Re: Behaviour of \paper and \layout in ly:book-process

[Urs Liska]

Am 18.07.2016 um 19:19 schrieb David Kastrup:
> Urs Liska <address@hidden> writes:
>
>> Am 18.07.2016 um 13:46 schrieb David Kastrup:
>>
>>> The defaultpaper argument of ly:book-process is only consulted when the
>>> book argument does not already have a paper block of its own, and every
>>> \book block takes the global \paper block when nothing else is given.
>> Thank you for the hint.
>>
>>> If you really want to pass the paper block in yourself during
>>> ly:book-process (rather than incorporating it in the \book explicitly),
>> No, I didn't do that intentionally but was misled by the fact that I
>> have to supply that default-paper and -layout arguments.
> Well, I wrote:
>
>>> If that sounds like I have any clue about how the hierarchy of books
>>> and bookparts is supposed to work, that would be misleading.  That's
>>> basically just a report on what some code does.  Why one would want
>>> it to do that, I have no idea.
> and indeed I did not have any clue about this difference until you
> popped the question and I looked into the code for the answer.  I don't
> think that there is any reasonable other way to discover that.

All the more thank you for looking into this.
Through that I also managed to make the \layout block work now.

As said I have a Scheme function producing the \score block. And when I
apply the \layout block directly within that function's \score block it
seems to be respected.

Somewhat strange though that I *need* to put these two empty expressions
in ly:process-book.

Best
Urs

>
> And I could not really write useful documentation for this since I fail
> to understand the underlying design.
>
> The commits are
>
> commit e9b10d6b0e1549a3d3d9ca81c63e1b2d9b431910
> Merge: 3dbfeb1 c45e558
> Author: Nicolas Sceaux <address@hidden>
> Date:   Sun Nov 16 23:32:33 2008 +0100
>
>     Book parts: \bookpart implementation
>     
>     Book parts aim at splitting a book into several parts, in order to be
>     able to use eg. different page breaking functions, or to make the page
>     breaking problem less difficult and more likely to finish.
>     
>     - Book and Paper_book instances respectively are nestable: children
>       book or paper_book are added to the bookparts_ slot;
>     
>     - the paper_ slot of a child Book (or Book_paper) is created empty,
>       and has its parent set to the paper object of the parent Book (or
>       Paper_book), so that default paper properties are got from the
>       higher level paper object, and child objects only store part-wide
>       overrides. This way, we ensure that fonts are loaded in the higher
>       level paper object, so that the output framework can get all the
>       loaded fonts from the top level book;
>     
>     - a Paper_book::top_paper() method is added to access the higher level
>       paper object, to access properties that are book-wide, for instance
>       the table used to store labels and page numbers;
>     
>     - in the parser, \bookpart blocks are introduced, which can be used at
>       toplevel, or inside a \book block. It can contain the same things as
>       \book blocks (except \bookpart blocks, though that would be
>       possible). The associated handlers are added.
>     
>     - in header and footer markups, the following predicates can be used
>       to determine if a page is the first or the last one in a book part:
>       part-first-page, part-last-page.
>
> commit dbefd4b8d0249c6a739d09118f3e0a71001c1c52
> Author: Nicolas Sceaux <address@hidden>
> Date:   Sat Aug 23 18:34:30 2008 +0200
>
>     Book parts: nestable book parts
>     
>     - Book and Paper_book instances respectively are nestable: children
>       book or paper_book are added to the bookparts_ slot;
>     
>     - the paper_ slot of a child Book (or Book_paper) is created empty,
>       and has its parent set to the paper object of the parent Book (or
>       Paper_book), so that default paper properties are got from the
>       higher level paper object, and child objects only store part-wide
>       overrides. This way, we ensure that fonts are loaded in the higher
>       level paper object, so that the output framework can get all the
>       loaded fonts from the top level book;
>     
>     - a Paper_book::top_paper() method is added to access the higher level
>       paper object, to access properties that are book-wide, for instance
>       the table used to store labels and page numbers;
>     
>     - in the parser, \bookpart blocks are introduced, which can be used at
>       toplevel, or inside a \book block. It can contain the same things as
>       \book blocks (except \bookpart blocks, though that would be
>       possible). The associated handlers are added.
>
>