Enhancement: tabalture chord repetition

[lilypond.git] / ly / chord-repetition-init.ly

diff --git a/ly/chord-repetition-init.ly b/ly/chord-repetition-init.ly
index f19e3a10b50d5433168ed4c92bafedf90526599d..1056cdec2feac1bbf83e84be7bfccb5d4ab62b86 100644 (file)
--- a/ly/chord-repetition-init.ly
+++ b/ly/chord-repetition-init.ly
@@ -1,5 +1,5 @@
 %%% -*- Mode: Scheme -*-
-\version "2.13.9"
+\version "2.13.17"
 %{
 
 The following functions define the chord repetition behavior, and may
@@ -16,36 +16,63 @@ ly:parser-set-repetition-function
   (previous-chord, location, duration, list of articulations) which is
   supposed to return a new chord.
   `default-repeat-chord' is the default function set in this file.
+  `tab-repeat-chord' may be used in tablatures to preserve the string information.
 %}
 
-#(define-public (default-repeat-chord previous-chord location duration articulations)
-   "Copy the previous chord, filter out events which are not notes, set
-the chord duration, add articulations."
+#(define-public ((make-repeat-chord-function chord-element-types note-articulation-types)
+                 previous-chord location duration articulations)
+   "Make a chord repetition function.
+The returned functions copies the notes from @var{previous-chord} into a new chord.
+Chord elements, which type is found in @var{chord-element-types}, are copied into
+the new chord. Note articulations, which type is found in @var{note-articulation-types},
+are also copied. All other events are not copied into the new chord."
+   (define (filter-events events event-types)
+     (filter (lambda (event)
+              (and (memq (ly:music-property event 'name) event-types) event))
+            events))
    ;; If previous-chord has an length property, then it means that it
    ;; has been processed by a music iterator.  In other words, the chord
-   ;; has been memorized in an other music block, which is certainly not
-   ;; what the user has intended.  In that case, raise a warning.
+   ;; has been memorized from an other music block, which is certainly not
+   ;; what the user has intended, as anywy the result will be buggy.
+   ;; In that case, raise a warning.
    (if (not (and (ly:music? previous-chord)
-                 (null? (ly:music-property previous-chord 'length))))
+                (null? (ly:music-property previous-chord 'length))))
        (ly:input-message location
-                         (_ "No memorized chord in music block before chord repetition")))
+                        (_ "No memorized chord in music block before chord repetition")))
    ;; Instead of copying the previous chord, then removing the
-   ;; undesired elements (like articulations), a new empty chord is
-   ;; built.  Then, the pitch found in the previous chord are added to
-   ;; the new chord, without any "decoration" (e.g. cautionary
-   ;; accidentals, fingerings, text scripts, articulations).
-   (make-music
-    'EventChord
-    'origin location
-    'elements (append! (filter identity
-                               (map (lambda (event)
-                                      (and (eqv? (ly:music-property event 'name) 'NoteEvent)
-                                           (make-music
-                                            'NoteEvent
-                                            'pitch (ly:music-property event 'pitch)
-                                            'duration duration)))
-                                    (ly:music-property previous-chord 'elements)))
-                       articulations)))
+   ;; undesired elements (like articulations), a new empty chord is built.
+   ;; Then, the pitch found in the previous chord are added to the new
+   ;; chord, without any "decoration" (e.g. cautionary accidentals,
+   ;; fingerings, text scripts, articulations).  Only the events of types
+   ;; given in `chord-elements-types' and `note-articulation-types' are
+   ;; copied from the original chord elements and note articulations,
+   ;; respectively.
+   (let ((elements (ly:music-property (ly:music-deep-copy previous-chord) 'elements)))
+     (make-music
+      'EventChord
+      'origin location
+      'elements (append!
+                 (map (lambda (note)
+                        (let ((new-note (make-music 'NoteEvent
+                                                    'pitch (ly:music-property note 'pitch)
+                                                    'duration duration))
+                              (articulations
+                               (filter-events (ly:music-property note 'articulations)
+                                              note-articulation-types)))
+                          (if (not (null? articulations))
+                              (set! (ly:music-property new-note 'articulations)
+                                    articulations))
+                          new-note))
+                      (filter-events elements '(NoteEvent)))
+                 (filter-events elements chord-element-types)
+                 articulations))))
 
+#(define-public default-repeat-chord
+   (make-repeat-chord-function '() '()))
+
+#(define-public tab-repeat-chord
+   (make-repeat-chord-function '(StringNumberEvent) '(StringNumberEvent)))
+
+% default settings
 #(ly:parser-set-repetition-symbol parser 'q)
 #(ly:parser-set-repetition-function parser default-repeat-chord)