\version "2.18.2"

#(use-modules (ice-9 regex))

#(define-public (lalily-test-location? parser location)
   (let ((outname (ly:parser-output-name parser))
         (locname (car (ly:input-file-line-char-column location))))
     ; check if parser-output-name and location-name match
     (regexp-match? (string-match (format "^(.*/)?~A\\.i?ly$" outname) locname))
     ))

doScore =
#(define-void-function (parser location cond? mus)(procedure? ly:music?)
   ; if condition is met, parser shall create score
   (if (cond? parser location)
       (begin
        (ly:parser-define! parser 'doScoreMusic mus)
        (ly:parser-include-string parser (format "\\score { \\doScoreMusic }"))
        )))

% music definition
exampleMusic = \relative c'' { c4 b bes a }

% create score, if condition is met
\doScore #lalily-test-location? \exampleMusic