Re: Feature request: let \layout accept several \layouts stored in variables

[Simon Albrecht]

On 15.07.2018 16:48, David Kastrup wrote:
> What?  Being able to specify two conflicting \layout definitions at once
> and having LilyPond magically merge them by guessing correctly how the
> user wants every conflict to be resolved?
>
> Magic is always a great thing to wish for.  Until it does stuff you
> actually did not intend it to do.

That’s not what the request was about. Lily already merges subsequent 
toplevel layout definitions, IIUC simply following the order at which 
they are encountered, and why shouldn’t the same be possible inside one 
layout block?

This works just as expected:

%%%%%%%%%%%%%%%%%%%%
\version "2.19.82"

\score {
  { c'8 }
  \layout {
    \context {
      \Voice
      \override NoteHead.color = #red
    }
    \context {
      \Voice
      \omit Flag
      \override NoteHead.color = #green
    }
  }
}
%%%%%%%%%%%%%%%%%%%%

and IIUC the request asks for this

%%%%%%%%%%%%%%%%%%%%
\version "2.19.82"

redhead = \layout {
  \context {
    \Voice
    \override NoteHead.color = #red
  }
}
greenhead = \layout {
  \context {
    \Voice
    \omit Flag
    \override NoteHead.color = #green
  }
}
\score {
  { c'8 }
  \layout {
    \redhead
    \greenhead
  }
}
%%%%%%%%%%%%%%%%

to be treated exactly the same instead of discarding \greenhead.
Of course, I don’t have sufficient understanding to judge whether Lily 
has trouble discerning the order if it’s stored in variables.

Best, Simon