Re: Combining \layout variables

[Trevor Daniels]

David, you wrote Tuesday, May 05, 2015 3:57 PM


> "Trevor Daniels" <address@hidden> writes:
> 
>> Multiple layout blocks can be combined in sensible ways, with later
>> definitions taking precedence over earlier ones on an item by item
>> basis, but the same is not true when layout blocks are assigned to
>> variables.  See
>> http://www.lilypond.org/doc/v2.19/Documentation/notation/the-layout-block
>>
>> What I would like to do is to combine two layout blocks contained in
>> variables in the same way as layout blocks at top level are combined,
>> item by item, but it seems this is not possible, at least I haven't
>> been able to achieve it.  Is this indeed not possible?
> 
> \layout blocks at the top level are not combined.  You can only modify
> an existing layout block by putting new definitions inside.  But those
> definitions are never in a layout block of their own but always added to
> an existing layout block.

Well, yes, I knew that, but the effect is that existing definitions
are overridden iff they appear later, while new definitions are added,
so definitions assigned early can act as defaults.

I want to set some default layout definitions in the satb.ly template,
so that they may be overridden by the user if they appear in the
user's layout variable.  But the way it works is the user's layout
variable is taken as a new base, so all the default definitions are
lost, including ones the user has not redefined.  It looks like there
is no way of doing this at present, unless I've missed something.

Trevor