(define-public (make-autochange-music parser music)
(define (generate-split-list change-moment event-list acc)
(if (null? event-list)
- acc
- (let* ((now-tun (caar event-list))
- (evs (map car (cdar event-list)))
- (now (car now-tun))
- (notes (filter (lambda (x)
- (ly:in-event-class? x 'note-event))
- evs))
- (pitch (if (pair? notes)
- (ly:event-property (car notes) 'pitch)
- #f)))
- ;; tail recursive.
- (if (and pitch (not (= (ly:pitch-steps pitch) 0)))
- (generate-split-list #f
- (cdr event-list)
- (cons (cons
+ acc
+ (let* ((now-tun (caar event-list))
+ (evs (map car (cdar event-list)))
+ (now (car now-tun))
+ (notes (filter (lambda (x)
+ (ly:in-event-class? x 'note-event))
+ evs))
+ (pitch (if (pair? notes)
+ (ly:event-property (car notes) 'pitch)
+ #f)))
+ ;; tail recursive.
+ (if (and pitch (not (= (ly:pitch-steps pitch) 0)))
+ (generate-split-list #f
+ (cdr event-list)
+ (cons (cons
+
+ (if change-moment
+ change-moment
+ now)
+ (sign (ly:pitch-steps pitch))) acc))
+ (generate-split-list
+ (if pitch #f now)
+ (cdr event-list) acc)))))
- (if change-moment
- change-moment
- now)
- (sign (ly:pitch-steps pitch))) acc))
- (generate-split-list
- (if pitch #f now)
- (cdr event-list) acc)))))
-
(let* ((m (make-music 'AutoChangeMusic))
- (m1 (make-non-relative-music (context-spec-music music 'Voice "one")))
- (context-list (recording-group-emulate music
- (ly:parser-lookup parser 'partCombineListener)))
- (evs (car context-list))
+ (m1 (make-non-relative-music (context-spec-music music 'Voice "one")))
+ (context-list (recording-group-emulate music
+ (ly:parser-lookup parser 'partCombineListener)))
+ (evs (car context-list))
(rev (reverse! (cdar context-list)))
- (split (reverse! (generate-split-list
- #f
- rev
- '())
- '())))
+ (split (reverse! (generate-split-list
+ #f
+ rev
+ '())
+ '())))
(set! (ly:music-property m 'element) music)
(set! (ly:music-property m 'split-list) split)
m))