StringNumberEvents [was: Re: How to evaluate 'articulations entries?}

[Marc Hohl]

Am 01.09.2011 10:02, schrieb Marc Hohl:
> [...]
>
> I noticed that
>
> a)
> I can detect string numbers within < ... > only, so
> < c\3 > is recognized, d\4 not, but I need to cover *both* cases.
>
> [...]
> Ok, so \4 isn't an articulation (which is obvious, but I had 
> overlooked it).
> AFAIK, the string-number won't be accessible in this case, so I tried to
> acknowledge the string-number-interface, too.
Meanwhile, I found out that the string-number-interface isn't used in 
this case, so
I searched in the sources and found that I had to use string-number-events
instead, which are addressed to by listeners, IIUC.

So I wrote a simple test case:
\version "2.15.9"

#(define-public (test_string_engraver context)
  (let ((stringnumbers '()))
  `(;; the list of listeners
    (listeners
      (string-number-event .
        ,(lambda (engraver event)
           (set! stringnumbers (cons event stringnumbers)))))
       ;; once the acknowledging stage has finished,
       ;; process the grobs we've found
    (process-music
      . ,(lambda (trans)
           (for-each (lambda (strnum)
               (let* ((stringnum (ly:event-property strnum 
'string-number)))

                     (display "We have  a string-number-event: ")
                     (display stringnum)
                    (display " \n"))
             ) ;; end lambda (strnum)
             stringnumbers)
             ))
    (stop-translation-timestep
      . ,(lambda (trans)
                 (set! stringnumbers '()))))))

\layout {
  \context {
    \Voice
    \consists \test_string_engraver
  }
}

test = \relative c'{
  c4\4 < e\2 >
}
%\displayMusic { \test }
\new Voice { \test }

So I think I am on the right track for now, but any hints, optimizations 
etc.
are highly welcome!

Marc