Re: RemoveEmptyStaffContext erases previous setting

[Reinhold Kainhofer]

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On Friday 05 February 2010 18:20:23 Mats Bengtsson wrote:
> On the other hand, \RemoveEmptyStaffContext is a variable containing a
> full list of settings, which replace the current list of settings for a
> Staff context.

Yes, that's the problem. The real solution would be to change it to some kind 
of function/macro, which is not evaluated when it is defined but rather when it 
is called. That way it would modify the current Staff context and not reset 
Staff to the default state during startup.

> A pedagogical problem is that the syntax looks the same in both cases,
> but what really happens is fundamentally different. Apart from the
> warning in the manual, mentioned above, the only way to know if
> \layout{
>   \SomeName
>   ...
> 
> will do one or the other, is to look in the file
> .../ly/engraver-init.ly and see if \SomeName is defined as a variable
> or if it's the name of a context.
[...]
> If would be pedagogically simpler to realize this difference if the
> syntax was separate if you define a context from scratch (as is the
> case with \RemoveEmptyStaffContext) or if it's defined by adding onto
> an existing context. 

That's just fighting the symptoms, but not the cause. The cause is that there 
is no wayto store a group of context modifications for later application 
without storing the whole context (thus resetting all other settings).


- -- 
- ------------------------------------------------------------------
Reinhold Kainhofer, Vienna University of Technology, Austria
email: address@hidden, http://reinhold.kainhofer.com/
 * Financial and Actuarial Mathematics, TU Wien, http://www.fam.tuwien.ac.at/
 * Edition Kainhofer Music Publishing, http://www.edition-kainhofer.com/
 * LilyPond music typesetting software, http://www.lilypond.org/
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