Reinhold Kainhofer wrote:
Our problems with \RemoveEmptyStaffContext resetting previous context
modifications highlights one problem we have: So far, it was not possible to
store a bunch of context modifications into a variable and apply them later
on.
Right!
Another incarnation of this problem is that it is not possible to collect some
modifications and use them in a \with block. So far, the contents of the \with
block had to be explicitly written out. I had the problem that in a full score
I needed several staves to be smaller (since they are optional), but I
couldn't use a global definition of the settings (defining my own Staff-
derived context was also not possible, because in the instrumental part, I
need a normal Staff, so all \override Staff.... would break in one or the
other case).
No, that's not a problem, as long as you include a
\alias "Staff"
line in the definition of your new context.
So, here is a patch against current origin/master:
http://codereview.appspot.com/475041
It modifies the parser so that context mods can be stored in variables and can
be inserted into \with or \context blocks:
-) context modifications lists are stored in a dedicated simple scheme object
(C++ class Context_mod)
-) Changes to the parser:
-) context_modifications objects (stored in variables) are now also allowed
with \with clauses
-) context_modifications objects are also allowed inside \context
-) this allows us to rewrite \RemoveEmptyStaffContext (unfortunately with
a little different syntax, since we no longer store \Staff inside the
new \RemoveEmptyStaves command) so that it no longer erases previous
settings to the Staff context. Now, instead of
\context { \RemoveEmptyStaffContext }
one can do
\context { \Staff \RemoveEmptyStaves }
with the same effect and preserve previous changes to the Staff
context. (The same applies of course to \DrumStaff, \RhythmicStaff,
etc. as well)
-) Adjusted engraver-init.ly and the regtests accordingly; Also added regtest
that checks for RESC not discarding previous settings to the Staff context
Without looking at the actual patch, it looks like a very good thing.
The next step would be to somehow also be able to handle music functions
and/or Scheme functions in \with and \context blocks, so that you could
do a setting like
\overrideBeamSettings ...
or
#(set-accidental-style ...)
in such a block, so you can better separate layout settings from the
actual music.
Of course, such a change is probably much more difficult than your
current patch.
/Mats
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