What should the relation between \book / \bookpart be?

Sorry, I had accidentally replied only to you. – and then added the user 
list instead of devel. Oh my depression brain.

On 08/08/2026 16:55, David Kastrup wrote:
> Simon Albrecht <[email protected]> writes:
>
>> If they would not, in effect, be nested book environments, then they
>> shouldn’t be declared as such in the input file, I think. What about
>> defining a new kind of environment that simply wraps up a number of
>> elements (like \scores and \markups) to be output in sequence, without
>> specifying their use in \bookpart or \book? I don’t think I have the
>> right catchy name for that, but something like
>> \outputSequence {}
>> \outputColumn {}
>> \outputLines {}
>> if you get what I mean?
> What is wrong with a \bookpart?

It causes a page break, and I understood your goal was to allow for the 
greatest possible flexibility in reusing segments of a project 
inside/outside of \book and \bookpart. That was me reading between the 
lines, which I felt to be necessary.

> If you want to think of things as mere text, you can use include, but
> then they _are_ mere text without inherent structure, and depending on
> the syntactic context they are included in, the structure may become
> different or incoherent.
>
> There is a reason text-based macros are a nightmare.  You cannot use
> them as black box.  You cannot rely on them being interpreted in a
> particular manner.

I don’t understand. Are you arguing against using \include to modularise 
a project? Of course using it always requires smart handling of what’s 
inside and outside any \includes.

Best, Simon