syntactic equivalent for if __name__ == '__main__' in lilypond

[Mike Solomon]

Hey all,

I’m developing a score where I’m including a lot of smaller .ily files into a 
bigger one and I often want to compile these .ily files by themselves.  
Currently, I’m following the pattern of creating a new .ly file for the 
individual compilation, but that results in jostling between files and 
sometimes I get lost in the workflow.  Is there a pattern à la python 
equivalent to something like.

%% foo.ily

foo = \relative c’ {
  a4 b c d
}

if __name__ == ‘__main__’
  \new Staff \foo

Cheers,
MS