff
like resolving page references and adding head- and footlines and
footnotes and so on.

So what it does at the time of page building is closed in its
functionality and most certainly not accessible to decision-making.

> (If the answer is "no, it can't do that and it never will be able to,"
> then that's the answer. I'm not trying to argue with you, just
> clarifying what I was imagining.)

I am not saying "it never will be able to do" things like that but the
mechanisms are not there even in rudimentary form, so the manner in
which it may be done at some prospective future time is not clear.

-- 
David Kastrup