Re: calculation of the total duration of a score

[Paul]

On 09/09/2016 05:27 PM, Thomas Morley wrote:

> Attached you'll find a different version.
> It avoids creating all those grobs and killing most of them in the
> end. Instead a preexisting RehearsalMark (or more of them) is taken
> and 'text is reset.
> Some other changes for better usability.

Hi Harm,  Nice work!  I'd say this is a good candidate for the LSR, 
particularly because it demonstrates listeners, acknowledgers, and 
finalize in one engraver.

One little thing I noticed is that

  (if duration-marks

should be something like

  (if (not (null? duration-marks))

Because:

  \version "2.19.42"
  #(define empty-list '())
  #(display (if empty-list #t #f))
  % --> #t
  #(display (if (not (null? empty-list)) #t #f))
  % --> #f

Also, I wonder, where you clear out these variables at the end of the 
finalize stage:

         (set! evts '())
         (set! last-evt #f)
         (set! tempo-change-evts '())
         (set! duration-marks '())

Of course, it doesn't hurt, but is it necessary?  If so I need to do 
that in my code.

-Paul