Controlling compilation

[David Sumbler]

When editing a piece with several instruments and several movements,
there are various outputs I would like, such as a complete full score, a
full score of a single movement, a complete instrumental part, the
instrument part of a single movement, and also a midi file of any of
these items.

I thought perhaps I could control this in my top-level file by having
the compilation instructions for these possibilities defined in
variables in an included file, and simply defining variables (or not, if
there is a way of checking the existence of a variable) in the top level
file.

As an experiment, I produced this:

File: experimentNotes.ly

\version "2.19.24" 

compileA =
\score {
  \new Staff {
   a' a' a' a'
  }
  \layout { }
}

compileB =
\score {
  \new Staff {
    b' b' b' b'
  }
  \layout { }
}



File: experiment.ly

\version "2.19.24" 

\include "experimentNotes.ly"

sectionA = ##t


#(if sectionA #{ \compileA #} )

\compileB



When I compile experiment.ly, the "B" section compiles and no errors or
warnings are produced, but section "A" is ignored.

Can this be modified to make it work?

David