Re: Multiple variables in one scope

[David Kastrup]

Samuel Speer <address@hidden> writes:

> I've been trying to create several choral scores using the same
> template, but sometimes I need to change just a small part of the
> template, so I end up copying the original and naming it style_two.ily
> or style_piecename.ily etc. For example, in one piece I need to shrink
> the PianoStaff and reduce the basic-distance for a 'rehearsal piano'
> sort of look, and in another I need a full sized PianoStaff for a real
> keyboard accompaniment.
>
> To simplify the process, I've been trying to split up the 'style' into
> chunks (i.e. margins, paper size, ragged or not, fonts, vertical
> spacing, etc. in the paper block; lyric tweaks, pianostaff shrinking
> for rehearsal piano, etc in the layout block), but it seems I can't
> combine the chunks into one scope.

Correct.

> When I try to compile the snippet below, I get
>
> error: syntax error, unexpected OUTPUT_DEF_IDENTIFIER
>   \choralOctavoMargins
>
> %%%%%%%
> \version "2.18.2"
>
> choralOctavoDimensions = \paper { paper-height = 10.5\in }
> choralOctavoMargins = \paper { top-margin = 0.5\in }

If you take a look at either of those variables afterwards, they are a
full paper variable with all the settings in $defaultpaper, with only a
single setting changed compared with the default.

Basically you would need a three-way merge/diff on those variables while
referencing $defaultpaper for comparison.

You can do something like
choralOctavoMargins =
#(define-void-function (parser location) ()
                       (module-set! (current-module) 'top-margin
                              (* 0.5 (module-ref (current-module) 'in))))

in order to do an incremental change like that.  But it might possibly
make sense to put your various settings into separate files and include
those.

Something like

\include octavodim.ly
\include octavomarg.ly

with each of the respective files being, indeed, something like
\paper { paper-height = 10.5\in }

and so on.  In that usage, they redefine $defaultpaper rather than
deriving a separate paper variable from it.

-- 
David Kastrup